Ethiopian Journal of Science and Technology (EJST)

Eth. J. Sci. & Technol. ISSN 1816-3378

Ethiopian Journal of

Science and Technology

Volume VI No. 1 February 2013

Bahir Dar University Bahir Dar, Ethiopia

Ethiopian Journal of Science and Technology (EJST)

Editors

Melaku Wale (PhD) Department of Biology, Bahir Dar University, Ethiopia (Editor-in-chief)

Zewdu Emiru (PhD) Department of English Language and Literature, Bahir Dar (Managing Editor) University, Ethiopia

Editorial Board Members

Firew Tegegne (PhD) Department of Animal Production & Technology , Bahir Dar University, Ethiopia Berhanu Abraha (PhD) Department of Biology, Bahir Dar University, Ethiopia Ali Said (PhD) Department of Biology, Bahir Dar University, Ethiopia Baylie Damtie (PhD) Department of Physics, Bahir Dar University, Ethiopia Solomon Tesfamariam (PhD) School of Mechanical & Industrial Engineering, Bahir Dar University, Ethiopia

Advisory Board members

Prof. Zinabu G. Mariam Hawasa University, Hawasa, Ethiopia Prof. Zerihun Woldu Department of Biology , Addis Ababa University, Ethiopia Prof. Teketel Yohannes Department of Chemistry, Addis Ababa University, Ethiopia

About EJST

Ethiopian Journal of Science and Technology (EJST) is published bi- annually by the Vice President‟s Office, Research and Community Services, Bahir Dar University, PO Box 79, Bahir Dar, Ethiopia.

Contact Address: Office of the Vice President, Research and Community Services, Bahir Dar University, PO Box 79, Bahir Dar, Ethiopia.

Tel.: 251-058-222 1908 Fax: 251-058-220 2025 Web Site: http://www.bdu.edu.et.

Ethiopian Journal of Science and Technology

Vol. V I No.1 February 2013

Contents

Symbiotic Blue Green Algae (Azolla): A Potential Biofertilizer for Paddy Rice 1-11 Production in Fogera Plain, Northwestern Ethiopia Tesfaye Feyisa, Tadele Amare, Enyew Adgo and Yihenew G. Selassie

Effect of Harvesting and Threshing Time and Grain Fumigation of Field Peas 13-24 (Pisum sativum L.) on Pea Weevil (Bruchus pisorum (L.) (Coleoptera: Bruchidae) Development and Damage Esmelealem Mihiretu and Melaku Wale

Influence of Time of Nitrogen Application on Productivity and Nitrogen Use 25-31 Efficiency of Rain-fed Lowland Rice (Oryza sativa L.) in the Vertisols of Fogera Plain, Northwestern Ethiopia Alemayehu Assefa, Tilahun Tadesse, and Minale Liben

Floristic Composition and Structure of Yegof Mountain Forest, South Wollo, 33-45 Ethiopia Sultan Mohammed and Berhanu Abraha

Effect of Transplanting on Rice in Northwestern Ethiopia 47-54 Tilahun Tadesse, Minale Liben, Alemayehu Assefa and Zelalem Tadesse

Effect of Apple Supplement and Unsupervised Home-based Brisk Walking on 55-63 Low Density Lipoprotein Cholesterol Khelifa Nida Bartrua, M.S. Sohal, Kiranjeet Kaur and Maninder Kaur

GUIDE TO AUTHORS 65-67

Eth. J. Sci & Technol., Vol. VI, no.1: 1-11, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013

Symbiotic Blue Green Algae (Azolla): A Potential Bio fertilizer for Paddy Rice Production in Fogera Plain, Northwestern Ethiopia

Tesfaye Feyisa1, Tadele Amare1, Enyew Adgo2 and Yihenew G. Selassie2* 1Adet Agricultural Research Center, PO Box 08, Bahir Dar, Ethiopia 2Bahir Dar University, PO Box 79, Bahir Dar, Ethiopia * Corresponding author:[email protected]

Abstract Keywords: Azolla, biofertilizer, fresh biomass, nitrogen, rice, symbiotic A field experiment was carried out in Fogera plain, where lowland rice is widely grown, to assess the adaptability and yield of Azzola strains and to determine the level of nitrogen they generate in 1. Introduction 2005 and 2006. A year earlier, 2004, the two Azolla strains (Azolla filiculoides and Azolla microphylla) Nitrogen is the key element required for were introduced from India. They were maintained plant growth and productivity. It is and multiplied in plastic containers at Adet in a greenhouse and then inoculated into concrete tanks abundant and constitutes 78% of the for testing their adaptability. Both strains were well atmosphere, but cannot be utilized by adapted to Adet condition. The actual experiment plants as such and has to be converted to was laid out in a randomized complete block design nitrates or ammonium form either by replicated three times. In the summer season, Azolla chemical or biological processes (Singh, filiculoides gave an average of 48 tons/ha (range: 42-56.4 tons) and Azolla microphylla yielded 40 1998; Banu et al., 2003). Chemical tons/ha fresh biomass (range: 30-45 tons). In synthesis of nitrogen by industrial means is autumn and winter seasons, biomass production was energy intensive and expensive. However, reduced because of fluctuating temperatures. An the same process can be carried out by -1 average of 54.4 t ha of Azolla fresh biomass was certain species of bacteria such as harvested at Fogera. Maximum plant height, number of tillers, straw yield and grain yield of rice cyanobacteria, which are equipped with the was recorded on the treatment that was planted by appropriate enzymes. Most of the using 64 kg N + 20 kg P ha-1 followed by Azolla cyanobacteria exist under free living filiculoides + 20 kg P ha-1, 32 kg N + 10 kg P ha-1. conditions but some are found in symbiotic Inoculation of Azzola by incorporating once into association with lower plants like water the soil has increased rice yield by 911 kg ha-1 (19%) on Azolla filiculoides plots and 721 kg ha-1 fern Azolla (Singh, 1998). (15%) on Azolla microphylla plots. However, there was temperature fluctuation and colonization of Azolla partners blue green algae inside its Azolla roots by algae. Multiplication and lobes and is capable of harvesting maintenance of Azolla needs special attention. It atmospheric nitrogen. Due to this invisible also needs continuous watering to a depth of 5 -10 cm and P fertilizer application, thus, irrigation partnership, the fern multiplies very fast. facility and alternate P sources are vital. Azolla The symbiotic association of the algae aids gives a lot of biomass and it is easy to manage and in the creation of a large amount of establish, which means that it is logical and cost- biomass on the surface of the water. In effective to use it as biofertilizer for paddy rice. Its Azolla-anabaena symbiosis, the fern is a effect on high value and perennial crops may be the subject of further research. macro symbiont which gives protective environment and nutrients to the blue green algae (the micro symbiont) which in turn gives nitrogen and other growth hormones

Tesfaye et al., 2013 to the fern for its growth and low cost rice production technology. multiplication. Both partners harvest solar Biological nitrogen fixation through Azolla energy via photosynthesis and the total anabaena complex is considered as nitrogen requirement can be supplied by potential biological system for increasing the assimilation of N fixed by anabaena. rice yield at comparatively low cost (Singh, Each leaf of Azolla has the potential of 1998). According to Kikuchi et al. (1984), harboring 75 thousand anabaena cells maximum biomass production ranged from containing 3 to 3.5% nitrogen 0.4 to 5.2 t dry matter ha-1 (average = 2.1 t (www.ineedcoffee.com/06 /azolla/). The ha-1); and the N content ranged from 40- beauty of this fern is that it is quite hardy 146 kg ha-1 with an average of 70 kg N ha- and during favorable environmental 1. conditions it multiplies exponentially. The algal symbiont is closely associated with Azolla derives more than 80% of its N all stages of the fern‟s development and from Nitrogen fixation in the field (Giller, resides in the cavities formed in the dorsal 2001). Annual N production rates by lobe of the fern. Rapid multiplication of the Azolla can be as high as 500 kg N ha-1 (for fern takes place in summer months. Azolla A. pinnata) to 1200 kg N ha-1 (for A. lives on the water surface of rice fields filiculoides) with average of 1000 kg N ha-1 harmoniously under the canopy of rice yr-1 with daily production rates of 0.4 - 3.6 plants without affecting the growth of rice kg ha-1 day-1 with average of 2 kg N ha-1 (Gevrek, 1999), and on small ponds, day-1 (Kikuchi et al., 1984). Azolla grown canals, and rivers (Ferentinos et al., 2002; as an intercrop with rice can accumulate Dhar et al., 2003). Generally, it multiplies 40-170 kg N ha-1 (average 70 kg N ha-1) vegetatively and often sexually. Its size is (Kikuchi et al., 1984). Singh (1979) in 1- 5 cm. Azolla has high protein content of Gevrek (1999) reported that the mineral approximately 23-37% of the dry biomass. nutrient composition inside the plant body Hence, it can also be used as, feed of A. pinnata was Nitrogen 4-5%; supplement with other low protein rations, phosphorus 0.5-0.9%; potassium 2-4.5%; feed for fish, pigs, ducks, chicken and calcium 0.4-4 %; magnesium 0.5-0.65%; cattle that like to eat it fresh as well as iron 0.06-0.26%; manganese 0.11-0.16% dried and used in salads and sandwiches, and crude protein 24-30% on dry matter just as alfalfa and bean sprouts are used basis. Gevrek and Yagmur (1997), also (Gevrek, 1999; Ferentinos et al., 2002). recorded the chemical composition of A. mexicana as N 3.92%; P 0.52%; K 1.25%; Azolla is distributed worldwide. Seven Ca 4.3%; Mg 1.10%; Na 1.08%; Zn 0.1%; species are recognized in temperate and Mn 0.3% and etc on dry matter basis. This tropics viz. Azolla filiculoides, A. rubra, A. indicates that Azolla has higher rate of caroliniana, A. mexicana, A. microphylla, nitrogen than compost (0.5 – 0.9% N) and A. pinnata and A. nilotica (Dhar et al., animal manure. 2003). All these species have anabaena as symbiont in leaves (Singh, 1998). Losses of Azolla N were found to be small (0-11%) in comparison to the loss from an The high nitrogen fixing ability, rapid equivalent amount of urea fertilizer (30%) growth, high biomass accumulation and N which was probably due to direct content determines the potential of Azolla volatilization of ammonia to the as fertilizer for increasing rice yield under atmosphere (Watanabe and Berja, 1983). Giller (2001) observed that the pH of the 2

Eth. J. Sci & Technol., Vol. VI, no.1: 1-11, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013 flood water was reduced by 2 pH units due compost to be used as fertilizer for dryland to the presence of mat of Azolla on its crops and vegetables (Singh, 1998). In surface and resulted in the reduction of N other countries, rice yield has been losses by ammonia volatilization and increased by 1,470 kg (112%) over the increased the recovery of fertilizer N control when one layer of 60 kg N ha-1of A. applied as urea up to 60%. When Azolla filiculoides was incorporated into the was incorporated into the soil, overall paddy soil and further increased by 2700 fertilizer losses were reduced by 35-55% kg ha-1 (216%) by incorporating one layer (Kumarasighe and Eskew, 1993). and then growing Azolla as dual crop with Biological N2 fixation through Azolla rice (Talley et al,. 1977). Since Azolla is a anabaena complex is considered a low cost nitrogen source, ecologically potential biological system for increasing friendly, easy for management and used as rice yield at comparatively low cost (Khan, nitrogen fertilizer source in different 1988; Main, 1993; Singh, 1998). Recently, countries in the world, introduction and use Azolla has been used as biofertilizer in of this cheap and ecologically friendly N many countries in the world viz. China, source to our system is vital to increase rice Vietnam, India, North America, Thailand, yield. Hence, this work was initiated with Philippines, Korea, Srilanka, Bangladesh, the objective of introducing Azolla strains Nepal, West Africa and etc (Khan, 1988; and generating information on their N Dhar et al., 2003). Some of these countries contribution to the newly introduced paddy use Azolla as one of the substitutes to rice at Fogera plain. commercial fertilizer. A report made by Gevrek (1999) revealed that Azolla is used 2. Materials and Methods in more than a million hectares of rice land in China and in more than 400 thousand 2.1 Experimental Procedure hectars in Viet Nam. Culturing and maintenance Low-land rice is a recent introduction to Two Azolla strains namely, Azolla Ethiopia and has received special attention filiculoides and Azolla microphylla were at Fogera plain and it is well adopted by introduced from India in 2004 and were farmers. According to Fogera Office of maintained in Addis Ababa at the National Rural and Agricultural Development, its Soils Research Center greenhouse in a area coverage has increased from a mere nutrient media and were brought to Adet 80 ha to 64 hundred ha within less than a Agricultural Research Center to maintain decade (1996-2004) with yields not and test their adaptability. Labeled plastic exceeding 3.5 t ha-1. However, its containers were filled with 5 kg of forest productivity constantly declined from time soil and tap water was added at a depth of to time due to continuous cereal to cereal 10 cm and left overnight to let the cultivation and nutrient depletion and suspended materials settle down. To farmers‟ failure to use chemical fertilizer maintain the mother culture, fresh and due to increasing price (Gezahegn and healthy Azolla fronds were inoculated to Tekalign, 1995). the containers and water was maintained to > 5 cm depth every day. A pinch of TSP Azolla can be used as a biological was added initially and when the substitute for the rather expensive artificial deficiency symptom was seen to each fertilizers. Azolla is converted into container. There was no insect problem in 3

Tesfaye et al., 2013 the plastic containers. Both strains with three replications. The experimental multiplied very well and covered the site of size 13 m × 34 m was selected each surface of the containers in the greenhouse year and prepared as per the farmers‟ within three weeks. practice and divided to replications and experimental plots of 2 m × 3 m. The After enough biomass of both strains was distance between plots and blocks was 2 m attained, two concrete tanks of a dimension each. The plots were leveled and rows at a 4 m × 1.5 m × 0.45 m were constructed and spacing of 20 cm were prepared and 2 fertilizer was applied to rows of respective filled with forest soil at a rate of 5 kg /m -1 (i.e., 30 kg of forest soil per tank) and filled plots evenly at a rate of 64 kg N ha plus 20 kg P ha-1, 32 kg N ha-1 plus 10 kg P ha-1, with tap water at a depth of 10 cm and left -1 -1 overnight to let the suspended materials 20 kg P ha plus 10 kg P ha then mixed with the soil and rice variety X-Jigna was settle down. The next day, fresh Azolla -1 filiculoides was added to one tank and sown at a rate of 80 kg ha in rows with 20 Azolla microphylla to the other tank at a cm spacing between rows. Split application rate of 1 kg per tank. The water level was of N was practiced, i.e., half of N and all P kept to a depth of > 5 cm every day; 87 g were applied initially and the split was applied at flowering during Azolla TSP (40 gm P2O5) was applied to each tank initially and when deficiency symptoms incorporation. Urea served as source of N were observed. and TSP for P. After sowing, ridges were made for each plot to collect water which could float the Azolla strains and then the The adaptability of the strains to the new strains were inoculated to their respective environment was studied based on the plots at a rate of 1 kg fresh biomass after biomass produced, phenotypical the field was flooded with water. The appearance at different weather conditions, strains were incorporated to the soil in a occurrence of disease and insect pests. Two plot by draining the water after producing additional concrete tanks of a size 5 × 10 2 enough biomass that forms a thick mat. m were constructed for multiplication of Azolla for the actual field experiment (to The experiment had the following produce enough biomass) following the treatments: same procedure, in which 250 kg of forest soil was added to each tank and the strains 1. Control were inoculated and the water level was 2. 64 kg N ha-1 + 20 kg P ha-1 maintained to 5-10 cm depth every day. 3. 32 kg N ha-1 + 10 kg P ha-1 Two third of the Azolla mat was collected 4. Azolla filiculoides + 20 kg P ha-1 every two weeks from each container and 5. Azolla microphylla + 20 kg P ha-1 tank leaving one third for further 6. Azolla filiculoides + 10 kg P ha-1 multiplication and the collected mat was 7. Azolla microphylla +10 kg P ha-1 weighed, sun dried and stored. 8. Azolla filiculoides 9. Azolla microphylla Field experiment The field experiment was conducted in 2005 and 2006 at Fogera plain where paddy rice is widely produced. It was laid out in a randomized complete block design

Eth. J. Sci & Technol., Vol. VI, no.1: 1-11, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013

2.2 Data Collection

Five representative plants were randomly selected from each plot and the number of tillers was counted and the average number was recorded. Similarly, the average plant height for the five randomly selected plants per plot was measured using a meter scale. Fresh biomass of Azolla was measured and recorded by taking a mat of the azolla on a 1 m × 1 m area. A quadrant was used in Fig. 1. Mother culture of A. filiculoides (left) defining the sampling area. It was then sun and A. microphylla (right) in the dried and the corresponding dry weight greenhouse at Adet was taken.

After enough biomass was produced from Among the 10 rows of rice per plot, eight the plastic containers, both strains were central rows were harvested from each plot inoculated to the outdoor concrete tanks at and grains and straws were separated to a rate of 1 kg fresh biomass per tank (Fig. measure straw and grain yield per plot. The 2b). The strains started multiplying and grain yield was recorded after adjusting the covered the surface of the tanks after three moisture to 12.5% and expressed as kg per weeks. After first harvest, the strains hectare. The straws separated from grains repeatedly covered the surface of the tanks were sun dried and weighed to determine -1 forming thick mat every two weeks (Fig. the straw yield in kg plot . 2c). The fern is light green in color until the micro symbiont (Anabaena azollae) 3. Results and Discussion makes association with and turns it deep green after association. The blue green Both strains were well adapted to Adet in a algae forms series of oval rings on the greenhouse and outdoor in concrete tanks. dorsal lobe of each leaf of the fern as seen The strains started multiplying within two under microscope and each leaf of Azolla days and covered the whole surface of the has the potential of harboring 75 thousand containers forming a thick mat within three anabaena cells that are excellent nitrogen weeks after inoculation (Fig. 1). The starter fixers (www.ineedcoffee.com/06/azolla/). inocula were very small in amount and From June to September, both strains hence the multiplied strains were performed well; they were deep green and inoculated to other containers to achieve formed thick mat (Fig. 2). enough biomass for further activities (Fig. 2a).

Tesfaye et al., 2013

a b c Fig. 2. Performance of A. filiculoides and A. microphylla in the greenhouse (a) and in concretetanks, (b) during June – October (c) thick mat of azolla . Anabaena filiculoides performed relatively 1. Both strains turned brown (Fig. 3a) better under low temperature (i.e., October when exposed to high temperature or low to January) and poorly from February to temperature and/or during maturity (Fig. April, when temperatures were high. In 3b) and turned green to slightly brown contrast, A. microphylla tolerated relatively otherwise. P deficiency was associated high temperature and performed better with pinkish color which can be corrected from February to April and poorly by applying P from sources such as TSP. performed from October to January. However, both strains may poorly perform Similar results have been reported earlier if the temperature is below 10OC or above by FAO (1982). 35 OC. Therefore, partial shade is needed for their better performance. The biomass produced by both strains during these seasons is indicated in Table

a b

Fig. 3. Azolla turned brown during temperature fluctuation (a) and during maturity (b)

Growth of algae was a common problem to remove it from the tanks manually. The from October to April and seriously lesson was that excess P should not be affected both strains. The reason was that applied and optimum amount should be we added excess P into the tanks, which applied in split. The objective of using P is caused excess algal growth and we failed ensuring maintenance.

Eth. J. Sci & Technol., Vol. VI, no.1: 1-11, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013

The field experiment that was conducted in A significant difference in the number of Fogera showed that both strains adapted tillers was observed among some well, multiplied and covered the plots treatments (Table 3). The maximum within two weeks. In 40 days after number of tillers was recorded by full inoculation, the fern formed a thick mat recommended NP followed by half (Fig. 4) and produced 54.4 t ha-1 fresh recommended NP (32 kg N ha-1 + 10 kg P biomass. According to the literature, fresh ha-1), A. filiculoides alone, A. microphylla biomass produced by Azolla ranges from alone and A. filiculoides + 20 kg P ha-1. 10 to 20 t ha-1 (Singh, 1998), an amount Both strains significantly (P<0.05) much lower than the present results. Insect increased the number of tillers per plant and disease problems were not observed on over the control. both strains at all locations. The relatively high fresh biomass produced in Ethiopia indicates that Azolla can adapt and perform well in this country and hence may serve as a source of nitrogen and other macro and micro nutrients for rice and other high value crops.

The control gave the lowest mean plant height followed by A. microphylla + 10 kg a P ha-1. The height of rice plants grown with b Azolla filiculoides alone and A. filiculoides Fig. 4. Thick mat of Azolla produced in a plot with full recommended P was more or less (a) and in a space between blocks (b) the same and considerably high. Both in Fogera Plain strains increased plant height more significantly than the control did (Table 2).

Table 1. Average fresh biomass produced by two Azolla strains in different seasons

Season Fresh biomass (t ha-1) Remark A. A. filiculoides microphylla May - Sep. 48 40 A. filiculoides gave a maximum biomass of 56.4 t ha-1 and A. microphylla gave 45 t ha-1 Oct. - Jan. 30 11 A. filiculoides performed well but it turned cloudy and pinkish as temperatures dropped; also they did not perform as good from May to September Feb. - April 14 32 A. microphylla performed well but it turned brown as temperature rose and did not perform as good from May to Sept

Tesfaye et al., 2013

Table 2. Effect of Azolla on plant height at Fogera in 2005 and 2006

Treatment Mean plant height (cm) 2005 2006 Combined Control 95.30 95.00 95.15 d 64 kg N + 20 kg P ha-1 107.27 102.20 104.70 a 32 kg N + 10 kg P ha-1 99.50 98.83 99.17 c Azolla filiculoides + 20 kg P ha-1 103.70 100.70 102.20 b Azolla microphylla + 20 kg P ha-1 101.53 97.30 99.42 c Azolla filiculoides + 10 kg P ha-1 101.90 96.30 99.10 c Azolla microphylla + 10 kg P ha-1 99.53 93.03 96.28 d Azolla filiculoides 101.63 100.70 101.20 b Azolla microphylla-1 100.47 96.93 98.70 c LSD (0.05) 1.76 1.69 1.66 C.V (%) 1.01 1.00 1.00

Table 3. Effect of Azolla on number of tillers of rice at Fogera during 2005 and 2006

Treatment Mean number of tillers per plant 2005 2006 Combined Control 9.67 8.33 9.00 c 64 kg N + 20 kg P ha-1 15.00 13.00 14.00 a 32 kg N + 10 kg P ha-1 12.00 11.33 11.67 b Azolla filiculoides + 20 kg P ha-1 11.00 10.00 10.33 bc Azolla microphylla + 20 kg P ha-1 10.67 9.33 10.17 bc Azolla filiculoides + 10 kg P ha-1 11.00 8.67 9.67 c Azolla microphylla + 10 kg P ha-1 10.67 9.00 10.00 bc Azolla filiculoides 11.67 9.67 10.50 bc Azolla microphylla-1 11.33 9.00 10.33 bc LSD (0.05) 2.55 1.25 1.93 C.V (%) 12.86 7.37 10.91

Recommended NP gave the maximum microphylla + 10 kg P ha-1, A. filiculoides straw yield followed by half recommended + 10 kg P ha-1and A. filiculoides alone (i.e., NP combined over years; whereas straw without P) recorded equal straw yield with yield of other treatments did not half recommended NP. However, the significantly differ from the control straw yield due to these combinations was (P<0.05) (Table 4). However, straw yield not significantly different from the control from treatments A. microphylla + 20 kg P and A. microphylla alone. ha-1, A. filiculoides + 20 kg P ha-1, A.

Eth. J. Sci & Technol., Vol. VI, no.1: 1-11, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013

Table 4. Effect of Azolla on straw yield of rice in Fogera in 2005 and 2006

Treatments Mean straw yield (kg ha-1) 2005 2006 Combined Control 7417 c 7359 g 7388 c 64 kg N + 20 kg P ha-1 10132 a 9035 a 9584 a 32 kg N + 10 kg P ha-1 8931 ab 8357 b 8644 ab Azolla filiculoides + 20 kg P ha-1 8396 bc 8063 c 8230 bc Azolla microphylla + 20 kg P ha-1 8757 abc 7799 de 8278 bc Azolla filiculoides + 10 kg P ha-1 8354 bc 7674 e 8014 bc Azolla microphylla + 10 kg P ha-1 8688 bc 7514 f 8101 bc Azolla filiculoides 7444 c 7924 cd 7684 bc Azolla microphylla-1 7708 bc 7480 fg 7594 c LSD (0.05) 1430 148 1017 C.V (%) 10.20 1.13 7.48

Grain yield significantly varied among recommended NP, which was followed by treatments (Table 5). The combined A. filiculoides alone. A. filiculoides alone analysis showed that recommended NP gave significantly more grain yield than A. fertilizer gave the maximum grain yield of microphylla alone (P<0.05). However, A. 6.2 t ha-1 followed by half recommended microphylla with and without P gave NP fertilizer with grain yield of 5.9 and A. significantly more grain yield than the filiculoides + 20 kg P ha-1 with grain yield control. A. filiculoides without of 5.8 t ha-1. All treatments gave incorporating P to the soil once has significantly more grain yield than the increased rice yield by 911 kg ha-1 (19%) control. Grain yield increment due to A. over the control and A. microphylla by 721 filiculoides + 20 kg P ha-1 was as much as kg ha-1 (15%). the one obtained from the half

Table 5. Effects of Azolla on grain yield of rice in Fogera in 2005 and 2006

Treatment Mean grain yield (kg ha-1) 2005 2006 Combined Control 4812 e 4932 f 4872 f 64 kg N + 20 kg P ha-1 6167 a 6219 a 6193 a 32 kg N + 10 kg P ha-1 6041 b 5826 b 5934 b Azolla filiculoides + 20 kg P ha-1 5937 bc 5758 b 5848 bc Azolla microphylla + 20 kg P ha-1 5791 d 5603 cd 5697 de Azolla filiculoides + 10 kg P ha-1 5812 d 5555 de 5683 de Azolla microphylla + 10 kg P ha-1 5749 d 5473 e 5611 e Azolla filiculoides 5840 cd 5726 bc 5783 cd Azolla microphylla-1 5729 d 5458 e 5593 e LSD (0.05) 117 125 121 C.V (%) 1.22 1.28 1.28

Tesfaye et al., 2013

In general, inoculation of A. filiculoides Drawbacks of Azolla include requirements and A. microphylla with and without P had of nurseries for multiplication, land for significant effect on most parameters production, continuous watering and more measured over the control. A. filiculoides labor for incorporating and watering, with 20 kg P ha-1 and half recommended irrigation facilities, the need for the rice NP were more or less similar in most crop to be grown in rows rather than the parameters. A. filiculoides alone and A. farmers‟ usual practice of broadcasting in filiculoides with 20 kg P ha-1 affected grain Fogera plain. Furthermore, temperature yield of rice combined over years more or fluctuations may make difficult to establish less equally. Azolla in the dry season, or it may fail to compete with other ordinary algae, it Azolla is rich in major nutrients such as N, requires high P fertilizer for multiplication P, K and S and micro nutrients such as Fe, and may turn to be a weed itself in Zn and others. It is a recycling source of P, irrigation channels. Any recommendation S and other nutrients to rice and hence the package may have to address these issues. increase in grain yield and other yield parameters may be due to this fact (Singh, From the results of the experiment, it is 1979; Main, 1993). Talley et al. (1977) possible to recommend the following for reported that rice yield was increased by scaling up of the technology: Simple 112% (1470 kg) over the control by multiplication tanks should be constructed incorporating A. filiculoides once (at the near places of steady water supply such as rate of 60 kg ha-1) and by 216% (2700 kg near irrigation schemes or rivers to ha-1) by incorporating once and then maintain the strains during the dry seasons. growing Azolla as a dual crop with rice. In Farmers should also be trained on how to China, azolla is reported to have increased manage, maintain and use Azolla as an rice yield that ranges between 0.4 and alternative N fertilizer source. Effects of 158% with an average of 18.6% (Lumpkin azolla on high value crops (vegetables and and Plunknet, 1980). fruit crops) should also be investigated.

4. Conclusion and Recommendation References

From the results of the study, it is possible Banu, R.; Main, M.H.; Jahitruddin, M and Hasan, M.A.(2003). Effect of Azolla urea application on to conclude that Azolla should be used as a yield and NPS uptake by BRRI Dhan 29 in Boro biofertilizer for rice production in Ethiopia season. Pakistan Journal of Biological Sciences, since it produces high biomass, is easy to 6(11): 968-971 Dhar, D.W.; Pabbi, S. and Parasana, R. (eds.) (2003). manage and establish, increases the Cyanobiotech-A. Training manual NCCUBGA, IARI, availability of macro and micronutrients (it New Delhi- 110 012, 95p scavenges K and recycles P and S), Ferentinos, L.; Smith, J. and Valenzuela, H. (2002). Azolla: Green manure crop. In: Sustainable improves soil physical and chemical Agriculture in Hawaii. University of Hawaii, Manoa, properties and fertilizer use efficiency, USA increases crop yield by 15-19% (by one Giller, K.E. (2001). Nitrogen fixation in tropical cropping system. 2nd Edition. CAB International, incorporation) in Ethiopia and releases United Kingdom. 409p. plant growth hormones and vitamins and Gevrek, M.N (1999). Adaptability of A. mexicana to Ege does not attract rice pests. conditions. International Rice Research Notes (IRRN) 24(1): 1-5 Gevrek, M.N. and Yagmur, B. (1997). Biochemical composition of Azolla mexicana under Menemen

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climatic condition. Turkish Journal of Field Crops (Eds.) Advances in Crop Science Society. 2(1): 13-16 Proceedings of the First Biennial Conference of Crop Gezahegn Ayele and Tekalign Mamo (1995). Science Society of Bangladesh, 18- 20 January 1992. Determinants of demand for fertilizer in a Vertisol pp 34-35 cropping system in Ethiopia. Tropical Agriculture Singh, P.K. (1979). Use of Azolla in rice production in (Trinidad), 72: 165-169. India. In: Nitrogen and Rice. IRRI, Los Banos, Khan, M.M (1988). A primer on Azolla production and Philippines. pp 407-418 utilization in Agriculture. IBSUPLB and SEARCA. Singh, P.K (1998). Water fern Azolla: A proven The Philippines, 2nd Edition.143p. biofertilizer for wetland rice. In: Soil and Plant Kikuchi, M.; Watanabe, I. and Haws, L.D. (1984). Microbe Interaction in Relation to Integrated Nutrient Economic evaluation of Azolla use in rice production. Management. pp 64-75 In: Organic matter and rice. International Rice Talley, S.N., Talley, B.J. and Rains, D.W. (1977). Research Institute, Manalia, pp 569-592 Nitrogen fixation by Azolla in rice fields. In: Kumarasinghe, K.S. and Eskew, D.L. (1993). Isotopic Alexander Holleander (Eds.) Genetic Engineering for studies of Azolla and Nitrogen fertilization of rice. nitrogen fixation. pp 259-281 Kluwer, Dordrecht, the Netherlands. Watanabe, I. and Berja, N.S. (1983). The growth of Lumpkin, T.A. and Plucknett, D.L., (1980). Azolla: four species of Azolla affected by P fertilizer. Aquatic Botany, Physiology and uses as a green manure. Botany 15: 175-185 Economic Botany, 34(2): 111-153 www.ineedcoffee.com/06/azolla/. Azolla as a Main, M.H (1993). Prospects of Azolla and Blue Green biofertilizer in coffee plantations Algae as nitrogenous biofertilizer for rice production in Bangladesh. In: Rahman, L. and M.A. Hashem

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Effect of Harvesting and Threshing Time and Grain Fumigation of Field Peas (Pisum sativum L.) on Pea Weevil (Bruchus pisorum (L.) (Coleoptera: Bruchidae) Development and Damage

Esmelealem Mihiretu1, Melaku Wale2 1Sekota Dryland Agricultural Research Center, PO Box 62, Sekota, Ethiopia; 2 Bahir Dar University, PO Box 79, Bahir Dar, Ethiopia.

Abstract 1. Introduction

Experiments were conducted in the field and in the Field pea is one of the so-called highland laboratory to investigate the effects of harvesting and threshing times and grain fumigation on pea pulses, also called cool-season food weevil, Bruchus pisorum (L.), development, the legumes that are widely cultivated in the damages they cause and the associated grain yield Amhara Region of Ethiopia. The region on field peas in Ethiopia. Pre-harvest data indicated accounts for more than 46% of the area and that significantly more eggs were found on flat and 42% of the total pulse production in the swollen pods than on other stages of the pod. Egg and larval density significantly varied with season. country (Wuletaw and Getachew, 2002). Grain yield was significantly higher on plots Pulse crops play a vital role in maintaining harvested early; seasons, fumigation and threshing sustainable agriculture by improving soil times did not affect yield. Delay in harvesting fertility, increasing food self sufficiency caused more infected seeds and seeds with infected and by serving as a source of animal feed black spots. Fumigation and threshing time did not affect the number of infested seeds and seeds with and cash. infected black spots. When data were recorded after four months of storage, all factors, i.e., season In Africa, field pea is cultivated only in (year), harvesting and threshing time and Ethiopia, the Democratic Republic of fumigation significantly affected the number of Congo and Burundi. The Ethiopian adult weevil emergence windows. Therefore, the number of windows was significantly higher in highlands still possess the largest reservoir 2004/05 than 2006/07, in non-fumigated seeds of field pea genetic diversity. Field pea, compared to fumigated ones, and in late harvested being one of the most important pulse and threshed seeds compared to others. Apart from crops in the cool highlands of Ethiopia, reducing the physical damage and reduction of seed forms an integral part of the daily diet weight loss of seeds in store, early harvesting, threshing, and fumigation immediately after harvest along with other cereals and pulses and contributed to the reduction in the inoculum of the makes the major protein source for most beetle in the future. It can; therefore, be concluded rural households in Ethiopia. that growers should practice early harvesting and threshing and fumigate immediately after threshing The Amhara region of Ethiopia covers to minimize the damage in an infested seed pea crop and also to reduce future inoculums. more than 47% of the total area allotted for field pea production in the country and Keywords: pea weevil, harvesting and threshing 44% of the field pea production (Worku, time, fumigation, field peas 2002). In the year 2000, about 100 thousand ha of land was allotted to field pea production from which about 70 thousand tons of grain was produced (CSA, 2000/01). Until recently, the pea aphid (Acyrthosiphon pisum L.) (Harris) and

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African bollworm (Heliothis armigera) the use of contact insecticides for adult pea (Hübner) were the most common pests of weevil management. Screening activities field peas. However, since 1992, field pea carried out in early 2000s in Ebinat area of was reported to have suffered from a newly Ethiopia revealed some degree of emerging pest, the pea weevil (Bruchus difference among accessions but none of pisorum) (Worku, 2002). Farmers in one of them were immune to the pest (Melaku et the districts expressed their concern for the al., 2002). In other countries, where pea future of field pea in their area; they weevils were well-known pests for a long claimed that the crop was going to be time and where sufficient research has been extinct. The pea weevil is spreading to the done on their management, some cultural nearby regions at an alarming rate pushing practices have been suggested to minimize local landraces towards extinction. Farmers the damages caused by the beetle. It is very have reported that this pest is the deadliest important to destroy crop residues and that they have ever seen on field pea. infested seeds should not be planted unless they are fumigated. Careful harvesting The pea weevil is cosmopolitan and it was prevents shattering, which otherwise known all over the world long before it allows weevils to disperse throughout invaded Ethiopia around 20 years ago. It is fields and harvesting must be done as early an important pest of peas in North and as possible, i.e., when the seed moisture South America (Pesho et al., 1977), the level falls to 12% (Baker, 1998). Volunteer Indian subcontinent (Basher et al., 1991), plants should be destroyed. Early planting Australia (Horne and Bailey, 1991), and harvesting is also desirable Europe (Girsh et al., 1999) and lately (Anonymous, 2007). Ethiopia (Adane et al., 2002; Birhane, 2002; Melaku et al., 2002; Worku, 2002). In Ethiopia, however, because this pest has appeared recently, there is little Economic infestations occur when adult information on its biology and females lay eggs on the surface of management. The present study elucidates developing green pea pods in the field and the effect of harvesting and threshing times neonate larvae burrow through the pod of field pea as they apply specifically to the walls and eventually into developing seeds Ethiopian condition and the fumigation of where weevil development is completed field pea grains in storage on pea weevil (Clement, 1992). Infested pea crops can development, the damage they cause and lose up to 20% of their weight from larval grain yield. feeding, and are prone to shattering when harvested, so that the total yield of a 2. Materials and Methods heavily infested crop may be reduced by 5 to 10% (Baker, 1998). In Australia, an This trial was conducted for two years infestation level as high as 72% is reported (2004/05 and 2006/07) in the cool semi- (Horne and Bailey, 1991). In Ethiopia arid area of Wag Hemra zone of the losses can rise as high as 85% (Worku, Amhara region, Ethiopia. Years were also 2002). Various management options of pea termed season for clarity. The study had weevil were suggested in different parts of two components: a field work and a the world (Horne and Bailey, 1991; laboratory study. McDonald, 1995). Resistant pea cultivars would help farmers to reduce losses and provide environmentally safer option than

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2.1 Field work the weight of the grains. To determine the loss in grain weight as time advances in The trial was laid out in a split-plot design store, the grains per plot were weighed with Randomized Complete Block Design, again at two and four months after replicated three times. The plot size was 4 threshing. m × 5 m. The local field pea seeds that are commonly grown in the area were planted Treatments following farmers‟ practices. Treatments were applied beginning from harvesting and threshing. The main plots Once pods started forming, the pod were the fumigated and non-fumigated development stages were scored until (applied on seeds in store after harvest), maturity in one of the categories of flat, while the subplots were the interaction swollen, filled, green wrinkled and yellow effects of harvesting and threshing times. wrinkled, and at the same time they were Harvesting times were the number of examined for the presence of eggs laid weeks after maturity (i.e., one, two, three between successive sampling dates or and four weeks). Threshing times were the censuses. The old and the new eggs on one length of time we waited after harvest to do pod between sampling dates were the threshing (i.e., immediately after distinguished by the following parameters: harvest, one week , two weeks and three the new eggs looked bright orange with no weeks later). The number of main plots apparent structural differentiation, while was two, replicated thrice made a total of the old ones looked dark brown because of six. The number of sub-plots was 16, the developing head capsule of the larvae. which was a factorial combination of 4 harvesting and 4 threshing times, replicated Ten pea plants were randomly selected thrice made a total of 48. The overall total from each plot and one pod was randomly number of plots was 96. This was chosen from each selected plant and equivalent to 2 plots × 4 harvesting times × inspected for the presence of eggs and 4 threshing times × 3 replications. larvae. This was repeated at each developmental stage of the pods, i.e., flat, 2.2. Laboratory study swollen, filled, green wrinkled and yellow wrinkled stages. The black dots or holes on Every time plants on each plot were the pods were counted to represent the harvested and threshed, i.e., according to number of larvae. The black dots on the treatment assignments, the seeds were pods represent the number of larvae that taken to the laboratory for the fumigation. are hatched and entered the pod. On the Half the plots were not fumigated as per other hand, days to flowering, heading and the treatment protocol. One phostoxin pod setting were recorded. At maturity, tablet was applied as a fumigant in seeds harvesting and threshing treatments were contained in gas-proof plastic bags. After done as outlined in the treatments section. seven days of exposure, the container was opened and ventilated. Yield data per plot were recorded immediately after threshing. They were The following data were recorded at then stored in the laboratory for further various times in the store by taking a follow up. Pea weevils inside seeds random sample of 100 seeds per plot: continued feeding in storage and reduced number of seeds with windows, number of

Esmelealem and Melaku, 2013 healthy and infected seeds, seeds with planting. The crop matured in 81-88 days. black spot infection, seeds blackened, 100- Harvesting dates varied from 85 to 106 seed weight and adults that emerged. As days after planting. pea weevils continued feeding, they invited microorganisms (particularly fungi) to take Pre-harvest data (eggs and larvae) over and cause infections. The identity of At the yellow wrinkled stage of pods, egg the fungi was not determined. density significantly varied between years (T1,7=159.43, P<0.0001). In 2004/05, the Statistical analysis density ranged between 2.4 to 5.0, with a An analysis of variance (ANOVA) was mean of 3.6 eggs. In 2006/07, it ranged conducted using the general linear model from 0 to 23 with a mean of 10.1. The (GLM) procedure (SAS, 1999-2000) to density of eggs at the flat stage of pods also assess effects of harvesting time, threshing significantly varied between years time and fumigation on pea weevil (T1,7=551.75, P<0.0001). In 2004/05, the development, the damages caused and the density of eggs at the flat stage of the pods grain yield and its components. Least ranged between 0.3 to 8.0, with a mean of square means were separated using the 2.1. In 2006/07, it ranged from 10 to 62 Student Newman-Keuls (SNK) test at P = with a mean of 34.2 flat eggs. The same 0.05. Differences between years and situation was observed with the density of fumigation levels were analyzed using t- eggs on swollen and filled pod stage. In test. Other treatments were analyzed using contrast, the density of eggs on the green F-test. wrinkled pods did not vary with season (T1,7=6.66, P=0.0712). Data taken at intervals were analyzed using the repeated measures analysis to In 2004/05, the density of eggs on swollen determine the differences in egg and larval pods ranged between 2.1 and 6.7, with a count among pod setting stages. The mean of 3.8. In 2006/07, on swollen pods, weevil damage symptoms that were the density ranged from 1 to 10 with an recorded at various intervals of time and average of 5.1 eggs. In 2004/05, eggs on the grain yield associated to each data filled pods ranged between 2.3 to 5.3 with collection date were also analyzed by the a mean of 3.6, while in 2006/07, the repeated measures procedure. The results density ranged from 1 to 12 with a mean of of the data that showed significant effect 6.6. In 2004/05, the eggs on green with respect to particular treatment(s) and/ wrinkled pod stage ranged from 2.1 to 11.1 or other sources of variation were with a mean of 4.7, while in 2006/07, the presented in tables and discussed. Those range was between 0 and 18.0 and a mean that were not significant were explained in of 5.9. the text without tabulation. The repeated measures analysis of egg 3. Results count at different pod stages showed significant difference among the pod stages Plant growth and development (Table 1). Egg count varied from 0 on The trial was planted on the 15th of July in wrinkled pods to 62 on flat pods, with a 2004/05 and on the 7th of July in 2006/07. mean of 4.4 on swollen pods to 18.1 on flat It flowered in 46 days; the first pods pods. In 2004/05, larvae were counted at appeared in about two months after the green and yellow wrinkled stage of the pods, which did vary with respect to any of

Eth. J. Sci & Technol., Vol. VI, no.1: 13-24, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013 the treatments. The repeated measures The number of larvae varied from 1 to 4, analysis of larval counts at the different with a mean of 2.7. pod stages showed no significant difference among the pod stages (Table 1).

Table 1. ANOVA table for the repeated measures analyses of egg and larval count at different pod stages.

Variables Effect Num DF* Den DF* F value Pr>F Eggs Pod stage 4 428 37.75 <0.0001 Larvae Pod stage 4 47 0.34 0.5621 * Num DF and Den DF stand for degrees of freedom for the numerator and denominator respectively. In the F-test, F stands for the F value and Pr>F stands for the level of significance.

Post-harvest data (grain yield and the grain was weighed two months after damage symptoms on seeds in store) harvest, again only harvesting time significantly affected grain yield. The Grain yield highest yield was recorded for the earliest At threshing time, both grain yield and harvesting time (Table 2). None of the 100-grain weight were significantly factors significantly affected both grain affected by harvesting time only (Table 2). yield and 100-grain weight four months Other factors, i.e., years, fumigation, and after harvest. threshing time did not affect yield. When

Table 2. Effect of harvesting time on grain yield and 100 grain weight of field pea in Sekota in 2004/05 and 2006/07.

At threshing time 2-month after harvest Harvest time Grain yield 100 grain Grain yield (g/plot)* weight (g)* (g/plot)* H1 1533.7±31.2a 13.9±0.17a 1500.8a H2 1397.6±60.0b 13.3±0.18ab 1376.8b H3 1262.6±39.0b 13.1±0.16b 1254.8b H4 1334.8±41.5b 13.3±0.17b 1315.6b F 6.78 3.53 5.66 P 0.0002 0.0160 0.0010 * These data were taken at threshing time; H1 to H4 stand for harvesting times; F and P stand for F value and P value; means within a column followed by the same letter are not significantly different at P<0.05 (SNK); H1, H2, etc. stand for harvesting dates; data are averages of the two years (2004/05 and 2006/07).

Infected seeds (Table 3). Fumigation and threshing time There was significant interaction between did not have significant influence on them. year and harvesting time on infected seeds In 2004/05, delay in harvesting caused per 100 seed sample per plot both at more infected seeds. threshing time and at 4-month in storage

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Table 3. Effect of harvesting time and season on the number of infected seeds of field pea in Sekota in 2004/05 and 2006/07.

At threshing 4-month after Harvest threshing time 2004/05 2006/07 T P 2004/05 2006/07 T P H1 37.9bA 27.8aB 7.06 <0.0001 36.4bA 27.5aB 4.76 <0.0001 H2 42.0abA 28.6aB 9.43 <0.0001 39.3bA 28.3aB 7.82 <0.0001 H3 41.7abA 28.8aB 7.83 <0.0001 43.7aA 28.5aB 9.34 <0.0001 H4 44.2aA 29.0aB 7.64 <0.0001 43.5aA 28.7aB 13.50 <0.0001 F 3.35 0.39 7.33 0.41 P 0.0224 0.7630 0.0002 0.7463 F and P of the F-test stand for F value and P value (or the significance level of the test); T and P of the t-test stand for T value and P value; the t-test compares the two years for each harvesting treatment; for each of the threshing time and 4-month after threshing, means within rows followed by the same upper case letter and within a column followed by the same lower case letter are not significantly different at P<0.05 (SNK); H1, H2, etc. stand for harvesting dates.

Infected black spots on seeds 2006/07. Fumigation and threshing did not The number of infected black spots on influence the number of infected black seeds significantly varied between spots. In 2004/05, delay in harvesting harvesting times in 2004/05 but not in increased seed numbers with infected black 2006/07 (Table 4). The numbers were also spots. significantly higher in 2004/05 than in

Table 4. Effect of harvesting time and season on the number of black spots infested seeds of field pea in Sekota in 2004/05 and 2006/07.

At threshing At 4-month after threshing Harvest 2004/05 2006/07 T P 2004/05 2006/07 T P H1 37.4bA 28.8aB 6.84 <0.0001 36.2bA 27.6aB 4.43 <0.0001 H2 41.3abA 28.8aB 8.68 <0.0001 38.3abA 28.5aB 7.02 <0.0001 H3 40.6abA 28.9aB 7.42 <0.0001 41.7aA 28.5aB 8.27 <0.0001 H4 42.9aA 29.0aB 6.83 <0.0001 40.6aA 28.7aB 11.14 <0.0001 F 2.62 0.50 3.55 0.36 P 0.0557 0.6850 0.0175 0.7828 For each of the threshing time and 4-month after threshing, means within rows followed by the same upper case letter and within a column followed by the same lower case letter are not significantly different at P<0.05 (SNK); H1, H2, etc. stand for harvesting dates; F and P of the F-test stand for F value and P value (or the significance level of the test); T and P of the t-test stand for T value and P value; the t-test compares the two years for each harvesting treatment.

Eth. J. Sci & Technol., Vol. VI, no.1: 13-24, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013

Number of windows harvesting time significantly increased the All factors, i.e., season or year, harvesting number of windows in both years. Number and threshing time, significantly affected of windows was significantly higher in the number of windows on seeds except 2006/07 than in 2004/05 on the earliest fumigation (Table 5). All other harvested grains. There was no significant combinations were not significant. Delay in difference on late harvested ones (Table 5) . Table 5. Effect of harvesting time and season on the number of weevil emergence windows on field pea in Sekota in 2004/05 and 2006/07.

At threshing Harvest time 2004/05 2006/07 T P H1 0.58bB 1.4bA -2.5 0.0161 H2 1.00bB 1.8bA - 3.2 0.0025 H3 1.54bA 2.0bA - 1.2 0.2444 H4 3.17aA 2.8aA 0.73 0.4666 F 15.47 4.62 P <0.0001 0.0047 Means within rows followed by the same upper case letter and means within a column followed by the same lower case letter are not significantly different at P<0.05; H1, H2, etc. stand for harvesting dates; F and P of the F-test stand for F value and P value (or the significance level of the test); T and P of the t-test stand for T value and P value; the t-test compares the two years (2004/04 and 2006/07) for each harvesting treatment.

Four months later, fumigation also had contributed significantly to the number of Effect of sampling date as time factor on windows; all factors significantly weevil damage symptoms on seeds and contributed to the number of windows and grain yield the interaction among the factors was highly significant (Tables 6 and 7). By analyzing damage caused by weevils across sampling dates, the repeated The number of windows significantly measures analyses showed that fumigation, increased with delay in harvesting (Tables harvesting time, threshing time, and data 6 and 7). Non-fumigated grains had collection date consistently and significantly more windows than the significantly affected the number of adult fumigated ones (Table 6). The interaction emergence windows but not other damage between harvesting and threshing time was symptoms and the associated grain yield more apparent on the two earliest harvested (Table 8). Harvesting time also appeared to treatments than those harvested later (Table significantly affect the number of infected 7). On these early harvested seeds, late seeds, seeds with black spots infection threshing, i.e., three weeks after harvest, (Table 8). resulted in significantly more windows than other threshing treatments (Table 7). This was true for early, i.e., first and second harvested plots. Late harvested ones, i.e., third and fourth, did not show significant difference (Table 7).

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Table 6. Effect of season, harvesting time and fumigation on the number of weevil emergence windows on field pea in Sekota in 2004/05 and 2006/07.

Fumigated Non-fumigated T P

2004/05 H1 0.3cB 3.1dA -2.076 0.0498 H2 2.5bB 6.8cA -3.223 0.0039 H3 4.3aB 12.8bA -7.440 <0.0001 H4 5.6aB 16.3aA -9.541 <0.0001 F 17.54 28.53 P <0.0001 <0.0001

2006/07 H1 1.5bA 3.3dA -1.817 0.0768 H2 1.8bB 5.8cA -4.042 0.0005 H3 2.7bB 8.4b A -5.759 <0.0001 H4 5.6aB 13.7aA -8.493 <0.0001 F 13.78 29.18 P <0.0001 <0.0001 For each year, means within rows followed by the same upper case letter and means within a column followed by the same lower case letter are not significantly different at P<0.05 (SNK); H1, H2, etc. stand for harvesting dates; F and P of the F-test stand for F value and P value (or the significance level of the test); T and P of the t-test stand for T value and P value; the t-test compares the two years for each harvesting treatment.

Table 7. Effect of season, harvesting time and threshing time on the number of weevil emergence windows on field pea in Sekota in 2004/05 and 2006/07.

TT0W TT1W TT2W TT3W F P

2004/05 H1 0.0bB 0.3bB 1.0bB 5.5bA 4.96 0.0098 H2 0.8bB 4.5abAB 5.2abAB 8.2ab A 5.79 0.0051 H3 7.2aA 7.0aA 7.7aA 12.3abA 1.63 0.2150 H4 9.0aA 9.2aA 11.0aA 14.7aA 1.13 0.3607 F 10.50 4.59 6.46 3.26 P 0.0002 0.0133 0.0031 0.0431

2006/07 H1 0.7bB 0.8bB 2.5bB 5.5bA 13.35 <0.0001 H2 1.2bB 3.5abAB 4.0bAB 6.5bA 4.42 0.0153 H3 2.8bA 5.8aA 6.7abA 6.8bA 1.55 0.2335 H4 8.2aA 7.8aA 10.0aA 12.5aA 1.28 0.3081 F 13.89 5.26 5.45 3.71 P <0.0001 0.0077 0.0067 0.0285 NB: TT0W stands for threshing conducted immediately after harvest, TT1W stands for threshing conducted one week after harvest, TT2W two weeks after harvest and TT3W three weeks after harvest; H1 to H4 stand for harvesting times; for each year, means within rows followed by the same upper case letter and means within a column followed by the same lower case letter are not significantly different at P<0.05 (SNK); F and P of the F-test stand for F value and P value (or the significance level of the test).

Eth. J. Sci & Technol., Vol. VI, no.1: 13-24, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013

Table 8. ANOVA tables for the repeated measures analyses of different weevil damage symptoms and grain yield data taken at various times across the season.

Damage symptoms Effect Num DF Den DF F Pr>F and grain yield value

Number of infected Year 1 333 526.9 <.0001 seeds per 100 seeds Fumigation 1 333 0.2 0.6585 Harvesting time 3 41 6.4 0.0012 Threshing time 3 41 0.7 0.5904 Data collection date 2 333 0.9 0.3522

Black spots infected Year 1 333 443.1 <.0001 Fumigation 1 333 3.1 0.0773 Harvesting time 3 41 3.9 0.0150 Threshing time 3 41 0.7 0.5341 Data collection date 1 333 2.4 0.1243

Number of weevil Year 1 333 1.6 0.2068 emergence windows Fumigation 1 333 99.5 <0.0001 Harvesting time 3 41 185.5 <0.0001 Threshing time 3 41 101.2 <0.0001 Data collection date 1 333 204. 8 <0.0001

Grain yield Year 1 523 3.3 0.0714 Fumigation 1 523 0.5 0.4918 Harvesting time 3 41 1.3 0.2801 Threshing time 3 41 0.1 0.9835 Data collection date 2 523 0.3 0.7383

100 grain weight Year 1 333 3.4 0.0672 Fumigation 1 333 0.1 0.6165 Harvesting time 3 41 1.8 0.1688 Threshing time 3 41 0.1 0.7095 Data collection date 1 333 0. 8 0.5211 * Num DF and Den DF stand for degrees of freedom for the numerator and denominator respectively. In the F-test, F stands for the F value and Pr>F stands for the level of significance.

4. Discussion the subsequent development of the weevil already inside the grain at the prevailing This study was intended to determine if the conditions of the present area. We wanted particular treatments we applied could to prove whether or not proper harvesting, contribute for the reduction of the weevil threshing and fumigation practices would inoculum and subsequent damage on an bring significant effect on weevil survival already harvested grain in the store. If in this particular study area. The treatments properly practiced, such cultural control were not meant to prevent infesting adult methods were believed to gradually weevils and their oviposition on young decrease the carryover of the pest. All the developing pea pods. Egg density was treatments were designed to be applied significantly higher on flat and swollen starting from maturity of the crop in order pods. This corroborates the reports by to determine if this activity would reduce Hardie and Clement (2001). In a field and laboratory experiment, Hardie and Clement

Esmelealem and Melaku, 2013

(2001) reported that flat and swollen P. and its damage on existing crop in the field sativum pods longer than 10-20 mm can only be achieved by preventing adults provide optimal or near optimal oviposition from egg laying on young pods substrates. They used this technique (McDonald, 1995). The treatment in the successfully to screen pea accessions for current experiment can; thus, contribute for resistance to the weevil. The female lays the future weevil reduction as well as eggs on developing pods of any size; eggs reducing the damage on seeds containing are first laid on young pods at about the the weevil inside. time the flowers begin to wither (McDonald, 1995). McDonald (1995) reported that when peas were harvested early, only 26% of the The results also indicated that the earlier maximum possible damage, i.e., seed the harvesting time, the more the grain weight loss, occurred. The remainder of the yield at threshing time and also two months weight loss occurred around or after after harvest. Early harvesting is one of the harvest because pea weevil larvae mechanisms to reduce future carryover. continued feeding for two more months in The application of these current treatments, store. Hence, about 74% of the seed weight i.e., the manipulation of time of harvesting loss could be prevented by early harvest and threshing and the practice of and fumigation of the crop immediately fumigation can contribute more for the following harvest, which in effect arrests reduction of the future inoculum than the further development of the weevil to make direct impact on this particular trial. adulthood (McDonald, 1995). This may This is because the treatments are meant to mean fumigating the invisible pest because reduce carryover but not prevent feeding larvae are hard to see even when infestation of plants on this particular trial. peas are cracked open. The sooner the fumigation is done, the more possible it is However, these particular treatments can to minimize the loss. This was clearly contribute for the reduction of weevil shown in this study where the yield attack of an already infested grain in the significantly increased when harvesting store. This was the objective it was meant was done one week after maturity than to meet. While Callosobruchus spp. can doing it two, three or four weeks after. The re-infest dry legumes in storage, Bruchus longer the delay between harvest and pisorum is generally reported not to be able fumigation, the better the chance to see to attack dry pulses but it has the ability to developed weevils when peas are cracked successfully over-winter and leave the open, but by then the insect has caused the storage in order to infest the new crop in maximum damage possible. the field. This needs to be clarified from literature data and additional field studies. Most beetles emerge through exit holes in The development of B. pisorum starts only spring leaving behind a hollowed-out pea. at the young pod stage; fresh attacks are Some may not emerge from the seed until never reported on harvested grains in the the seed is disturbed. If harvesting has been field or in the store (Baker, 1998). delayed, the beetles may fly out of the crop However, feeding continues even in store and take shelter so that they will once the seed carries the weevil inside it. overwinter until the next cropping. Even if So, if practiced widely in the hot spot area there are no beetles in the seed, they leave of the pest, the weevil can gradually be clean holes behind. reduced to a minor pest. Control of the pest

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Shattering can be kept to a minimum by Because the current study has revealed that harvesting the crop as soon as it is ripe early harvesting and threshing and (McDonald, 1995). Sheep can be used to fumigation reduced the damage caused by clean up crop residues immediately pea weevils on already infested crop, following harvest. Sheep eat infested peas mobilization of the affected community and larvae and the remainder of the beetles simultaneously will significantly reduce becomes exposed to sunlight. Heavy subsequent infestation in the area. If the grazing also reduces the likelihood of fumigation and the cultural practices such volunteer peas surviving as hosts for as optimal harvesting and threshing are weevils in subsequent years (McDonald, done in hotspot areas (districts) for a 1995). Thus, timely harvesting and couple of years (in sort of a campaign), pea threshing are indispensable. weevils will gradually disappear.

In the current experiment, fumigation In conclusion, growers should practice significantly reduced the number of weevil integrated management practices including emergence windows. However, the most cultural practices such as early harvesting advisable way to control pea weevil is and threshing and also early fumigation to spraying insecticides against the adults reduce damage on already infested and before they manage to lay eggs on harvested grain and future inoculum. An developing pods (McDonald, 1995). This additional option can be trying to stop egg mechanism can be made effective if pea laying on the developing pods by plants are sprayed when beetles first fly to preventing adults from approaching pea the crop in the field. If this is not done and fields for egg laying. This may be done by the seed appears to be infested, fumigation, spraying effective insecticides targeted early harvest and threshing are the last against adult weevils-an issue that can be lines of defense. taken as further research agenda.

In field trials in Australia, a single spray of References cypermethrin applied to plots in a field pea crop at the rate of 40 g a.i./ha and Adane, T.; Mohammed, D.; Asmare, D. and Shimelis, endosulfan at the rate of 350 g a.i/ha G. (2002). Suggested management options of reduced damage by pea weevil from 11% Bruchus pisorum L. (Coleoptera: Bruchidae). In: Proceedings of a national workshop on the in the unsprayed plot to 4%; peas sprayed management of pea weevil, Bruchus pisorum. with methomyl (340 g a.i./ha) or November 25-27, 2002. Bahir Dar, Ethiopia. fenvalerate (40 g a.i./ha) suffered 6% and ARARI/EARO. Anonymous. (2007). Peas vs. pea weevil: pea weevil 8% damage, respectively (Horne and reference page. Treasure Valley and Pest Alert Bailey, 1991). By conducting further Network. University of Idaho and Oregon State bioassays in the laboratory and by University. Baker, G. (1998). Pea weevil: Fact sheet. Primary extrapolation, they concluded that Industries and Resources, South Australia, and the cypermethrin was the most effective as a South Australian Research and Development knock-down effect pesticide against pea Institute. Australia. Basher, MA; Begum, A; and Akter, N. (1991). weevils (Horne and Bailey, 1991). This is a Preliminary study on the synchronization of the future research agenda in the present study developmental stages of Bruchus pisorum L. area. (Coleoptera: Bruchidae) in stores and in field on Pisum sativum L. (Leguminasae). Dhaka University Studies. Part E 6:31-41.

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Adane, T.; Mohammed, D.; Asmare, D. and Shimelis, bean beetle (Bruchus rufimanus) and pea beetle G. (2002). Suggested management options of (Bruchus pisorum), respectively. Seed Science and Bruchus pisorum L. (Coleoptera: Bruchidae). In: Technology 27: 377-383 Proceedings of a national workshop on the Hardie, DC and Clement, SL. (2001). Development of management of pea weevil, Bruchus pisorum. bioassays to evaluate wild pea germplasm for November 25-27, 2002. Bahir Dar, Ethiopia. resistance to pea weevil (Coleoptera: Bruchidae). ARARI/EARO. Crop Protection 20(6): 517-522. Anonymous. (2007). Peas vs. pea weevil: pea weevil Horne, J; and Bailey, P. (1991). Bruchus pisorum L. reference page. Treasure Valley and Pest Alert (Coleoptera: Bruchidae) control by knockdown Network. University of Idaho and Oregon State pyrethroid in field peas. Crop Protection 10: 53-56. University. McDonald, G. (1995). Pea weevil information notes. La Baker, G. (1998). Pea weevil: Fact sheet. Primary Trobe University, Australia. Industries and Resources, South Australia, and the Melaku, W.; Birhane A and Fentahun M. (2002). South Australian Research and Development Research attempts on the management of pea weevil Institute. Australia. (Bruchus pisorum) on field pea. Pp 60-66. In: Basher, MA; Begum, A; and Akter, N. (1991). Proceedings of a national workshop on the Preliminary study on the synchronization of the management of pea weevil, Bruchus pisorum. developmental stages of Bruchus pisorum L. November 25-27, 2002. Bahir Dar, Ethiopia. (Coleoptera: Bruchidae) in stores and in field on ARARI/EARO. Pisum sativum L. (Leguminasae). Dhaka University Pesho, GR; Muehlbauer, FJ; and Harberts, WH. Studies. Part E 6:31-41. (1997). Resistance of pea introductions to the pea Birhane, A. (2002). The biology and ecology of pea weevil. Journal of Economic Entomology 70: 30-33. weevil (Bruchus pisorum L.), Coleoptera, Bruchidea. SAS. 1999-2000. SAS Institute, SAS/STAT user‟s guide. Pp 37-46. In: Proceedings of a national workshop on Version 8.01. SAS Institute Inc. Cary, North the management of pea weevil, Bruchus pisorum. Carolina, USA. November 25-27, 2002. Bahir Dar, Ethiopia. Worku, T. (2002). Proceedings of a national workshop ARARI/EARO. on the management of pea weevil, Bruchus pisorum. Clement, SL. (1992). On the function of pea flower November 25-27, 2002. Bahir Dar, Ethiopia. feeding by Bruchus pisorum. Entomologia ARARI/EARO. Experimentalis et Applicata 63: 115-121. Wuletaw, T. and Getachew, A. (2002). Economic CSA (Central Statistical Authority). (2000/01). importance of pulses in the Amhara region of Forecast of area and production of major crops for Ethiopia. Pp 2-13. In: Proceedings of a national private peasant holdings. Bulletin No. 233. Addis workshop on the management of pea weevil, Bruchus Ababa, Ethiopia. pisorum. November 25-27, 2002. Bahir Dar, Ethiopia. Girsh, L; Cate, PC; and Weinhappel, M. (1999). A ARARI/EARO. new method for determining the infestation of field beans (Vicia faba) and peas (Pisum sativum) with

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Influence of Time of Nitrogen Application on Productivity and Nitrogen Use Efficiency of Rain- fed Lowland Rice (Oryza sativa L.) in the Vertisols of Fogera plain, Northwestern Ethiopia

Alemayehu Assefa1, Tilahun Tadese1*, and Minale Liben1 1Agronomists, Adet Agricultural Reserch Center, PO Box 8, Bahir Dar, Ethiopia *Corresponding author: [email protected]

Abstract Agronomic management factors play an important role in rice production. For An experiment consisting of two fertilizer rates -1 instance, fertilizer rate recommendations of (69/10 and 46/20 kg N/P ha ) and five nitrogen (N) 69/23 and 46/46 kg N/P O ha-1 increased application times (half at planting + half at tillering 2 5 (control), half at planting + half at panicle initiation, rice grain yield by 43% and 38% one-third at planting + two-third at tillering, one- respectively over the unfertilized treatment third at planting + two-third at panicle initiation and in the Fogera plain (Tilahun et al., 2007). one-third at planting + one-third at tillering +one- There is a wide difference between third at panicle initiation) was conducted in factorial Ethiopia (3 t ha-1) and other countries such RCBD on the Vertisols of Fogera plain during the as China (6.05 t ha-1); Japan (6.21 t ha-1) 2006 and 2007 cropping seasons. The objective of -1 the experiment was to identify the best time of N and South Korea (6.99 t ha ) in terms of application for maximum rain-fed lowland rice average yield (Aamer et al., 2000; Tesfaye, yield in the Fogera plain. Results showed significant et al., 2005). An inadequate fertilizer difference in grain yield in response to the time of N applied through improper application application. The highest mean grain yield (4409 kg ha-1) was recorded when N was applied one-third at technique is one of the factors responsible planting and two-third at the tillering stage of the for low yield of rice (Aamer et al., 2000). crop. Nitrogen fertilizer rates and the interaction Availability of plant nutrients, particularly with its time of application showed non-significant nitrogen at various plant growth stages is differences for all parameters. The agronomic of crucial importance in rice production. Nitrogen Use Efficiency (NUE) was found to be higher for one-third at planting and two-third at Increasing the fertilizer use efficiency is tillering nitrogen application compared to the other very important, particularly in developing treatments. Hence, application of nitrogen one-third countries where the cost of fertilizer is at planting and two-third at tillering stage of rice, rather very high and increasing. The irrespective of the fertilizer rate, is recommended judicious use of fertilizers contributes a lot for rice production in the Fogera plain. ______towards improving the yield and quality of Keywords: split application, yield, NUE,. grain (Aamer et al., 2000).

Most crop plants recover only 25-35% of 1. Introduction the nitrogen applied as fertilizers (Kissan- Kerala, 2007). Losses occur by Rice (Oryza sativa L.) is an important food volatilization, denitrification, and crop of the world. In Ethiopia, rice has immobilization to organic forms, leaching become one of the most important crops and run off. Measures to reduce the loss of whereby its production and area coverage N from applied urea include use of slow N increase every year, especially in the releasing fertilizers like urea super granules Fogera plain (Tesfaye et al., 2005). or urea briquettes or sulphur or lac coated

Alemayehu et al., 2013 urea (Kissan-Kerala, 2007). Utmost care studied. Thus, this study was conducted to should be bestowed in selecting the type of find out the best time of nitrogen fertilizer fertilizer as well as the timing and method application for maximum rice productivity. of application. Increasing the congruence between crop N demand and N supply 2. Materials and Methods improves N use efficiency in lowland rice (Cassman et al., 1998). Description of the site

Slow-releasing N fertilizers of silica- The experiment was conducted during the polymer-coated urea and sulfur-coated urea 2006 and 2007 cropping seasons on the improve the availability of the nutrient to Vertisols of Fogera plain. Fogera plain the crop and increase the rice yield belongs to the moist tepid to cool agro- (Aragon et al., 1984). However, the slow- ecological zone and to the tepid to cool releasing N fertilizers are mostly expensive moist plains sub agro-ecology (CEDEP, and unavailable. Linquist and Sengxua 1999). It is located in the South Gondar (2003) reported that deep placement of Administrative Zone, north western Urea Super Granules (USG) has not been Ethiopia, located at 130 19‟ latitude, 370 03‟ adopted by farmers because it is very longitude and altitude of 1815 meters laborious. Taking into account the above sea level. The nine years‟ (1998- unavailability and cost of controlled release 2004, 2006 & 2007) mean annual rainfall fertilizers, multiple applications of urea in the area, as to Woreta metrology station, remain a better option than use of is 1317 mm. Based on the available controlled release fertilizers for farmers in temperature data at Addis Zemen rain-fed lowland areas (Castillo, 2006). metrology station, which is at the vicinity Split application of nitrogen fertilizer was of the experimentation area, the four years‟ found to increase rice yield whereby two to (2004-2007) mean monthly maximum and three equal splits at different growth stages minimum temperature is 29.8OC and resulted in significant increase in yield and 9.4OC, respectively. The experimental soil yield components over single dose (Zaheen was clayey in texture with a pH of 5.8. et al., 2006). . Experimental Design and Procedure Recommendations on different period of nitrogen fertilizer application were given The experiment was laid in a factorial for various production systems. randomized complete block design with Dobermann and Fairhurst (2000) indicated three replications. Two economically that the number of splits is affected by the feasible fertilizer rates (69/10 and 46/20 kg total amount of nitrogen fertilizer to be N/P ha-1) recommended for the area applied based on the desired yield level. (Tilahun et al., 2007) were combined with According to James and Stribbling (1995), five nitrogen fertilizer application times the optimum time of nitrogen fertilizer (half at planting + half at tillering (control), application could be affected by several half at planting + half at panicle initiation, factors like rice variety, total amount of one-third at planting + two-third at nitrogen to be applied, soil type, climate tillering, one-third at planting + two-third and crop rotation. For the Fogera plain, at panicle initiation and one-third at fertilizer recommendations were given for planting + one-third at tillering + one-third rice production. However, the number of at panicle initiation). Applications at splits and time of application were not yet

Eth. J. Sci & Technol., Vol. VI, no.1: 25-31, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013 tillering and panicle initiation stages were The yields of the two treatments were done at about 50 and 105 days after significantly different from the application planting, respectively. All doses of of N 1/3 at planting and 2/3 at tillering. phosphorus fertilizer were applied at Nitrogen rate and its interaction with time planting. The gross and net plot sizes were of N application did not show any 4 m x 3 m and 3 m x 2 m, respectively. significant difference for all the Variety X-Jigna was used as test crop and parameters. Site interaction with any of the broadcasted at the rate of 100 kg ha-1. Data factors (N rate and/or time of N on grain yield, fertile panicle number, application) showed non significant thousand grain weight, and plant height difference for grain yield indicating the were collected from the net plot. The data similarity of the sites and the possibility of were subjected to analysis using Statistical applying the same package in Fogera plain Analysis System (SAS) Version 9.2 (SAS irrespective of sites. Though the interaction Inc., 2002). Agronomic Nitrogen Use effect of N rate by time of its application Efficiency (NUE) was calculated as extra was insignificant, the highest yields for kilogram of grain per extra kilogram of N both N rates (69 and 46 kg N ha-1) were applied (Mushayi et al., 1999; Hatfield and achieved when split was applied one-third Prueger, 2004). at planting and two-third at tillering stage of the crop. This indicates that relatively 3. Results the highest amount of nitrogen should be applied at tillering as compared to planting The analysis of variance for individual sites time and panicle initiation so as to promote indicated significant grain yield differences the maximum number of grains and in response to time of nitrogen application subsequently higher grain yield. The in two of the four sites (Table 1). However, highest NUE was observed when nitrogen the interaction effects of nitrogen fertilizer was applied one-third at planting and two- rates and time of application were not third at tillering stage of the crop (Table 4). significant in all sites. In all of the sites, the The specified N application gave an application of nitrogen (one-third at average of 80% NUE which was 8% planting and two-third at tillering) gave the superior over the control, split application highest yield, with a yield advantage of half at planting and the other half at ranging from 1 to 24% over the control. tillering.

The combined analysis over sites and years 4. Discussion revealed significant difference in grain yield in response to time of nitrogen The results indicated that the highest yields application (Table 2). The highest mean for both 69 and 46 kg N ha-1 were achieved grain yield of 4409 kg ha-1 was obtained when N was split applied, one-third at when nitrogen was applied one-third at planting and two-third at tillering stage of planting and two-third at tillering. The the crop. The finding is in harmony with lowest yields of 3767 and 3772 kg ha-1 previous recommendations on split were obtained when nitrogen was applied applications of N fertilizer for rice half at planting plus half at panicle production (George, 1980; Marqueses et initiation, and one-third at planting plus al., 1988; Haefele et al., 2006). Though a one-third at tilleting plus one-third at number of authors recommended two split panicle initiation respectively (Table 3). applications, there are variations in the

Alemayehu et al., 2013 timings of nitrogen application for rice. et al. (1996) stated that nitrogen fertilizer Marqueses et al. (1988) reported that band needs to be applied in four splits; at basal, application of 1/3 N at 20 days after maximum tillering, panicle initiation and seeding + 2/3 N at 5-7 days before panicle flowering. initiation gave significantly higher grain yield (8.5 t/ha) and agronomic efficiency. The results of the current experiment George (1980) indicated two splits revealed the advantage of applying one- application given at maximum tillering and third of the recommended N at planting panicle initiation stages was found to be and two-third at tillering stage of the crop. better in grain yield. For the rain-fed In line with this finding, Cassman et al. lowland rice production of Thailand, (1998) claimed that a greater portion of the Haefele et al. (2006) recommended N requirement should be applied during nitrogen application in two splits as basal active tillering, when crop growth is rapid and top dressed at panicle initiation. and N demand is high. The N demand at Charles (2003) also recommended two the very young growth stage of the rice splits application of nitrogen for rice where crop is so low (Schnier et al. 1987). the first split is applied at planting and the Furthermore, N availability from the remaining at internodes elongation. mineralization of organic matter is high According to Aamer et al. (2000), half of during the early growing stage (Dei and the nitrogen should be applied at planting Yamasaki, 1979) and should be adequate to and the remaining half at the tillering stage meet crop needs. of the crop. Low Nitrogen Use Efficiency (NUE) On the other hand, Stevens et al. (2001) continues to be a problem in wetland rice recommended three times application of situation as nitrogen (N) is subjected to nitrogen; at basal, at early-maximum several transformation losses in the rice tillering and panicle initiation. Zaheen et ecosystem (Hussain et al., 2009). The al. (2006) indicated that the treatment with optimum use of N can be achieved by N applied in three equal splits (1/3 N at matching supply with crop demand planting + 1/3 N at 50 % tillering + 1/3 N (Hussain et al., 2009). The agronomic at panicle initiation) showed maximum Nitrogen Use Efficiency (NUE), which was paddy yield over once and twice split N expressed as grain production per unit of N applications. Similarly, a number of applied, showed higher value when findings showed that application of N in nitrogen was applied one-third at planting three equal splits at planting, active and two-third at tillering stage of the rice tillering and panicle initiation increased crop as compared to the other treatments. yields compared to a single application at planting (De Datta et al., 1988; Ohnishi et The specified treatment gave 95 and 65% al., 1999, Linquist and Sengxua, 2003; NUE for the rates of 46 N and 69 kg/ha N FAO, 2005). There are also some reports respectively. Compared to the control recommending four splits of nitrogen treatment, where one-half was applied at applications. Sathiya and Ramesh (2009) planting and the other half at tillering, recommended nitrogen application in four application of one-third N at planting and splits – 1/6 at 15 days after sowing, 1/3 at two-third at tillering gave 49% and 8% tillering, 1/3 at panicle initiation, 1/6 at NUE advantage at the 46 and 69 kg/ha N, flowering- is suitable nitrogen management respectively. Similar to this finding, James technique for rice. Furthermore, Consuelo and Stribbling, (1995) reported that split

Eth. J. Sci & Technol., Vol. VI, no.1: 25-31, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013 application of nitrogen increased nitrogen nitrogen loss by volatilization and leaching, uptake and use efficiency of the rice crop. which in turn resulted in efficient nitrogen They further elaborated the increase in uptake by rice plants and finally resulted in grain yield with increasing number of N better growth development and yield. splits might be due to a reduction in

Table 1. Analysis of variance for the grain yield of rice for individual sites in the Vertisols of Fogera plain

Source of variation Site-1 Site-2 Site-3 Site-4 N rate (N) NS NS NS NS Time of N application (T) * * NS NS N X T NS NS NS NS Mean yield (kg ha-1) of control (T1) 4309 3872 2912 4796 Highest mean yield (kg ha-1) 5353 4142 2940 5203 Time of N application for highest mean yield T3 T3 T3 T3 Yield advantage over the control (%) 24.2 7.0 1.0 8.5 SE 153.65 108.17 112.21 152.08 * Significant at 5 % level of significance, NS Non-significant T1 = N applied half at planting + half at tillering (control) T3 = N applied one-third at planting + two-third at tillering

Table 2. Combined analysis of variance for the grain yield and other yield components of rice in the Vertisols of Fogera plain, 2006 and 2007

Source of variation Grain yield Number of fertile Thousand Plant (kg/ha) panicles grain weight height (cm) /m2 (g) Site(S) ** NS ** ** N NS NS NS NS SxN NS NS * NS Time of N application (T) * NS NS NS SxT NS NS NS NS NxT NS NS NS NS SxN x T NS NS NS NS SE 101.44 5.19 0.23 0.78 *, ** Significant at 5 & 1% level of significance respectively, NS= Non-significant

Alemayehu et al., 2013

Table 3. Effect of nitrogen fertilizer rate and nitrogen application time on the grain yield of rice in the Vertisols of Fogera plain, combined over sites

Fertilizer rates (kg/ha) Time of N application 46/20N/P 69/10 N/P Mean Half at planting and half at tillering (control) 4001 3944 3972b Half at planting and half at panicle initiation 3899 3635 3767b One-third at planting and two-third at tillering 4357 4462 4409a One-third at planting and two-third at panicle initiation 3961 4215 4088ab One-third at planting, one-third at tillering and one-third at 4120 3425 3772b panicle initiation Mean 4067 3936 SE 101.44 Numbers followed by different letters on the same column indicate significant differences at 5% level of significance using Duncan‟s multiple range test.

Table 4. Effect of nitrogen fertilizer split applications on Nutrient Use Efficiency (NUE) of rice

Time of N application NUE at NUE at 46 kg N 69 kg N Half at planting and half at tillering (control) 87 57 Half at planting and half at panicle initiation 85 53 One-third at planting and two-third at tillering 95 65 One-third at planting and two-third at panicle initiation 86 61 One-third at planting, one-third at tillering and one-third at 90 50 panicle initiation

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Buresh, M.I. Samson and Kai- Maize production technology for the future: Rong W. (1988). Nitrogen use efficiency and Challenges and opportunities, Proceddings of the nitrogen-15 balances in broadcast flooded and sixth Eastern and Southern Africa Regional Maize transplanted rice. Soil Sci. Soc. Am. J. 52: 849–855. Conference, Addis Ababa, Ethiopia: CIMMYT and Dei Y. and S. Yamasaki. (1979). Effect of water and Ethiopian Agricultural Research Organization. Pp. crop management on the nitrogen-supplying capacity 278-81. of paddy soils. In: Nitrogen and Rice. International Ohnishi M., T. Horie, K. Homma, N. Supapoj, H. Rice Research Institute, Los Ban˜os, Philippines, pp. Takano and S. Yamamoto. (1999). Nitrogen 451–463. management and cultivar effects on rice yield and Dobermann, A. and T. Fairhurst. (2000). Rice: Nutrient nitrogen use efficiency in Northeast Thailand. Field disorders and management. International rice research Crops Res. 64: 109–120. Institute. Manila, Philippines. SAS Institute. (2002). Users guide, basic version 9.1 FAO. (2005). Fertilizer use by crop in Egypt First Edition. Carry, NC: SAS Institute, USA. version, published by FAO, Rome, 2005. Pp 33-35. Sathiya, K. and T. Ramesh. (2009). Effect of Split George I. (1980). Effects of level, time, and splitting of Application of Nitrogen on Growth and Yield of urea on the yield of irrigated direct seeded rice. Plant Aerobic Rice. Asian J. Exp. Sci. 23(1):303-306. and Soil 56(2):209-215. Schnier H.F., S.K. De Datta and K. Mengel. (1987). Haefele, S.M., K. Naklang, D. Harnpichitvitaya, S. Dynamics of N labeled ammonium sulfate in various Jearakongman, E. Skulkhu, P. Romyen, S. inorganic and organic soil fractions of wetland rice Phasopa, S. Tabtim, D. Suriya-arunroj, S. soils. Biol. Fert. Soils 4: 171–177. Khunthasuvon, D. Kraisorakul, P. Youngsuk, S.T. Stevens, G., S. Hefner and T. Gladbach. (2001). Effect Amarante, and L.J. Wade. (2006). Factors affecting of nitrogen timing and rates on tillering and yield of rice yield and fertilizer response in rainfed lowlands rice. Soil Science and Plant analysis 32: 421-428. of northeast Thailand. Field Crops Research 98: 39– Tesfaye Zegeye, Befekadu Alemayehu and Aklilu 51. Agidie. (2005). Rice production, consumption and Hatfield J.L. and J.H. Prueger. (2004). Nitrogen Over- marketing: The case of Fogera, Dera and use, Under-use, and Efficiency. "New directions for a Libokemkem Districts of Amhara Region. Paper diverse planet". Proceedings of the 4th International presented on the National workshop on the status of Crop Science Congress, 26 Sep – 1 Oct 2004, rice research and promotion in Ethiopia. 3-4 June Brisbane, Australia. Pp 21-29. 2005, Bahir Dar, Ethiopia. Hussain, M Z, S.A Khan, T.M Thiyagarajan. (2009). Tilahun Tadesse, Minale Liben, Alemayehu Assefa, Increasing Nitrogen Use Efficiency in Rice (Oryza Belesti Yeshalem and Tesfaye Wossen. (2007). sativa L.) with Chlorophyll Meter and Leaf Color Effect of nitrogen and phosphorus fertilizers on the Chart. The IUP Journal of Soil and Water Sciences yield of rice in Fogera and Metema areas. In: Ermiase 12:233-253. A., Akalu T., Alemayehu A., Melaku W., Tadesse D., James, E. and L. Stribbling. (1995). Fertilizer and Tilahun T. (eds.). Proceedings of the 1st Annual management to protect water quality. In: Agricultural Regional Conference on Completed Crop Research and Natural resource water quality controlling. Activities, 14- 17 August 2006. Amhara Regional Alabama A & M and Auburan Universities. Agricultural Research Institute. Bahir Dar, Ethiopia. Kissan-Kerala. (2007). Fertilizers Management. Zaheen, M., R.I. Ali, T. Awan, N. Khalid and M. http://www.kissankerala.net/kissancontents/.jsp. Ahmad. (2006). Appropriate time of nitrogen 29/10/2007 12:53. application To fine rice, Oryza sativa. J. Agric. Res., Linquist B. and P. Sengxua. (2003). Efficient and 44(4):261-266. flexible management of nitrogen for rainfed lowland Zaheen, M., R.I. Ali, T. H. Awan, N. Khalid and M. rice. Nutrient Cycling in Agroecosystems. 67(2). Ahmad. (2006). Appropriate time of nitrogen Kluwer Academic Publishers, the Netherlands. application to fine rice, Oryza sativa. J. Agric. Res. Pp.107-115. 44(4):75-79.

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Floristic Composition and Structure of Yegof Mountain Forest, South Wollo, Ethiopia

1Sultan Mohammed and 2Berhanu Abraha* *Corresponding Author 1Department of Biology, Woldia University, Ethiopia 2Department of Biology, Bahir Dar University, Ethiopia

Abstract population dynamics and ethno botany are recommended. In this study, Floristic composition, diversity, population structure and regeneration status of woody plant species of Yegof Forest in South Key phrases: Floristic composition, Endemic Wollo Zone, Amhara Regional State, Ethiopia were species, IUCN Red list Phytogeographical analyzed. Data were collected from 72 quadrants, Comparison, Population Structure, Yegof each of which was 20 m × 20 m area. Sorensen‟s Forest similarity coefficient was used to detect similarities and differences among different forests of Ethiopia. Shannon -Wiener diversity index was applied to quantify species diversity and richness. A total of 1. Introduction 123 vascular plant species, representing 109 genera and 63 families were recorded. One hundred and The diverse topography and climatic twelve of the species collected from sample plots conditions of Ethiopia led to the creation of were used for floristic and structural analysis. The habitats that are suitable for evolution. rest 11 were collected out of the sample plots but from the same forest and were used to describe the These have led to the occurrence of some complete floristic list. Out of the total plant species unique plant and animal species and their which have been included in the preliminary list assemblages. As a result, Ethiopia is one of assessed for IUCN Red data List, 9 were found to the countries in the world with high level be endemic to Ethiopia. The family Fabaceae had of genetic diversity and endemism the highest number of species (8) followed by Asteraceae (7 species), Poaceae (6 species), (WCMC, 1992). The flora of Ethiopia is Lamiaceae and Solanaceae (5 species each). The very heterogeneous and has a rich endemic five most abundant woody plant species in the element that is estimated to contain forest were Dodonaea angustifolia, Myrsine between 6 thousand and 7 thousand species africana, Olea europaea subsp cuspidata, Juniperus of higher plants, of which 12 percent is procera and Erica arborea. In the forest, the overall Shannon-Wiener diversity was 3.73 and endemic (Tewolde Birhan, 1990). evenness of woody species was 0.79, indicating Nevertheless, continued exploitation of that the diversity and evenness of woody species in natural forests without giving due the forest is relatively high. Woody species density -1 consideration to their propagation, for mature individuals was 1685 stems ha , density domestication and cultivation has resulted of saplings was 1800 stems ha-1 and the density of seedlings was 2089 stems ha-1. Density decreased in a vicious cycle where increased forest with increasing tree height and DBH classes. The destruction has led to increased scarcity 2 basal area of the forest was 25.4 m /ha. We and/or rarity of forest resources which in prioritized tree species for conservation using turn has resulted in increased demand for criteria such as species population structure, forest products and subsequent and further important value index and regeneration status. The destruction (Zewge and Healey, 2001). As population structure in the forest revealed that there a result, most of the northern parts of the is a need for conservation priority of woody plant with poor regeneration status. Based on the result country, particularly Wollo has become of the study, research on the soil seed bank, one of the most environmentally degraded

Sultan and Berhanu, 2013 regions in Ethiopia. At present the original construction, timber and fuel wood vegetation is found around churches and in collection are still common with farmers other isolated and protected areas, where it residing inside the forest boundaries. is forbidden to cut trees (Alemayehu et al., Consequently, the most valuable 2005). Yegof is one of these remnant indigenous tree species as well as wild forests of the area. It is one of the 58 animals are becoming severely affected in National Forest Priority Areas (NFPAs), the area. Despite the disturbing scenario, which was identified with the aim to the vegetation structure and composition of introduce improved management systems. the mountain forest has not been studied The natural vegetation of Yegof and except a few general botanical studies surrounding highlands was broadly associated with the drought in Wollo. classified as Juniperus procera forest or These few studies include Natural “dry evergreen montane forest” with J. Resource Management in Post-conflict procera and/or Olea europaea ssp. Situations by Alula Punkhurst (2001), cuspidata as dominant species (Friis, Deforestation in Wállo by Crummey 1992). (1988) and Historical Perspective of Forest Management in Wollo by Bahru Zewde Although Mt. Yegof has experienced a (1998). long history of deforestation, intensified deforestation of the area started around Thus, the present study was initiated to 1850 AD (Ali, 1983) and large part of the investigate and document the floristic original natural forest has disappeared composition, structure and regeneration during the Italian occupation, 1935–1941 status of the forest, which could enable to (Bahru, 1998). Two major forest fires also properly manage and sustainably use the devastated it in 1923 and 1971 (Ali, 1983). resources. Moreover, cultivation (for purposes other than forestry) and grazing were intense 2. Materials and methods until the ecological rehabilitation program started in 1973, an afforestation and Study site hillside closure scheme (Kebrom, 1998). Yegof was declared a State Forest in 1965 The study was conducted in South Wollo and some limited afforestation was carried Zone of the Amhara Regional State, on a out prior to the 1974 revolution. In fact, steep mountain ridge overlooking Bahru (1998) noted that it was one of only Kombolcha town, 380 km north of Addis two out of thirty-nine State Forests in Ababa. The site is located between 110 01' Ethiopia that had plantations before the to 110 03' North latitude and 390 4' to 390 44 revolution. However, human encroachment East longitude with an elevation between into the forest remained the major threat. It 2000 and 3014 masl (Fig. 1). According to is under extreme pressure from settlement, the closest weather station at Kombolcha land-use conversion for farming and town, the area has a mean annual minimum grazing, excessive extraction, and neglect temperature of 12.70C and maximum of in terms of forest management and 27.10C while the average annual rainfall is protection. Because of these problems the about 1001 mm. In the forested areas of the plantation is thinned on an irregular basis. mountain, higher rainfall and cooler In spite of the presence of 35 guards who temperatures prevail because of altitude. keep the forest from human pressure, The soil pH ranges from 6.0 to 7.26 and the grazing and illegal logging of trees for

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texture varies from loam to clay loam with evergreen, mixed conifer, and broadleaved textural compositions of 19–28% clay, 32– trees (Bahiru, 1988). Lower down the 41% silt and 27–46% sand (Zewdu, 2002). mountain, various plant species are evident. The place is also one of the The forest is composed of natural highland important bird areas in Ethiopia; a survey trees and plantations of fast-growing exotic conducted in April 1996 in the area trees. The natural forest, which once indicated 62 bird species (Bird Life covered Mt. Yegof, comprised dry International, 2009).

Figure 1. Map of the study site. (Source: Tesfaye Bekele, 2000 with certain modifications).

Methods established within the center of each main quadrant to assess grasses, herbs and To investigate the floristic composition and regeneration. structure of plants, line transects were systematically laid at the eastern face of the Plant species having DBH >2 cm were mountain. A total of 72 sample quadrants measured by using diameter tape and measuring 20 m × 20 m (2.88 ha) were height > 2 m by hypsometer (type 65, used at every 100 m along transect lines Swedish made). Physiographic variables and 400 m apart from each other. The same were recorded such as altitude by using an number but 1 m by 1 m nested plots were altimeter, longitude and latitude using GPS 35

Sultan and Berhanu, 2013 and aspect by Compass. Those plant basal area values were computed on species having a height less than 2 m and hectare basis. DBH less than 2 cm were counted by species for floristic composition and The diversity and evenness of woody regeneration assessments. plants was analyzed using the Shannon- Wiener Diversity Index and Shannon‟s For the purpose of analyzing population evenness (equitability) Index (Kent and structure of the woody species, individuals Coker, 1992). Phytogeographical of the same species were categorized into comparison of Yegof Forest with other dry seven diameter and eight height classes. evergreen forests in Ethiopia was carried The percent cover-abundance value for out by using Sorensen‟s Similarity each species within the sample plot was coefficient. visually estimated. The percentage frequency distribution of individuals in 3. Results and Discussions each class was calculated. The tree or shrub density and basal area values were A total of 123 species of vascular plants computed on hectare basis. In addition, representing 63 families were recorded in seedlings and saplings of woody species the study area both inside and outside the were counted and recorded. study quadrants (Appendix 1). From all the species identified in 72 quadrants, 33 Woody plant species outside the study species were trees, 26 species were shrubs, quadrants were also recorded to prepare a 24 species were trees/shrubs, 18 species complete checklist of plants in the area. For were herbs, 12 species were climbers, 7 species that were difficult to identify in the species were grasses and 3 species were field, their local names were recorded, epiphytes. The most diverse families were herbarium specimens were collected, Fabaceae (8 species), Asteraceae pressed, dried and transported to the (7species), Poaceae (6 species), Lamiaceae National Herbarium at the Department of and Solanaceae (5 species each), Biology in the Addis Ababa University for Euphorbiaceae (4 species) and seven other identification. In addition, Azene (2007) families were represented by 3 species was referred for identification purposes. each.

Data analyses Species Diversity

Structural analysis of the vegetation was The overall Shannon-Wiener diversity of described based on the analysis of species woody species in Yegof forest was 3.73 density, DBH, height, basal area, and evenness was 0.79, indicating that the frequency, and Important Value Index diversity and evenness of woody species in (IVI) for those individual species having the forest is relatively high. About 48.1% DBH greater than 2 cm and height greater of woody plant species in the forest were than 2 m. The Diameter at Breast Height under 1% of relative abundance and rare to (DBH) and tree height were arbitrarily find. Therefore, they fall on rare cover classified into seven DBH and eight height classes. About 46.2% of the woody species classes. The percentage and frequency were categorized under common cover distribution of individuals in each class was classes. Only 5.8% of woody plant species calculated. The tree or shrub density and were categorized under abundant cover

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classes. This clearly shows that the forest first height (46.5%) and DBH (49.9%) was dominated with small sized trees and classes. As the tree height and DBH class shrubs, which in turn indicates that woody size increases, the number of individuals plants of the forest were under heavy gradually decreases which appears to be a disturbance and habitat degradation. regular inverted J-shaped distribution. This indicates the dominance of small-sized Density individuals in the forest and the good regeneration and recruitment potential The density (number of individuals per ha) status of the forest. The frequency of of mature tree species of the forest was occurrence of woody species went in 1685 stems/ha. Of these mature plant parallel to the height and DBH, and higher species, Dodonaea angustifolia had 143 percentage in the number of species in the individuals ha-1(8.4%), Myrsine africana lower frequency classes and low 110 ha-1 (6.5%), Olea europaea subsp percentage in the number of species in the cuspidata 87.2 ha-1 (5.2%), and Juniperus higher frequency class indicated a high procera 77.8 ha-1(4.6%), contributed to the degree of floristic heterogeneity. The three largest proportion of individuals per most frequently observed species which hectare. As to tree and shrub density, 557 regenerate by their own are Juniperus individuals were counted per ha which procera, Olea europaea subsp. cuspidata measured a DBH value between 10 and 20 and Myrsine africana. cm and 286 individuals per ha which had DBH greater than 20 cm. The ratio The basal area of all tree species in Yegof described as a/b, is taken as the measure of forest is found to be 25.4 m2/ha. High size class distribution (Grubb et al., 1963). density and high frequency coupled with Accordingly, at Yegof Forest, the ratio of high BA indicates the overall dominant individuals with DBH between 10 and 20 species of the forest (Lamprecht, 1989). cm (a) to DBH > 20 cm (b) was 1.95. For this reason, Juniperus procera, Olea When this value was compared with that of europaea subsp cuspidata and Myrsine six other Dry afromontane forests in africana are the top three dominant species Ethiopia, it is comparable to Dindin forest of the forest since all the three are found in (Simon and Girma, 2004), greater than that the top five of the ranks of basal area, of Wof-Washa (Tamrat, 1993), Denkoro relative density, relative frequency and IVI (Abate et al., 2006) and Gedo (Birhanu, per hectare of the top ten dominant 2010) forests, but lower than those of species. Chilmo and Menagesha (Tamrat, 1993) forests. This indicates that the proportion Population Structure of Tree Species of lower and medium-sized individuals is larger than the large- sized individuals, From the results of the analyses five indicating that Yegof forest is at the stage general patterns of population structure of secondary regeneration. were recognized. The first group exhibited typical inverted J-shaped curves, i.e., Tree height and DBH species having many individuals at the lower diameter classes and decreasing The height and DBH class distribution of number of individuals at successively the woody species showed that the majority higher diameter classes (Fig. 2a), which is of the tree individuals are distributed in the an indication for good biological functions

Sultan and Berhanu, 2013 and recruitment capacity for a species. The DBH classes which depicted a bell-shaped second pattern shows a J-shaped pattern of distribution pattern (Fig. 2c) that indicate a distribution (Fig.2b). In this pattern, DBH poor reproduction and recruitment classes were missed from three or more potential. The forth pattern is characterized lower classes and one or more higher DBH by having large number of individuals in classes. Some species under this pattern the first lower DBH class and disappearing have big individuals that are less competent in the next two or three middle classes and to reproduce and hence reveal poor finally increasing with an increase in DBH reproduction and weak position of forming a U-shaped pattern (Fig. 2d) which regeneration. In the third pattern, lowest is due to human intervention. The fifth DBH classes have lower densities followed class shows an irregular pattern (Fig. 2e) by an increase in the number of individuals that arises from selective cutting by the towards the middle classes and then a local people for different purposes. progressive decrease towards the higher

30 5 8 C a b 4 6 20 3

2 4

Density Density

Density 10 1 2 0 0 0 1 2 3 4 5 6 7 1 2 3 4 5 6 7 1 2 3 4 5 6 7 DBH Class DBH class DBH class

8 d e Class Scale Class Scale 6 5 4 1 2.1-10 5 40.01-50 4 3 2 10.01-20 6 50.01-60

2 Density Density 3 20.01-30 7 >70 2 1 0 4 30.01-40

0 1 2 3 4 5 6 7

1 2 3 4 5 6 7 DBH Class DBH class

Figure 2a-e. Five representative patterns of population structure an Yegof Forest

Regeneration Status of Yegof Forest densities of trees, tree/shrub, and shrub species saplings were 804.2 ha-1, 662.2 ha-1 The composition and density of seedlings and 333.3 ha-1 respectively (Fig. 3). The and saplings of tree species in Yegof forest ratio of seedlings to adult individuals of were counted. Accordingly, a total of woody species in the forest was 1.24:1; the 2088.9 seedlings/ha, 1799.71 saplings/ha ratio of seedling to saplings was 1.16: 1 and 1685 mature individuals/ha were and sapling to mature individuals was recorded. From the analysis of seedlings 1.07:1. The result shows the presence of and saplings data, the density of trees was more seedlings than saplings and saplings 949.3 ha-1, tree/shrubs 836.2 ha-1 and shrub than mature trees, which indicates seedlings 301.4 ha-1. Similarly, the successful regeneration of forest species.

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Generally, most of the seedling and sapling Calpurnia aurea and Carissa edulis. densities were contributed by species such Hence, these species have high as Myrsine africana, Rhus natalensis, Olea regeneration status while others do not. europaea subsp cuspidata, Rhus glutinosa, Juniperus procera, Otostegia tomentosa,

1000 949.3 Seedling Sapling 900 836.2 804.2 791.3 800 667.7 700 662.2 Mature 600 500

400 333.3 304.3 300

Density of individuals ofDensity 226.4 200 100 0 Tree Tree/shrub Shrub

Life form

Figure 3. Seedling and sapling distribution of woody species of Yegof forest

This situation calls for conservation the country to see the distribution pattern measures through prioritization. To ensure of woody species in the study area and to this, the woody species in the area were determine the relative similarity in its grouped into three regeneration status woody species composition (Table 2). classes on the basis of their seedling and These forests were: Menagesha Suba, sapling densities per hectare (Table1). Dindin, Denkoro, Biteyu and Sanka Meda. Those species that had no seedling and In the analysis of the data from the seven sapling at all were grouped under class I; forests, Sorensen‟s (1948) similarity index others whose seedling and sapling density was used. is between one and fifteen were categorized under class II and the The overall similarities indices between remaining species were put under class III. Yegof and the other five forests in Ethiopia ranged between 0.34 and 0.51. For all Phyto geographical Comparison compared forests, Sorensen‟s similarity index which is dependent on the number of Comparison of the species diversity of one common species shared by the forests forest with other forests can give more or being compared indicated that Yegof forest less a general impression of the overall shared significant number of species with species richness, diversity and Denkoro (51%), Menagesha Suba (48%), phytogeographical similarity (Tadesse, Dindin (40%), and Biteyu (36%) forests of 2003). In this regard, Yegof Forest is Ethiopia in decreasing order. compared with five afromontane forests in

Sultan and Berhanu, 2013

Table 1. List of tree species under regeneration status classes.

Class I Class II Class III Discopodium penninerxium Scolopia theifolia Gilg. Hypericum revolutum Ekebergia capensis Acacia polyacantha sub sp Croton macrostachyus. Euphorbia candelabrum campylacatha Dombeya torrida Millettia ferruginea Hibiscus ludwigil Vernonia amygdalina Zizyphus spina- christi Pinus radiata Bersama abyssinica Podocarpus falcatus Eucalyptus camaldulensis Buddleja polystachya Cordia africana Eucalyptus globulus Caesalpina spinosa Olinia rochetiana Maytenus arbutifolia Maytenus undata Pygeum africanum Acacia abyssinica Euclea racemosa Vernonia bipontinnii Ximenia americana Euphorbia tirucalli Dovyalis verrucosa Clerodendron alatum Casuarina equisetifolia Mytenus undata Galiniera saxifraga Cupressus lucitanica Combretum collinum. Capparis tomentosa Nuxia congesta Dodonaea angustifolia Osyris quadripartite Allophyllus abyssinicus Otostegia tomentosa Juniperus procera Rhus glutinosa Olea europaea subsp cuspidata

The high similarity observed between forests. The dissimilarities might have risen Denkoro and Yegof forest could be due to from the different sample sizes and the close geographical proximity of the methods of the study, altitudinal forests to each other and similar tradition differences, location (far away from Yegof of forest disturbance by anthropogenic forest), degree of human impact, over factors. Lower number of species was grazing and climatic conditions. shared between Yegof and Sanka Meda

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Table 2. The floristic distribution similarity between Yegof and other five afromontane forests in Ethiopia, as calculated by Sorensen similarity index. Forest Altitude range a b c Ss Yegof0 1900-3014 - - - 1 Menagesha1 2440-3400 44 39 55 0.48 Dindin2 2150-3000 32 51 45 0.40 Denkoro3 2300-3500 45 38 48 0.51 Biteyu4 2590-2890 30 53 47 0.36 Sanka Meda5 2400-2748 28 55 54 0.34

Key: 0. The present study, 1.Tamrat Bekele (1993, 1994), 2. Simon Shibiru and Girma Balcha (2004), 3. Abate Ayalew et al. (2006), 4. Mekonnen Biru (2003), 5. Shambel Bantiwalu (2010).

4. Conclusion and recommendations significant number of tree species, i.e., 11, without seedlings, 10 tree species without Conclusion sapling stage and some, i.e., 6, are without The results of the study indicated that the seedling and sapling stage in the forest, forest had high species diversity. Fabaceae while others are represented by all stages was found to be the most dominant family (seedling, spacing and mature). This shows followed by Asteraceae and Poaceae. Out the need for prioritized conservation of the plants identified in this study, 9 were strategy. endemic species which are included in the IUCN Red Data List. Recommendations The present study was limited to floristic The overall Shannon-Wiener diversity and composition and structure of woody plants. evenness of woody species in Yegof forest This requires further studies on soil seed was 3.73 and 0.79, respectively, indicating bank, seed physiology, and land use that the diversity and evenness of woody management system of the area. Moreover, species in the forest is relatively high. The detailed ethnobotanical studies are density of tree species in the forest necessary to explore the wealth of decreases with increasing DBH and Height indigenous knowledge on the plant classes which shows that the forest is in the community and its conservation. This secondary state of development. could be considered as part of the integrated efforts for the implementation of Analysis of population structure of most the rules of conservation and sustainable common species of trees and shrubs use of forest resources. Further, the species revealed high variation among species in the first and second priority classes for population dynamics within the forest. conservation should be given appropriate Accordingly, five population patterns have attention and should be conserved in-situ been observed (J-shaped, bell shaped, through the collaboration of local inverted J-shaped, irregular and U-shaped). communities, the District Agriculture and Rural Development Office, other interested The assessment of regeneration status of individuals and stakeholders. The forest is some selected woody species based on a good recreational area and real live seedling and sapling count revealed that a teaching site for the community and

Sultan and Berhanu, 2013 university students in and around the area. Kent, M. and Coker, P. (1992). VegetationD escription and Analysis: A practical approach. Belhaven press Especially, it has interesting sites for London. recreation during weddings and holiday Lamprecht, H. (1989). Silverculture in Tropics. Tropical celebrations. Therefore, establishment of Forest Ecosystems and their Tree Species- Possibilities and Methods of their Long-term roads, hotels, and tourism is beneficial. Utilization. T2-Velagsgesells chaft GmbH, RoBdort, Germany. Mekonnen Biru (2003). An Ecological Study of Biteyu References Forest, Gurage Zone, Southern Nations, Nationalities Peoples Region. Unpublished M.Sc. Thesis, Addis Abate Ayalew, Tamirat Bekele and Sebsebe Demissew Ababa University, Addis Ababa. (2006). The Undifferentiated afromontane forest of Shambel Bantiwalu (2010). Floristic composition, Denkoro in the central highland of Ethiopia: A structure and regeneration status of plant species in floristic and Structral Analysis. SINET: Ethiop. J. Sanka Meda forest,Guna District,Arsi Zone of Sci., 29(1): 45-56. Oromia Region, South east Ethiopia. M.Sc. Thesis, Alemayehu Wassie, Demel Teketay and Powell, N. Addis Ababa University.Addis Ababa. (2005). Church forests in North Gondar Simon Shibru and Girma Balcha (2004). Composition, Administrative Zone, northern Ethiopia. Forests, Structure and regeneration status of woody species in Trees and Livelihoods 15: 349-374. Dindin Natural Forest, Southeast Ethiopia: An Ali Abate (1983). Aspects of the political history of implication for conservation. Ethiop. J. of Biol. Sci. Wello: 1872–1916.MA Thesis Addis Ababa (1) 3:15-35. University, Addis Ababa. Tadesse Woldemariam (2003). Vegetation of the Yayu Azene Bekele (2007). Useful Trees and Shrubs for forest in Southwest Ethiopia: Impacts of human use Ethiopia. Identification, Propagation and and Implications for In situ conservation of Wild Management for 17 Agro climatic zones. Technical Coffea arabica L. populations. Ecology and manual, pp.550, (Tengnas,B.,Ensermu Kelbessa, Development Series No. 10. Center for Development Sebsebe Demissew and Maundu, P. eds). World Research, University of Bonn. Agroforestry Tamrat Bekele (1993). Vegetation and ecology of Bahru Zewde (1998). Forests and forest management in Afromontane forests on the central plateau of Shewa, Wollo, in historical perspective. Journal of Ethiopian Ethiopia. Acta phytogeorgr. Suec. 79. Studies 31(1):87-122. Tamrat Bekele (1994). Phyosociology and Ecology of Bird Life International (2009). Important Bird Area fact Humid Afromontane Forest on the Central plateau of sheet: Yegof forest, Ethiopia. Downloaded from the Ethiopia. J. Veg. Sci., 5:87-98. Data Zone at http://www.birdlife.org,accessed on Tewolde Brhane Gebre Egziabher. (1990). Diversity of 6/10/2010. Ethiopian flora. In: Engles, J.M.M.,Hawkes, J.G and Birhanu Kebede (2010). Floristic Composition and Melaku Worede (eds.), Plant genetic resources of Structural Analysis of Gedo Dry Evergreen Montane Ethiopia, Cambridge University Press, Cambridge, Forest, West Shewa Zone of Oromia National pp.75-81. Regional StateCentral Ethiopia. MSc. thesis WCMC (World Conservation Monitoring Center) (Unpublished). Addis Ababa University. Addis (1992). Global Biodiversity:status of the earth’s Ababa. living resourceces. Champman and Hall, London. Friis, I. (1992). Forest and Forest Trees of Northeast Zewdu Eshetu (2002). Historical C3-C4 Vegetation Tropical Africa: their natural habitats and distribution Pattern on Forested Mountain Slopes: It‟s Implication pattern in Ethiopia, Djibouti, and Somalia. Kew. Bull. for Ecological Rehabilitation of Degraded Highlands Add. Ser. 15: 396. of Ethiopia. Journal of Tropical Ecology, Vol. 18, Grubb, P. J. Lloyd, J. R., Penigton, J. D. and No. 5 pp. 743-758P: Cambridge University Whimore, J. C. (1963). A comparison of montane Press.USA. and lowland rain forests in Ecuador. J. Ecol. 51: 567 Zewge Teklehaimanot & Healey, J. (2001). – 601. Biodiversity conservation in ancient church and Kebrom Tekle(1998). Ecological rehabilitation of Monastery Yards in Ethiopia. In: Proceedings of a degraded hill slopes in southern Wello Ethiopia. workshop on biodiversity conservation. Ethiopian Doctoral Thesis. Uppsala University, Uppsala, Wild life and Natural History Society, Addis Ababa, Sweden Ethiopia.

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Appendix 1. Species list collected from Yegof Forest, South Wollo, Ethiopia

Scientific name Family name Vernacular name Habit (Amhric) Acacia abyssinica Hoechst. ex Benth Fabaceae Yabesha grar Tree Acacia polyacantha Wild sub sp campylacatha Fabaceae Nech grar Tree Acacia seyal Del Fabaceae Key grar Tree Achanthus sennii chiove. Acanthaceae Kosheshela Shrub Achranths aspera L. Amaranthaceae Telenji Shrub Agrocharis sp. Apiaceae Chegogot Herb Allophyllus abyssinicus Sapindaceae Embis Tree Aloe spp. (Aloe vera L.) Liliaceae Erret Shrub Anthoxanthum aethopicum I. hedberg Poaceae Yekok sar Grass Arisaema shimperianum schott. Araceae Amoch Herb Asparagus africanus Lam. Liliaceae Yeset-qest Shrub Asplenium aethopicum (Burm.f.) Becherer Aspleniaceae Amsa Anketkit Herb Bersama abyssinica Fresen Melianthaceae Azamir Tree/shrub Bidens bitenata L Asteraceae Aday Ababa Herb Bidens pilosa L. Compositae Yesytan-merfie Herb Brucea antidysenterica J.F.Miller Simaroubaceae Yedega Abalo Tree/shrub Buddleja polystachya Fresen. Buddlejaceae Anfar Tree Cadaba farinose Forssk. Malvaceae Dengay-seber Shrub Caesalpina spinosa (Molina) Kuntze Caesalpinioideae Konter Tree/shrub Calpurnia aurea (Alt.) Benth Fabaceae Zegeta Tree/Shrub Capparis tomentosa Lam. Capparidaceae Gemero Tree/shrub Carissa edulis (Forssk.) Vahl Apocynaceae Agam Tree/shrub Cassia siamea (Senna siamea) Caesalpinioideae Yeferenji Zegeta Shrub Casuarina equisetifolia L Casuarinaceae Shewashewe Tree Cerastium octandrum A. Rich. Caryophyllaceae Chegof Sar Grass Cissus qudrangularis L. Vitaceae Yezhon Anjet Shrub Clematis simensis Fresen. Ranunculaceae Tero hareg Climber Clerodendron alatum Gurke Verbenaceae Bujite Tree/Shrub Clerodendrum myricoides (Hochst.) R. Br. Umbelliferae Missiritch, Shrub Clutia abyssinica Jaub & Spach Euphorbiaceae Feyelefej Shrub Combretum collinum Fres. Combretaceae Tinjut Tree/shrub Commelina africana L. Commelinaceae Weha-ankur Herb Convolvulus kilimandschari Engl. Convolvulaceae Yeayt Areg Herb Cordia africana Lam. Boraginaceae Wanza Tree Crinum abyssinicum Amarlyllidaceae Yejib shinkurt Herb Croton macrostachyus Del.Hochest. ex. Del. Euphorbiaceae Bisana Tree Cupressus lucitanica Miller Cupressaceae Yeferenj Tid Tree Cyathula cylindrica Moq. Amaranthaceae Kundo sar Grass Cynodon dactylon (L.) Pers. Poaceae Serdo Grass Datura stramonium L. Solanaceae Etse-faris Herb Delphinium dasycanslon Fresen. Ranunculaceae Gedel admik Climber Desmodium repandum (Vahl) DC. Fabaceae Yeayt Misir Herb Diplolaphium africanum Fresen. Apiaceae Dog Shrub DiscopodiumpenninerxiumHochst. Solanaceae Ameraro Tree/shrub Dodonaea angustifolia L.f Sapindaceae Kitketa Tree/Shrub Dombeya torrida (J.F. Gmel) P.Bamps Sterculiaceae Wulkefa Tree Dovyalis verrucosa (Hochst.)Warb. Flacourtiaceae Koshim Tree/shrub Echinops giganteus Acanthaceae Kosheshela Shrub Ekebergia capensis Sparrm. Asteraceae Sembo Tree Erianmthemum dregei (Eckl.& Zeyh.) V. Tiegh. Loranthaceae Yembis-teketela Epiphyte Erica arborea L. Ericaceae Asta Tree/shrub

Sultan and Berhanu, 2013

Eucalyptus camaldulensis Dehnh Myrtaceae Key bahirzaf Tree Eucalyptus globulus Labill Myrtaceae Nech bahir-zaf Tree Euclea racemosa subsp schimperi Ebenaceae Dedeho Tree/shrub Euphorbia candelabrum Kotschy. Euphorbiaceae Kulkual Tree Euphorbia tirucalli L Euphorbiaceae Kinchibt Tree/shrub Ficus sur Forssk Moraceae Sholla Tree Foeniculum vulgare Mill. Umbelliferae Ensilal Herb Galiniera saxifrage Rubiaceae Yetota buna Tree Galium asparinoides Forssk. Rubiaceae Ashket Herb Gladiolus candidus L Araceae Milas golgul Climber Guizotia scabra (Vis.)Chiov Asteraceae Mech Herb Hibiscus ludwigil Eckl & Zeyha Malvaceae Nacha Tree/shrub Himpocrata africana (Willd.) Loes. Acaliaceae Ye-ayit hareg Climber Hyeperrhinia antchisteriodes Poaceae Quaya sar Grass Hypericum revolutum Vahl Clusiaceae Amja Tree/shrub Hyperrhenia variabilis Poaceae Senbelate Herb Jasminum abyssinicumHochstex.DC. Oleaceae Nech hareg Climber Jasminum grandiflorm L. Oleaceae Tembelel Climber Juniperus procera Endl Cupressaceae Yabesha Tid Tree Justicia schimperana (Hochst ex Nees) Acanthaceae Sensel Shrub Kalanchoe petitiana A. Rich. Crassulaceae Indahula/Bosoqe Herb Laggera tomentosa Sch. - Bip. Asteraceae Alashume Shrub Lippia adoensis Hochst.ex Walp. Verbenaceae Kesse Shrub Maesa lanceolata Forsk Myrsinaceae Abaye/debebosh Tree Maytenus arbutifolia (Hochst ex. A. Rich.) Wilczex Celastraceae Atat Tree/shrub Maytenus addat (Loes.) Sebsebe Celastraceae Geram Atat Tree/shrub Millettia ferruginea (Hochst.) Bak Fabaceae Birbira Tree Myrica salicifolia A.Rich. Myricaceae Shinet Tree/shrub Myrsine africana L. Myrsinaceae kechemo Tree/shrub Mytenus undata(A.D.C)f.wheat celastraceae Checho Tree/shrub Nuxia congesta R. Br. Ex Fresen Loganiaceae Asquar Tree Ocimum basilicum Hochst. Ex Benth. Lamiaceae Besobila Herb Ocimum lamiifolium Hochst. ex Benth. Lamiaceae Dama kessie Shrub Olea europaea subsp cuspidata (Wall. ex DC.) Oleaceae Weyra Tree Cifferri Olinia rochetiana A. Juss. Oliniaceae Beye/tife Tree/shrub Opuntia ficus-indica (L) Miller Cactaceae Beles Kulkual Tree Osyris quadripartite Deen. Santalaceae keret Tree/shrub Otostegia integrifolia Benth. Lamiaceae Tinjut Shrub Otostegia tomentosa A. Rich Lamiaceae Yeferes Zeng Shrub Otostegia tomentosa subsp ambigiens (chiov.) Lamiaceae Nechelo Tree/shrub Sebald Partentum misterophonus Asteraceae Kinche arem Herb Phragmanthera regularis (Sprague) M. Gilbert Loranthaceae Yequamo-teketela Epiphyte Phytolacca dodecandra L. Her Phytolacaceae Endod Climber Pinus patula L. Pinaceae Pachula Tree Pinus radiata D. Don. Pinaceae Radiata Tree Podocarpus falcatus (Thun) Mirb. Podocarpaceae Zigba Tree Pteroloblum stellautm (Forssk.) Brenan. Fabaceae Kentefa Climber Pygeum africanum Hook. f. Rosaceae Tikur-inchet Tree Rhus glutinosa Hochst. ex A. Rich Anacardiaceae Qamo Tree Rhus natalensis A.Rich. Anacardiaceae Takuma Tree Rosa abyssinica Lindley Rosaceae Kega Shrub Rubia discolor Turcz Rubiaceae Enchibrr Shrub Rubus aethiopicus R.A.Grah. Rosaceae Injorie Shrub Rumex nervosus (Vahl) Polygonaceae Embacho Shrub

Eth. J. Sci & Technol., Vol. VI, no.1: 33-45, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013

Rytidosperma grandiflora (Hochst.ex A. Arich.) Poaceae Ginchire sar Grass S.M. Phillips Scolopia theifolia Gilg. Flacourtiaceae Wanaye Tree Senna singuenana Fabaceae Gonfa Shrub Sida ovata Forsk Malvaceae Chifreg Shrub Solanum giganteum Jacq. Solanaceae Embuway (Whiteleaf) Shrub Solanum indicum L. Solanaceae Embuway Shrub Solanum nigrum L. Solanaceae Teqr-awete Climber Tapinanthus globiferus (A.Rich) Tiegh. Loranthaceae Teketela red Epiphyte Thymus schimperi Ron. Labiatae Tossigne Herb Trifolium schimperi A. Rich. Poaceae Washma Grass Urera hypselodendron (A.Rich.)Wedd. Urticaceae Lankuso Climber Verbascum sinaiticum Benth. Scrophulariaceae Ketetina Shrub Vernonia amygdalina Del. In Caill. Asteraceae Sete Gerawa Tree Vernonia bipontinnii Vatke. Asteraceae Mechela Tree Ximenia americana L. Apocynaceae Inkoy Tree Zehneria scabra (L. fil) sonder Cucurbitaceae Areg-ressa Climber Zizyphus spina- christi (L.)Wild Rhamnaceae Kurkura Tree

Eth. J. Sci & Technol., Vol. VI, no.1: 47-54, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013

Effect of Transplanting on Rice in Northwestern Ethiopia

Tilahun Tadesse*, Minale Liben, Alemayehu Assefa and Zelalem Tadesse Adet Agricultural Research Center, PO Box 08, Bahir Dar, Ethiopia *Corresponding author: [email protected]

Abstract of the world people (Ahmad et al., 2009). It is the most important food grain in the Rice transplanting experiment was conducted for diets of hundreds of millions of Asians, two years in Fogera plain, northwestern Ethiopia, so as to give transplanting recommendation for rain- Africans and Latin Americans living in the fed lowland rice production system. Two varieties tropics and subtropics (Tari et al., 2009). (X-Jigna and Gummara /IAC-164/), two seedling stages (2nd and 4th leaf stages, two spacings (25 cm Basically, there are two methods of rice x 20 cm and 25 cm x 25 cm) and two number of plant establishment namely; transplanting seedlings (2 and 3 plants/hill) were factorially combined and tested in randomized complete block and direct seeding (Abeysiriwardena et al., designs with three replications. Besides, dry 2005). Stand establishment depends on broadcast sowing of the two varieties was used as climate, soil, the availability of water, the control treatment. The comparison of transplanting availability and cost of labor and the choice with dry seed sowing showed that the former of variety. Transplanting is the practice of outsmarted the latter in yield and other yield components. Transplanting gave an average grain raising seedlings in a nursery and planting yield of 4140.8 kg ha-1 while dry sowing had an them into a separate field. The crop is average yield of 3008.1 kg ha-1. Transplanting was grown without disturbance thereafter observed to have a grain yield advantage of 1132.7 (Singh and Singh, 2000). On the other -1 kg ha (37.7%) over dry sowing. Concerning the hand, direct sowing is the practice of other yield components, transplanting gave higher number of tillers/ hill and higher number of fertile sowing seeds directly in the main field, panicles/hill as compared to dry seeding. The eliminating the process of seedling raising. economic analysis showed that transplanting was Direct sowing is the main crop advantageous over dry sowing. The different establishment practice in all the upland transplanting methods gave net benefit of Birr 7796 sub-ecosystems. It could also be used in to Birr 9454. Compared to the lowest net benefit obtained from dry seed sowing, a maximum wet soils. The seeds are sown either by increase in net benefit of Birr 1934 was obtained broadcast or in lines in the furrows (Singh because of transplanting. From this experiment it is and Singh, 2000). recommended that in northwestern Ethiopia and other similar agro ecologies, rice seedlings should Broadcasting is the only method of rice be transplanted at 4 leaf stages with a spacing of 25 cm x 20 cm by planting 3 seedlings per hill. planting being used in Fogera plain. However, transplanting is the major means ______of rice planting used in other parts of the Key words: Dry seeding; Plants per hill; Seedling world (Morris, 1980; Patel and age, Transplanting. Charugamba, 1981; and Uphoof, 2003). Patel and Charugamba (1981) stated that transplanted rice is capable of yielding 1. Introduction 30% more than broadcasted rice. The other advantage of transplanting is effective Rice is one of the most important cereal utilization of rainy season and faster crops and is the staple food for the majority maturity of the rice crop particularly in

Tilahun et al., 2013 rain-fed lowland rice ecosystems since the is situated 60 km North-East of Bahir Dar crop partly passes some of its growth stage Town. The experimental site is located at in nursery (Morris, 1980; Abeysiriwardena Latitude of 130 19‟, Longitude of 370 03‟ et al., 2005). As compared to broadcasted and at an altitude of 1815 m.a.s.l. The rice, transplanted rice competes better with climatic data of Woreta shows that the weeds (Uphoof, 2003). Labor intensiveness mean annual minimum temperature is at the time of planting is the only drawback 11.50C and the mean annual maximum of transplanting compared to direct seeding temperature is 27.890C and the annual (Morris, 1980 and Uphoof, 2003). Though mean temperature is nearly 18.30C. transplanting is mainly used in areas with Rainfall of the area is uni-modal; usually irrigation facilities, it could also be used for occurring during June to October, and the rain-fed rice by constructing water average mean annual rainfall reaches to harvesting soil bunds around leveled fields 1300 mm. (Morris, 1980 and Patel and Charugamba, 1981). Factorial combinations varieties, seedling stages, spacings and the number of Ages of seedlings, spacing and number of seedlings per hill were tested in RCB seedlings per hill during transplanting are design with three replications. Two among the major factors that determine the varieties (X-Jigna and Gummara /IAC- extent of the system's advantage (Morris, 164/), two seedling stages (2nd leaf stage 1980; and Uphoof, 2003). To improve the which is about 12 days after emergence yield and quality of fine rice, seedlings and 4th leaf stage which is about 14-30 need to be transplanted at their optimum days after emergence), two spacings (25 age. Numerous evidences have confirmed cm × 20 cm and 25 cm ×25 cm) and two that recommendations on transplanting; number of seedlings (2 plants/hill and 3 particularly on age of seedlings, spacing plants/hill) were factorially combined and and number of seedlings per hill vary tested. Dry broadcast sowing at a seed rate considerably with varietal differences of of 100 kg ha-1 of the two varieties was which tillering capacity being the included as control treatment. governing factor (Morris, 1980; Viraktamath et al., 1998 and Uphoff, In order to raise the seedlings, first a 2003). Shortage of cultivable land, mixture of soil and rice husk at a volume availability of labour resource, and plain ratio of 8:1 was prepared. Then, the land in the Fogera plain allow rice mixture was spread on the plastic covered production intensification practices like seed bed at a thickness of about 5 cm. The transplanting. This study was conducted to rice seeds were broadcasted at a rate of 15 give recommendations on transplanting to kg seed/ 150 m2 seed bed. Finally, the Fogera plain rain-fed lowland rice seeds were covered with very thin layer of production system. soil and dry grass. The grass was removed when the seeds started to emerge. The seed 2. Materials and Methods bed was watered every day both in the morning and at night till the transplanting. A rice transplanting experiment was Urea was applied at a rate of 50 kg/ha on conducted for two years (2005-2006) in all plots few days after transplanting (just Fogera plain. Fogera, which is found in after the seedlings recover from the South Gondar Zone of the Amhara Region, transplanting shook). Gross and net plot sizes were 4 m × 3 m and 3 m × 2 m,

Eth. J. Sci & Technol., Vol. VI, no.1: 47-54, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013

respectively. The central twelve rows were With respect to the spacing between hills taken as net rows for the row planted plots. and number of seedlings per hill, 25 cm x Data on maturity date, plant height, number 20 cm spacing and 3 plants at each hill, of tillers of fertile and infertile panicles, respectively, were found to be better. thousand seeds weight, grain yield, labor Concerning the age of the seedlings, cost for planting and labor cost for weeding transplanting seedlings at 4 leaf stage were collected. The collected data were (about 14-30 DAE) is more advisable than subjected to Analysis of Variance using younger seedlings at 2 leaf stage (about 12 Statistical Analysis System (SAS) Version DAE) so as to reduce the risk of failure due 9.2 (SAS Inc., 2002). The grain yield was to moisture stress just after transplanting. further subjected to partial budget analysis following CIMMYT (1988). A rice seed Concerning the other yield components, and grain price of Birr 2.5/kg was used for transplanting gave higher number of tillers the economic analysis. hill-1 than dry seed sowing did (Table 2). Similarly, the number of fertile panicles 3. Results hill-1 was higher in the case of transplanting than in the dry seeding (Table In 2005, the comparison among 3). Compared with transplanting, the dry transplanted treatments indicated that there sown rice was having lesser number of was statistically equivalent response for fertile panicles. In the case of dry sowing, most of the parameters. However, the the growth of the panicles was less uniform comparison of transplanting with the in that the majorities of the panicles were control (dry sowing) showed that there was matured and near to shatter while some significant difference for most of the yield were still immature and harvested as are components including the grain yield. X- infertile. On the other hand, for the Jigna gave an average grain yield of 3493 transplanting, most of the panicles were kg ha-1 during transplanting while 2347 kg found fertile with lesser number of the ha-1by dry sowing. Similarly, Gumara gave infertile during maturity. an average grain yield of 4304 kg ha-1 when transplanted but it gave 2616 kg ha-1 The economic analysis had also indicated when dry sown. that transplanting was advantageous over dry sowing. The different transplanting The two years combined analysis of methods gave net benefit ranging from Birr variance indicated that the transplanted 7796 to Birr 9454 as compared to the treatments did not have significant effect lowest net benefit (Birr 7520) obtained on grain yield and other yield components. from dry seed sowing (Table 4). However, the comparison of transplanting with dry seed sowing showed that the 4. Discussion former significantly out yielded the latter in terms of yield and other yield components The observed increase in rice grain yield (Tables 1-3). Transplanting gave an due to transplanting is in line with the -1 average grain yield of 4140.8 kg ha while findings of many authors. An experiment dry sowing had an average yield of 3008.1 comprised of transplanting and direct -1 kg ha (Table 1). Transplanting showed a seeding treatments indicated that -1 grain yield advantage of 1132.7 kg ha transplanting resulted in maximum paddy (37.7%) over dry sowing. yield than the direct seeding methods

Tilahun et al., 2013

(Ehsanullah et al., 2000). The report of establishment of rice. In the present Patel and Charugamba (1981) indicated investigation it was observed that that transplanted rice is capable of yielding transplanting rice seedlings at 4 leaf stage 30% more than broadcasted rice. Mitchell seedling age is better yielding than 2 leaf et al., (2004) have also indicated a highly stage seedlings. This finding is different significant positive correlation between the from the reports of Uphoff and Erick performance of genotypes in direct seeding (2002); Zheng et al., (2004) and Uphoff (DS) and transplanting (TP) experiments in (2006) who recommended 2 leaf staged which TP rice had a 6-30% yield advantage rice seedling transplanting. However, the over DS rice. Similarly, Uphoof (2003) present finding is in line with numerous reported that rice yield could be increased reports. A report stated that seedlings are by 1.35 to 2.48 t ha-1 by transplanting ready to be pulled out when they attain the rather than seed broadcast sowing. As stage of 4-5 leaves, about 18 days after stated by Singh et al., (2002), direct dry sowing in the case of short duration seeding of rice reduced yield by 23–41% varieties and 20-25 days after sowing in the on flat land and by 41–54% on raised beds case of medium duration varieties compared with transplanted rice. Major (Anonymous, 2002). Agronomic research problems of direct seeded rice attributed to aimed at developing technologies to its low yield are poor crop establishment, improve lowland rice yields in Laos dominance of weeds, pests and lodging indicated that, to obtain high yields from (Fukai et al., 1998; Mitchell et al., 2004). rain-fed lowland transplanted rice, high- yielding seedlings should be 25 days old In the present investigation the yield when transplanted (Sipaseuth, 2000). From increase of transplanting over dry seed their experiment in Iran, Mobasser et al., sowing is associated with the increase in (2007) stated that when the age of the number of effective tillers and seedlings is less than optimum, the tender increased number of fertile panicles. In line seedlings may die in greater number due to with this, Mobasser et al., (2007) reported high temperature and ultimately the plant that transplanting of healthy seedlings population is reduced. Pasuquin et al., ensures better rice yield by promoting (2004) stated that if the age of seedlings is better tillering and growth. Apart from more than optimum, the seedlings produce tillers and fertile panicles, Singh et al., fewer tillers and thereby result in poor (2002) and Mitchell et al., (2004) yield. Transplanting seedlings at optimum explained that the yield difference between age induced higher tiller production and the two planting methods is attributed to higher plant shoot dry matter accumulation lodging, pest and weed problems during and hence ensure higher rice grain yield dry seed sowing. Fukai et al., (1998) had (Pasuquin et al., 2004). also reported that major problems of direct seeded rice are poor crop establishment and From the economic analysis of this study, presence of weeds. The loss in grain yield transplanting is found to be more profitable of direct-sown rice caused by unchecked than the direct seed sowing. Although it is weed growth ranged from 18.2 to 59.2% in labor intensive, requires pre-harvest labor the different years, and was greater when N ranging from 72 to 79 man-days, fertilizer was applied (Sharma, 1997). transplanting is still the predominant method of rice production (PRRI, 2006). In Age of seedling at the time of transplanting the current experiment it is mainly the is an important factor for uniform stand higher yielding ability which makes

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transplanting economically advantageous transplanting unlike most other Asian over dry seed sowing. Moreover, the lower countries, mostly because of the climate seed requirement of transplanting makes it (the land is subject to a cold temperate economical. Similar to the present winter) (Maruyama, 2005). Direct seeding observation, Singh and Singh (2000) technologies are, generally speaking, not reported that lower seed requirement is also compatible with the Japanese climate (cool the other advantage of transplanting over temperate), since direct seeding results in direct seeding. Direct sowing requires more slow germination and the short elongation seed than transplanting does, 50 to 100 of rice in cooler temperatures (Maruyama, kg/ha depending on the method of sowing 2005). Rice requires a hot and humid and the rice variety (Singh and Singh, climate. High altitude and low temperature 2000). delay its flowering and maturity. Temperature ranging from 210C to 350C Beside its better weed control advantage throughout the life cycle is conducive to its and higher yields, there are also other growth and development (Datta and reasons which make transplanting a Patrick, 1986). With regard to its preferred method of rice establishment. temperature, Fogera plain is a bit cooler for After conducting research in Bangladesh rice production. The mean minimum and by sowing seeds in nursery for maximum temperatures at Fogera during transplanting and sowing the direct seeded the critical rice growing period (June- rice in field both in the same day, Mazid et September) are 12.30C and 26.20C al., (2002) indicated that rice established respectively (Sewnet, 2005). Therefore, by dry seeding matured 7–10 days earlier transplanting is an appropriate technology than transplanted rice. In case of rain fed- for rice production in the area. lowland rice, for farmers practicing the seedling raising during off-seasons, 5. Conclusion transplanting is effective in utilization of rainy season since the crop partly passes Transplanting of rice was found to be some of its growth stage in nursery biologically and economically compared to seed broadcasting (Morris, advantageous over dry seed sowing. From 1980). Transplanting may have also helped this experiment it is recommended that rice farmers to deal with the low temperature seedlings should be transplanted at 4 leaf that can adversely affect the performance stage age with a spacing of 25 cm x 20 cm of direct-seeded rice at higher altitudes and 3 seedlings per hill. (Pandey and Velasco, 2002). Despite its long history of rice production, Japan‟s rice production industry is still practicing

Tilahun et al., 2013

Table 1. Two-year combined effect of seedling age, spacing and number of plants per hill on grain yield (kg ha-1) of transplanted rice

Number of X-Jigna (V1) Gumara (V2) plants per 25 cm × 20 cm 25 cm × 25 cm 25 cm × 20 cm 25 cm × 25 cm hill 4 leaf 2 leaf 4 leaf 2 leaf 4 leaf 2 leaf 4 leaf 2 leaf stage stage stage stage stage stage stage stage 2 plants/ hill 3839E-I 3673GHI 3921D-I 3478I 4511A-D 4241A-G 4241A-G 4030C-I 3 plants/ hill 4181B-H 3998D-I 3829F-I 3635HI 4716A 4654ABC 4677AB 4629ABC Mean 4010C-I 3835E-I 3875E-I 3556I 4613ABC 4448A-E 4459A-E 4330A-F

Table 2. The two years combined effect of seedling age, spacing and number of plants per hill on number of tillers/ hill

Number of X-Jigna (V1) Gumara (V2) plants per hill 25 cm × 20 cm 25 cm × 25 cm 25 cm × 20 cm 25 cm × 25 cm 4 leaf 2 leaf 4 leaf 2 leaf 4 leaf 2 leaf 4 leaf 2 leaf stage stage stage stage stage stage stage stage 2 plants/ hill 9.9C-F 9.7DEF 9.7DEF 11.1A-D 11.9A 9.8DEF 10.7A-E 11.0A-D 3 plants/ hill 10.6A-E 8.3F 11.4A-D 10.3A-E 11.3A-D 11.1A-D 11.7AB 11.1A-D Mean 10.2B-E 9.0F 10.6A-E 10.7A-E 11.6ABC 10.5A-E 11.2A-D 11.1A-D

Table 3. The two years combined effect of seedling age, spacing and number of plants per hill on number of fertile panicles/ hill

Number of X-Jigna (V1) Gumara (V2) plants per hill 25 cm × 20 cm 25 cm × 25 cm 25 cm × 20 cm 25 cm × 25 cm 4 leaf 2 leaf 4 leaf 2 leaf 4 leaf 2 leaf 4 leaf 2 leaf stage stage stage stage stage stage stage stage 2 plants/ hill 117GH 116H 121FGH 109H 144B 126D-G 134B-F 135B-F 3 plants/ hill 126D-G 130C-G 119GH 125E-H 141B-D 149A 140B-D 120FGH Mean 121FGH 123E-H 120FGH 117GH 142BC 137B-E 137B-E 127C-G

Table 4. Economic analysis for transplanted and dry seeded rice

Adjusted grain Labor cost for Labour cost for Gross Treatment yield (kgha-1) seedling raising transplanting TVC benefit Net benefit Ag1S1H1 3757.23 540 1200 1740 10436.75 8696.8 Ag1S1H2 3921.21 540 1200 1740 10892.25 9152.3 Ag1S2H1 3378.78 540 1050 1590 9385.5 7795.5 Ag1S2H2 3806.01 540 1050 1590 10572.25 8982.3 Ag2S1H1 3561.39 390 1200 1590 9892.75 8302.8 Ag2S1H2 3975.75 390 1200 1590 11043.75 9453.8 Ag2S2H1 3672.9 390 1050 1440 10202.5 8762.5 Ag2S2H2 3739.95 390 1050 1440 10388.75 8948.8 Dry Sown 2707.2 0 0 0 7520 7520.0

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Bouman Mortimer M, Wade L, Tuong TP, Lopez K, Hardy B (2002). Effects of rice establishment methods on crop (eds) editors. 2002. Direct seeding: research issues performance, water use, and mineral nitrogen. In: and opportunities. Proceedings of the International Water-wise rice production. Proceedings of Workshop on Direct Seeding in Asian Rice Systems: a thematic workshop on water-wise rice production, Strategic Research Issues and Opportunities, 25-28 8-11 April 2002 at IRRI headquarters in Los Baños, January 2000, Bangkok, Thailand. International Rice Philippines. Pp 76-89. Research Institute. Pp 185-196. Singh, V.P. and R.K. Singh, editors (2000). Rainfed Mitchell, J., Shu Fukai and Jayampathi Basnayake Rice: A Sourcebook of Best Practices and Strategies (2004). Grain yield of direct seeded and transplanted in Eastern India. International Rice Research rice in rainfed lowlands of South East Asia. In: Institute. 292 p. Proceedings of the 4th International Crop Science Sipaseuth, E. 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Effects of Apple Supplement and Unsupervised Home-based Brisk Walking on Low Density Lipoprotein Cholesterol Khelifa Nida Bartrua1, M.S. Sohal2, Kiranjeet Kaur3, Maninder Kaur4 1Department of Sport Science, Bahir Dar University, Ethiopia 2Professor, Punjabi University, Patiala, India 3 Professor, Department of Biochemistry, Government Medical College, Patiala, India 4Assistant Professor, Department of Biochemistry, Government Medical College, Patiala, India.

Abstract and genetic forms of hypercholesterolemia indicate that elevated serum level of Low- Elevated levels of cholesterol present in Low- Density Lipoprotein (LDL) are directly associated Density Lipoprotein Cholesterol (LDL-C) with atherosclerosis. Therefore, the present study is an important independent risk factor for was an attempt to analyze the effect of apple Coronary Heart Diseases (CHD) (Stefanick supplement, restricted dietary fat and unsupervised et al., 1998; Davidson et al., 1998; NCEP, home-based brisk walking program on the level of 2001; Grundy et al., 2004; Zoeller, 2007). LDL-Cholesterol (LDL-C). Fourteen participants (11 males and 3 females) recruited voluntarily from Fruit intake, reducing intake of low-fat Punjabi University, Patiala, constituted the study dairy products, and engaging in a regular group. They were further subdivided into 2 groups. Physical Activity (PA) are considered as a Whereas Group I consisted of participants with protective factor for many chronic diseases 2 body mass index > 25 kg/m and LDL-C> 110 (U.S. Department of Health and Human mg/dl, Group II consisted of members with body mass index between 20-25 kg/m2 and LDL-C<110 Services, 1996; Krauss et al., 2000; Hyson, mg/dl. Members in Group I (n = 7) were given 2002; WHO/FAO, 2003; Tully et al., 2005; apple fruit (Pyrus Malus) twice a day free of charge Varady & Jones, 2005) and dietary and were advised unsupervised home-based guidelines have consistently recommended walking activity for three weeks. Members in Group increased intake of fruits and vegetables, II (n = 7) were given apple fruit alone. During the period of the study all participants were advised low-fat diet and PA (Krauss et al., 2000). dietary fat restriction and their fasting serum lipid However, the effect of combined use of profiles were estimated at 0 and 3 weeks. After 3 fruits and PA on lowering LDL-C is not weeks of the study period, Group II lowered LDL-C determined. The two mechanisms have a by 18.57 mg/dl (95% confidence interval = 9.05- potential to lower serum cholesterol and 28.09, p=0.03), so did group I by 38.33 mg/dl (95% confidence interval = 25.62-51.04, p=0.01). Apple LDL-C. Most studies on the role of apples supplement combined with dietary advice to reduce on health have focused on their lipid- fat intake and unsupervised home-based brisk lowering effects and more recently on their walking program may result in significant reduction anti-oxidative properties. The fiber in in LDL-C level in sedentary individuals. apples is thought to play an important role

______in the reduction of lipids (Aprikan et al., Keywords: apple, brisk walking, dietary 2003). restriction, home-based, LDL-C, low-fat, Physical activity, sedentary, Extensive studies on experimental animals unsupervised indicate that the addition of different types of dietary fibers have advantageous physiological effects such as reducing 1. Introduction cholesterol levels in serum (Sembries et al., 2004). Apples are good sources of dietary Research from experimental animals, fiber and have been shown to lower serum laboratory investigations, epidemiology,

Khelifa et al., 2013 cholesterol concentrations in 2. Materials and Methods hypercholesterolemia (Brown et al., 1999; Bazzano et al., 2003; Boyer & Liu, 2004; Participants Sembries et al., 2004; Edijala et al., 2005). Consuming apples lowered cholesterol and This study is a one-time experimental trial LDL-C on obese Zucker rats (Boyer & Liu, involving a normal and overweight 2004). On the other hand, it is generally sedentary individual, which is being carried accepted that dietary advice to lower fat out in Panjabi University, Patiala (PUP), intake (King & Gibney, 1999), low-fat India. The study was not randomized and diets, in particular reducing saturated fat controlled. Rather fourteen (3 females) intake, significantly lowers total and voluntary participants, who were regular plasma LDL-C concentrations. However, students pursuing their undergraduate and such diets also decrease High-Density graduate program, were recruited. Subjects Lipoprotein concentrations (HDL-C) and were selected based on the following may increase plasma triacylglycerol criteria: they were (1) between the ages 18- concentrations (Hannah et al., 1997; 26 years, (2) in good health, with no Kasim-Karakas et al., 2000; Tully et al., history of cardiovascular or metabolic 2005). disease, (3) a body mass index between 20- 40 kg/m2, (4) non-smokers or abusing Many studies support moderate-intensity alcohol, (5) not taking medications known (such as brisk walking) to high-intensity to interfere with lipid profile, (6) sedentary, exercise 3 to 5 times per week for at least and (7) no musculoskeletal 30 min per session to manage or improve contraindications to exercise were included cholesterol profiles (Tully et al., 2005; in the study. Brief discussion about the Zoeller, 2007). Regular exercise such as 30 experiment was organized to the min of brisk walking daily and increased participants to ensure better understanding levels of PA can lower levels of total of the protocols and procedures, benefits cholesterol and LDL-C (U.S. Department and associated risks of the study prior to of Health and Human Services, 1996; the intervention; hence consent was NCEP, 2001; Bernstein et al., 2002). acquired from the participants. In addition, Walking is a very acceptable form of seven participants (2 females) with body exercise to a wide proportion of the mass index > 25 kg/m2 and level of LDL-C population. It does not require any formal ≥110 mg/dl) were grouped into Group I (an training or special equipment and can be exercise plus apple group); and the rest performed in an individual‟s own locality seven participants (a female) with body 2 and time (Tully et al., 2005). mass index between 20-25 kg/m and level of LDL-C<110 mg/dl were grouped into Therefore, we carried out an experimental Group II (apple group). trial among normal and overweight 11 males and 3 females to determine primarily Procedures the effect of apple supplement and dietary advice to reduce fat intake and Prior to the experiment, participants were unsupervised home-based brisk walking instructed to fast between 8 to 11 hours for program on the level of LDL-C. blood sampling. On the pre- and post- blood sampling days (i.e., 22 February 2007 and 16 March 2007, respectively), all participants were asked to arrive to the laboratory at 9:00 AM. They were asked to

Eth. J. Sci & Technol., Vol. VI, no.1: 55-63, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013 undergo one time 5ml blood sample and walking activity for 3 consecutive wks. body weight measures before and after the The diary was prepared in such a manner experiment. Written guidelines were given that the total minutes of brisk walking were to each of the participants indicating the partitioned into the following categories importance of fasting from food and avoid based on CDC/ACSM guidelines (Pate et PA in the preceding blood sampling day al., 1995) recommending a minimum of 30 and this was verbally reiterated to each min of activity daily: 0 min, 1-29 min, 30- participant a day prior to the pre- and post- 59 min, 60-89 min, 90-119 min, 120-149 blood testing periods. All participants were min, and 150 plus min. Bearing the small instructed by a dietitian to reduce their fat number and sedentary nature of (mainly saturated, trans-fatty acid and participants in mind, we amended the cholesterol food stuffs) prior to the categories as follows: 0 min, 1-29 min, 30- experiment. Adherence to dietary fat intake 59 min and 60 min or more. Following the was assessed on the basis of advice and collection of the diary report, the total time guidelines. Guiding principles associated that participants spent in brisk walking with this had been given to all participants. activity was estimated. On the other hand, Furthermore, either of the group‟s intakes Group II participants received a free of of dietary fat was not supervised or charge red royal apple fruit that weighs 250 standardized; rather it was on the basis of gram on average twice a day. They were dietary advice or guidelines to reduce the also instructed to refrain themselves from fat intake. No advice was given to restrict any kind of PA. the participants‟ normal habitual eating practices. Participants in both groups were Blood sampling Procedures instructed to eat two apples: one in the morning (before breakfast) and one in the Following 8 to 11 hr overnight fast, 5 ml of evening (before dinner) (without removing venous blood was taken under aseptic the skin) per day for 3 wk. conditions by venipuncture with the participant in a seated position. Blood Intervention samples were obtained at 0 and 3 week. Blood samples were collected in serum Participants who were assigned in Group I tubes, allowed clotting for 1 hr by keeping received free of charge red royal apple fruit it undisturbed, and then the serum was (Pyrus Malus) that weighs 250 gram on separated in a clean, dry test tube average twice a day and engaged in an centrifuged on Microsil laboratory at 3000 unsupervised home-based moderate- rpm for 5 min. intensity (brisk walking) activity for the period of 3 wk. Brisk walking was defined Analytical procedures as a pace faster than normal and leaves the individual slightly breathless but still able All the pre- and post- blood samples were to converse. Participants received detailed analyzed on fully automatic analyzer demonstration regarding how to do the (Metrolab 2300 Random Access, Clinical brisk walking. Adherence to advice was analyzer made in Argentina) at the assessed using a self-reported diary and Government Medical College, Patiala, and stopwatch. In other words, all participants Department of Biochemistry. The whole were instructed to record on their diary the blood was analyzed to perform a detail time only they covered during brisk lipid profile estimation including total

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lipids, serum cholesterol, triglycerides, The participant reported that she started HDL-C and LDL-C. Also, the participants‟ taking medications (namely Desogestrol lipid profile results were obtained nearly and Ethinylestradiol) in the mid of the four hours following blood collection. intervention. Thus, the medications might have interfered with the lipid profiles. Statistical analysis Table 1 and 2 show the lipid and lipoprotein variables of the participants at A paired samples t-test was employed to pre- and post- intervention. After 3 weeks examine differences in the level of LDL-C of intervention, Group II lowered LDL-C from pre- to post-intervention for the two by 18.57 mg/dl (95% confidence interval = groups using the SPSS software program, 9.05 – 28.09, P = 0.03); Group I lowered version 15.0 (Statistical Package for Social by 38.33 mg/dl (95% confidence interval = Science, Chicago, IL). In all cases, p < 0.05 25.62 – 51.04, P = 0.01). There was no was taken as the level of significance in significant change in Cholesterol; 19.29 two-tailed tests. mg/dl (95% confidence interval = -8.39 –

46.96, P = 0.139) obtained in Group II 3. Results while a change in cholesterol of 36.67 mg/dl (95% confidence interval = 17.69 – The post level of LDL-C of one participant 55.63, P = 0.04) was observed in Group I. from Group I could not be calculated due With respect to HDL-C and triglyceride to elevated triglycerides and total lipids. levels, no significant changes were So, data for Group I was treated for 6 obtained in both groups from pre-to-post participants. On the other hand, similar interventions. level of LDL-C was observed in the pre- and post-test of one participant in Group II.

Table 1. Changes in Total Lipids, Cholesterol, Triglycerides, HDL-C & LDL-C for Group II (BMI ≤ 25 kg/m2, level of LDL-C < 110mg/dl)

Paired differences Pre Post Change Mean SEM P Total Lipids 476.43 470.71 -0.0119 5.71 39.79 0.891 Cholesterol 151.43 132.14 -0.127 19.28 11.30 0.139 TG 125.00 140.71 0.125 -15.71 30.64 0.626 HDL-C 37.14 35.00 -0.057 2.14 2.40 0.407 LDL-C 85.00 66.43 -0.22 18.57 3.89 0.03

4. Discussion dietary advice to reduce fat intake and unsupervised home-based brisk walking in Such experimental design is the first to lowering LDL-C. To date CVD remains examine the usefulness of regular one of the leading causes of morbidity and consumption of apple fruit combined with mortality worldwide.

Table 2. Changes in Total Lipids, Cholesterol, Triglycerides, HDL-C & LDL-C for Group I (BMI > 25 kg/m2, level of LDL-C> 110mg/dl)

Paired differences Pre Post Change Mean SEM P Total Lipids 435.83 425.00 -0.025 10.83 26.06 0.695 Cholesterol 172.50 135.83 -0.21 36.67 7.37 0.04 TG 70.00 90.83 0.29 -20.83 23.64 0.419 HDL-C 39.17 34.17 -0.11 4.17 3.96 0.341 LDL-C 121.67 83.33 -0.32 38.33 4.94 0.01

Participants in Group I were reported that they were engaged in brisk walking activity. The diary report for brisk walking program is presented in the following table: Table 3. Descriptive Statistics for unsupervised brisk walking activity (n=6)

Walking Minutes Sum Average walking Percentage minutes in 20 days 0 13 0.65 3.25% 1-29 31 1.55 7.75% 30-59 58 2.9 14.5% 60+ 18 0.9 4.5%

Available evidence indicates that persons consumed, rich source of phytochemicals, who consume more fruits and vegetables and epidemiological studies have linked often have lower prevalence of important the consumption of apples with reduced risk factors for CVD, including risk of some cancers, CVD, asthma, and hypertension, obesity, and type 2 diabetes diabetes. In the laboratory, apples have mellitus. Some large, prospective studies been found to have very strong antioxidant showed a direct inverse association activity, inhibit cancer cell proliferation, between fruit and vegetable intake and the decrease lipid oxidation, and lower development of CVD incidents such as cholesterol. Apples, and especially apple CHD and stroke (Ignarro et al., 2007). peels, have been found to have a potent Indeed, the health protective effects of fruit antioxidant activity and can greatly inhibit and vegetable intake observed in the growth of liver cancer and colon cancer epidemiological studies may be due, in cells (Boyer & Liu, 2004). Studies found part, to the presence of antioxidants in that apples had a greater cholesterol these foods (Hyson et al., 2000). lowering effect than the other two fruits such as peaches and pears (Leontowicz et Evidence suggests that a diet high in fruits al., 2002). A number of studies have and vegetables may decrease the risk of indicated that LDL oxidation is reduced in chronic diseases, such as CVD and cancer vitro by a variety of fruits or fruit extracts and phytochemicals including phenolics, (Hyson et al., 2000). flavonoids and carotenoids from fruits and vegetables may play a key role in reducing Long-term consumption of a low-fat diet chronic disease risk. Apples are a widely might be associated with even greater

Khelifa et al., 2013 weight loss and additional improvement of programs delivered in more formal plasma lipid concentrations. Moreover, a settings. diet low in saturated fat has become accepted (Franz et al., 2002; Gerhard et al., In the present study, a significant decrease 2004). in total cholesterol and LDL-C levels was noted following post-intervention. In On the other hand, a home-based walking addition, participants in both groups program may be a safe and effective way showed elevated triglycerides and lowered for high-risk individuals to increase their HDL-C. However, the decrease in HDL-C PA. Walking is a moderate-intensity form was coupled with large reductions in both of PA that carries less risk for adverse LDL-C and total-C. Moreover, in this study cardiovascular or musculoskeletal events LDL-C decreased by 22% in Group II; than more vigorous forms of PA. However, whereas 32% of the reduction in LDL-C little is known about the risk for adverse was found in Group I in the period of 3 wk. events among high-risk individuals in Apparently, one participant had shown a response to unsupervised lifestyle activity significant reduction (a change of -0.38889 programs that emphasize moderate mg/dl) of LDL-C in Group II. Conversely, intensity PA like walking. A recent study the post- test of LDL-C concentration (a showed that individuals at high risk for change of -0.15385 mg/dl) of one CVD could safely start an unsupervised participant in Group I showed similar result home-based walking program with a low as those of Group II participants. The risk for adverse reactions to walking reasons behind all those observed changes, (Goodrich et al., 2007). Walking, either in however, are unclear. Specifically, whether the form of supervised group walks or the LDL-C reduction was due to apple unsupervised home-based walking, is one supplement or voluntary restriction of of the easiest, safest, and most inexpensive dietary fat intake or unsupervised home- type of exercise to promote, and it is also based brisk walking program or the one of the most popular forms of exercise combination of the three is uncertain. among those with and without chronic illness. Programs that encourage PA during 5. Implications leisure time or unsupervised home-based activities have better long-term adherence The results of our analyses may have rates (Richardson et al., 2005). several implications for sedentary people who are at risk for developing CVD and for Results of recent studies indicated that 30 researchers and health care professionals. min, 12- week self-paced, unsupervised brisk walking, 5 days per week improves First, the addition of fruits and vegetables fitness and decreases cardiovascular risk in conjunction with healthy diet and (Tully et al., 2005). The study added to the physical activity has the capacity to reduce evidence of the health benefits of the risk of CVD/CHD and should be more moderate-intensity exercise to sedentary emphasized either in the clinical settings or adults. Home-based programs of moderate in a controlled and targeted studies though intensity activity with ongoing professional it is difficult to evaluate prospectively the contact have been suggested to be more causal relationship of diet and physical likely to lead to longer term changes in activity on major CVD events. activity levels (Hillsodon et al., 1995) than Second, the findings indicate that awareness of unsupervised home-based

Eth. J. Sci & Technol., Vol. VI, no.1: 55-63, 2013 ISSN 1816-3378 © Bahir Dar University, February 2013 walking program is the safest, effective in 6. Conclusion the promotion and achieving the sedentary individual‟s PA goals despite the fact that In summary, we observed that sedentary previous studies have shown that self- individuals are at low risk from CVD if reported measures tend to be overestimates they could engage themselves safely in an of actual activity (Bassett et al., 2000). unsupervised home-based walking program Also, long-term participation in walking along with healthy diet and lifestyle. This program can produce more desirable result study addressed the gap in the literature by than it does in the short-term ones. Third, targeting the population (sedentary the addition of fruits in a normal habitual individuals) that regular fruit consumption, eating practice, following the voluntary unsupervised home-based walking program restriction of dietary fat intake and and advice to lower dietary fat intake may engaging in regular PA in an unsupervised play an important role in lowering LDL- home-based manner has increased the (“bad”) C concentrations, which is the participant‟s understanding toward changes major cause for CVD/CHD. in lipid profiles particularly LDL-C and health maintenance in general. In general, from this novel study an apple a day in conjunction with voluntary Lastly, the most encouraging thing in this restriction of dietary fat intake especially study is that the participants were in saturated fatty acids, trans fatty acids and normal range of LDL-C level and were not cholesterol food stuffs and engaging in a clinically disturbed. Therefore, if similar home-based regular PA (such as brisk study is conducted on those individuals walking) may keep LDL- (“bad”) C away who are clinically disturbed LDL-C level, in sedentary individuals. However, further there may be a chance to get remarkable study in a large sample size sedentary outcomes. Besides, if blood sampling was individuals or high- risk individuals is taken 3 wks after stopping eating apple, it needed. would equally be important. In conclusion, integrated approaches (such Some limitations of our study deserve as including fruits, vegetables, and fiber comment. Firstly, as we explained in the foods, limiting high fat intake particularly methodology section, the study was not saturated fatty acids, trans-fatty acids, randomized and the participants were cholesterol and high sugar, promoting motivated to take part in the intervention; regular PA) are highly influential in health hence, we cannot extrapolate adherence to maintenance and tackling the risk factors. the general population. Nevertheless, the Apple fruit supplement, which is high in findings document that benefits are fiber content and high in antioxidant possible in motivated participants. potent, combined with dietary advice to Secondly, the sample size was inadequate reduce fat intake and unsupervised home- to examine in greater detail. Thirdly, based moderate-intensity PA (such as brisk unsupervised diet to reduce fat intake may walking) at least 30 minutes a day may affect the finding and lead to unreliable result in significant reduction in serum inference. Lastly, the relationship between lipids particularly LDL-C level in cholesterol and time of brisk walking was sedentary individuals. An intervention of not determined. this type may help reduce the risk of CVD/CHD in high-risk individuals.

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dietary guidelines. Revision 2000: a statement for Stefanick, M.L., Mackey, S., Sheehan, M., Ellsworth, healthcare professionals from the nutrition committee N., Hakell, W.L., & Wood, P.D. (1998). Effects of of the American Heart Association. Circulation, 102, diet and exercise in men and postmenopausal women 2284-2299. with low level of HDL cholesterol and high levels of Leontowicz, H., Gorinstein, S., Lojek, A., Leontowicz, LDL cholesterol. New England Journal of Medicine, M., Ciz, M., Solvia-Fortuny, R. et al. (2002). 339, 12-20. Comparative content of some bioactive compounds in Sembries, S., Dongowski, G., Mehrlander, K., Will, F., apples, peaches and pears and their influence on lipids & Dietrich, H. (2004). Dietary fiber-rich colloids and antioxidant capacity in rats. Journal of from apple pomace extraction juices do not affect Nutritional Biochemistry, 13, 603-610. food intake and blood serum lipids levels, but NCEP (National Cholesterol Education Program) enhance fecal excretion of steroids in rats. Journal of (2001). Third report of the national cholesterol Nutritional Biochemistry, 15, 296-302. education program (NCEP) expert panel on detection, Tully, M.A., Cupples, M.E., Chan, W.S., McGlade, K., evaluation, and treatment of high blood cholesterol in & Young, I.S. (2005). Brisk walking, fitness, and adults (adult treatment panel III) executive summary. cardiovascular risk: a randomized controlled trial in NIH publication No. 01-3670. primary care. Preventive Medicine, 41, 622-628. Nutrition and the Prevention of Chronic Disease. Report U.S. Department of Health and Human Services of a joint WHO/FAO Expert Consultations, (1996). Physical activity and health: a report of the Geneva:WHO. Available Online: surgeon general. Atlanta, GA: U.S. Department of http://www.who.int/dietphysicalactivity/publications/t Health and Human Services, Centers for Disease and rs916/en/ Prevention, National Center for Chronic Disease Pate, R.R., Pratt, M., Blair, S.N., Haskell, W.L., Prevention and Health Promotion. pp. 9-208. Macera, C.A., Bouchard, C. et al. (1995). Physical Varady, K.A.,& Jones, P.J. (2005). Combination Diet activity and public health- a recommendation from and Exercise Interventions for the Treatment of the centers for disease control and prevention and the Dyslipidemida: an Effective Preliminary Strategy to American college of sports medicine. Journal of the Lower Cholesterol Levels? Journal of Nutrition, 135, American Medical Association, 273, 402-407. 1829-1835. Richardson, C.R., Faulkner, G., McDevitt, J., Skrinar, Zoeller, R.F. (2007). Phsical Activity and Fitness in the G.S., Hutchinson, D.S., &Piette, J.D. (2005). Prevention of Coronary heart disesase and associated Integrating physical activity into mental health risk factors. American Journal of Lifestyle Medicine, services for persons with serious mental illness. 1, 29-33. Psychiatric Services, 56, 324-331.

GUIDE TO AUTHORS

AIM: The Ethiopian Journal of Science and Technology (Eth. J. Sci. & Technol.) aims to disseminate scientific and technological information to the public, nationally and internationally.

SCOPE: Eth. J. Sci. & Technol. publishes original, full-length research articles, feature articles, short communications, and review articles in sciences and technology.

FORMAT: Manuscripts should be written in the following layout: Title Page, Abstract, Introduction, Materials and Methods, Results (Combined results and Discussion is permissible), Discussion, Conclusion, Recommendation (when necessary), Acknowledgments, and References.

NATURE OF FULL-LENGTH RESEARCH ARTICLES

1. Manuscripts should be written in English or Amharic.

2. Manuscripts should not exceed 20 pages, including the abstract. However, the Editorial Committee may accept longer papers if deemed necessary. Papers should be written in Times New Roman, 12 font size and single spacing between the lines.

3. Two copies of original manuscript (plus a soft copy) printed double-spaced throughout and with wide margins on good quality paper should be submitted.

4. Statement of authorship should be submitted with the manuscript. This should state that:  All the authors have agreed to its submission and are responsible for its contents. All authors should preferably sign this statement.  The paper, other than an abstract or an oral presentation, has not been or will not be submitted elsewhere. 5. The different sections of manuscripts should look like the following: a) Title page, includes the following:  A full title of the manuscript.  The name(s) and address (es) of the author(s), and Institution(s) in which the research was carried out or similar affiliation(s) of the author(s). The author to whom all correspondences should be addressed has to be indicated.

b) The Abstract should be informative and completely self-explanatory. Briefly present the topic, state the scope of the experiments and point out major findings and conclusions. It should be of 100 to 300 words in length

c) Following the abstract, about 3 to 10 key words could be listed.

d) The Introduction should provide a clear statement of the problem, the relevant literature on the subject, and the objectives of the work (all together in one section). It should be understandable to colleagues from a broad range of scientific disciplines.

e) Materials and methods should be complete and sufficiently enough to allow experiments to be reproduced. However, only truly new procedures should be described in detail; previously

published procedures should be cited, and important modifications of published procedures should be mentioned briefly. f) Results should be presented with clarity and precision. The results should be written in the past tense when describing findings in the authors' experiments. They should be explained, but largely without referring to the literature. Discussion, speculation and detailed interpretation of data should not be included in the Results but should be presented in the discussion section.

g) The discussion should interpret the findings in view of the results obtained in this and/or in past studies on this topic. State the conclusions in a few sentences at the end of the paper. However, a separate conclusion is also permissible. The Results and Discussion sections, when appropriate, could be combined.

h) The acknowledgments of people, grants, funds, etc should be brief.

i) Tables should be kept to a minimum and be designed to be as simple as possible. Tables are to be typed double-spaced throughout, including headings and footnotes. Each table should be numbered consecutively in Arabic numerals and supplied with legend on a separate sheet. The horizontal row wise lines of the table should be deleted except for heading.

j) Figures and legends should be typed in numerical order on a separate sheet. Use Arabic numerals to designate figures. Information given in legends should not be repeated in the text.

k) Citation and References: All referred materials should be acknowledged. In the text, a reference identified by means of an author„s name should be followed by the date of the reference in parentheses. When there are more than two authors, only the first author„s name should be mentioned, followed by ‟et al„. In the event that an author cited has had two or more works published during the same year, the reference, both in the text and in the reference list, should be identified by a lower case letter like ‟a„ and ‟b„ after the date to distinguish the works. Ethiopian names should be presented as are written in Amharic. 1. Examples of citations in the text. Each reference should have the following form in the text: o Alexander and Levis (2003), or if more than two authors, Alexander et al. (2003). o Put dates of publication chronologically when references are large (Robertson and Charles, 1992; Flint, 1997; Alemayehu Belay et al., 2001). o Ethiopian names should be in direct order, i.e., the full first name followed by the father's name; e.g. (Amare Belay et al., 1990) and not Belay A.

2. Examples of references in the reference section: References in the reference section should be written as follows:

Berhanu Abraha and Berhanu A. Gashe (1992). Cellulase Production and Activity in a species of Cladosporium. World Journal of Microbiology and Biotechnology. 8: 164 -166.

Ogunseitan OA (1998). Protein method for investigating mercuric reductase gene expression in aquatic environments. Appl. Environ. Microbiol. 64: 695–702.

Gueye M, Ndoye I, Dianda M, Danso SKA, Dreyfus B (1997). Active N2 fixation in several Faidherbia albida provenances. Ar. Soil Res. Rehabil. 11:63-70.

Charnley AK (1992). Mechanisms of fungal pathogenesis in insects with particular reference to locusts. In: Lomer CJ, Prior C (eds). Biological Controls of Locusts and Grasshoppers: Proceedings of an international workshop held at Cotonou, Benin. Oxford: CAB International, pp 181-190.

FAO (1998). Food and Agricultural Organizations of the United Nations. Food Security in Ethiopia. FAO technical report NO. 65. Rome, Italy.

Arrange the reference alphabetically from A to Z.

OTHER COLUMNS Review Articles These are aimed at giving an overview of a particular subject suitable for a wider audience that includes recent advances in an area in which an author has been actively engaged.

Short Communications Short communications must report completed work, not preliminary findings. They are an alternative format for describing smaller pieces of work. They should not be more than eight pages and should not contain more than two figures, tables or combinations.

Feature Articles These are articles that may cover a range of topics in basic and applied sciences, technology, and related fields.

Note: Please see recently published papers in Eth. J. Sci. & Technol. for references not mentioned in this guide.

SUBMISSION OF MANUSCRIPT Manuscripts should be sent to: The Editor, Ethiopian Journal of Science and Technology The Research and Publications Office PO Box 79, Bahir Dar, Ethiopia. Tel. +251 058 222 1908 E-mail: [email protected]

Previous Issue

Eth. J. Sci. & Technol., Vol. V, No.2 (April 2008)

Performance Stability Analysis of Potato Varieties under Rainfed and Irrigated Potato Production Systems in Northwestern Ethiopia Yigzaw Dessalegn, Fentahun Mengistu and Tesfaye Abebe

Biologically Active Compounds of Plant Foods: Prospective Impact on Human Health and Dilemmas Associated with these Compounds Shimelis Admassu

Spectral Psychoanalysis of Speech under Strain Durga Prasad Sharma, Prathap M and Solomon Tadesse

Design of a Fuzzy Rule Base Expert System to Predict and Classify the Cardiac Risk to Reduce the Rate of Mortality N Nalayini

Performance Analysis of Throughput at Bahir Dar University Local Area Network (LAN) M Prathap and E Chandra

Techniques and Assessment of Small Business Capital S Raja Narayanan and D Arthi

Motives for Labeobarbus Fish Species Migration to Gumara River, Lake Tana, Ethiopia Miheret Endalew Tegegne

ETHIOPIAN JOURNAL OF SCIENCE AND TECHNOLOGY

Vol. VI No.1 February 2013

Contents

Symbiotic Blue Green Algae (Azolla): A Potential 1-11 Biofertilizer for Paddy Rice Production in Fogera Plain, Northwestern Ethiopia Tesfaye Feyisa, Tadele Amare, Enyew Adgo and Yihenew G. Selassie

Effect of Harvesting and Threshing Time and Grain 13-24 Fumigation of Field Peas (Pisum sativum L.) on Pea Weevil (Bruchus pisorum (L.) (Coleoptera: Bruchidae) Development and Damage Esmelealem Mihiretu and Melaku Wale

Influence of Time of Nitrogen Application on Productivity 25-31 and Nitrogen Use Efficiency of Rain-fed Lowland Rice (Oryza sativa L.) in the Vertisols of Fogera Plain, Northwestern Ethiopia Alemayehu Assefa, Tilahun Tadesse, and Minale Liben

Floristic Composition and Structure of Yegof Mountain 33-45 Forest, South Wollo, Ethiopia Sultan Mohammed and Berhanu Abraha

Effect of Transplanting on Rice in Northwestern Ethiopia 47-54 Tilahun Tadesse, Minale Liben, Alemayehu Assefa and Zelalem Tadesse

Effect of Apple Supplement and Unsupervised Home-based 55-63 Brisk Walking on Low Density Lipoprotein Cholesterol Khelifa Nida Bartrua, M.S. Sohal, Kiranjeet Kaur and Maninder Kaur

GUIDE TO AUTHORS 65-67