Phenoloy and Yield of Sweet Corn Landraces Influenced by Planting Dates
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Sarhad J. Agric. Vol.25, No.2, 2009 PHENOLOY AND YIELD OF SWEET CORN LANDRACES INFLUENCED BY PLANTING DATES ZAFAR HAYAT KHAN*, SHAD KHAN KHALIL*, SHAHEEN NIGAR**, IFTIKHAR H. KHALIL***, IKRAMUL HAQ*****, IFTIKHAR AHMAD*****, ASAD ALI**** and M. YASIR KHAN*** * Department of Agronomy, NWFP Agricultural University, Peshawar, Pakistan ** Institute of Development Studies, NWFP Agricultural University, Peshawar, Pakistan *** Department of Plant Breeding & Genetics, NWFP Agricultural University, Peshawar, Pakistan **** Department of Plant Pathology, NWFP Agricultural University, Peshawar, Pakistan ***** Department of Agricultural Extension Education & Communication, NWFP Agricultural University, Peshawar, Pakistan ABSTRACT This study was conducted to determine the production potential and optimum sowing date for various landraces of sweet corn. The research was carried out at New Developmental Farm, NWFP Agricultural University Peshawar, Pakistan during 2007 crop season. Sowing dates were 25 April (D1), 25 May (D2), 16 June (D3), 26 July (D4) and 18 August (D5). Sweet corn landraces Mingora, Mansehra, Swabi, Parachinar and cv. Azam were used. All parameters were significantly affected by sowing dates, landraces and their interaction. Days to 50 % tasseling and 50 % silking decreased as the date of sowing was delayed from D1 to D5. Days to maturity decreased as the date of sowing was delayed from D1 to D3 and then increased again as sowing was delayed from D3 to D5. Sweet corn landrace Swabi produced maximum (17292 kg ha-1) biological yield from D1 sowing compared to minimum (7083 kg ha-1) produced by Parachinar on D5. Azam produced maximum grain yield (4097 kg ha-1) and harvest index (27.21 %) when sown on D4, where as minimum grain yield (621 kg ha-1) and harvest index (7.16 %) was observed for Parachinar and Mingora respectively on D5 sowing. Key Words: Phenology, Yield, Landraces, Sweet Corn Citation: Khan, Z.H., S.K. Khalil, S. Nigar, I.H. Khalil, Ikramul Haq, I, Ahmad, A. Ali and M.Y. Khan. 2009. Phenology and yield of sweet corn landraces influenced by planting dates. Sarhad J. Agric. 25(2): 153-157. INTRODUCTION Sweet corn (Zea mays saccharata) is primarily grown in North America. However sweet corn consumption has considerably increased over the past 30 years worldwide. Sweet corn differs from field corn in terms of its genetic makeup rather than in its systematic or taxonomic characterization (Marshall, 1987). The pericarp and endosperm tissues of sweet corn are the primary products consumed. Sweet corn is produced for human consumption either as fresh or processed product. Before it ripe and dry – it has a sweeter taste than do other corn types because its endosperm contains sugar as well as starch. Sweet corn is grown for local markets in Azad Jammu Kashmir and several areas of NWFP. Planting at proper time and selection of suitable varies are important components of cropping system. Significant effects of sowing dates on fresh ear yield, duration of tasseling, ear diameter, kernel numbers ear-1, fresh ear weight and husk ratio have been reported by Oktem et al. (2004). Earliest planting of corn is preferable because of utilization of the entire growing season, achieving physiological maturity before frost, and proper drying; thereby increasing profit through reduced drying costs (Joseph et al., 1999). Beside corn growth has been affected by planting date as reported by Swanson and Wilhelm (1996). Nafziger (1994) stated that yields increased from mid- April to late April planting dates, then declined as planting was delayed to late May. Ahmadi et al. (1993) investigated planting date and population combinations in four field experiments; and reported significant interaction between planting date and hybrid. Arif et al. (2001) concluded that planting methods, varieties and their interaction significantly affected cob length, number of grains cob-1, grain weight cob-1, biological yield and grain yield. The present study was therefore initiated to study sweet corn landraces under different sowing dates for various parameters and to workout optimum planting date for Peshawar region. Zafar Hayat Khan et al. Phenoloy and yield of sweet corn landraces influenced by planting dates… 154 MATERIALS AND METHODS In order to study landraces of sweet corn under different planting dates, an experiment was carried out at New Developmental Farm, NWFP Agricultural University Peshawar, Pakistan during 2007. Sowing dates were 25 April, 25 May, 16 June, 26 July and 18 August while landraces were Mingora, Mansehra, Swabi, Parachinar and cv. Azam (check). The crop was planted in 4m × 3.6m plots having 6 rows, each 4m long. Treatments were replicated three times in randomized complete block design with split plot arrangements. Planting dates were allotted to main plots while landraces were maintained in sub-plots. Treatments were randomized in main and sub-plots. The crop was sown in 60cm spaced out rows with the help of hand hoe. Plant population of 120000 plants ha-1 was maintained by thinning. A basal dose of 120:70 N: P kg ha-1 was used. Urea and SSP were used as sources of N and P2O5, respectively. Table I Monthly climate data during the growth period of sweet corn in 2007 in Peshawar Months Temperature (°C) Mean Relative Maximum Minimum Mean Humidity (%) April 34.20 16.20 25.20 55.38 May 36.06 19.88 27.97 49.61 June 40.12 24.71 32.42 49.35 July 36.71 25.90 31.31 64.73 August 37.41 26.48 31.95 65.77 September 35.13 23.37 29.26 66.72 October 31.53 14.59 23.06 46.88 November 26.67 10.20 18.44 73.60 December 22.63 6.74 14.69 68.22 Standard agronomical practices were followed throughout the growing season. The following observations were recorded during the course of study; i. Days to 50% tasseling ii. Days to 50% silking iii. Days to maturity iv. Grain yield v. Biological yield vi. Harvest index Days to 50% tasseling and 50% silking were counted from sowing till 50% of the plants in each subplot produced tassels and silk, respectively. Days to maturity were counted from sowing till maturity. Biological yield was measured by harvesting two central rows of each sub-plot and weighing them. The data were then constructed into biological yield ha-1. Biological Yield of 2 rows Biological Yield (Kg/ha) = ×100,000 No. of rows × Row - Row distance × Row length Sun dried plants were threshed to record grain yield and then converted in to grain yield ha-1, accordingly. Harvest index was calculated as follows: Grain Yield Harvest Index (%) = ×100 Biological Yield RESULTS AND DISCUSSION Statistical analysis of the data showed that, days to 50% tasseling (Table II) were significantly affected by sowing dates, landraces and their interaction. Maximum days to tasseling were observed in plots sown on D1 with landrace Parachinar, whereas Mingora was the earliest to tassel when planted on D5. These results showed a decrease in days to tasseling from April sowing to August sowing. This decrease may be due to higher temperature and humidity during later months which hasten plant growth and development. These results are in conformity with Daughtry et al., (1984) and Shaw (1988) who reported dependence of tasseling duration on temperature and variety. Shaw and Thom (1951) concluded that the period from emergence to tasseling was more variable than the others. They found a negative relationship between the length of period from planting to tasseling and average temperature. Sarhad J. Agric. Vol.25, No.2, 2009 155 Table II. Days to 50% tasseling for different landraces/varieties and sowing dates Sowing Landraces Means dates Azam Mingora Mansehra Swabi Parachinar 25th April 60 e 62 c 63 b 62 c 64 a 62 a 25th May 60 e 61 d 61 d 62 c 62 c 61 b 16th June 58 f 56 g 60 e 61 d 56 g 58 c 26th July 53 h 47 m 50 j 52 i 49 k 50 d 18th August 48 l 45n 47 m 49 k 47 m 47 e Means 56 b 54 c 56 b 57 a 56 b LSD for sowing dates at P<0.05 = 0.29 LSD for varieties at P<0.05 = 0.24 LSD value for interaction at P<0.05 = 0.53 Data on days to 50 % silking are presented in Table III. Sowing dates, landraces and their interaction showed significant effect on days to silking. Parachinar took maximum days to silking on April sowing (D1), whereas Mingora with August (D5) sowing took minimum days. Days to silking are related with tasseling and showed similar trend of decrease with later sowings. Table III. Days to 50% silking for different landraces/varieties and sowing dates Sowing dates Landraces Means Azam Mingora Mansehra Swabi Parachinar th 25 April 66 d 67 c 68 b 68 b 69 a 68 a th 25 May 63 f 65 e 65 e 66 d 68 b 65 b th 16 June 62 g 60 h 62 g 62 g 63 f 62 c th 26 July 56 j 52 n 55 k 59 i 53 m 55 d th 18 August 53 m 49 p 52 n 54 l 51 o 52 e Means 60 c 59 d 60 c 62 a 61 b LSD for sowing dates at P<0.05 = 0.45 LSD for varieties at P<0.05 = 0.39 LSD value for interaction at P<0.05 = 0.86 Table IV reveals significant effects of sowing dates, landraces and their interaction on days to maturity. Maximum days to maturity were taken by Parachinar planted on D1 while Mingora took minimum days to maturity when planted on D4. Similar results are reported by Zaki et al., (1994) who reported decrease in days to maturity with delaying of sowing from 16 April to 16 June and then increase again as sowing was delayed from 16 July to 16 August.