IRRN GUIDELINES

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Genetic resources Soil microbiology and biological N fertilizer 4 Screening for duplicates in the germplasm collections 23 Boiling water treatment to improve germination of Sesbania rostrata Breeding methods 4 Propagation of Porteresia caarctata using immature seeds Crop management 4 Performance of anther-derived rice lines 24 Effect of sowing and planting method on rice yield 5 Oryza nivara sources of cytoplasmic male sterility (CMS) in rice 24 Selecting rice varieties for double transplanting in flood-affected areas 6 Floral characters of CMS and maintainer lines in hybrid rice 25 Effect of a new abscisic acid analog on chilled rice leaves 6 Effect of row ratio and leaf clipping on MR365A outcrossing and seed yield 26 Yield ability of tillers separated from standing transplanted aman rice and replanted 6 Somatic embryogenesis in rice cultivar IR50 26 Effect of Triacontanol on rice seedling weight and grain yield 7 A medium-duration. high-yielding, scented hybrid rice 7 Evaluation of some F 1 rice hybrids developed using MR365A as Soil fertility and fertilizer management CMS line 26 Large granule urea efficiency in rice 8 Identification of restorers and maintainen for four CMS lines of rice 27 Synergistic effect of organic manure and N fertilizer on irrigated 8 Media conditioning to convert nonembryogenic rice calli to rice embryogenic calli 27 Effect of zincated diammonium phosphate (Zn-DAP) on rainfed lowland rice Yield potential 28 Efficiency of prilled urea (PU) and urea supergranules (USG) in 9 A path-coefficient analysis of rice panicle characters rapidly percolating soil 10 Heterosis and heterobeltiosis for high density grain index (HDI) and 29 Sesbania rostrata— a lowercost same of N for rice other rice panicle characters 29 Nitrogen-use efficiency with hand- and machine-applied N 11 Adaptability of rice varieties to low light intensity fertilizers in wetland rice soils 12 Correlations between allogamic and agronomic traits in rice 30 Effect of Zn and Cu on growth and nutrition of rice 12 Screening long-duration rice cultivars for ratooning ability 30 Biofertilizer production of stem-cut planted and seeded Sesbania 13 Effect of high temperature on rice spikelet fertility rostrata Grain quality and nutritional value 31 Effect of sesbania green manure and wheat straw on ammonia 14 Using silica gel desiccant to dry rough rice samples volatilization loss in wetland soil Disease resistance 32 Soil test fertilizer recommendations increase economic yields of rice 14 Resistance to sheath blight (ShB) in China 33 Source and time of phosphate application in irrigated rice 15 A new inoculation technique for rice blast (Bl) Disease management 15 Rice sheath blotch incidence in Haryana 34 Suitability of iodine test for detecting rice tungro virus (RTV) Insect resistance infection 16 Registration of brown planthopper (BPH)-resistant germplasm lines 34 Biological control of rice blast (Bl) with antagonistic bacteria in Japan Insect management 16 Rice resistance to whitebacked planthopper (WBPH) Sogatella 35 Effect of plant age on whitebacked planthopper (WBPH) feeding furcifera in Bangladesh 35 Virus diseases of some lepidopterous rice pests in the Philippines 17 A potential donor for resistance to the gall midge (GM) population 36 Weed hosts of rice hispa Dicladispa armigera Olivier (Coleoptera: of Srikakulam District, Andhra Pradesh Hispidae) 17 Screening for resistance to rice gall midge (GM) 37 Effect of parasitization on food consumption of rice leaffolder (LF) 18 Resistance of rice varieties to brown planthopper (BPH), Marasmia patnalis whitebacked planthopper (WBPH), and gall midge (GM) in India 38 White stem borer (WSB) effect on upland yield Excess water tolerance Weed management 19 Heritability of stem elongation ability in rice 38 Effect of herbicides on Ischaemum rugosum Integrated germplasm improvement 39 Weed management in rainfed rice - lentil crop sequence 20 IET9783: a salt-tolerant rice for coastal saline soil Managing other pests 20 Performance of upland and rainfed lowland rice varieties in farmers’ 40 Effect of bund dimensions on rodent infestation in irrigated fields in Mali ricefields 21 Ranbir Basmati--an early-maturing aromatic rice Farming system 21 RAU4045-10, a new variety for rainfed areas 40 Rice-based cropping sequences for rainfed conditions in midhills of 21 CN705-18--a promising rice variety for deepwater rice areas Uttar Pradesh 22 SiPi 692033: a promising rainfed lowland rice variety 41 Vegetables for high return and water use efficiency in irrigated rice- Seed technology based systems 23 Influence of Acrocylindriun oryzae Sawada on rice seed 42 Supplementary irrigation using shallow groundwater for soybean germination and seedling vigor after wetland rice

ERRATA GERMPLASM IMPROVEMENT

Genetic resources We have a collection of about 19,000 Gurmatia, and Jhilli) showed variable indigenous rice varieties, many with reactions to the pest and disease under identical names. We screened a small study. Screening for duplicates in sample of accessions with similar names, This study examined a small sample the germplasm collections maturity, grain features, and origins for against only BB and WBPH. More resistance to bacterial blight (BB) caused variable reactions might be expected if R. K. Sahu, Indira Gandhi Agricultural by Xanthomonas campestris pv. oryzae the materials were evaluated for other University, Raipur, India and to whitebacked planthopper traits and with various pathotypes or (WBPH) Sogatella furcifera at IRRI. biotypes of diseases and pests. These Rice researchers in the tropics often The results are presented in the table. results suggest that land races collected have difficulty maintaining a large Of the 14 accessions of Badshahbhog from different fields or villages that have germplasm collection in limited storage evaluated, B248 and B1209 were rated identical names and morphoagronomic facilities. Often the advice is to reject resistant to BB. B189 was found features may not have the same pest duplicates within a collection. Usually resistant to WBPH. Other accessions resistance. They should not be discarded samples are discarded when two of them were susceptible to both. Other from a collection before thorough have similar names, identical grain accessions having identical names evaluation. features, identical maturity and other (Bhata dudgi, Chhatri, Dubraj, morphoagronomic features, and the same or neighboring places of origin.

Results from screening similarly named germ- Breeding methods immature seeds (soft dough stage) plasm for BB and WBPH resistance. germinated (average 90%) in both distilled water and 1/4 concentration Raipur Reaction a Cultivar accession Propagation of Porteresia MS medium. no. BB WBPH coarctata using immature Some germinated seeds failed to develop fully. Some lacked shoots or B54 S S seeds Badshahbhog roots. Others dried up after emergence. Badshahbhog B189 S R Badshahbhog B220 S S G. D. Encarnacion and F. J. Zapata, Tissue Of 36 seeds that germinated, 12 plantlets Badshahbhog B227 S S Culture Laboratory, Plant Breeding survived and were transferred to B236 S S Badshahbhog Department, IRRI Yoshida’s water culture solution. Badshahbhog B248 R S Badshahbhog B466 S S Propagating P. coarctata through Badshahbhog B670 S S P. coarctata Tateoka (n=48) (formerly immature seeds could be important in S S Badshahbhog B799 Oryza coarctata Roxb.), a wild rice germplasm exchange, since immature Badshahbhog B973 S S Badshahbhog B1005 S S species native to the coastal regions of seeds are more easily transported from Badshahbhog B1209 R S India and Bangladesh, abounds along place to place than runners or Badshahbhog B1322 S S the mouths of estuaries. Because it cuttings. Badshahbhog B1899 S S Bhata dudgi B1627 S S flourishes in highly saline water, it could Bhata dudgi B2177 R S be a source of genes for salt tolerance to Chhatri C90 S S transfer into cultivated rices. Chhatri C364 R S Dubraj Dl2 S R Part of the problem with Performance of anther- D61 R S Dubraj hybridization is that mature seeds of P. derived rice lines Dubraj D341 S S coarctata do not germinate. At IRRI, Dubraj D422 S MR Dubraj D1026 S R we have been limited to using runners S. R. S. Rangasamy, S. K. Raina, W. W. Gurmatia G123 S R and cuttings for propagation. Manuel, K. Natarajamoorthy, S. Gurmatia G185 S R We experimented with different Gurmatia G245 S S Palanisamy, and M. Gurunathan, Paddy Gurmatia deshi G7 R R conditions for inducing germination of Breeding Station, Tamil Nadu Agricultural Jhilli J107 S R P. coarctata seeds. Mature seeds did not University (TNAU), Coimbatore 641003, R R Jhilli J273 germinate, even after they were treated Tamil Nadu, India Jhilli J274 R MR Jhilli J388 S R with varying concentrations of sodium Jhilli parag J105 S S chloride and the embryos excised and Seven anther-derived cultures from the aR = resistant, MR = moderatrely resistant, S = inoculated in Murashige and Skoog F1 s of Vaigai/Co 40 (developed in a susceptible. (MS) culture medium. However, TNAU-Indian Agricultural Research

4 IRRN 14:2 (April 1989) Institute collaboration) were tested in insensitive (duration 134-137 d); Culture 433A-R1 is resistant to blast seven trials against check Co 43. duration fluctuated 11-20 d in other (Bl) and rice tungro virus (RTV); 433A- Cultures 433A-R5 and 433A-R6 cultures. All cultures are semidwarf R5 is resistant to Bl and moderately performed better than Co 43 during kar (plant height 57-76 cm) and all have 6.9- resistant to RTV and bacterial blight (Jul-Oct) season (8.8 and 11.4% yield increase) (see table). short and bold; in 433A-R6, it is long moderately resistant to RTV, BB, and Culture 433A-R6 was photoperiod and slender. Rice color is white. brown spot.

Performance of anther culture-derived rice lines at Coimbatore, India, 1982-83 to 1986-87. a

Mean grain yield (t/ha) Duration (d) Culture Productivity Plant Panicles 1000-grain Kar Cold Navarai Overall (kg/d) Kar Cold Navarai Mean height (no./hill) wt (g) weather mean weather (cm) 433A-R1 5.2 4.5 5.9 5.2 37.1 141 148 132 140 76 7.1 19.6 433A-R2 5.0 4.5 5.5 5.0 35.8 136 150 132 139 72 7.3 20.9 433A-R3 5.3 4.1 4.8 4.8 34.1 139 151 134 141 75 7.7 19.4 433A-R4 5.2 4.2 5.5 5 .0 35.8 138 151 132 140 69 6.9 19.0 433A-R5 5.4 4.9 5.8 5.4 38.6 137 152 132 140 75 7.5 18.8 433A-R6 5.6 4.6 5.7 5.3 39.1 137 136 134 136 57 7.3 19.0 433A-R7 5.1 4.8 4.7 4.9 34.9 138 149 134 140 76 7.1 19.0 Co 43 (check) 5.0 4.9 5.9 5.22 38.4 139 141 130 136 74 7.2 20.0 aKar = Jul-Oct, navarai = Feb-Apr.

Oryza nivara sources of Table 1. Comparison of N-Zhen Shan 97A with W-Zhen Shan 97A. Puzhou, China, 1987. Pollen fertility (%) cytoplasmic male sterility Panicle Exserted Days to 50% Height (CMS) in rice CMS A-line exsertion stigma Typical Round heading (cm) (cm) (%) abortive abortive C. Yang, N. Y. Wang, and K. J. Liang, Fujian Agricultural College, Fuzhou, China N-Zhen Shan 97A 68.5 57.0 –6.1 25.9 92.1 7.9 W-Zhen Shan 97A 70.0 56.3 –5.8 24.1 89.3 10.7 Cytoplasmic diversity is an important a problem in hybrid rice breeding and Table 2. Pollen fertility of F 1 progenies. Hainan, China, 1988. production. Only a few CMS sources are being used in China, making hybrid Female parent rice potentially vulnerable to a disease or N-Zhen Shan 97A W-Zhen Shan 97A insect epidemic. Male parent To find new sources for hybrid rice Plants F 1 plants (no.) in Plants F 1 plants (no.) in pollen pollen fertility class fertility class breeding and to study the cytogenic (no.) (no.) interaction in Oryza spp., we have used F PF PS CS F PF PS CS O. nivara introduced from IRRI (acc. IR22 20 16 4 0 0 20 17 3 0 0 101508 and 101466) as donors of CMS IR24 20 20 0 0 0 20 18 2 0 0 cytoplasm in crosses with one set of Ming 63 20 19 1 0 0 18 18 0 0 0 cultivars. So far, we have developed four Taiyin 1 18 16 1 1 0 20 18 2 0 0 Milyang 46 20 18 2 0 0 20 19 1 0 0 CMS lines—Chao Yang 1A (indica), IR46826B 20 0 0 3 17 20 0 0 2 18 Zhen Shan 97A (indica), Nan Jin 56A IR46827B 20 0 0 1 19 20 0 0 1 19 (japonica), and Rei-Min A (japonica)— IR46828B 20 0 0 4 16 20 0 0 2 18 Hong 410 20 0 3 13 4 20 0 4 12 4 that have the cytoplasm of O. nivara acc. 101508. a Pollen fertility classes: F = fertile, 91-100% pollen fertility; PF = partially fertile, 51-90% pollen Preliminary studies show no fertility; PS = partially sterile, 6-50% pollen fertility; CS = completely sterile, 0-5% pollen fertility. significant difference between Zhen Shan 97A (nivara cytoplasm) and Zhen CMS sources seem to be genetically Milyang 23, and Milyang 46 were Shan 97A (WA cytoplasm) in similar. classified as effective restorers; Hong 410 agrocharacter, floral characters, and In a crossing experiment based on F 1 as a partial maintainer; and IR46826B, pollen fertility (Table 1), and in pollen fertility, IR22, IR24, Ming 63, IR46827B, and IR46828B as complete cytogenic interaction (Table 2). The two Taiyin 1, IR1055, Yin Ni Ai He, maintainers to both A-lines.

IRRN 14:2 (April 1989) 5 Floral characters of CMS and Expression of floral characters in A, B, and R lines of hybrid rice. maintainer lines in hybrid rice Stamen (mm) Pistil (mm) Line C. R. Anandakumar, G. Soundrapandian, Filament Anther Anther Stamen Ovary Style Stigma Pistil length length breadth length length length length length and M. Subramanian, Agricultural Botany Department, Agricultural College and V20A 2.75 2.78 0.32 5.53 0.801 0.840 1.280 2.921 Research Institute, Madurai, Tamil Nadu, V20B 3.59 2.39 0.50 5.98 0.944 1.024 1.240 3.208 India V41A 2.12 2.03 0.37 4.15 0.704 0.640 0.816 2.160 V4 1B 3.05 2.08 0.41 5.13 0.816 0.832 0.936 2.584 Zhen Shan 97A 2.99 2.12 0.48 5.11 0.576 0.872 1.112 2.560 We screened five male sterile lines and Zhen Shan 97B 3.48 2.57 0.48 6.05 0.728 0.984 0.992 2.704 their maintainers for pistil and stamen IR46830A 2.65 2.13 0.38 4.78 1.104 0.881 1.080 3.065 length during 1986 wet season (kharif). IR46830B 3.30 2.21 0.42 5.51 1.267 1.216 1.320 3.803 IR54752A 1.33 1.68 0.34 3.01 0.760 0.720 0.826 2.306 Fifty spikelets/line were measured. IR54752B 1.70 1.73 0.36 3.43 0.770 0.760 0.880 2.410 Among the A lines, IR46830A had SE 0.44 0.22 0.09 0.45 0.21 0.17 0.17 0.28 the longest pistil, V41A the shortest. Among B lines, Zhen Shan 97B had the longest stamen, IR54752B the shortest. V20A and Zhen Shan 97B had the between lemma and palea, facilitated In general, all the male sterile (A) longest filament (see table). easy transfer of pollen to the stigma of lines had smaller stamens and pistils The long Zhen Shan 97B stamen, corresponding A lines in the adjoining than their respective maintainers. prominently protruding from the gap row.

Effect of row ratio and leaf season, in a split-plot design with three perhaps because of lower panicle clipping on MR365A replications. Seedlings (21 d) were exsertion. Filled grains/panicle and seed 2 outcrossing and seed yield transplanted at 1 seedling/hill with 20- yield/ m were not affected by leaf × 20-cm spacing. clipping (Table 2). There was no Satoto, Plant Breeding Department, Among the three male-to-female interaction between row ratio and leaf Sukamandi Research Institute for Food ratios tested, seed yields of 1B:4A and clipping. Crops, Subang, Indonesia 1B:2A were significantly higher than that of 2B:4A (Table 1). Seed set was We evaluated the effect of row ratio and not significantly different among the leaf clipping on outcrossing rate and ratios. Somatic embryogenesis in seed yield of MR365A (a CMS line Leaf clipping increased seed set, but developed at IRRI) during 1984-85 wet significantly reduced grains/ panicle, rice cultivar IR50 M. Maheswaran and S. R. S. Rangasamy, Table 1. Effect of row ratio on seed yield, seed set, number of grains, and number of filled grains of Tamil Nadu Agricultural University, MR365A. Coimbatore 641003, Tamil Nadu, India

Seed Seed set/ Grains/ Filled Initiation and development of embryos Row ratio yield panicle panicle grains/panicle (g/m 2) (%) (no.) (no.) from somatic tissues in rice have been achieved by culturing seed-derived callus 2B:4A 67.6 b 23.76 a 94.16 b 22.28 b of IR50. Mature dehulled seeds were 1B:4A 85.4 a 22.82 a 98.96 ab 22.33 b 1B:2A 88.5 a 23.41 a 107.32 a 24.95 a inoculated on Murashige and Skoog (MS) medium with varying CV (%) 6.5 17.29 7.81 15.04 concentrations of 2, 4- dichlorophenoxyacetic acid (2, 4-D) and kinetin (see table). Medium pH was Table 2. Effect of leaf clipping on seed yield, seed set, number of grains, and number of filled grains of MR365A. adjusted to 5.8. The cultures were kept in light for 14 h daylength at 24 ± 2 °C. Seed Seed set/ Grains/ Filled Calli were initiated from the Leaf clipping yield panicle panicle grains/panicle hypocotyls of the seedlings within 15 d (g/m 2) (%) (no.) (no.) after inoculation. Callus induction Clipped 83.21 a 25.14 a 92.19 b 23.26 a increased with increasing concentrations 108.10 a 23.12 a Unclipped 77.75 a 21.52 b of 2, 4-D to 2 mg/liter. Higher CV (%) 15.96 10.15 8.69 12.55 concentrations inhibited callus growth.

6 IRRN 14:2 (April 1989) Effect of 2,4-D and kinetin on callus induction and plant regeneration with IR50 seeds in MS Callus pieces were transferred to medium. regeneration medium containing kinetin Callus induction medium Regeneration medium a and NAA at a concentration of 1 mg/ liter each. Regeneration was better 2,4-D Kinetin Seeds Seeds Callus Calli Calli Regene- (mg/liter) (mg/liter) inoculated producing production transferred regenerated ration from calli induced from the C medium (no.) calli (no.) (%) (no .) (no.) (%) containing 2 mg 2,4-D/liter and 0.5 mg kinetin/ liter through the process of 0.0 0.0 74 – – – – – 0.5 0.0 68 10 14.7 36 3 8.3 somatic embryogenesis (established by 0.5 0.5 74 12 16.2 38 4 10.5 histological studies). 0.5 1.0 72 12 16.6 42 6 14.3 The somatic embryos formed had two 1.0 0.0 74 31 41.8 44 8 18.2 1.0 0.5 73 34 46.6 44 11 25.0 distinct poles and were attached to the 1.0 1.0 72 36 50.0 42 7 16.6 callus piece through their broader 1.5 0.0 68 37 54.4 40 9 22.5 surface. Embryoids of different shapes 1.5 0.5 74 42 56.7 38 8 21.4 1.5 1.0 69 42 60.8 42 6 14.3 were also traced out during early stages 2.0 0.0 72 46 63.8 32 2 6.2 of embryogenesis. Other treatments did 2.0 0.5 68 42 61.7 44 18 40.9 b not yield somatic embryos. 2.0 1.0 67 29 43.2 42 + – 5.0 0.0 72 26 36.1 32 + – + – 5.0 0.5 74 28 37.8 32 Individuals, organizations, and media are 5.0 1.0 74 25 33.7 36 + – invited to quote or reprint articles or a Regeneration medium = basal medium + 1 mg kinetin/liter + 1 mg NAA/liter. + = rhizogenesis. excerpts from articles in the IRRN. b Formation of somatic embryos.

A medium-duration, high- complete restorer for the CMS line primarily to more effective tillers/ plant yielding, scented hybrid rice IR46830A. and higher 1,000-grain weight. Although Hybrid IR46830A/ Basmati 370 was yield of the hybrid was not significantly J. P. Sharma and S. C. Mani, Plant evaluated for yield and quality higher than that of check variety Pant Breeding Department, G. B. Pant University components (Table 1,2). The hybrid Dhan 4, better quality attributes make it of Agriculture and Technology, Pantnagar, flowered earlier and was shorter than more suitable for commercial India the better parent. Positive and production. Its medium growth duration significant heterosis over the better would make it suitable for a rice - wheat We have identified tall, late-maturing, parent was recorded for most characters. cropping pattern. scented cultivar Basmati 370 as a Increase in grain yield/ plant was due

Table 1. Mean performance of the hybrid Table 2. Mean value for 5 grain quality traits in Basmati 370, hybrid IR46830A/Basmati 370, and IR46830A/Basmati 370, and estimates of hete- Pant Dhan 4. a Pantnagar, India, 1988. rosis over the better parent and check variety Pant Dhan 4. a Pantnagar, India, 1988. Character studied Basmati 370 Hybrid Pant Dhan 4

Mean Heterosis b Length of grain (mm) 7.88 7.38 6.34 Character for Breadth of grain (mm) 1.72 2.04 2.10 F 1 Better Check L/B ratio 4.58 3.61 3.11 parent Alkali digestion value 2.25 3.00 3.50 Aroma Strong Intermediate – Days to 50% 95.0 –24.60* –20.16* a flowering AV of 5 replications. Plant height (cm) 137.2 –12.50* –30.66* Effective tillers/ 20.8 44.45* 23.80* plant (no.) Length of panicle 32.2 5.59 20.81* (cm) Evaluation of some F 1 rice Jan-May 1984. The hybrids, Cisadane, Primary branches/ 12.2 19.60* –9.83 panicle (no.) hybrids developed using and IR36 were transplanted at 20- × 20- Secondary branches/ 40.4 36.50* 34.50* MR365A as CMS line cm spacing in 2- × 5-m plots, with 2 panicle (no.) replications. Fertilizer was 135-45-45 kg Spikelets/panicle 202.6 35.25* 30.20* B. Sutaryo, Sukamandi Research Institute NPK/ha. (no.) for Food Crops, Subang, Indonesia Grains/panicle (no.) 164.0 19.80* 17.64* Hybrid combinations MR365A/ IR36, 1000-grain weight 22.9 31.24* –0.62 MR365A/IR52, and MR365A/BR10 (g) We evaluated yield and heterosis of yielded about 1 t/ha more than Grain yield/plant (g) 63.0 83.89* 16.50 eight F 1 rice hybrids developed using Cisadane and showed significant a Av of 5 plants. b * = significant at 5% level. MR365A (CMS line developed at IRRI) heterosis (14.63-27.65%) (see table). For

IRRN 14:2 (April 1989) 7 Yield components and standard heterosis for yield in some F 1 rice hybrids evaluated in Sukamandi, Indonesian conditions, MR365A could Indonesia, 1984 wet season. be used in developing F 1 rice hybrids using IR36, JR52, and BR10 as restorer Panicle Filled 1000- Growth Disease or insect Standard Hybrid length grains/ grain duration score a Yield b heterosis lines. However, the CMS line is not (cm) panicle wt (d) GM BLS (t/ha) to Cisadane stable for pollen sterility. (%) (g) (%) MR365A/BR10 23.4 74.4 22.9 120 0 0 4.8 a 27.65 MR365A/IR36 22.8 74.2 23.0 112 1 1 4.6 a 22.87 MR365A/IR52 23.2 73.1 24.0 109 1 1 4.3 b 14.63 The International Rice Research MR365A/IR54 23.8 64.2 23.6 116 1 1 3.5 d –7.44 Newsletter is published to expedite MR365A/IR60 22.0 61.4 19.8 130 1 1 3.5 d –7.97 communication among scientists MR365A/IR46 21.7 79.5 23.0 132 1 5 3.4 de –9.04 concerned with rice research and the MR365A/IR26 23.5 77.7 23.5 134 1 1 3.2 e –16.22 MR365A/IR50 22.6 62.4 21.0 120 1 1 3.2 e –15.69 development of improved technology for Cisadane c 23.7 81.9 28.9 142 1 1 3.8 c – rice and rice-based farming systems. IR36 22.9 83.9 20.7 120 3 3 3.6 cd – Readers are encouraged to write authors at their published addresses to discuss a Scoring based on 1980 Standard evaluation system for rice. GM = gall midge, BLS = bacterial leaf the research and obtain more details. streak. b Means followed by a common letter are not significantly different at the 5% level by DMRT c Best check variety.

Identification of restorers and Fertility restorers, partial restorers, and maintainers for 4 CMS lines. Pantnagar, India. maintainers for four CMS CMS line Fertility restorer Partial restorer Maintainer lines of rice IR46830A Narendra 1 IET7613 Ratna Saket Narendra 2 N22 J. P. Sharma and S. C. Mani, Plant Basmati 370 Mahsuri Rasi Breeding Department, G. B. Pant University Govind of Agriculture and Technology, Pantnagar, IR58 Manhar India UPR82-42 Pant Dhan 6 We crossed 17 cultivars of early, IR46831A – Manhar Pant Dhan 4 Pant Dhan 6 medium, and late duration (as male UPR79-123 parents) with 4 cytoplasmic genetic male Govind sterile lines (IR46830A, IR46831A, Zhen Zhen Shan 97A – Saket 4 – – Pant Dhan 4 – Shan 97A, and V20A) to identify their V20A fertility restorers and maintainers. The F 1 seeds were germinated in petri dishes, transferred to pots, and maintainers = <10%. for the CMS line IR46831A. transplanted in the field 30 d after Narendra 1, Saket 4, and Basmati 370 No fertility restorer was identified for germination. were effective restorers for IR46830A. Zhen Shan 97A, V20A, and IR46831A. Varieties were classified on the basis Ratna, N22, and Rasi were identified as There was segregation for fertility in the of spikelet fertility in their F 1 hybrids: maintainers for this CMS line (see F1 when V20A was crossed with Pant restorers = >80% spikelet fertility, table). Pant Dhan 4 was a maintainer Dhan 4. partial restorers = 10-79%, and

Media conditioning to convert nonembryogenic (NE) callus to 0.7% Difco Bacto agar (pH 5.7). nonembryogenic rice calli to embryogenic (E) callus. Cultures were incubated under complete darkness at 22 ± 2°C. embryogenic calli Rice ( Oryzae sativa L. cv. S201) seeds were dehulled mechanically, surface Ten-day-old seedlings were cut in 2- to sterilized in 5% sodium hypochloride 3-mm pieces and cultured in a callus M. B. Sticklen, Forestry Department, formation medium consisting of Michigan State University, East Lansing, MI solution for 30 min, and rinsed 3 times 48824; and M. E. Rumpho and R. A. with sterile distilled water. Seeds were germination medium supplemented with Kennedy, Horticulture Department, Ohio sown in basal salts and vitamins of 20 µM 2,4-dichlorophenoxyacetic acid State University, OH 43210, USA Murashige and Skoog (MS) medium (2,4-D). Five petri dishes each supplemented with 200 mg myo- containing pieces of four seedlings were We investigated the effect of media inositol/liter, 100 mg thiamine used per treatment. All cultures were conditioning on converting rice HCl/liter, 3% (wt/vol) sucrose, and subcultured every 4 wk.

8 IRRN 14:2 (April 1989) Two weeks after the second callus pieces were transferred onto all 20 under dim light (30 µ E/m2 per s). The subculture, five samples of callus from petri dishes. NE calli that produced E nodules that were produced developed each treatment were microscopically calli were counted after 2 wk. into normal-appearing embryos 2 wk examined to identify E and NE calli (see No NE calli cultured in unconditioned after they were subcultured onto growth figure, a). The E calli were smooth and medium produced E calli; 16% of the regulator-free differentiation media. All yellowish and were composed of small NE calli grown in conditioned medium somatic embryos looked normal (see compact cells with dense cytoplasm. The produced some organized cells. Those figure, b), germinated in 5-7 d, and NE calli were pale and loosely packed cells were subcultured onto medium produced plants (see figure, c). and were composed of larger, crescent- containing 2.5 µ M 2, 4-D and incubated shaped cells. To condition the medium (5 ml of MS medium supplemented with 20 µ M 2, 4-D), 5 g E callus were subcultured to 10 15-mm petri dishes (conditioned Yield potential panicles from F2s. HD grain index medium). Ten petri dishes with medium (HDI) was calculated by dividing the but without E callus were the control number of HD grains by the total (unconditioned medium). All dishes A path-coeff icient analysis of number of spikelets per panicle on were sealed and kept in darkness for rice panicle characters primary and secondary branches. Path- 10 d. coefficient analysis was used to assess E calli were removed from the S. Mallik, A. M. Aguilar, and B. S. Vergara, the direct and indirect influence of conditioned medium and 5 2-3 mm NE Plant Physiology Department, IRRI different panicle characters on HDI on primary branches (HDIPB). The relationship between high density The number of primary branches and (HD) grains (those with specific gravity number of spikelets on primary of 1.20 or higher) and other panicle branches had a strong positive characters could be an effective selection association with HDIPB in all criterion, generations (see table). Those characters We studied 50 panicles from 9 are probably controlled by an additive

parents, 50 panicles from 6 F1s, and 250 gene action. The number of secondary

Direct (underlined) and indirect effects of associated traits on high density grain index on primary branches (HDIFB). a IRRI, 1988.

Trait Generation Tiller PB SB SPB SSB StPB StSB HDISB r

Tiller P –0.19 –0.02 – –0.01 – 0.01 –0.02 0.64 0.40* F 1 0.26 0.02 – 0.03 0.01 – – 0.34 0.65** F 2 0.04 0.01 –0.01 –0.01 0.01 0.01 –0.04 0.23 0.39** Primary P –0.03 –0.14 0.04 0.28 – –0.01 –0.11 0.38 0.44** branch (PB) F 1 0.07 0.08 – 0.07 – 0.01 – 0.26 0.49** F 2 – 0.14 –0.02 –0.10 0.03 0.06 –0.02 0.20 0.31** Secondary P – –0.09 0.06 0.24 0.01 0.02 –0.22 0.33 0.34* branch (SB) F 1 0.01 – – 0.01 0.13 –0.07 – –0.15 –0.07 F 2 0.01 0.08 –0.04 –0.05 0.06 0.05 –0.01 0.06 0.17* Spikelet on P – –0.11 0.04 0.34 – –0.03 –0.11 0.39 0.54** PB (SPB) F 1 0.07 0.06 – 0.11 – 0.02 – 0.31 0.56** F 2 – 0.13 –0.02 –0.15 0.03 0.09 –0.02 0.21 0.31** Spikelet on P 0.01 –0.09 0.05 0.24 0.01 0.02 –0.22 0.40 0.43* SB (SSB) F 1 0.01 – – – 0.18 –0.08 – –0.19 –0.17 F 2 0.01 0.07 –0.04 –0.05 0.07 0.05 –0.01 0.03 0.13 Sterility on P –0.02 0.01 0.01 –0.09 – 0.11 –0.33 –0.08 –0.39* PB (StPB) F 1 – – – –0.01 0.06 –0.23 0.01 –0.32 –0.49** F 2 –0.01 –0.02 0.01 0.03 –0.01 –0.36 0.16 –0.48 –0.70** Sterility on P –0.01 –0.03 0.03 0.08 – 0.09 –0.44 0.15 –0.13 SB (StSB) F 1 –0.01 –0.01 – –0.01 0.05 –0.20 0.01 –0.37 –0.56** F 2 –0.01 –0.01 – 0.01 – –0.28 0.22 –0.56 –0.63** Rice somatic embryogenesis: a) E callus vs NE HDI on SB P –0.13 –0.06 0.02 0.14 – –0.01 –0.07 0.91 0.81** callus formed in cultures; b) a normal somatic (HDISB) F 1 0.14 0.03 – 0.05 –0.06 0.12 – 0.61 0.90** embryo with distinct coleoptile (CP), coleorhiza F 0.01 0.03 – –0.03 – 0.22 –0.15 0.81 0.89** (CR), and scutellum (SC), ×80; c) plants grown 2 a from somatic embryos, × 0.17. – indicates value almost equal to zero. Residual effects: parent (P), 0.41; F 1 , 0.31; F 2 , 0.39.

IRRN 14:2 (April 1989) 9 branches and of spikelets on secondary (see figure) and nonsegregating primary branches, and not on number branches was correlated positively with generations. In most cases, negative of spikelets on secondary branches. A HDIPB only in parents; it was not correlations and direct and indirect plant type for increased yield should consistent in the F 1 and F 2 . HDI on effects were found between HDISB and have more primary branches and secondary branches (HDISB) was sterility. spikelets on primary branches, with few correlated positively with and had direct Higher HDI depends on more secondary branches and spikelets on effects on HDIPB in both segregating primary branches and more spikelets on secondary branches.

Path diagram and coefficients of factors influencing HDIPB in F 2.

Heterosis and heterobeltiosis as number of HD grains divided by total interactions or differences among for high density grain index number of spikelets/panicle on primary parents. (HDI) and other rice panicle (PB) and secondary (SB) branches. The individual F 1 family differed from characters Estimates of overall degree and overall estimates for different characters direction of heterosis (Fmac 1- Pmac) showing positive, negative, or no S. Mallik, A. M. Aguilar, and B. S. Vergara, were significantly positive for number of heterosis. The F 1 means deviated Plant Physiology Department, IRRI tillers (1.74*), PB (1.27*), SB (3.28*), conspicuously from parental and spikelets on PB (8.65*), spikelets on SB midparental values, indicating We assessed heterosis and heterobeltiosis (8.41*), and sterility on SB (5.37*), involvement of nonadditive gene action for 9 quantitative characters in 6 crosses, indicating dominance of higher values. in the expression of most characters. using 6 high density (HD)-grain parents Heterosis was negative only for number Substantial heterosis in the desirable (at least 30% of grains with more than of spikelets on PB (-3.01*). Low or direction was observed in PB number, 1.20 specific gravity) and 2 low density nonsignificant heterosis for other spikelets on PB, and HDI on PB and (LD)-grain parents. HDI was calculated characters may be due to little genetic SB. Three crosses among HD-grain

10 IRRN 14:2 (April 1989) Heterosis and heterobeltiosis (%) of 7 quantitative characters in 6 crosses. a IRRI, 1988. P /P P /P P /P P /P P /P LSD H or Hb P 1 /P 2 3 4 5 2 2 6 3 7 2 8 Trait (HD/HD) (HD/HD) (HD/HD) (HD/HD) (HD/LD) (HD/LD) (0.05)

Tiller (no.) H 25.6 2.1 11.1 13.7 –11.6 19.6 7.6 Hb – –11.1 –7.4 – –25.9 1.8 6.1 Primary branch - PB (no.) H 28.4 – 4.1 30.6 11.1 5.4 21.3 7.9 Hb 28.3 –11.0 27.0 4.2 –8.5 12.1 9.8 Secondary branch - SB (no.) H 29.0 –12.9 57.4 65.4 10.3 23.8 16.9 Hb 1.1 –34.3 42.3 48.5 –18.7 10.4 18.9 Spikelet on PB (no.) H 45.6 –7.4 56.4 19.1 –2.5 31.0 14.8 Hb 45.4 – 9.6 43.3 9.7 –7.8 19.6 13.9 Spikelet on SB (no.) H 28.4 –16.3 49.3 72.5 –0.7 38.4 18.8 Hb –4.3 –38.5 21.6 46.8 –22.1 30.4 19.0 Sterility on PB (no.) H –28.7 87.9 –12. 9 9.9 –25.7 –66.2 30.2 Hb –35.6 24.3 –22.6 –7.9 –27.2 –70.2 18.0 Sterility on SB (no.) H 18.8 146.7 25.7 93.1 –15.8 –59.9 43.0 Hb 9.0 68.7 15.9 37.2 –25.6 –65.1 27.1 a H = heterosis, Hb = heterobeltiosis. P 1 = IR32307-75-1-3-1, P 2 = IR30, P 3 = IR34615-75-1-1, P4 = IR29725-135-2-2-3, P 5 = IR29692-117-1-2-2, P6 = IR35337-61-2-2-2, P 7 = IR32419-102-3-2-3, P 8 = IR32385-37-3-3-3.

P3 /P 4 and P3 /P 7 , showed negative heterosis for almost all characters. Number of HD grains was higher on PB of parents and hybrids. Substantial heterosis for this character may lead to higher yield, since HD grains have higher test weight and higher head rice recovery. The cross P 2 / P 8 had positive heterosis for all desirable traits and exceeded the highest parent for HDI on both PB and SB.

Adaptability of rice varieties to low light intensity

M. S. Islam and M. Z. Haque, Plant Physiology Division, Bangladesh Rice Research Institute (BRRI), Joydebpur, Gazipur, Bangladesh

A major cause of low yields in the aus season in Bangladesh is low light intensity at later growth stages, mostly at ripening, due to continuous cloudy weather Jul-Aug. Wide variation in grain yield is also observed. We studied varietal adaptability to low light intensity at ripening. Five Percentage of heterosis and heterobeltiosis for HDI. IRRI, 1988. modern and five traditional varieties were seeded so that the ripening stage would occur at the same time, late in the parents (P1 /P 2 , P5 /P 2 , P2 /P 6 ) and one manifested positive heterosis and aus season to avoid cloudy weather. We cross between HD- and LD-grain heterobeltiosis for HDI on PB (see transplanted 25-d-old seedlings in pots parents (P2 /P 8) exhibited positive figure). The cross P2 /P 8 showed positive fertilized at 40-80-60 kg NPK/ ha; 80 kg heterosis and heterobeltiosis for number heterosis for all characters except N/ ha and 40 kg N/ ha were topdressed of PB and spikelets on PB (see table). sterility on PB and SB, where negative in modern varieties and traditional Only two crosses, P5 /P 2 and P2 /P 8 , heterosis is desirable. Two crosses, varieties, respectively.

IRRN 14:2 (April 1989) 11 As soon as panicles began to emerge, with six replications. both light intensities, and was the least the plants were covered with cloth Grain yield in all varieties decreased affected modern variety. The highest screens to provide 22-26% of full significantly with low light exposure yield reduction was in BR6, followed by sunlight for 28 d. Check plants were (see table). Hashikalmi was least BRl. Filled spikelets were more affected grown in full daylight. The experiment affected, followed by BR9 and than 1,000-grain weight. was in a randomized complete block Kataktara. BR9 had the highest yields at

Effect of low light intensity at ripening on yield and 2 yield components of aus varieties.a BRRI, Bangladesh.

Grain yield Filled spikelets 1000-grain weight Variety Normal light Low light Reduction Normal Low light Reduction Normal light Low light Reduction (%) (g/pot) (g/pot) (%) due to light (%) (%) due to (g) (g) due to low light low light (%) low light

BR1 10.98 g 3.96 ef 64 e 73 cd 47 d 36 cd 19.89 e 16.50 g 17 cd BR3 25.24 b 10.74 b 57 de 81 abc 52 cd 35 cd 25.64 ab 21.91 ab 15 bc BR6 14.73 f 3.47 f 76 f 85 ab 48 d 44 de 23.82 c 20.03 de 19 d BR9 31.81 a 17.19 a 46 b 77 bc 56 bcd 26 bc 21.64 d 20.55 cd 5 a BR12 18.69 de 7.73 c e 58 de 90 a 65 b 28 bc 20.98 de 17.42 fg 17 cd Hashikalmi 17.14 ef 11.93 b 30 a 90 a 80 a 11 a 24.56 bc 23.03 a 6 a Dharail 16.37 e 6.45 de 61 de 69 d 32 e 52 a 23.65 c 21.76 bc 7 a Morichboti 21.23 cd 9.30 bc 56 cde 83 ab 54 cd 34 bcd 26.33 a 23.21 a 13 b Dular 24.31 b 12.04 b 51 bcd 82 ab 57 bc 30 bc 23.50 c 21.99 ab 14 bc Kataktara 22.43 bc 11.63 b 48 b 83 ab 65 b 22 ab 21.82 d 19.12 e 12 b a In a column, means followed by the same letter are not significantly different at the 5% level (DMRT). Within a variety, treatment effect was significant at the % level (DMRT).

Correlations between Table 1. Coefficient of heritability and average length of stigma, anther, spikelet, and panicle. Coefficient of Average allogamic and agronomic Trait heritability length traits in rice Stigma length (mm) 0.9163 1.53 ± 0.27 P. de C. F. Neves, E. P. Guimarães, and Anther length (mm) 0.9413 2.62 ± 0.33 Spikelet length (mm) 0.9215 7.39 ± 0.50 J. Taillebois, EMBRAPA/ Centro Nacional Panicle length (cm) 0.6389 19.11 ± 2.81 de Pesquisa de Arroz e Feijão (CNPAF), Caixa Postal 179, 74000 Goiânia, Goiás, Brazil Table 2. Genetic (G), phenotypic (P), and envi- ronmental (E) correlations between stigma, We studied the correlations between anther, spikelet, and panicle length. Screening long-duration rice allogamic and agronomic traits in F3- Anther Spikelet Panicle cultivars for ratooning ability derived lines from the BC2 generation of Stigma G 0.5548** 0.1565 0.0900 the cross Oryza sativa L. / Oryza P 0.5138** 0.1393 0.0349 S. Gupta and S. K. Bardhan Roy, Rice longistaminata A. Chev. The male E 0.2980 0.1614* 0.2278 Research Station, Chinsurah, West Bengal, parent possesses well-developed floral Anther G –0.0280 0.1979 India parts. The F3 lines were evaluated in a P –0.0076 0.1881 E 0.2020 0.1231 completely randomized block design We screened 210 entries from IRTP with four replications at two locations in Spikelet G –0.3006 nurseries (1986 International Rice P –0.1336 1986-87. E 0.3785 Shallow Water Observational Nurseries Allogamic traits evaluated were [IRSWON], 1986 International Rice stigma and anther length, agronomic Deepwater Observational Nurseries characters were spikelet and panicle Table 2 shows significant and positive [IRDWON], and 1985 International length. Variance and covariance genetic and phenotypic correlations Upland Rice Yield Nurseries [IURYN]) analyses were used. between the allogamic characters, to select semidwarf long-duration or Table 1 shows the very high indicating that selection for one photoperiod-sensitive rice cultivars that, coefficients of heritability found for character can positively change the when sown in November, could be stigma, anther, and spikelet length (0.92, other. harvested in April/ May with a ratoon 0.94, and 0.92, respectively). These No significant correlations were found crop flowering in late Sep. results indicate that visual selection can between the two allogamic traits and Entries were sown 28 Nov 1986 and be used efficiently for these traits. spikelet and panicle length. transplanted 16 Jan 1987 in 2 rows at

12 IRRN 14:2 (April 1989) 20- × 15-cm spacing. Plant height, Ratooning ability of semidwarf photoperiod-sensitive rice varieties. Chinsurah, India, Nov 1986. flowering duration, and yield/ plant were Main crop Ratooning Ratoon recorded for the main crop. Ability to Entry Source ability flowering produce ratoon tillers and flowering Plant ht Days to 50% Yield (cm) flowering (g/plant) (%) date behavior of the ratoon were the bases for selecting suitable varieties. SPR7292-0-0-0-0-1 IRSWON 83 ± 4 155 20 ± 7 86 25 Sep 1987 Entries with plants less than 100 cm RAU4057-35-20 IRSWON 77 ± 2 136 8 ± 4 100 29 Oct 1987 Leuang Yai 148 IRSWON 77 ± 2 144 20 ± 7 100 29 Oct 1987 tall were favored for ratooning, since the IR13149-43-2-P IRSWON 96 ± 4 15 3 16 ± 4 100 3 Oct 1987 main crop was grown under controlled RTN90-4 IRSWON 96 ± 3 158 11 ± 4 100 26 Oct 1987 conditions and at higher fertilizer rates TKM9 IRDWON 93 ± 2 123 8 ± 4 100 17 Oct 1987 (100-22-42 kg NPK/ha) for maximum IR38787-26-2-1-2 IRDWON 100 ± 5 127 9 ± 3 100 18 Oct 1987 NC500 IRDWON 96 ± 7 161 6 ± 4 100 26 Oct 1987 yield. Nine entries were identified for C924-9 IURYN (M) 87 ± 6 140 19 ± 6 100 31 Oct 1987 further study (see table). RAU4057-35-20, Leuang Yai 148, and C924-9 have semidwarf plant type, high probably because the lines have shorter IR13 149-43-2-P in early Oct. These yields, and 1% ratooning ability. Their critical photoperiod. SPR7292-0-0-0-0-1 dates are more or less desirable for ratoons flowered the end of Oct, planted in late Sep, followed by establishing the next crop in Nov.

Effect of high temperature on different heading dates. Spikelet fertility SFP differed significantly among rice spikelet fertility percentage (SFP) was measured on 7-41 plants with different heading dates from randomly selected plants, 3 the same cultivar. SFP at normal Xu Yunbi, Shen Zongtan, and Shi Chunhai, panicles/plant, for each cultivar and temperatures 24-28 Jun was higher than Agronomy Department, Zhejiang each planting date. at high temperatures 2-14 Jul (see table Agricultural University, Hangzhou, China

An abnormally high percentage of Empty spikelets in first crop indica rice occurs in ricefields south of the Yangtze River when flowering takes place in the heat of July. Daily maximum temperatures of 35.5-38.9 °C 1-20 Jul 1988 in Hangzhou lowered rice yields. We studied the effect of high temperature on spikelet fertility by using different seeding dates to result in

Spikelet fertility at different heading dates. a Hangzhou, China, 1988.

Spikelet fertility (%) at Variety heading date

27 Jun 1 Jul 5 Jul

Yuanfengzao 93.9 a 84.3 b 76.8 c (15) (15) (15) Erjiunan 1 89.1 a 80.5 b 34.9 c (11) (15) ( 10) Zhe 85-2 88.2 a 87.2 a 76.2 b (15) (15) (15) Guangluai 4 85.3 a 78.5 b 70.5 c (8) (15) (15) Zaolian 31 85.2 a 74.3 b 68.5 c (15) (15) (15) Erjiufeng 79.6 a 78.4 a 58.1 b (7) (15) (15) Relationship between mean spikelet fertility percentage ( Y ) of varieties with the same heading date and mean maximum temperature 3 d after heading ( X ) ( r YX= –0.9570, Y = 73.47 – 0.44 X ). Cultivars: 1 = a Figures in parentheses are sample sizes. In a Erjiufeng, 2 = Zhefu 802, 3 = Erjiuqing, 4 = Guangluai 4, 5 = Zhong 83-49, 6 = Erjiunan 1, 7 = w, figures followed by the same letter are not Yuanfengzao, 8 = Zhe 85-2, 9 = Zaolian 31, 10 = Ainanzao 39, 11 = Guiluai 8, 12 = Zhuxi 26, 13 = significantly different at the 5% level by DMRT. Guangliuzao, 14 = Qingganhuang, 15 = Zhuyunnuo, 16 = Ezao 6, 17 = IR58, 18 = IR28, 19 = IR50.

IRRN 14:2 (April 1989) 13 and figure). Yuanfengzao and Zhe 85-2 respectively). after heading. SFP decreased with that headed at >35 °C had higher SFP There was a significantly negative increasing MMT. The critical day for (76.8, and 76.2, respectively) than correlation between SFP and mean significantly decreased SFP was 30 Jun, Erjiunan 1 and Erjiufeng (34.9 and 58.1, daily maximum temperature (MMT) 3 d when MMT was 35.9 °C for 3 d.

Grain quality and nutritional value

Using silica gel desiccant to Grain quality was measured as grain results at least as good as, and some dry rough rice samples breakage on milling. The table compares better than, traditional methods, with gel-dried samples with sun- and air-dried higher control and resource P. A. Clarke, Overseas Development Natural samples. The gel technique produced optimization. Resources Institute (ODNRI), Culham, Moisture content and milling quality of rice dried in a contact mix with ID silica gel and by air and Abingdon, Oxon OX14 5PR, UK; and M. sun. A. Quasem, Bangladesh Rice Research Institute (BRRI), Joydebpur, Gazipur, Moisture content (%) Milling quality (% brown rice) Bangladesh Drying process Initial Residual Degree of milling Broken grain

The method and rate by which rough BR1 rice is dried changes the characteristics Gel 19.2 12.4 16.1 a 20.2 a Air 19.2 14.3 15.8 a 21.2 ab by which grain quality is judged. We Sun 19.2 14.1 15.9 a 21.7 b have developed a method that achieves BR3 high standardization of large numbers of Gel 24.6 13.7 13.5 a 10.4 a small samples of grain (less than 1 kg). Air 24.6 14.1 13.0 a 10.4 a Sun 24.6 14.5 12.5 a It is based on the sorptive capacity of a 9.1 a special grade of silica gel mixed directly BR4 Gel 27.1 14.5 13.2 a 5.0 a with field-wet rice. Air 27.1 15.6 13.9 b 5.3 a Intermediate density (ID) grade silica Sun 27.1 13.2 13.0 a 5.6 a gel is dried, cooled, mixed with field-wet BR10 rice in the ratio 1:2 by weight, and the Gel 28.9 15.2 14.0 a 6.2 ab Air 28.9 14.8 15.1 b 6.6 b mixture sealed in a moistureproof Sun 28.9 13.9 14.4 a 5.9 a container. After 24 h, the 2 constituents In a column for a variety, means followed by the same letter are not significantly different by DMRT are separated by screening. at p = 0.05. The figure shows the linear regression of field (input) moisture content on residual (output) moisture content within 20-30% wet basis for the model Disease resistance susceptible parent to study the Y = 4.17 × 0.38; r = 0.91, p=0.01. inheritance of reaction to artificial ShB inoculation at booting by virulent isolate Resistance to sheath blight RH-9, collected in Jiangsu Province. (ShB) in China The F1 of four combinations of moderately resistant and susceptible Xue-Yan Sha and Li-Hong Zhu, Nanjing parents showed intermediate reaction to Agricultural University, Nanjing, China inoculation; the F 2 distributions tended to be continuous. That implies that ShB caused by Rhizoctonia solani resistance to ShB is controlled by [Thanatephorus cucumeris (Frank) multiple genes (see figure). Broad and Donk] is a major disease in the rice narrow sense heritabilities estimated areas along the middle and lower from the cross IR9752-71-3-2/IET4699 reaches of the Yangtze River and in were h 2 B = 0.516+0.0654 (broad) and South China. In 1985-87, we used Tetep, h 2 N = 0.373+0.063 (narrow). Analysis of combining abilities based Effect of contact mix with ID silica gel on rice IET4699, Jawa no. 14, and Yedao as input and output moisture content. resistance donors and IR9752-71-3-2 as on the performance of 28 diallelic F 1 s

14 IRRN 14:2 (April 1989) Analysis of variance in combining abilities of reactions to rice ShB, 1986.

F values a Sum of Mean Source of variation DF squares square Model 1 2

General combining ability 7 16.0891 2.2984 257.67** 18.87** Specific combining ability 20 10.5383 0.5269 59.07** 4.33** Error Model 1 924 0.0089 2 54 0.1218

a ** = significant at 0.01.

without reciprocals among Tetep, an elite line with a resistance level IET4699, Mianhuatiao, Jawa no. 14, similar or superior to that of moderately Yedao, 84-3019, Shuidaobawang, and resistant parents through recurrent IR9752-71-3-2 showed that general selection. combining abilities were more prominent than specific combining For informatton on ordering IRRI abilities. That means that additive gene publications, write Communication and effects play a more important role in Publications Dept., Div. R, IRRI, P.O. BOX Distribution of resistance to ShB in F 2 of PI- Tetep, P2-IET4699, P3-Jawa no. 14, P4-Yedao, inheritance of resistance to ShB (see 933, Manila, Philippines. and P8-IR9752-71-3-2. table). It would not be possible to derive

Table 1. Effect of smear inoculation on leaf B1. Hangzhou, China, 1987. A new inoculation technique for rice blast (BI) Bl index a Bl scoreb Variety Injection Smear Spraying Injection Smear Spraying Sun Guochang and Sun Shuyuan, Plant Protection Institute, Zhejiang Academy of Indica Agricultural Sciences, Hangzhou; and Shen Chei-Tang 0 0 0 0 0 0 Zongtan, Agronomy Department, Zhejiang Nong 8506 0 0 0 0 0 0 Gui-Chao 2 0 0 0 0 0 0 Agricultural University, Hangzhou, China Hou-Zeng-Zao 5.6 4.9 1.5 0.5 0.4 0.1 Zao-Shuang 1 14.8 14.3 4.0 1.3 1.3 0.4 We studied a smear method for Zhong 83-40 69.6 29.4 17.8 6.3 2.6 1.6 Zhong 83-49 76.4 68.6 45.5 6.9 6.2 4.1 inoculating with the rice Bl pathogen Hong-Tu 3 86.9 71.2 48.9 7.8 6.4 4.4 Pyricularia oryzae Cav. for resistance B40 83.0 80.4 45.8 7.5 7.2 4.1 screening. Smear inoculation conditions 8004 96.9 73.9 48.3 8.7 6.6 4.4 Er-Jiu-Qing 95.1 85.8 53.5 8.6 7.7 4.8 are similar to natural infection. Zuo 5 94.8 80.4 56.2 8.5 7.2 5.1 The method requires only a small Japonica amount of spore suspension and gives a Pi-4 0 0 0 0 0 0 high infection frequency. Inoculation is Kusabue 18.3 24.3 3.5 1.6 2.2 0.3 carried out by smearing the mixture 1-2 BL 1 87.2 52.4 41.0 7.8 4.7 3.7 Dong-Nong 363 71.8 68.6 42.7 6.5 6.2 3.8 5 × 10 conidia/ ml suspended in 1-2% Li-Jiang-Xing-Tuan-He-Guo 100.0 100.0 92.4 9.0 9.0 8.3 carboxymethyl cellulose onto the rice S (number of plants with a given score × value of that score) leaf with a brush. a Disease index = total number of plants × value of the highest score The method is suitable for inoculation b at several stages, but especially at the 2- Based on Standard evaluation system for rice. 4-leaf stage. A spore suspension of 1 × 10 5 conidia/ml gives nearly 100% leaf Table 2. Effect of smear inoculation on neck Rice sheath blotch incidence Bl. Hangzhou, China, 1987. infection. Smear inoculation produces a in Haryana higher disease index than spray Inoculation Plants Plants with Infection inoculation, but lower than injection method (no.) Bl infection frequency U. Bhan and S. C. Ahuja, Indian (no.) (%) Agricultural Research Institute, New Delhi, inoculation (Table 1). India This method also is useful as a simple Injection 10 10 100.00 and precise method for evaluating neck Gear 22 22 100.00 Sheath blotch caused by Pyrenochaeta Spraying 10 6 60.0 Bl resistance (Table 2). oryzae Shirai ex Miyake is increasing in

IRRN 14:2 (April 1989) 15 Resistance a of rice varieties to sheath blotch in ricefields in Haryana. The disease Hisar and Sirsa districts. Disease Kaul, India. appears as irregular and brownish incidence was higher on rice variety Lesion lesions that enlarge and become sepia- PR107, followed by Jaya, Basmata, and length Group Variety colored. The middle portion of the PR106. (mm) lesion finally turns whitish and is Incidence on varieties or genotypes 10-15 1 IET7662, IET7738, IET7753, studded with pycnidia, the characteristic grown under field conditions at IR13420-6-3-3-1, IR17494-32- symptom of the disease. Haryana Agricultural University Rice 1-1-3-3, RP2151-21-1, We conducted a roving survey 15-1 8 Research Station, Kaul, was measured RP2151-33-4, RP2151-7752, RP2240-86-84, CN758-1-1-1, Oct 1986, when the rice crop was at the during 1986 wet season. Those varieties UPR80-149. dough to maturity stage. Disease were categorized into five groupings on 15-30 2 Jaya, Ratna, HKR101, incidence was recorded on both sides of the basis of lesion length on the outer HAU3800-1, HAU3855-1, the road every 8 km. Of 52 villages, in leaf sheath. Entries with lesion lengths RP1832-23-34, RP2151-27-1. Ambala, Jind, Karnal, and Kurukshetra 1-30 mm were categorized as resistant; 30-45 3 HAU101-88, RP2151-76-1. districts, disease was found in 11 30-45 mm, moderately resistant; and 45-60 4 HAU47-6045-1, HAU101-60. >60 5 IET7641,1R19661-23-3-2-2. villages, more in Kurukshetra than in more than 45 mm, susceptible (see other districts. No disease was found in table). a Resistant = groups 1 and 2, moderately resis- tant = group 3, susceptible = groups 4 and 5.

Insect resistance Germplasm lines with BPH resistance. Culm Resistance Days to length Line gene Donor parent heading (cm) Registration of brown Norin PL 3 Bph 1 Mudgo 128 71 planthopper (BPH)-resistant Norin PL 4 bph 2 IR1154-243 128 67 germplasm lines in Japan Norin PL 7 bph 4 Babawee 127 83 Norin PL 10 Bph 3 Rathu Heenati 131 80 Tsukushibare – – 130 73 H. Nemoto, E. Shimura, and C. Kaneda, Asominori – – 130 76 National Agriculture Research Center, Tsukuba, Ibaraki 305, Japan 4 from Babawee. It was registered in Their morphological characteristics Breeding to introduce the BPH 1987. are mostly those of japonica varieties, resistance gene from indica to japonica Norin PL 10, selected from the cross except for a few traits, such as the rice varieties started in 1968. Since then, Tsukushibare/3/Tsukushibare*3/ Rathu amylose content of Norin PL 10. we have developed four japonica type Heenatil /Tsukushibare, inherited Bph 3 When these lines are crossed with lines, each with one of four different from Rathu Heenati. It was registered in other japonica varieties, the F 1 does not resistance genes ( Bph 1, bph 2, Bph 3, 1988. show hybrid sterility, except with Norin and bph 4 ) (see table). The antibiosis of these lines to BPH is PL 7. Partial seed sterility was observed Norin PL 3, with the Bph 1 gene, was similar to or slightly weaker than that of in F 1 plants of Norin PL 7/a Japanese selected from the cross F 6 324/ Akitsuho the donor indica varieties. The lines line. // Tsukushibare. F 6 324 is the donor show inhibitory effect on BPH survival These four lines are being used to parent, with Bph 1 from and population increase and different breed BPH-resistant varieties in Hoyoku/ Mudgo/2/ Kochikaze/3/ reactions to the biotypes. Japan. IR781-1-94/4/Hoyoku. In 1984, Norin PL 3 was registered as a germplasm line by the Ministry of Agriculture, Forestry, Rice resistance to WBPH incidence has increased in recent and Fisheries (MAFF), Japan. whitebacked planthopper years, particularly in the irrigated boro Norin PL 4 inherited bph 2 from (WBPH) Sogatella furcifera in (Dec-Mar) crop. We screened BRRI IRI 154-243 through the cross Bangladesh varieties BR1-BR12 and BR14-BR21 combination of Asominori/ IRI 154- and 22 IR varieties, using the standard 2431 / 2*Asominori. It was registered in A. N. M. R. Karim and Q. M. A. Razzaque, seedbox test. TN1 was the susceptib1e 1985. Entomology Division, Bangladesh Rice check. Norin PL 7 from the cross Research Institute (BRRI), Gazipur, Seedlings (20/ 12-cm row) were Tsukushibare *2/ Babawee inherited bph Bangladesh infested with 2d- and 3d-instar nymphs

16 IRRN 14:2 (April 1989) from a stock culture, at 5 and BR2070-15-6, exotic variety Lua improvement and evaluation before they nymphs/seedling. Plant damage was Ngu (Vietnam), and local varieties can be released. measured (Standard evaluation system Rajasail 3 and Rajasail 8 (BRRI acc. no. Babawee, Hondarwala, Rathu for rice 0 to 9 scale) 10 d after 2436 and 2440) were moderately Heenati, and Gangala are resistant to infestation, when all TN1 seedlings were resistant. WBPH at IRRI, but susceptible at killed. While varieties with moderate BRRI. Further studies are needed to All test varieties except IR64 were resistance may be planted if WBPH determine whether the differential susceptible (see table). IR64, which incidence is low, the breeding lines varietal reactions are due to differences exhibited moderate resistance, is not identified will require further in WBPH populations. grown in Bangladesh. We screened 18 BRRI elite breeding lines, 41 promising exotic varieties, and 23 local germplasm collections using the A potential donor for in 21 hills at 30 and 50 d after same procedure. Only BR1711-7-24-2 resistance to the gall midge transplanting (DT). (GM) population of Only Banglei showed no GM (see Srikakulam District, Andhra table), and could be a donor for Reaction of BR and IR varieties to WBPH in resistance to the GM population of Bangladesh. BRRI, Gazipur, 1987. Pradesh Srikakulam District. The other potential Plant donors (Eswarakora, Leaung 152, and Variety damage Reaction b P. Subbarami Reddy, M. A. Khader, I. N. score a Rao, and R. Radhakrishna, Andhra Pradesh Velluthacheera) showed no resistance. Agricultural University, Agricultural The two GM-resistant derivatives, BR1 9.0 S Research Station, RA GOLU-532484, W 1263 (MTU 15/ Eswarakora) and BR2 8.3 S BR3 7.7 S Srikakulam District, A. P., India Phalguna (IR8/Siam 29), also did not BR4 8.3 S show resistance reaction to the local BR5 9.0 S We evaluated four donors and two GM population. BR6 9.0 S BR7 8.3 S derivatives against the GM population In view of these reactions of proven BR8 7.0 S of Srikakulam during rainy season 1988. donors and derivatives, we strongly BR9 7.0 S Twenty-day-old seedlings of each entry suspect the existence of a new GM BR10 8.3 S BR11 7.7 S were planted in 3-m rows at 15- × 15- biotype in the district. BR12 7.7 S cm spacing. GM incidence was recorded BR14 7.7 S BR15 8.3 S BR16 7.7 S Reaction of donors and derivatives to GM. Srikakulam District, A. P., India, 1988. BR17 9.0 S BR18 7.7 S GM incidence (%) BR19 9.0 S Variety Parentage BR20 9.0 S 30 DT 50 DT BR21 9.0 S IR5 8.3 S Hill Tiller Hill Tiller IR8 9.0 S IR20 9.0 S Eswarakora Donor 23.8 2.9 47.6 3.1 IR22 9.0 S W1263 MTUlS/Eswarakora 38.1 5.5 81.0 9.8 IR24 9.0 S Phalguna IR8/Siam 29 42.9 7.5 90.5 24.1 IR26 9.0 S Leaung 152 Donor 28.6 4.5 85.7 13.9 IR28 7.7 S Velluthacheera Donor 9.5 1.0 57.1 6.2 IR29 8.3 S Banglei Donor 0 0 0 0 IR30 8.3 S TN1 Susceptible check 69.0 8.9 100.0 27.2 IR32 8.3 S IR34 8.3 S IR36 8.3 S IR38 8.3 S IR40 9.0 S Screening for resistance to rice crop in the plateau region of Bihar, IR42 9.0 S both upland and lowland. Six GM IR44 7.7 S rice gall midge (GM) IR45 7.0 S biotypes have been identified (one each IR46 7.0 S S. C. Prasad, J. B. Tomar, and S. D. Tomar, in China, Indonesia, Sri Lanka, IR50 7.7 S Plant Breeding and Genetics Department, Thailand, and in Andhra Pradesh and IR52 7.0 S IR56 6.3 MS Birsa Agricultural University, Kanke, Ranchi Orissa in India). The biotype at Ranchi IR64 5.0 MR 834006, India appears to be different (Table 1). In 1986 wet season, 60 rice genotypes a Average of 3 sets, scored on a scale of 0-9 b S = susceptible, MS = moderately susceptible, GM Orseolia oryzae Wood-Mason is a received from the All India Coordinated R = moderately resistant. major pest in India. This pest attacks the Rice Improvement Project, Hyderabad,

IRRN 14:2 (April 1989) 17 Table 1. Reaction of the Ranchi GM biotype and of 6 established biotypes to 5 differential varieties. No silvershoots were found in Reaction a RP1579-92-85-203. Resistance levels of Origin cultivars are given in Table 2. Cultivars Eswarakora Siam 29 OB677 PTB Leaung 152 scoring 0-3 can be used as donor parents group derivative derivative in the breeding programs. China R R R S – Indonesia S R R S R Sri Lanka S R R R R India (Andhra Pradesh) R R R R R For information on ordering IRRI India (Orissa) S R R R R publications, write Communication and Thailand R S S S S Publications Dept., Div. R, IRRI, P.O. Box India (Ranchi) R S S MR S 933, Manila, Philippines. a R = resistant, MR = moderately resistant, S = susceptible.

Table 2. Evaluation of rice cultivars for field resistance to GM. Test lines with damage scores of 5.0 or lower a Resistance of rice varieties to Score Cultivars brown planthopper (BPH), against BPH, WBPH, and GM at Hyderabad, India. 0 RP1579-92-85-203 whitebacked planthopper 1 RP2199-3-3-5-1, RP2190-104-64-18-1, (WBPH), and gall midge (GM) Accession no. Cultivar Damage RP2434-24-2-2, Phalguna score 3 RP2235-163-33-8, RP2235-48-54-6, in India RP2091-272-34-8, WGL 48684, R270- Brown planthopper 3188, RP2431-6-62, RP2434-79-2-6 A440 Anjania 4.1 R. K. Sahu and M. N. Shrivastava, Indira 5 Rp1125-606-637-1, W1125-630-667~1, A61 i Bainspath 5.0 RP1125-638-1-1, RTN81, RP2435-50- Gandhi Krishi Vishwa Vidyalaya, Raipur B2112 Bhakwa 5.0 1, RP2434-24-1-2, RP2434-22-3-3, 492012, Madhya Pradesh: and M. B. C62 iii Chhatri 3.8 RP1579-34-54, RP2235-136-65-10, Kalode, Directorate of Rice Research, – – – E.B. 17 4.7 RP2235-91-15-1, RP1579-43, RP1579- K2351 Kabari 2.0 Hyderabad, India 43-48, CR400-16, CR406-16,OR447- L289 ii Lalbasant 4.1 3, RP2199-32-30-47-46, RP1607-1629- S644 Safeddhanwar 1.9 44-221, RP1606-29-232, RP2431-5-3-4 BPH, WBPH, and GM cause Whitebacked planthopper 7 RP1125-604-1-1, RP1125-637-673-1, Batri substantial yield losses in Chattisgarh 2.9 RP2199-84-2, WGL 44645, RP2432- D307 i Dihula 3.0 34-3-1 ,RP2432-34-3-4, RP2434-22-3-2, region (the rice bowl of Madhya Dl061 Dihula 2.8 RP1579-38-48, RP1579-36-33, Pradesh State). We screened about 400 Dl064 Dihula 2.7 RP2235-85-62-8, RP2235-62-33-1, – – – Karanphool 3.0 RP2199-34-6-1, CR404-6, CR400-15, accessions using the standard seedbox Khalasu 2.0 screening technique at Hyderabad 1983- – – – CR404-9-1, R278-3528,OR633-7, Gall midge RP2199-3-3-3-2, RP1528-86-43-220, 87. For BPH and WBPH, damage was B2712 Bhakwa Resistant RP1579-59-227, RP2434-79-2-4, scored on the Standard evaluation Dehradodi Resistant RP2434-22-3-3, Vikas Resistant system for rice scale 1-9; absence of Gurmatia 9 RP2432-34-4-5, RP2432-34-5-4, Jhitpiti Resistant OR706-4, RP2432-34-3-4, RP2432-34- silvershoots was rated resistant to GM. Kudunjan Resistant 5-1, Jaya Entries with damage scores 5 or lower Lalbogri Resistant Tulasimanjari Resistant a Based on Standard evaluation system for rice in replicated tests are presented in the Viruppu Resistant scale. table. Most of these varieties possess resistance to one pest; Bhakwa was resistant to both BPH and GM. were screened against GM. The genotypes were sown in 4.50- × 2.0-m plots at 20- × l5-cm spacing with 2 replications. All recommended agronomic cultural practices were used. The International Rice Research Newsletter invites contributions of concise summaries Maximum GM infestation was in the of significant current rice research for publication. Contributions should be limited to no last week of Sep to the first week of Oct. more than 2 pages typed double-spaced accompanied by no more than 2 figures, tables, At 50 d after transplanting, 15 randomly or photographs. Contributions are reviewed by appropriate IRRI scientists and those selected hills were scored for number of accepted are subject to editing and abridgment to meet space limitations. Authors are hills having silvershoot and for number identified by name and research organization. See inside front cover for more of silvershoots/infested hill. Susceptible information about submissions. checks Jaya and Vikas had severe infestation (more than 40%).

18 IRRN 14:2 (April 1989) Excess water tolerance

Heritability of stem elongation ability in rice

P. K. S. Ray, Plant Breeding Division, Bangladesh Rice Research Institute, Gazipur, Bangladesh; and D. HilleRisLambers, IRRI

Inheritance of stem elongation ability in four semidwarf rice crosses was found to be controlled by two dominant genes. Four semidwarf, nonelongating advanced lines were crossed with IR11288-B-B-69-1, which has stem elongation ability in addition to a dwarfing gene, and F 1 and F 2 seeds sown in 5- × 5-cm plastic pots. The pots were placed in galvanized iron trays in the glasshouse. At 35 d after seeding, the trays were placed in a tank and the water level raised, at 5 cm/day, to a maximum depth of 90 cm. This depth was maintained 7 d, then the tank was drained. Stem length was measured from the root base to the uppermost node and plants categorized as elongating (stem length >20 cm) and nonelongating (stem length <20 cm). Plants of all crosses survived a water depth of 1 m (see figure). Mean stem length of the F 1 and F 2 of all crosses was >20 cm. Most plants tended toward the elongating parents, indicating dominance of the stem elongation genotype over the nonelongating Distribution and means of parent, F1 and F2 plants for stem elongation ability in 4 crosses. Arrows show genotype. the mean. Distributions of all F 2 populations were unimodal and continuous with single peaks. The segregation ratios of Inheritance of stem elongation ability in 4 crosses. IRRI, 1987. all crosses in the F 2 suggest that stem elongation ability was dominant. F 2 seedlings (no.) Two types of segregation ratios were Cross F Total Ratio x 2 P> 1 Elongating Nonelongating observed in the F 2 , 13:3 for the cross BKNFR76106-16-0-1/IR11288-B-B-69-1 BKNFR76106-13-2/ Elongating 78 6 84 15:l 0.11 0.70 and 151 for the others (see table). Such IR11288-B-B-69-1 ratios can be explained by the presence BKNFR76106-16-0-1/ Elongating 80 11 91 13:3 2.60 0.10 of a minimum of two genes. When the IR11288-B-B69-1 two dominant genes remain together, IR8234-OT-9-2/ Elongating 154 16 170 15:l 2.90 0.05 the typical stem elongating feature IR11288-B-B-69-1 develops and plants carrying the genes IR42/IR11288-B- Elongating 149 7 156 15:l 0.83 0.30 B-69-1 resist about 1-m water depth.

IRRN 14:2 (April 1989) 19 Integrated germplasm improvement The WS crop was rainfed; the DS crop was irrigated with poor quality lift irrigation water. IET9783 : a salt-tolerant rice fine clayey, mixed, hyperthermic family, IET10676 yielded highest (4.0 t/ ha) in for coastal saline soil Vertic Halaquept; pH of the WS (see table). Soil salinity delayed experimental site was 7.2 in WS and 8.0 crop maturity in DS 1149 d, and yields P. N. Jagadev and D. Jena, National in DS. EC values were 1.2-6.8 dS/m did not differ significantly. Agricultural Research Project, Motto, during Jul-Nov and 2.7-13.5 dS/m Balasore District 756132, Orissa, India during Dec-Mar. In 1987-88 DS, we evaluated 28 Coastal saline soil occurs in a narrow cultivars from the All India Coordinated Peformance of upland and strip along the Bay of Bengal, 375 km Rice Improvement Project, Hyderabad, rainfed lowland rice varieties long and 2.25 km wide and covering 2 resistant checks, and local checks 2.54 million ha. Rice is the main crop of SR26-B in WS and CSR4 (Mohan). in farmers' fields in Mali wet season (WS), fields are fallow in The experiments were in a randomized dry season (DS). In a year of poor block design with three replications. R. B. Kagbo OHV/USAID, 12411 monsoon, the crop fails. Three 35-old seedlings/variety were Antoine#413, Houston, TX 77067, USA The Regional Research Station, transplanted on 25 Jul 1987 and 9 Jan Motto, is situated on the coast 10 km 1988 at 20- × 15-cm spacing in 4-m 2 Rice variety trials in farmers' fields of away from the Bay of Bengal. Soil is plots. Fertilizer was 60-26 kg NP/ ha. the Operation Haute Vallée (OHV) were carried out in collaboration with the Multilocational Unit of the Institute of Performance of rice varieties and cultivars in coastal saline soil at Motto, Balasore, India, 1987-88 WS Rural Economy and USAID farming and DS. systems research (FSR/ E) project. Grain yield Upland soils were sandy loam, Cultivar Parentage Duration (d) (t/ha) lowland soils were hydromorphic with some standing water during some ws DS ws DS periods of the cropping season. IET10344 SAR41/Jaya 111 123 2.1 1.0 Ammonium phosphate and urea were IET10345 SAR43/IR8 110 130 2.0 0.6 applied at 100 kg/ha in lowland and 50 IET10346 IR1702-74-3/IR2061464-2 129 156 1.7 0.8 IET10348 CSRl/Basmati370//CSR5 134 154 2.2 1.l kg/ ha in upland. Urea was applied at IET10349 M40-431-24-114/Jaya 110 143 1.8 1.3 planting and at panicle initiation. Two CSRl Mutant CSR 1 111 134 1.3 1.1 farmers each for upland and lowland IET10354 – 113 133 2.3 1.4 IET10357 Rasi/IET6238 114 156 1.3 0.7 conditions conducted trials, with four IET10358 IET6238/IR36 116 150 1.2 0.3 replications. – IETT9783 115 155 1.6 2.0 In upland conditions, the introduced IET10672 CO 22 / Vaigai 105 153 1.3 0.7 IET9784 – 115 126 1.1 0.4 varieties had almost three times the yield IET10675 – 115 137 3.0 1.2 of the local check (see table). In lowland IET10683 TNl/CO 29 102 141 3.1 0.4 IET10676 – 127 166 4.0 0.7 IET10684 IR13240-108-2-2-3/ 120 137 2.0 1.1 IR9129-209-2-2-2-1 Grain yield and approximate duration of selec- IET10685 T22/Mahsuri 117 166 2.2 0.5 ted rice varieties in farmers' fields testing in the IET10689 TNl/CSR5 122 167 2.9 0.5 Operation Haute Vallée project, Mali, 1987-88 CSR 1 Mutant CSRl 120 137 2.6 0.7 cropping season. IET10692 – 106 139 2.4 0.9 Yield Duration ET10693 M40-431-24-114/ 122 154 2.9 0.8 Variety Basmati 370 (t/ha) (d) IET10694 M40-431-24-114/Jaya 116 141 3.2 1.4 IR36/MR340 115 139 2.9 1.1 Upland conditions IET10696 a IET10697 IET6238/MR340 106 141 2.8 1.0 Linke 0.6 100 IET10698 IET6238/Mk340 125 139 2.3 1.4 IRAT144 1.8 110 IET10699 IET6238/MR342 113 138 3.1 1.7 Dourado 1.6 103 Pokkali (resistant check) – 125 136 1.9 0.8 Lowland conditions – Vikas (resistant check) 125 141 0.8 0.8 BG90-2 2.5 124 – – SR26-B (local check) – 155 2.7 IET2911 2.5 127 – – Damodar (local check) – 140 0.8 BKNLR75001 2.2 129 Mohan (local check) – – 152 – 1.6 a LSD (0.05) 2.3 10.9 0.5 n.s. Local check; farmers in lowland conditions did not have a local variety.

20 IRRN 14:2 (April 1989) conditions, the three varieties yielded RAU4045 -10, a new variety Project (AICRIP) experiments. In the similarly. The participating farmers were for rainfed areas 1984 Preliminary Varietal Trial 1 (PVT- generally satisfied with the performance 1), it yielded 5.5 t/ha at Hyderabad. In of the new varieties. OHV has S. C. Prasad and J. B. Tomar, Plant the 1985 Uniform Varietal Trial in 15 undertaken seed multiplication of all Breeding and Genetics Department, Birsa locations all over India, it yielded an three varieties. Agricultural University, Kanke, Ranchi average 2.6 t/ha and took 74 d to 834006, India flowering under direct seeded rainfed conditions (Table 1) and 3.7 t/ha under RAU4045-10 (IET7978), a semidwarf direct seeded irrigated conditions. It Ranbir Basmati — an early- variety derived from Finegora/ IET2832, ranked third in transplanted conditions maturing aromatic rice is moderately resistant to blast and in 16 locations. averages 70 d to 50% flowering. Mean In 1986, IET7978 was the top yielder J. S. Bijral, K. S. Kanwal, and Y. P. yield over 4 yr of experimental trials was (3 t/ha) over all locations (Table 2). It Khanna, SKUAST, Regional Agriculture 3.6 t/ha, significantly higher than that of significantly outyielded national as well Research Station (RARS), R.S. Pura, J & check varieties Akashi (2.3 t/ha) and as local checks under rainfed conditions K, India Brown gora (2.1 t/ha). in Bihar and Orissa and has been IET7978 was tested for 3 yr in All- recommended for rainfed fields in Bihar The quality basmati rices of India and India Coordinated Rice Improvement and Orissa. Pakistan, characterized by late maturity, are difficult to fit into multiple farming Table 1. Performance of RAU4045-10 in station trials at Birsa Agricultural University, Kanke, systems, and are grown on limited Ranchi, India. hectarage. Development of early- maturing basmati types would help Yield (t/ha) Variety bring larger areas under superfine rices. 1983 1984 1985 1986 Mean In 1982, we isolated an early- maturing, slightly dwarf plant from RAU4045-10 4.2 3.8 3.0 3.4 3.6 (IET7978) farmers' fields. The strain, Ranbir Akashi 2.5 2.4 2.1 2.4 2.3 Basmati, was evaluated against Basmati Brown gora 1.9 2.0 2.2 2.3 2.1 370 for 2 yr at RARS, and in farmers' LSD (0.05) 0.3 0.4 0.4 0.5 0.4 fields for performance, stability, and adaptability. Ranbir Basmati duration is 115-120 d from sowing to maturity, 30- Table 2. Performance of RAU4045-10 in All India Coordinated Rice Improvement Project trials 35 d shorter than that of Basmati 370, during 1986. with comparable yields. Yield per day of Yield (t/ha) Ranbir Basmati was 20-25% higher. Grain quality equaled or surpassed that Zone III Zone 5 Zone 8 Transplanting Variety Mean condition of Basmati 370 (see table). Assam Assam and Kanke Faizabad Himachal Tamil Tripura Bihar (U.P.) Pradesh Nadu Delhi Rajasthan

Comparative qualities of Ranbir Basmati and RAU4045-10 2.6 3.1 4.1 4.1 3.1 3.7 5.0 5.9 3.0 Basmati 370. Akashi 2.1 3.0 3.2 4.4 2.9 2.1 4.0 3.4 2.4 Cauvery 1.4 2.2 2.4 3.2 2.3 1.8 4.5 4.8 2.9 Character Ranbir Basmati Local checks – – 2.2 3.6 2.8 4.7 – – Basmati 370 (N22) (HPU741) (IR50) Plant height (cm) 155 170 Duration (d) 115 150 Threshability Easy Easy Grain length (mm) 7.2 7.1 Grain breadth (mm) 1.8 1.9 Length/breadth ratio 3.9 3.8 CN705-18 — a promising Mahsuril CN643) is a promising variety Chalkiness 5 9 rice variety for deepwater rice for deepwater rice areas (water 1,000-grain wt (g) 22.8 21.5 Amylose content (%) 24.0 21.3 areas accumulates up to 1 m during the wet Gelatinization temperature a I/L H/I season) in West Bengal, Bihar, Andhra Average proportional S. Mallik, C. Kundu, and B. K. Mandal, Pradesh, and Assam. elongation ratio 2.05 2.03 Protein content (%) 7.7 7 .0 Rice Research Station, Chinsurah 712102, Photoperiod-sensitive CN705-18 Aroma Strong Strong India flowered 28-30 Oct in West Bengal. Cooking quality Good Good Depending on water depth, it attained Eating quality Good Good Based on overall performance in 1985- 175-210 cm height, with 10-12 a L = low, H = high, I = intermediate. 87 national trials, CN705-18 (IET9065 = tillers/ hill. It has very good submergence

IRRN 14:2 (April 1989) 21 a Performance of CN705-18 in multilocational trials in India, 1985-87. tolerance, elongation ability, kneeing Grain yield c (t/ha) ability, and drought tolerance at the Max water Site b early vegetative stage. Panicles are about depth (cm) CN705-18 Local check 24 cm long with good exsertion and Preliminary Variety Trial 5, 1985 about 215 grains/panicle. Grain is Bhubaneswar 2.1* 1.0 (Khajuniachar) na medium and bold (length-5.9 mm, CRRI 3.6* 1.2 (CR1030) 40 breadth-2.9 mm, L/B 2.0), 1,000-grain Patna 2.5 2.7 (Janki) na weight is 27.3 g. It has a yellow-colored Chinsurah 3.3* 1.8 (NC492) 55 hull at maturity, red kernel, and strong Uniform Variety Trial 5, 1986 Chinsurah 3.3* 1.2 (TCA212) 110 (3 mo) seed dormancy. Malda 3.6 3.2 (CN540) 62 On average, CN705-18 outyielded Pusa 1.2 1.8 (TCA214) 85 check varieties (2.9 t/ha to 2.1 t/ha) Ranital 2.2 1.7 (CR1030) 65 over 17 sites (see table), with an overall Physiology screening Cuttack 4.7* 3.4 (CR1018) 50 yield increase of 38%. CN705-18 yield Patna 3.2* 2.2 (Janki) 50 was significantly higher than check at 9 Uniform Variety Trial 5, 1987 sites, superior at 4, equal at 2, and lower CRRI 3.5 * 1.9 (na) 75 at 2. Yield varied from 4.7 to 1.2 t/ha. Bhubaneswar 2.1 2.0 (Rambha) 50 North Lakhimpur 2.9 2.9 (Panikekau) 108 This variation under similar water Chinsurah 3.4 2.9 (NC492) 85 depths over sites reflects the role of time, Pulla 2.0* 1.1 (CN540) 75 duration, and intensity of water Physiology screening stagnation in determining variety Chinsurah 4.0 4.0 (Jogen) 65 adaptability. Maruteru 2.0* 0.7 (Marutan) 50 CN705-18 has been recommended for Mean (1 7 sites) 2.9 2.1 large-scale demonstration trials in a na = data not available. b CRRI = Central Rice Research Institute. c * = significant at the 5% level of farmers’ fields. probability.

Table 1. Yield of rice lines and varieties in multilocation trials in Nigeria, 1986. a SiPi 692033: a promising Grain yield (t/ha) rainfed lowland rice variety Line or variety Parentage 1 23 4 5 6 Mean

J. K. Kehinde, S. O. Fagade, and P. G. FAROX 228-3-1-1 FARO 15/IR28 1.1 5.4 4.4 6.1 8.2 8.2 5.6 Pillai, National Cereals Research Institute, FAROX 228-4-1-1 FARO 15/IR28 1.3 5.7 5.0 5.1 7.8 7.1 5.3 Private Mail Bag 5042, Ibadan, Nigeria FAROX 239-3-3-2 IR28/FARO 12 1.0 4.8 6.4 6.5 5.7 7.6 5.3 FAROX 233-7-1-2 FARO 12/IR28 1.3 3.9 4.5 5.8 4.6 6.9 4.5 FAROX 239-2-1-1 IR28/FARO 12 1.0 3.3 3.6 5.5 4.1 6.4 4.0 SiPi 692033 (introduced from Taiwan), FAROX 233-1-1-1 FARO 12/IR28 1.1 5.5 5.9 5.7 5.2 7.0 5.1 seven FAROX rice lines (Table 1), and FAROX 234-3-1-1 FARO 12/TOS103 1.5 4.5 5.7 7.0 6.0 6.8 5.3 FARO 27 (a widely cultivated rice SiPi 692033 SiPi 661044/ 1.5 5.9 5.9 8.9 8.3 8.8 6.6 SiPi 651020 variety) were evaluated at six sites across FARO 27 (check) – 1.3 5.2 5.0 6.9 3.6 7.2 4.9 the country in 1986. Sites 1, 2, and 3 lie Mean 1.2 4.9 5.2 6.4 5.9 7.3 within the rain forest and sites 4, 5, and a 6 lie in the Sudan savanna vegetational Locations: 1 = Ogoja, 2 = Ibadan, 3 = Bende, 4 = Wurno, 5 = Birnin-Kebbi, 6 = Kadawa. zones. All cultural operations except weed Table 2. Agronomic characteristics of rice lines and varieties. a Nigeria, 1986. control were common to all locations. Plant Grain yield (14% moisture) was taken Panicles Maturity Grain Line or variety height 2 (d) type b from the middle 6 m2 of each test plot. ( cm) (no./m ) SiPi 692033 was the highest yielder FAROX 228-3-1-1 110 335 117 MB overall and at five sites. Its yield FAROX 228-4-1-1 106 311 114 MB advantage ranged from 18% over FAROX 239-3-3-2 109 362 114 MB FAROX 228-3-1-1 to 65% over FAROX 233-7-1-2 97 356 110 LS FAROX 239-2-1-1 78 362 108 LS FAROX 239-2-1-1. FAROX 233-1-1-1 108 379 115 LS In general, grain yields were higher at FAROX 234-3-1-1 94 371 119 LS the Sudan savanna sites with low annual SiPi 692033 106 339 122 LS FARO 27 (check) 95 355 120 MB rainfall (<1,000 mm) than at the rain forest sites with high annual rainfall a Mean of 6 sites. b LS = long slender, MB = medium bold.

22 IRRN 14:2 (April 1989) (>1,500 mm). Rice in the savanna ripens were semidwarf ( £ 110 cm). gel consistency (26-35 mm). SiPi 692033 under higher solar radiation. Both SiPi 692033 and FARO 27 have has long, slender grains and higher yield Panicles/m 2 were similar for all high amylose content (>25%) with hard than FARO 27. varieties tested (Table 2). All varieties

Influence of Acrocylindrium oryzae on seed germination and rice seedling vigor. Tamil Nadu, India, Seed technology 1988.

Seedling vigor a Seed germination (%) Influence of Acrocylindrium Cultivar Shoot length (mm) Root length (mm) oryzae Sawada on rice seed Healthy Inoculated Day 4 Day 7 Day 4 Day 7 germination and seedling vigor NI I NI I NI I NI I IET9233 95 93 15.3 10.7 32.4 29.1 14.6 13.9 32.2 29.1 R. Velazhahan, R. Ramabadran, and R. ET8611 89 84 6.6 4.8 19.1 18.7 16.2 14.8 33.0 31.3 Sudhakar, Plant Pathology Department, IET8584 96 92 5.3 3.6 25.9 25.2 15.0 13.2 30.4 30.3 Faculty of Agriculture, Annamalai IR62 90 87 4.8 3.6 15.4 7.8 12.0 10.3 29.6 27.2 AU1 90 86 University, Annamalainagar 608002, Tamil 10.5 7.3 26.1 23.1 20.3 17.2 59.9 47.2 J58 92 89 7.6 6.3 33.5 24.7 15.7 13.6 41.8 40.4 Nadu, India ADT37 94 91 4.3 3.6 9.7 1.9 16.8 15.6 44.0 39.3 LSD We studied the influence of Sarocladium (P = 0.05) 4.34 2.35 3.42 oryzae (Sawada) W. Gams and D. a NI = not inoculated, I = inoculated. Hawksw. (syn. Acrocylindrium oryzae Sawada) on seed germination and seedling vigor of seven rice varieties. seeds were sprayed with a 4 × 10 6 after inoculation. Seeds were thoroughly washed with spores/ml suspension of the fungus. Inoculation considerably reduced seed sterile distilled water and 10 seeds were (Control seeds were sprayed with sterile germination in all varieties (see table). lated on moistened filter paper in a distilled water.) Seed germination and Shoot and root lengths of all the rices petri dish, with 10 replications. The seedling vigor were assessed 4 and 7 d also were reduced.

CROP AND RESOURCE MANAGEMENT Soil microbiology and biological N fertilizer

Boiling water treatment to Germination of S. rostrata seeds treated with boiling water (98 °C). Dharwad, India, 1988. improve germination of Germination (%) at indicated period after treatment Sesbania rostrata Treatment 3 d 4 d 5 d 6 d 7 d M. N. Sheelavantar, S. Rao, P. S. Matiwade, and A. S. Halepyati, Agronomy Control (no boiling water) 2 4 4 4 4 Department, University of Agricultural Treatment with 98 °C water 15 s 34 40 50 62 62 Sciences, Dharwad 580005, India 30 s 42 52 54 70 70 45 s 42 52 60 72 76 The hard seed coat in Sesbania rostrata 60 s 52 66 66 74 76 75 s 42 60 66 78 78 can be broken by treating seeds with 90 s 54 62 62 70 72 (4) a concentrated sulfuric acid for 40 min. 120 s 64 76 76 76 76 (8) However, sulfuric acid is costly and 150 s 50 60 60 60 60 (10) 180 s 50 68 68 68 68 (10) requires care. Dormancy due to hard seed coat in many legumes could be a Figures in parentheses = percent deformed seeds.

IRRN 14:2 (April 1989) 23 broken using boiling water. We studied 15-180 s at intervals of 15 s. Treated Treatment with boiling water the effect of boiling water treatment for seeds and untreated seeds were arranged increased germination from 4 to 78% varying times on the germinability of on filter paper, placed in petri dishes, with 75-s treatment (see table). Boiling seeds of S. rostrata. and moistened with distilled water. The water treatment beyond 75 s began to Welldeveloped seeds were selected, germination test was carried out at deform seeds. 50/set, and treated with 98 °C water for room temperature (27-30 °C).

Crop management Influence of sowing and transplanting methods on yield and yield attributes of rice. Orissa, India, 1982 kharif.

1000- Panicles Grains grain Grain Cost of Net Effect of sowing and planting Sowing or planting method (no./m 2) (no./panicle) weight yield cultivation profit method on rice yield (g) (t/ha) ($/ha) ($/ha) Broadcast seeding 298 82 19.7 3.4 156 246 D. Rout and A. Mishra, Agronomy Broadcast seeding followed by 265 83 20.2 3.2 175 210 Department, OUAT, Bhubaneswar 751003: beushaning and T. Barik, Regional Research Station, Line sowing sprouted seeds 313 82 20.3 3.8 185 264 Bhawanipatna 766001, Orissa, India 15 cm apart Transplanting at 15- × 10-cm spacing 344 83 20.0 4.3 232 285 Skip-row (3:1) transplanting with 290 87 20.4 4.3 202 314 Performance of two dwarf and one tall 60-30-30 kg NPK/ha indica varieties—OR152-2-17, Pratap, Skip-row (3: 1) transplanting with 295 85 20.6 4.3 221 295 80-40-40 kg NPK/ha and Mahsuri, all with 135-140 d SE (m) ± 5 1 0.3 0.1 – – duration-was compared under LSD (0.05) 16 3 ns 0.2 – – different sowing and planting methods during 1982 wet season. Treatments were broadcast seeding with and without beushaning (operating three replications. normal fertilizer were not statistically narrow wooden plow in standing crop Soil of the experimental site was different (see table). Skip-row planting under 10-15 cm standing water 30-35 d sandy loam with pH 6.1. Total N with 75% normal fertilizer produced the after germination), line sowing sprouted content was 0.031%, 17.3 kg available highest net profit, followed by skip-row seeds in puddled soil, line transplanting, P/ ha, and 104 kg available K/ ha. planting with full fertilizer. These and skip-row planting with full and 75% The interaction between variety and methods saved 25% of the cost seedlings recommended fertilizer (80-40-40 kg planting method was not significant. or fertilizers. Broadcast seeding followed NPK/ ha). The design was split plot with Grain yields under normal line planting, by beushaning produced the lowest varieties in the main plots and sowing or skip-row planting with 75% normal grain yield and net profit, probably transplanting method as subplots, with fertilizer, and skip-row planting with because of low plant population.

Selecting rice varieties for rice in early Jul. If flooding comes late transplanted crop gives yields higher double transplanting in flood- or is mild, the transplanted crop suffers than a single-transplanted crop. We conducted a field trial on silty- affected areas least. Most farmers, however, do not want to risk transplanting early because clay loam soil at the Rajendra they cannot afford to manage seedlings Agricultural University Farm, Pusa B. K. Singh, Agronomy Department, Rajendra Agricultural University, Pusa for retransplanting if the Jul crop is (Bihar) during wet season using six 813210, Bihar (present address: National flooded. They usually transplant in Sep, photoperiod-sensitive rice varieties— Agricultural Research Project, RAU when the chance of flooding ceases. Janaki, BR8, T141, B14, C62-68, and Campus, Bihar Agricultural College, Sabour Two types of seedlings-conventional Bakol (local check)—and three dates of 813210, Bihar), India seedlings brought directly from the first transplanting—1 Sep, 16 Sep, and 1 nursery and kharuhan seedlings Oct. Large areas on the riverbanks in uprooted from the first nursery and The trial was in a split-plot design, northeastern India frequently become transplanted closely in a second with date of transplanting in the main flooded two to three times during the nursery—are transplanted. Seedlings of plot and varieties in subplots, with three wet season, severely damaging the rice any available photoperiod-sensitive rice replications. Kharuhan seedlings (30 d in crop. Some farmers risk transplanting variety are used. The double- first nursery + 45 d in the second) were

24 IRRN 14:2 (April 1989) transplanted at 15- × 10-cm spacing Grain yield of double-transplanted, photoperiod-sensitive rice varieties by transplanting dates in with 2 seedlings/ hill. A uniform 40 kg flood-affected area of Pusa (Bihar), India. N, 8.8 kg P/ha was applied at Grain yield (t/ha) transplanting. The crop was irrigated as needed and harvested in the second 1 Sep 16 Sep 1 Oct Mean week of Dec. Janaki 3.6 2.7 1.2 2.5 The grain yield differed among BR8 2.2 2.2 0.9 1.8 varieties and with date of transplanting T141 2.5 1.6 0.3 1.5 BR14 2.8 1.9 0.4 1.7 (see table). Variety C62-68 and Janaki C62-68 3.8 3.0 1.5 2.8 gave significantly higher yields (C62-68 Bakol (local check) 2.3 1.1 0.5 1.3 grain weight was lower than that of Mean 2.9 2.1 0.8 Janaki, but it had more grains/ panicle). LSD (0.05) For variety 0.3 Grain yield decreased significantly For date of transplanting 0.6 with delay in transplanting. The crop For variety at same date of transplanting 0.5 transplanted 16 Sep gave 27.6% lower For date of transplanting of same variety 0.6 grain yield than that transplanted 1 Sep; the 1 Oct crop gave 72.4% lower yield. The variety by date of transplanting Panicle exsertion in the two varieties consequently higher grain yields under interaction also significantly influenced was complete even with the last extremely late transplanting. In other grain yield. Reduction in yield of C62-68 transplanting date. This probably varieties, incomplete panicle exsertion and Janaki due to delay in transplanting resulted in higher percentage of fertile occurred with delay in transplanting. was less than that with other varieties. spikelets in C62-68 and Janaki, and

Effect of a new abscisic acid analog on chilled rice leaves

A. A. Flores and K. Dörffling, Institut für Allgemeine Botanik und Botanischer Garten, Universitat Hamburg, Federal Republic of Germany; and B. S. Vergara, Plant Physiology Department, IRRI

One factor that limits rice growth and yield in many rice-growing countries is chilling injury. One measure to minimize this problem is chemical treatment. New abscisic acid analogs developed by BASF, Ludwigshafen, FRG, and coded LAB 173711 and LAB 144143 have been reported to increase chilling tolerance in cucumber, tomato, and wheat. We investigated the effects of the analog in chilled rice leaves. 2. Differences in leaf fresh weight of LAB 173711- treated plants chilled at 5 °C and transferred to Pregerminated seeds of IR42 and 1. Percent leaf area injury in LAB 173711-treated 29 °C for recovery. Data are means ± SE of 10 Fujisaka 5 were seeded directly in 1-liter rice plants chilled at 5 °C for 24 h and transferred measurements. pot containing Maahas soil and kept at to 29 °C for recovery. Data are means ± SE of 10 measurements. 29/21 °C, 12 h photoperiod, and 80% Injured leaf area was markedly lower relative humidity. Uniform seedlings in LAB 173711-treated plants (Fig. 1), Damaged leaf area was observed were selected and sprayed with LAB and leaf fresh weight in control was visually (wilted and brown color) and 173711 at 10 -3 mol/liter, and 10 -4 much lower than in LAB 173711-treated estimated using the formula mol/liter. After 24 h, plants were plants (Fig. 2). This protective effect of length of transferred to 5 °C for 1, 2, 3, 5, and Injured injured portion the applied abscisic acid analog may d. After chilling exposure, they were leaf area = = 100 be due in part to its water returned to 29 °C for recovery. length of (%) whole leaf blade conserving-activity.

IRRN 14:2 (April 1989) 25 Yield ability of tillers from a standing crop. We examined the block design with 4 replications. All separated from standing number of tillers/ hill needed for an plots were fertilized with 80-60-40 kg transplanted aman rice and economic yield and using old seedlings NPK/ ha, using urea, triple replanted for late planting. In fields that had been superphosphate, and muriate of potash. planted with 45-d-old BR11 seedlings, Tiller counts were done at 2-wk P. K. Biswas, S. K. Roy, and A. Quasem, we pulled the hill 35 d after intervals from 10 randomly selected Regional Agricultural Research Station, transplanting and separated the tillers hills/plot. Grain and straw yield was Hathazari, Chittagong, Bangladesh with roots. The uprooted tillers were measured at 15% moisture. replanted 17 Sep 1987 at 1, 3, 5, and 7 It is possible to multiply seedlings by To help farmers in postflood tillers/ hill. Control was 65-d-old detaching tillers from mother hills and agricultural rehabilitation when new seedlings. replanting at 3 tillers/ hill (see table). seedlings are not available, we conducted Soil was silty loam with pH 6.0-6.5. Planting 65-d-old seedlings could cause an experiment using rice tillers separated Plots were 5 × 3 m in a randomized heavy yield loss.

Plant development, yield components, yield, and harvest index (HI) of replanted tillers of transplanted Mukta rice in Bangladesh. a

Days to Plant Panicles Grains (no./panicle) 1000- Yield (t/ha) Treatment height (no./m 2 ) grain HI Flowering Maturity (cm) Filled Unfilled wt (g) Grain Straw

65-d-old seedlings 74 104 88.0 266 93 21 21.62 3.8 7.1 0.35 Retransplanted 1 tiller/hill 68 99 100.5 218 149 21 20.78 4.4 5.5 0.44 Retransplanted 3 tillers/hill 62 96 100.3 228 149 22 21.00 5.3 5.3 0.48 Retransplanted 5 tillers/hill 59 91 105.0 230 147 23 21.20 5.3 5.0 0.51 Retransplanted 7 tillers/hill 56 87 106.8 228 149 24 21.35 5.2 5.2 0.50 LSD (0.05) 1 2 4.2 10.2 10 ns ns 0.938 1.2 – CV (%) 1.5 1.3 2.6 2.7 4.7 9.6 3.2 12.2 13.3 –

a Mean of 4 replications. ns = not significant.

Effect of Triacontanol on rice Seeds were soaked 1 h just before Table 2. Grain yield of IR54R treated with Triacontanol. seedling weight and grain seeding in pots containing evenly mixed yield soil. Biomass weight was measured 22 d Triacontanol Grain yield after seeding. Seedlings treated at 0.01 (ppm) (t/ha) M. Mahadevappa, R. A. K. Murthy, and B. and 0.10 ppm were superior to those 0.01 10.2 B. Biradar, University of Agricultural with no Triacontanol (Table 1). 0.10 9.8 Sciences, Bangalore 560065, India In a field experiment, IR54R 1.00 9.7 0 (control) 8.9 seedlings were sprayed with the same concentrations of Triacontanol, at 3 d CV (%) 2.7 Triacontanol has been found to LSD 0.4 stimulate growth of several crop plants. before transplanting (15 Mar 1988), at We treated seeds of rice cultivars Jaya, maximum tillering (15 Apr), and at IR20, and Mukthi with Triacontanol grain ripening (3 Jun). Grain yield (source: Trianol-CF) at 3 increased slightly with all treatments change, but 1,000-grain weight was concentrations: 0.01, 0.1, and 1.00 ppm. (Table 2). Tillering capacity did not higher with 0.01 ppm.

Table 1. Dry weight 22 d after sowing of 3 rice varieties grown in pots after 1-h seed treatment withTriacontanol. Soil fertility and fertilizer management Biomass (mg dry wt/plant) Triacontanol (ppm) IR20 Jaya Mukthi Large granule urea efficiency With increasing fertilizer prices, it has become important to increase the 0.01 248 271 410 in rice 0.10 309 292 399 efficiency of applied fertilizer without 1.00 216 249 309 B. Rabindra, B. S. Naidu, T. G. Devi, and S. additional cost. One technique is to use 0 (control) 231 226 318 N. S. Gowda, University of Agricultural modified large size or large granule urea CV (%) 11.3 9.1 11.5 Sciences, Regional Research Station, (LSU/LGU). We studied the LSD 19 14 17 Mandya 571405, Karnataka, India performance of LSU/LGU (6-8 mm) in

26 IRRN 14:2 (April 1989) transplanted irrigated rice during 1987 Rice yield as affected by LSU/LGU. wet season (kharif). Total N uptake (kg/ha) Soil was red sandy loam (Alfisols), Grain yield (t/ha) in grain + straw Cumulative loss of a b with pH 6.7, 0.031% available N, 10.9 Treatment Fertilizer N Rasi Mandya Vijaya Rasi Mandya Vijaya (kg/ha) kg available P/ha, 171 kg K/ha, and cation exchange capacity of 12.6 Control, no N 2.0 3.7 43 56 – meq/100 g. Rice varieties were Rasi (120 LSU/LGU, all basal 4.8 5.3 94 126 24 PU in 3 splits (recommended 4.5 5.4 95 112 28 d) and Mandya Vijaya (145 d). practice of 50-25-25 at LGU was applied by broadcasting on planting, tillering, PI) drained soil. Prilled urea (PU) was LSU/LGU in 2 splits 5.1 5.8 136 129 20 (66-34 at planting and applied according to recommended tillering) practice in the area (50% broadcast and LSU/LGU in 3 splits 4.9 5.5 105 117 19 incorporated 3-4 h before planting, 25% (50-25-25 at planting, tillering, PI) broadcast without incorporation at tillering, and 25% broadcast at panicle LSD (0.05) 0.3 0.3 CV (%) 7.5 7.5 initiation). a b Ammonia volatilization loss was N rate is 100 kg N/ha. All treatments received 22 kg P and 41 kg K/ha. Through volatilization and leaching. measured in the field by direct trapping procedure and leaching loss was measured by periodically inserting percolation loss of water using drum N through volatilization and leaching. leaching tubes (with microporous culture technique. Three splits of LSU/LGU did not show ceramic base) below the rooting zone, 30 Application of LSU/ LGU in two any advantage over two splits. cm deep to collect leachate for splits increased yield significantly in LSU/ LGU applied all basal did not determining ammoniacal and nitrate N. both varieties (see table). This appeared show any significant reduction in yield Cumulative loss of ammoniacal N and to be due mainly to better uptake of N from PU applied in three splits. nitrate N was computed on the basis of by the plant and lower loss of fertilizer

Synergistic effect of organic 0.70 dS/m and CEC 7.8 mmol (I)/ 100 USG was superior in all respects (see manure and N fertilizer on g. Organic matter was 0.52%; N content table). S. rostrata + PU was statistically 2 irrigated rice 0.04%. Plot size was 16 m and plant equivalent to USG. Growth and yield of spacing 20 × 20 cm in a randomized rice were low with S. aculeata + PU, T. Hussain and G. Jilani, Soil Science complete block design with 4 and BM + PU compared to PU alone, Department, University of Agriculture, replications. All plots received 40 kg but N recovery from PU alone was the Faisalabad, Pakistan PK/ha. lowest of all sources. Urea supergranules (USG) and prilled We evaluated the efficiency of N source urea (PU) were compared with S. and method of application in irrigated aculeata and S. rostrata as green Effect of zincated rice KS-282 in a field experiment. manure and barnyard manure (BM) in diammonium phosphate (Zn- Soil was Typic Camborthids, sandy combination with PU. N rate was 87 DAP) on rainfed lowland rice clay loam in texture having pH 7.9, ECe kg/ ha for each source. R. Ilangovan and S. Palaniappan, Effect of organic manure and N fertilizer on growth and yield of irrigated rice. a Agronomy Department, Tamil Nadu Agricultural University (TNAU), Plant Grain Straw Agronomic N Coimbatore 641003, Tamil Nadu, India Treatment b height TilIers/m 2 (t/ha) efficiency recovery (cm) (t/ha) (kg rice/kg N) (%) We studied the effect of different grades Control(no N) 80 c 239 d 3.7 c 4.4 e – – USG 95 a 340 a 5.7 a 7.8 a 23.1 54 of Zn-DAP on grain yield of IR50 in PU 87 b 266 cd 5.3 b 7.0 c 18.4 46 wet season (kharif) 1985 and summer S. aculeata + PU 86 b 298 bc 5.2 b 6.5 d 17.2 48 1986. Soils were clay loam with pH 7.5 S. rostrata + PU 89 b 307 ab 5.6 a 7.3 b 21.5 52 Barnyard manure 88 b 261 d 5.1 b 7.1 bc 16.7 48 and 7.9, low DTPA-Zn (0.7 and 1.1 + PU ppm) and organic C (0.21 and 0.34%), SE 2 11 0.06 0.08 low available N (234.5 and 210.6 kg/ha), a In a column, any 2 means followed by the same letters are not significantly different at 5% level by and high available P (38.5 and 40 LSD test. b N source applied at 40 kg N/ha. kg/ ha) and K (325.6 and 316.9 kg/ ha).

IRRN 14:2 (April 1989) 27 The experiment was laid out in a Effect of Zn-DAP on grain yield of rainfed lowland rice. split-plot design with three replications. 1985 wet season yield (t/ha) 1986 summer yield (t/ha) Zn Subplot treatments were grades of Zn- Treatment added DAP (1-6%) applied before With GM No GM With GM No GM (kg/ha) transplanting; ZnSO 4 soil application No Zn-SSP 5.2 5.1 5.3 5.1 – (25 kg/ ha); ZnSO 4 foliar application 1% Zn-DAP 5.9 5.7 5.7 5.6 1.1 (0.5% sprayed 30 and 45 d after 2% Zn-D AP 6.0 5.8 6.4 5.5 2.2 transplanting); seedling roots dipped in 3% Zn-DAP 6.1 5.9 6.7 6.0 3.4 4% Zn-DAP 6.2 5.9 6.6 5.7 4.6 2% ZnO suspension; and no Zn 5% Zn-DAP 6.2 5.9 6.8 6.2 5.8 (control). Main plots were with and 6% Zn-DAP 6.4 6.0 6.7 6.5 7.1 without green manure at 12.5 t/ha (sunn ZnSO 4 - basal 6.1 5.7 6.5 5.7 5.8 ZnSO 4 - foliar 5.9 5.7 6.1 5.9 – hemp Crotalaria juncea L. in wet season ZnO root dip 6.2 5.4 6.2 5.6 – and pongam leaves Pongamia glabra No Z n-D AP – – 5.6 5.1 – Vent. in summer). All plots received LSD (0.05) 100-21.9-41.5 kg NPK/ha. Green manure (GM) ns ns Zn application significantly increased Zn treatments 0.5 0.6 GM × Zn ns ns grain yield (see table); 6% Zn-DAP was Zn × GM ns ns both efficient and economical.

Efficiency of prilled urea (PU) Effect of N source and level on growth, yield, and N uptake of rice. and urea supergranules (USG) Plant Panicles Yield (t/ha) N uptake (kg/ha) Apparent recovery in rapidly percolating soil Treatment ht (no./m 2) (m) Grain Straw Grain Straw (%)

R. S. Rekhi and M. S. Bajwa, Punjab Control 84 232 3.7 4.5 36 11 – Agricultural University (PAU), Ludhiana, PU 37.5 89 297 5.0 6.0 49 18 55 India; and J. L. Starr, USDA-ARS, PU 75.0 96 308 5.7 7.3 57 25 48 PU 112.5 101 391 7.0 7.4 77 24 48 Beltsville, Maryland 20705, USA USG 37.5 82 255 3.7 4.1 37 12 4 USG 75.0 94 285 4.4 5.5 43 14 14 We studied the fate and efficiency of PU USG 112.5 91 267 4.8 4.7 45 13 10 and USG in rice grown on a rapidly LSD (0.05) 7 33 0.7 2.1 9 7 – percolating loamy sand at PAU farm. Soil was a Typic Ustochrept, CEC 4.5 meq/ 100 g, pH 8.2, 0.3% organic C, 0.06% total N, with an N mineralization rate of 16 mg N/ kg soil after 7 d anaerobic incubation at 40 °C. N was applied at 0, 37.5, 75.0, and 112.5 kg N/ha in plots measuring 4.8 × 4.8 m. In the plots with 75.0 kg N/ha, 15 N-labeled PU and USG with 5 atom percent excess 15 N were applied in rectangular metal frame microplots (1.2 × 0.8 × 0.3 m) within the main plots. PU was applied in 3 equal splits at transplanting, active tillering, and panicle initiation; USG was placed 8-10 Balance of 15 N-labeled cm deep in the center of 4 rice hills in fertilizer in rice. alternate rows. The experiment was laid out in a randomized block design with four replications. for total N content and N uptake. Soil Plant height, number of panicles, Rice variety PR106 was transplanted was destructively sampled at harvest yield, and N uptake showed that PU the last week of Jun, 35 d after seeding, with a rectangular soil sampler (30 × was significantly superior to USG (see and harvested the last week of Oct. 13.3 × 50 cm) for total Kjeldahl N and table). Apparent recovery of N was Grain and straw samples were analyzed 15 N analyses. higher with PU (48-55%) than with

28 IRRN 14:2 (April 1989) USG (4-14%). Labeled N utilization was straw N were derived from PU; 13% soil was 68% for PU, 21% for USG; 42% with PU, 30% in grain and 12% in grain N and 12% straw N were derived 32% PU N and 79% USG N was not straw (see figure). Only 8% of the from USG. accounted for in the N balance. The labeled N applied as USG was utilized Soil analysis at harvest showed that large deficit of N from USG was (6% in grain and 2% in straw). 26% of the labeled N from PU and 13% attributed to its rapid movement and Isotopic composition of rice grain and from USG were retained in the soil. leaching from concentrated zones at straw showed that 40% grain N and 35% Total recovery of labeled N in crop and placement sites.

Sesbania rostrata — a lower- Soil of the experimental site was red involved in supplying N through S. cost source of N for rice sandy loam (Alfisols), pH 6.3, medium rostrata was $12, compared to urea cost N (1.1% organic matter), 10.6 kg of $15. Use of S. rostrata increased net B. Rabindra, B. S. Naidu, T. G. Devi, and S. available Olsen’s P/ha, and 151 kg profit by $125/ha. S. rostrata (treatment N. S. Gowda, University of Agricultural available K/ha. N content was 4.1% in 4) could substitute for fertilizer N up to Sciences, Regional Research Station, V. C. S. rostrata and 3.2% in sunn hemp. 70 kg N/ha (treatment 6) without Farm, Mandya 571405, Karnataka, India At the same level of applied N, yield significant yield reduction. increased significantly (15%) over S. rostrata was significantly superior We studied the effect of stem-root farmers’ practice (treatment 1), with 30% to sunn hemp (treatment 5). Uptake of nodulating S. rostrata and sunn hemp N supplied through S. rostrata N was better with S. rostrata. Crotalaria jancea on transplanted (treatment 2) (see table). The cost irrigated rice Mandya Vijaya (145-150 d duration) during summer 1988.

Nitrogen-use efficiency with supergranules (USG) hand placed (H) a Effect of S. rostrata on rice yield. Karnataka, hand- and machine-applied N and AP were compared in a field India. fertilizers in wetland rice soils experiment during the 1986 dry season. Grain Total uptake BR3 was the test variety. yield of N in Soil was clay loam (Paleudults) with Treatment (t/ha) grain + straw N. I. Bhuiyan, M. A. Saleque, and S. K. (kg/ha) Zaman, Soil Chemistry Division, Bangladesh pH 6.5, 1.05% organic matter, CEC 24 Rice Research Institute (BRRI), Joydebpur, meq/100 g, 0.07% total N, and 1. 100 kg N/ha as urea 4.5 92 Gazipur, Bangladesh incubated 57 ppm NH + -N (incubated in 3 splits: 1/2 at 4 planting + 1/4 at at 30 °C for 1 wk). Two rates of N (58 tillering + 1/4 panicle Prilled urea (PU) farmer’s split (F), and 87 kg/ ha) and 1 control treatment initiation (farmers’ researcher's split (R), modified split (M), were used. P at 17.6 kg/ha, K at 33.2 practice) applicator placed (AP); and urea kg/ha, and S at 20 kg/ha were applied 2. 30 kg N/ha through 5.2 110 S. rostrata + 70 kg N/ha as urea in 2 splits: Effect of N fertilizer application method on yield of BR3 and agronomic efficiency of N, 1986 dry 1/2 at planting + 1/2 a at tillering season, BRRI, Joydebpur, Bangladesh. 3. 30 kg N/ha through 4.8 97 Plant Tillers Panicles Grain Agronomic sunn hemp C. juncea Treatment a height (no./m 2) (no./m 2 ) yield efficiency + 70 kg N/ha in 2 (cm) (t/ha) (kg grain/kg N) splits: 1/2 at planting + 1/2 at tillering Control 86 210 e 195 c 3.6 c - 4. S. rostrata to supply 3.4 76 58 PU (F) 93 243 d 231 b 4.9 ab 23 70 kg N/ha 58 PU (R) 91 286 bc 269 ab 4.6 b 18 58 PU (M) 89 267 bcd 256 ab 4.8 ab 20 5. Sunn hemp to supply 3.0 68 58 PU (AP) 94 309 a 295 a 5.3 a 30 70 kg N/ha 58 USG (H) 93 299 a 283 a 5.3 ab 29 6. 70 kg N/ha as urea 3.2 71 58 USG (AP) 94 285 abc 269 ab 5.4 a 31 in 2 splits: 1/2 at 87 PU (F) 91 272 abcd 263 ab 5.2 ab 19 planting + l/2 at 87 PU (R) 92 260 cd 242 b 5.0 ab 16 tillering 87 PU (M) 94 281 abcd 268 ab 4.9 ab 15 87 USG (H) 94 293 ab 271 ab 5.4 a 20 7. Control (no N) 2.4 47 CV (%) 4 2 2 8 LSD (0.05) 0.3 6 CV (%) 10.8 5.3 a Within a column, means followed by a common letter do not vary significantly at the 5% level of DMRT. b F = 1/3 basal + 1/3 30 d after transplanting (DT) + 1/3 at panicle initiation (PI), R = 2/3 a All treatments received 22 kg P and 41 kg basal + 1/3 at PI, M = 1/3 15 DT + 30 DT + 1/3 at PI, AP = applicator-placed at 10-12 cm depth, K/ha. H = hand-placed at about 10-12 cm depth.

IRRN 14:2 (April 1989) 29 during final land preparation. minimal. application methods with USG. Regardless of method, 58 kg N/ha Machine application increased yield Placement of N fertilizer in the reduced significantly improved panicles/m 2 and 0.4-0.7 t/ha over broadcast split with zone as PU by machine or as USG by yield (see table). USG gave a grain yield PU at 58 kg N/ha. There was no hand or machine gave higher agronomic advantage of 0.5 t/ha over PU. difference between hand and machine efficiency. Differences among F, R, and M were

a Effect of Zn and Cu on Effect of Zn and Cu on nutrient concentration in rice. growth and nutrition of rice Nutrient concentration Nutrient M. R. Gangwar, M. S. Gangwar, and P. C . levels (ppm) µg/g tissue mg/g tissue Srivastava, Soil Science Department, G. B. Zn Cu Fe Mn P Pant University of Agriculture and Technology, Pantnagar 263145, India S R S R S R S R S R

Zn 0 50.8 59.0 27.0 31.6 0.40 4.66 0.20 0.57 1.12 1.30 We studied the effect of soil application Zn 5 56.3 60.8 25.4 30.7 0.40 4.40 0.20 0.66 1.02 1.15 of Zn and Cu on dry matter yield and Zn 10 69.3 67.6 24.8 28.1 0.40 4.06 0.20 0.75 1.00 1.26 tissue concentration of Zn, Cu, Fe, Mn, Zn 20 73.7 72.8 20.5 24.1 0.34 3.44 0.19 0.64 0.90 1.26 and P in rice grown under submerged Cu 0 73.4 73.6 21.5 25.1 0.40 4.49 0.20 0.55 1.11 1.16 Cu 1 62.6 67.6 21.9 29.7 0.38 3.55 0.19 0.67 1.00 1.00 soil in a pot experiment in the Cu 2 62.6 60.5 26.6 28.6 0.40 4.47 0.20 0.62 0.99 1.28 greenhouse. Cu 5 51.6 58.6 27.8 31.1 0.36 4.02 0.20 0.78 0.95 1.53 Soil was silty clay loam containing 20 LSD (0.05) 5.4 1.8 1.9 1.9 0.02 0.25 0.01 0.06 0.02 0.04 ppm Olsen's P and DTPA extractable a S = shoots, R = roots. 0.64 ppm Zn, 0.46 ppm Cu, 11.6 ppm Fe, and 22.5 ppm Mn. Each pot contained 4.56 kg soil. Basal nutrient application was 100 Five 20-d-old IR8 seedlings were application (see table). Cu in roots and ppm N as urea, 26 ppm P as transplanted in each of 32 pots, thinned shoots increased with Cu application but diammonium phosphate, and 25 ppm K to 3 plants/pot, and grown for 72 d. decreased with Zn application of 10 as potassium chloride. Soil treatments Additional 20 ppm N as urea was ppm or more. Fe in roots decreased at were 0, 5, 10 and 20 ppm Zn and 0, 1, 2, applied 40 d after transplanting. all Zn levels and at 1 and 5 ppm Cu. Fe and 5 ppm Cu as sulfates in a factorial Highest increase in dry matter yield in shoots decreased with 20 ppm Zn and combination with 2 replications. was from 10 ppm Zn + 2 ppm Cu (see 1 and 5 ppm Cu. Mn in roots increased figure). Application of 5 ppm Zn + 1 or with Zn and Cu; in shoots, it decreased 2 ppm Cu also increased yield. The with 20 ppm Zn and 1 ppm Cu. P in highest rates of Zn (20 ppm) + Cu (5 shoots decreased with Zn and Cu. In ppm) failed to increase dry matter yield. roots, it decreased at all Zn levels and at Zn in roots and shoots increased with 1 ppm Cu. Application of 2 and 5 ppm Zn application but decreased with Cu Cu increased P in roots.

Biofertilizer production of farmers. Vegetative propagation appears stem-cut planted and seeded attractive because nodulation sites Sesbania rostrata constitute primordia of adventive roots able to grow under waterlogged M. Becker, R. P. Pareek, and J. K. Ladha, conditions. IRRI; and J. C. G. Ottow, University of We compared biofertilizer production Giessen, Federal Republic of Germany by vegetative propagation through stem cuttings (30 and 20 cm) and broadcast Although S. rostrata is a promising seeding, at 3 plant densities. green manure species for lowland rice The experiment May-Jun 1988 at farming systems, production of seed and IRRI farm was laid out in a randomized Effect of Zn and Cu on dry matter yield of rice. scarification may be a problem for split-plot design with four replications.

30 IRRN 14:2 (April 1989) Influence of planting method and planting density on dry matter yield and some yield parameters of cuttings. To accumulate the same S. rostrata biofertilizer. a amount of N/ ha, 30-cm-long cuttings Plant Branches/ Dead plants/ Dry weight require about 2 wk less growth than Treatment Density height plant m 2 (t/ha) seeded plants. Only about 2-3 kg of (cm) (no.) (no.) b seeds may be needed to produce enough 5-wk-old plants plants for cuttings to plant 1 ha. Seeding 20 kg/ha 39 e l c na 0.15 d Broadcast seeding rate is 25-40 kg 40 kg/ha 41 e 1 c na 0.41 bc seeds/ ha. 80 kg/ha 37 e 1 c na 0.55 bc Although additional labor is needed 20-cm cutting 25/m 2 52 de 1.2 bc 3.2 bc 0.41 bc 50/m 2 62 d 1.3 bc 7.1 ab 0.64 c to make and plant cuttings, it may be 100/m 2 76 c 1.3 bc 8.2 a 1.09 c economical compared to seeding 30-cm cutting 25 /m2 82 bc 1.9 a 1.2 c 0.89 c because it requires less seed, water 50/m 2 92 ab 1.5 b 2.6 c 2.31 b management, and land preparation. 2 100/m 101 a 1.3 b 3.4 b 3.51 a Plants for cuttings might be grown on 7-wk-old plants dikes and borders. Seeding 20 kg/ha 85 e 1d na 0.72 e 40 kg/ha 87 de 1d na 1.54 d 80 kg/ha 104 d 1d na 2.60 c 20-cm cutting 25/m 2 120 c 1.1 cd 2.9 bc 1.20 d 50/m 2 125 c 1.2 c 6.2 ab 1.64 d 2 146 b 1.4 b 8.3 a 3.48 bc 100/m Effect of sesbania green 30-cm cutting 25/m 2 148 b 1.8 a 1.5 c 2.19 c 50/m 2 165 a 1.3 b 2.5 c 4.31 b manure and wheat straw on 100/m 2 178 a 1.1 c 4.6 b 6.23 a ammonia volatilization loss in a Duncan's multiple range test at 0.05. b na = data not available. wetland soil

C. S. Khind, A. Garg, and M. S. Bajwa, Soils Department, Punjab Agricultural University, Ludhiana 141004, India

Attempts are being made to identify short-duration leguminous green manure (LGM) crops that can be inserted into intensified cropping systems. High-yielding cultivars also leave large amounts of residue, which is either burned or incorporated into soil. Crop residues and LGM may influence transformations of applied N. We studied the effect of sesbania green manure and wheat straw on ammonia volatilization from urea, in a laboratory study using the forced-draft chamber technique. Ten pots (10 liters) containing 7 kg air-dry soil (pH 10.0, 0.35% organic C, 0.07% total N, and CEC 9.5 meq/ 100 g) N accumulation in S. rostrata. were flooded, puddled, and preincubated with 1 cm standing water for 1 wk. Soil was then fertilized with 26 Plot size was 12 m 2 . Stem cuttings of 8- Increasing planting rate resulted in mg P/ kg as single superphosphate and wk-old plants were pushed about 5 cm increased biomass and N production. 50 mg K/ kg as muriate of potash. deep into newly plowed and water- Cuttings showed faster growth and more Treatments were N as urea alone or in saturated soil (pH [KCl] 6.3, 1.1 1% dry matter and N production than seeds combination with Sesbania aculeata organic C, 0.121% total N, 18.5 ppm P (see table and figure). Highest biomass green manure or wheat straw. N was Olsen), 1.44 meq exchangeable K/ 100 and N yield were with 30-cm-long applied at 100 and 200 kg N/ha. Finely mg CEC 33.9 meq/ 100 g). Plants were cuttings. They exhibited lower mortality chopped 2-mo-old fresh sesbania (2.5% harvested at 5 and 7 wk. and more branching than 20-cm-long N dry weight) was incorporated at

IRRN 14:2 (April 1989) 31 NH 3 that evolved from incubated samples was collected at intervals using a manifold, and estimated by absorbing in 2% boric acid-mixed indicator solution. Floodwater samples also were + taken to analyze NH 4 -N. Rate of N loss by ammonia volatilization in flooded soil was markedly affected by type of amendment (Fig. 1). Incorporating wheat straw resulted in the greatest N loss due to volatilization. At 16 d, cumulative ammonia volatilization was 11% for wheat straw + N, 4.5% for N alone, and 1% for green manure + N. No ammonia volatilization occurred in the soil amended with green manure alone. In the soil amended with wheat straw, NH 3 volatilization could already be detected at 2 d, the first sampling. Ammoniacal N concentration in the 1. Effect of sesbania green floodwater was greatest in soil amended manure and wheat straw on ammonia volatilization in with wheat straw + N (Fig. 2). flooded Ludhiana soil, These results suggest that higher N India. losses through ammonia volatilization in straw-amended soil were probably due maintain 5 cm standing water. to the high rate of urea application. Floodwater temperatures ranged from Incorporation of wheat straw may have 28.5 to 33 °C. Two pots/treatment were changed the urease kinetic parameters, fitted with chambers continuously which seem dependent on the organic flushed with NH 3 -free compressed air. material incorporated.

Soil test fertilizer extractable). Nutrient limits used for recommendations increase recommendations were as follows: economic yields of rice Nutrient limits (kg/ha) (elemental form) J. C. Sharma, S. P. S. Karwasra, A. P. N P K Zn(ppm) Sharma, and B. S. Panwar, Haryana Low <250 <5 <125 <0.6 Agricultural University, Regional Research Medium 250-500 5-10 125-300 High >500 >10 >300 Station, Uchani, Karnal 132001, India Seedlings of PR106 (30-35 d) duration We compared bases for N application were transplanted. Each treatment recommendations—state, soil test, and received the following nutrients: farmers’ practice in a farmer’s field Nutrients (kg/ha) (elemental form) during 1986. N P K ZnSO . 7H O Soil of the experimental field was 4 2 State 2. Effect of sesbania green manure and wheat sandy loam (Typic Ustochrept) with pH + recommendation 125 26.20 50 25 straw on floodwater NH 4 - N concentration. (1:2) 8.4, 0.36% organic C, EC (1:2) 0.10 Ludhiana, India. Soil test dS/m, CEC 10.9 meq/100 g soil, 190 kg recommendation 125 17.47 - available N/ha (alkaline permanganate Farmers’ practice 125 - - 30 t/ ha. Wheat straw (<2 mm) was method), 8.0 kg available P/ha incorporated at 7.5 t/ha. (NaHCO 3 extract), and 305 kg available One-third N and all the P, K, Zn were Soil was reflooded and evaporation K (ammonium acetate extract)/ha. applied at transplanting. The remaining losses were replenished daily, to Available Zn was 0.5 ppm (DTPA N was applied in 2 equal splits at 3 and

32 IRRN 14:2 (April 1989) Effect of basis for fertilizer application rate on yield, yield attributes, and profit in rice. a 6 wk after transplanting. The experiment was laid out in a State Soil test Farmers' recommendation recommendation practice randomized block design with three schedule LSD at 5% replications. Soil test fertilizer recommendation Rough rice yield (t/ha) 6.7 7.2 5.0 0.2 Increase in yield (t/ha) 1.7 2.2 – resulted in significantly higher economic over farmers' practice yields (see table). State fertilizer schedule Expenditure on fertilizers 96.25 67.90 47.50 ($/ha) resulted in significantly higher yields Increase in fertilizer 48.75 20.40 – over farmers’ practice. expenditure over farmers’ practice ($/ha) Yield price ($/ha) 939.40 1008.00 701.40 Net profit ($/ha) 550.20 647.15 360.95 Increase in profit over 189.25 286.20 – The International Hybrid Rice farmers' practice ($/ha) Newsletter is published for researchers Increase in profit over – 96.95 – in hybrid rice development and state fertilizer schedule technology. Its content focuses on ($/ha) Yield attributes discussions of current issues; it does not Plant ht (cm) 111.0 107.7 105.9 3.8 publish research reports. For more 1000-grain wt (g) 20.7 21.8 19.2 ns information, write Dr. S. S. Virmani. Number of tillers 8.1 8.4 6.9 0.9 Hybrid Rice Newsletter editor, IRRI, P.O. Box 933, Manila, Philippines. a Price ($/kg); N, 0.38; P, 0.51; K, 0.19; Zn, 0.27; paddy, 0.14. Expenditure on all agricultural opera- tions ($/ha) = 292.95.

Source and time of phosphate Effect of source and time of phosphate application on yield and yield response, Bhubaneswar, India, 1987. application in irrigated rice Rate (kg P/ha) and L Pradhan and L Dixit, Agronomy time of application Grain Panicles Panicle Yield a yield Source (no./m 2 ) wt (g) response Department, Orissa University of Basal Tillering (t/ha) (kg grain/kg p) Agriculture and Technology, Bhubaneswar (21 d) 751003, Orissa, India Control 0 0 2.7 170 1.33 – DAP 13 0 3.0 213 1.61 22.3 We studied the effect of basal and split DAP 26 0 3.6 270 1.86 37.3 application of phosphate through single DAP 6.5 6.5 3.2 228 1.67 41.5 DAP 13 13 3.9 282 1.85 48.4 superphosphate (6.9% P), diammonium SSP 13 0 3.2 222 1.54 41.5 phosphate (18-20.0), and ammonium SSP 26 0 3.7 275 1.65 39.6 polyphosphate (12-25.2-0) on irrigated SSP 6.5 6.5 3.1 226 1.61 33.8 rice in 1987 wet season, in a randomized SSP 13 13 3.7 268 1.80 37.7 APP 13 0 3.6 25 1 2.01 53.8 block design with 4 replications. APP 26 0 4.3 303 2.02 63.4 Soil was sandy loam with pH 6.2, APP 6.5 6.5 3.8 277 2.03 84.6 0.47% organic C, CEC 5.2 meq/ 100 g APP 13 13 4.8 308 2.19 82.3 soil, 9 kg Olsen's P/ ha, 0.15 meq LSD (0.05) 0.4 24 0.15 – exchangeable K/ 100 g soil, and 1.5 ppm a DAP = diammonium phosphate, SSP = single superphosphate, APP = ammonium polyphosphate. available Zn (DTPA extractable). Daya (125 d) was transplanted 27 Jul with 80- 33.3 kg NK/ha. Diammonium polyphosphate at 26 kg P/ha. Grain Panicle number/m2 and panicle phosphate and ammonium yields in general were low because of weight were highest on split application polyphosphate at 80 kg N/ha were continuous rain, coupled with strong of 26 kg P/ha as ammonium applied in 50-25-25 splits. Phosphate wind at flowering. polyphosphate. was mixed with double the weight of soil, wet to less than field capacity, and broadcast over 5 cm water in the field. Significantly higher yields were The International Azolla Newsletter is published for researchers in the development obtained with 26 kg P/ ha, irrespective and application of azolla in rice production. Its content focuses on discussions of current issues; it does not publish research reports. For more information, write Dr. I. Watanabe, of source and time of application (see Azolla Newsletter editor, IRRI, P. O. Box 933, Manila, Philippines. table). Highest yield (4.82 t/ ha) was with split application of ammonium

IRRN 14:2 (April 1989) 33 Disease management Table 1. Rice plant response to RTV inoculation.

Leaf discoloration + stunting Stunting No symptoms Variety Suitability of iodine test for No. % No. % No. % detecting rice tungro virus TN1 15 75 3 15 2 10 (RTV) infection TKM9 13 65 4 20 3 15 ADT31 11 55 6 30 3 15 Total 39 – 13 – 8 – P. Narayanasamy, Plant Pathology Department, Tamil Nadu Agricultural University, Coimbatore 641003, India Table 2. Reaction of tungro-inoculated rice plants in the iodine test.

Sets of 20 20-d-old plants each of TN1, Leaf discoloration + stunting Stunting No symptoms TKM9, and ADT31 rice varieties were Variety Plants (no.) % Plants Plants (no.) inoculated by confining viruliferous tested a green leafhopper Nephotettix virescens Tested With positive (no.) Tested With positive Distant at 2 insects/plant. Plants reaction reaction showing typical leaf discoloration and TN1 15 10 66.1 3 2 0 stunting, stunting alone, and no visible TKM9 13 11 84.6 3 4 0 symptom were grouped separately, by ADT31 11 9 81.8 6 3 1 variety (Table 1). Total 39 30 12 9 1 In iodine tests, most plants showing a None showed positive reaction. both leaf discoloration and stunting gave positive reactions (Table 2). No plants showing stunting alone reacted positively. should be done cautiously, since 23% of positively with the stain. In ADT3 1, one These results suggest that plants showing typical tungro symptoms of three plants showing no visible interpretation of iodine test results did not give positive reactions. symptoms of RTV infection reacted

Biological control of rice blast strains (2 fluorescent and 2 (BI) with antagonistic bacteria nonfluorescent) that caused maximum inhibition of P. oryzae were chosen for S. S. Gnanamanickam, R. C. Reyes, and T. testing. The average diameter of the W. Mew, Plant Pathology Department, inhibition zones was 38.5 mm for strain IRRI 7-14 (fluorescent), 30.4 mm for strain 4- 15 (fluorescent), 26.3 mm for strain 33, B1 caused by Pyricularia oryzae Cav. is and 21.1 mm for strain 4-03. Using found in most rice-growing areas of the standard procedures, mutant strains world. It is common in irrigated and were generated by incorporating rainfed bunded rice culture, but is more resistance to rifampicin (R) or serious in upland rice. Because of the rifampicin and nalidixic acid (RN) (100 instability of the Bl fungus and the ppm). The mutant strains retained their Inhibition of Pyricularia oryzae in PDA by ability to inhibit P. oryzae (see figure). fluorescent pseudomonad strain 7-14 and by its marked variability in its pathogenicity, mutant 7-14 RN. which results in different races of the The field experiment in a randomized organism, control and management are complete block design with four difficult. Use of fungicides is limited by replications was conducted at the IRRI with the bacterial suspension and cost and development of host resistance site for upland rice research for acid incubated overnight in polythene bags at has been only partially successful. soils in Mahipon, Cavinti, the 25 °C. Excess buffer-bacteria mixture In developing alternate strategies for Philippines. Seeds of UPLRi-5 rice were was drained and seeds were dried in disease management, we screened strains coated with bacteria as follows. sterile air for 12 h before sowing in of bacteria isolated from IRRI ricefields Bacterial cells from 24 h grown 4 × 5 m field plots. for their antagonism toward P. oryzae. cultures of test strains were scraped into At sowing, seeds had 10 9 colony- More than 100 bacterial strains were a 1% carboxymethylcellulose buffer. forming units (CFU)/g. Seeds coated initially screened in the laboratory. Four Seeds (1.3 kg per treatment) were mixed with fungarin (CGA 49104; 8 g/kg seed)

34 IRRN 14:2 (April 1989) and untreated seeds were sown as Effect of seed bacterization and sprays with antagonistic bacteria on B1 incidence in rice UPLRi-5. checks. The crop also received 3 Cavinti, Philippines, 1988 wet season. 8 additional sprays with bacteria (l0 Severity Grain CFU/ml) or fungarin when plants were Treatment yield c a b 20, 30, and 40 d old. Leaf Bl Neck Bl (g) Bacterial multiplication was Bacterial strain monitored from root and shoot samples 4-03R 3.32 2.96 100.4 removed at 10-d intervals on NBY-R or 33R 3.49 3.70 95.5 4-15R 2.57 2.95 9 2.5 NBY-RN agar. Fluorescent 7-14RN 3.29 2.75 102.6 pseudomonad strains 7-14RN and Fungarin 1.95 3.68 106.7 4-15R had low levels of 0.5 × l0 5 Check 6.27 3.77 96.3 CFU/g tissue up to 40 d, and were not LSD (0.05) 2.22 1.79 43.6 detected in subsequent samplings. a 2 b Nonfluorescent strains 33R and 4-03R Number of lesions/cm leaf area. Severity index = n (l) + n (2) + n (3) ...... n (9) × 100, where total n had high levels of 0.9 × l0 6 CFU/g n (l), n (2), etc. are number of tillers with disease score 1, 2, or 9. c From 100 panicles/plot. tissue at 30 d, and 1.0 × l0 5 CFU/g tissue at 60 d and 110 d. Leaf Bl and neck Bl were assessed (see pseudomonad bacteria strains, in spite more effective in reducing leaf and neck table). It appears that the fluorescent of lower population dynamics, were B1 severity.

Insect management Five newly emerged macropterous copper sulfate and 4.2 ml of 85% females, starved but water-satiated for 3- ethanol. 4 h, were introduced into the feeding Color intensity of the eluent was chamber, and the hole plugged with measured on a spectrophotometer at 475 Effect of plant age on cotton wool. The females were allowed nm. The quantity of amino acids in whitebacked planthopper to feed for 24 h. honeydew was expressed in glutamic (WBPH) feeding The filter paper discs were removed, acid standard. briefly immersed in a solution of 0.1% Regardless of plant age, two to four G. Liu and R. M. Wilkins, Agricultural and ninhydrin in acetone, and dried at room times less honeydew was excreted by Environmental Science Department, temperature. Purple or violet honeydew WBPH on resistant Rathu Heenati University of Newcastle upon Tyne, spots were cut off the disk and eluted in Newcastle upon Tyne NE1 7RU, UK; and plants than on susceptible TN1 (see R. C. Saxena, Entomology Department, a solution of 0.8 ml of 1.2% aqueous figure). The differences possibly are due IRRI to the presence of repellents, toxins, or a feeding inhibitor in Rathu Heenati. WBPH is a phloem feeder, with the WBPH feeding on both varieties amount of honeydew excreted regarded decreased with plant age, possibly as an index of feeding. We studied because of a decrease in the nutrient WBPH feeding and rate of honeydew value of the rice plants. excretion on potted plants of susceptible and resistant varieties of different ages. The secondary tillers of 4-, 6-, and 8- wk-old resistant Rathu Heenati and Virus diseases of some susceptible TNl plants were removed lepidopterous rice pests in the and each main tiller with soil placed in Philippines an 8- × 9-cm plastic pot. Each pot was covered with a medially perforated 8- D. J. Im, R. M. Aguda, and B. M. Shepard, cm-diameter plastic dish through which IRRI the tiller emerged. A medially perforated 7-cm-diameter filter paper disc was Dead and infected larvae of various placed over the dish around the base of Dry weight of honeydew excreted by Sogatella lepidopterous pests were collected from the tiller and covered by an inverted furcifera females on plants of different ages of ricefields at IRRI and in Laguna, perforated plastic cup for a feeding resistant Rathu Heenati and susceptible TN1. Batangas, Palawan, and South Columns with the same letter are not significantly chamber. The feeding chamber was different at the 5% level by DMRT. Bars indicate Cotabato Provinces in the Philippines. fastened to the dish with “Sellotape.” ± standard deviation. Live larvae were reared on host plants

IRRN 14:2 (April 1989) 35 Insect viruses found in the Philippines. IRRI. Shape of Virus Host plant Collection data Host Common name inclusion disease a found bodies Date Place

Mythimna separata (Walker) b Armyworm NPV Tetragonal Rice Aug 1985 IRRI Spodoptera litura (Fab.) Common cutworm NPV Tetragonal Rice, taro Jul 1985 IRRI Herpetogramma licarsisalis Grass webworm NPV Hexagonal Rice Sep 1984 South Cotabato (Walker) Mocis frugalis (Fab.) c Rice brown semilooper GV Ellipsoidal Rice Jul 1985 Palawan Cnaphalocrocis medinalis Rice leaffolder GV Ellipsoidal Rice Oct 1985 IRRI (Guenée) a NPV = nuclear polyhedrosis virus, GV = granulosis virus. b New species found in the Philippines. c New recorded virus disease of the host insect.

larvae slowly darkened, but the integument remained tough and leathery. Shape and size of polyhedra in different insect hosts varied (see figure). Polyhedra in Mythimna separata Walker and Spodoptera litura (Fab.) were tetragon mixed with triangular shapes. Polyhedra from Herpetogramma licarsisalis (Walker) were hexagonal. Capsules of GV of Mocis frugalis (Fab.) and Cnaphalocrocis medinalis (Guenée) were ellipsoidal. Some capsules in M. frugalis were irregular and sickle-shaped. The rod-shaped virion of M. frugalis granulosis were embedded singly in capsules, but polyhedra of S. litura were multi-embedded. Size of polyhedra were 2.12 ± 0.51 µm from S. litura; 1.87 ± 0.24 µm from M. separata, and 1.37 ± 0.17 µm from H. licarsisalis. Capsule size was 433 ± 15.4 nm long and 242.7 ± 17.4 nm wide in M. frugalis, and 412.9 ± 31.4 nm long and 234.1 ± 17.4 nm wide in C. medinalis. Light and electron micrographs showing the following: nuclear polyhedra isolated from M. separata (1a), S. litura (1b), and H. licarsisalis (1c); granular capsules of C. medinalis (1d) and M. frugalis (1e), with some abnormal forms (arrow); and virions of S. litura polyhedra after treatment with weak alkali for 30 min (1f).

Weed hosts of rice hispa or artificial diets to determine incidence feeding a few days after infection. Dicladispa armigera Olivier of virus diseases. Specimens were As the diseases progressed, a watery (Coleoptera: Hispidae) examined under the light and phase fluid exuding from the mouth of the contrast microscope. Virus particles larvae S. fitura changed from colorless Q. M. A. Razzaque and A. N. M. R. Karim, were examined with the electron to a pale tint to pink. Most larvae Entomology Division, Bangladesh Rice microscope. infected with NPV hung from their host Research Institute (BRRI), Gazipur, Three species of nuclear polyhedrosis plant by attaching the second abdominal Bangladesh viruses (NPV) and two species of legs to the plants. In late stages of the granulosis viruses (GV) were found (see disease, the cuticle ruptured, releasing a Rice hispa beetles sometimes infest table). The behavior of infected larvae milky white fluid. Mocis frugalis larvae weeds and wheat. We studied the was characteristic of most virus-infected infected with GV were yellow with suitability of some common weeds as insects: they become sluggish and cease shrunken abdominal segments. The hosts of rice hispa in 1985-86.

36 IRRN 14:2 (April 1989) Table 1. Rice hispa beetle feeding and development on some common weeds. BRRI, Gazipur, Bang- Table 2. Preference of rice hispa beetles for ladesh, 1985. rice, wheat, maize, and some common weeds. BRRI, Gazipur, Bangladesh, 1986. Feeding Eggs Grub Host damage a deposited development Beetles settling (%) Host on plants Cyperus rotundus 3 Few 0 (%) Digitaria ciliaris 9 Few 0 Digitaria setigera 9 Few 0 Rice (BR3) 24.2 a Echinochloa colona 9 Few 0 Echinochloa colona 19.2 ab Echinochloa crus-galli 9 Few 0 Eleusine indica 14.2 bc Eleusine indica 9 Few 0 Scirpus maritimus 9.0 cd Leersia hexandra 9 Few 0 Digitaria ciliaris 8.3 d Rice (BR3) 9 Many >50% Leersia hexandra 8.0 d Paspalum distichum 7.2 d a 0 to 9 scale: 0 = no damage, 9 = more than 50% leaves damaged. Monochoria vaginalis 2.7 e Maize (JC-2) 2.7 e Commelina benghalensis 2.4 e Cyperus rotundus 1.3 e Seven weed species and rice variety Cyperus rotundus was minimal (damage Wheat (Barkat) 0.7 e BR3 (30-d-old plants) were grown in 15- grade 3) and no grubs developed. All cm clay pots. Each pot was infested with other weeds and rice were heavily 4 greenhouse-reared, mated, hispa damaged. starved for 3 h and released at 100 females and enclosed in mylar film cages It appears that, while rice hispa may beetles/cage. Beetles that settled on for 7 d. Exposed plants were sprinkled use weeds as alternate food sources, it plants were counted 48 h after with water daily for grub development. cannot complete its life cycle on them. infestation. Feeding damage was graded on a 0 to 9 In a separate experiment, 30-d-old Rice was the most preferred site (24% scale. plants of rice (BR3), wheat (Barkat), beetles settled), followed by Echinochloa The beetles laid numerous eggs on maize (JC-2), and 9 species of weeds colona (19%) and Eleusine indica (14%) rice, but few on weeds (Table 1). Grubs were grown separately in 15-cm clay (Table 2). Wheat was least preferred. died at the 1st- or 2d-instar stage on pots enclosed in fine mesh wire net Hispa beetles probably disperse to other weeds, but more than 50% developed rectangular cages, with 4 replications. plants when the available rice canopy is into pupae on rice. Feeding damage on Greenhouse-reared hispa beetles were inadequate to support their numbers.

Effect of parasitization on The hatch was reared individually in d; G. triangulifer -parasitized larvae fed food consumption of rice tubes with cut leaves from 60-d-old rice 13.9 d; and unparasitized larvae fed 15.2 leaffolder (LF) Marasmia variety IR64. Leaves were changed every d. patnalis 24 h until LF larvae ceased feeding and The number of live larvae and the mummified. The area of leaf consumed percentage of damaged leaves are the G. S. Arida, B. M. Shepard, and L. P. was measured on graph paper. bases for deciding to spray LF with Almazan, IRRI In another experiment, 20 newly insecticide. Presence or absence of either hatched LF larvae were reared parasitoid might influence an integrated The amount of food the LF, an individually in tubes with cut leaves of control program. important defoliator of the rice plant, rice variety IR64. Leaves were changed consumes during feeding affects yields. daily. When the larvae reached the 4th But when LF is parasitized, the amount instar, 10 were placed individually in of leaf tissue consumed changes. tubes containing pairs of G. triangulifer. LF parasitoids are abundant in After parasitization, the larvae were ricefields. Copidomopsis nacoleiae, a returned to their original tube parasitoid of egg and larvae, and containing cut rice leaf until they Goniozus triangulifer, a parasitoid of stopped feeding. LF larvae, are important mortality The leaf area consumed was measured factors for LF in the Philippines. on graph paper. LF parasitized by C. We studied the influence of parasitism nacoleiae consumed more food than by C. nacoleiae on LF food unparasitized LF. The lowest food consumption. Ten newly laid LF eggs consumption was by larvae parasitized were exposed for 24 h in tubes by G. triangulifer (see figure). C. Influence of parasitization by C. nacoleiae and G. containing colonies of the parasitoid. nacoleiae -parasitized larvae fed for 16.4 triangulifer on leaf consumption by LF.

IRRN 14:2 (April 1989) 37 White stem borer (WSB) Yield loss caused by WSB S. innotata under upland conditions. Makariki, Seram Island, Indonesia, effect on upland yield 1982. WSB damage b (%) Grain Yield a M. S. Pabbage, Entomology Department, Treatment yield loss c Maros Research Institute for Food Crops, 3 WP 5 WP 7 WP 9 WP (t/ha) (%) P. O. Box 173, Ujung Pandang, South 1. Complete protection 7.2 1.2 1.5 1.9 2.4 – Sulawesi, Indonesia 2. Complete protection minus a 11.4 1.5 2.0 2.3 2.4 1.7 3. Complete protection minus b 21.9 7.9 4.4 3.3 1.8 25.6 4. Complete protection minus c 24.2 8.9 2.7 3.3 We studied the effect of WSB 1.8 25.6 5. Complete protection minus d 14.4 2.1 3.4 3.3 2.3 5.8 d Scirpophaga innotata on upland rice 6. Recommended protection 12.5 2.2 2.3 2.6 2.2 9.1 with seven levels of protection in an 7. No protection (control) 39.2 15.5 8.6 9.7 1.8 26.9 experiment at the Makariki LSD (0.05) 2.7 1.2 0.6 0.6 0.4 – Experimental Farm, Seram Island, CV (%) 9.7 14.6 11.2 9.9 14.6 – May-Aug 1982. IR36 was planted in a a a = seed treatment with carbaryl 85 S, b = carbofuran 3G (10 DP) + diazinon 60 EC (21 DP), c = b 5 × 5 m plot at 25 × 25 cm plant carbofuran 3G (42 DP) + diazinon 60 EC (63 DP), d = monocrotophos 15 WSC. WP = weeks after planting. c Compared with complete protection. Carbofuran 3G (10 DP) + diazinon 60 EC (when spacing in a randomized complete block deadhearts exceeded 10%). design with 4 replications. Fertilizers as urea, TSP, and KCl were applied at 120 kg N, 40 kg P, and 50 kg K/ha. Half the WSB damage at active tillering 3 wk significantly higher than control, no N and all the P and K were applied in after planting was high, an average protection during active tillering the row at the side of the plants 7 d after 39.2% in control (see table). As plants (treatment 3), and no protection at planting (DP). Half the N was applied grew, damage decreased. booting (treatment 4). 40 DP. Complete protection yielded 2.4 t/ha,

Weed management Effect of different herbicide treatments on shoot dry weight and height of I. rugosum 6 wk after seeding under simulated dry seeded and wetland conditions. a Effect of herbicides on Herbicide and Ischaemum rugosum Time of Shoot weight Plant application rate application (mg/plant) height (kg ai/ha) (mm) R. T. Lubigan and K. Moody, IRRI Dry seeded Butachlor (2.0) Preemergence 0.6 b 5 ab Ischaemum rugosum Salisb., reported to l-leaf 2.9 d 22 c be a major weed of partially irrigated 2-leaf 5.0 f 48 d and rainfed lowland rice in Thailand, Sri Thiobencarb (3.0) Preemergence 1.2 c 7 ab Lanka, and the Philippines, is very 1-leaf 3.3 de 24 c 2-leaf 4.3 ef 46 d competitive against rice. Pendimethalin (2.0) Preemergence 0.4 a 3 a We designed a greenhouse experiment l-leaf 3.0 d 22 c to study the effect of some herbicides on 2-leaf 5.6 b 44 d growth of I. rugosum under dry seeded Propanil (2.0) 2-leaf 1.4 c 43 d and wet seeded conditions. There were 3-leaf 0.5 ab 18 bc 12 treatments in the dry seeded trial and Untreated – 21.6 g 247 d 9 treatments in the wet seeded (see Wetland table). The experiment was laid out in a Butachlor (1.0) Preemergence 0 a – 1-leaf 119.9 c 42 a randomized complete block design with 2-leaf 119.6 c 54 b six replications. Thiobencarb (1.0) Preemergence 0 a – Plant height and shoot dry weight 1-leaf 112.7 bc 44 a were measured 6 wk after seeding. 2-leaf 67.2 b 52 b Under dry seeded conditions, both plant Propanil (2.0) 2-leaf 0 a – height and shoot dry weight were 3-leaf 0 a – reduced by all the herbicides at all Untreated – 124.6 c 156 c application times (see table). Even a In a column under each condition, means followed by the same letter are not significantly different though propanil applied at the two- and at the 5% level by DMRT.

38 IRRN 14:2 (April 1989) three-leaf stages killed all weeds, some application at the two- and three-leaf effective under dry seeded conditions seedlings emerged after its application. stages killed I. rugosum. Flooding a few because the herbicide is more easily Repeated applications may be needed to days after treatment increased the effect leached down into the root zone. achieve complete weed kill. of the preemergence treatments and, Butachlor applied at the one- and Preemergence applications of butachlor, with propanil, prevented further weed two-leaf stages did not reduce shoot thiobencarb, and pendimethalin were seedling emergence. Butachlor and weight. Thiobencarb applied at the two- superior to postemergence applications. thiobencarb applied at the one- and leaf stage reduced shoot weight. All Under wet seeded conditions, two-leaf stages were not as effective as plants that survived butachlor and preemergence applications of butachlor under dry seeded conditions. Herbicide thiobencarb treatments were stunted. and thiobencarb, and propanil uptake by the plant seems to be more

Weed, management in rainfed Rice - lentil is a widely adopted rainfed 19.86% field capacity, 5.18% wilting rice - lentil crop sequence crop sequence in eastern Uttar Pradesh. point, 0.32% organic C, 160 kg available Weed control affects yields. N/ha, 15 kg available P/ha, 166 kg R. P. Singh, J. P. Singh, Y. Singh, A. K. We conducted a field trial 1985-86 available K/ha, and pH 7.7. EC was Singh, and R. A. Singh, Dryland Research and 1987-88 cropping years. Seven 0.104 dS/m at 25 °C, bulk density 1.47 Project, Agronomy Department, Institute of treatments were laid out in a g/cc, and water-holding capacity 33.1%. Agricultural Sciences, Banaras Hindu randomized block design with four Akashi rice and Pant 209 lentil were the University (BHU), Varanasi 221005, India replications. Soil was sandy loam with test varieties.

Table 1. Effect of weed control method on weed dry weight and yield of rice and lentil at B.H.U., Varanasi, India.

Rice Lentil

Treatment Weed dry weight Weed dry weight (g/m 2 ) Yield (t/ha) (g/m 2 ) Yield (t/ha)

1985-86 1987-88 Grain Straw 1985-86 1987-88 Grain Straw

1985-86 198788 1985-86 1987-88 1985-86 1987-88 1985-86 1987-88

T1 Sowing of both crops with 403 280 0.4 0.4 2.6 3.5 113 163 0.7 1.0 1.1 1.5 normal tillage and no weed control in either T2 Farmer's method (2 hand 253 149 2.1 3.0 3.4 5.4 63 89 1.0 1.3 1.5 1.9 weedings in both crops) T3 Interculture twice by 325 241 0.9 1.6 3.0 4.3 82 101 0.8 1.1 1.0 1.6 dryland weeder in both crops T4 Interculture as in T3 + 262 169 2.8 3.6 4.2 5.5 36 40 1.0 1.4 1.3 1.6 intrarow hand weeding each time T5 Butachlor at 2.0 kg ai/ha 178 140 3.0 2.8 4.0 4.2 112 159 0.7 1.0 1.0 1.2 at preemergence in rice and no weeding in lentil T6 Butachlor at 2.0 kg ai/ha at 189 135 3.0 2.9 4.2 4.2 92 90 1.0 1.6 1.4 1.7 preemergence in rice, normal tillage for lentil sowing, and preemergence application of prometryn at 0.75 kg ai/ha in lentil T7 Butachlor at 2.0 kg ai/ha 116 146 3.0 2.9 4.2 4.2 93 90 1.0 1.7 1.9 2.8 at preemergence in rice, paraquat application at l.0 ai/ha after rice harvest, no tillage for lentil sowing, and prometryn at 0.75 kg ai/ha at preemergence in lentil LSD (0.05) 156 99 0.5 0.2 0.8 0.9 21 35 0.2 0.3 0.6 0.8

IRRN 14:2 (April 1989) 39 The rice crop received 861.9 mm total Table 2. Economics a of weed control treatments in rice - lentil sequence at BHU, Varanasi, India, rainfall in 1985-86 and 1,050.1 mm in 1985-88. 1987-88; lentil received 51.8 mm in 1985- Mean yield (t/ha) Total cost of Return to 86 and 74.1 mm in 1987-88. Value of land land Benefit Application of butachlor in wet Treatment Rice Lentil produce preparation and preparation and to-cost ($/ha) weed control weed control ratio season and prometryn in dry season, Grain Straw Grain Straw ($/ha) ($/ha) with and without paraquat, reduced weed dry weight in rice the most (Table T1 0.4 3.0 0.8 1.3 406.35 250.00 156.35 0.63 T2 2.6 4.4 1.2 1.7 831.07 367.65 463.42 1.26 1). In lentil, interculture with intrarow T3 1.3 3.7 0.9 1.3 551.72 279.41 272.31 0.97 hand weeding reduced weed dry weight T4 3.2 4.8 1.2 1.4 927.93 308.82 619.11 2.01 the most. T5 2.9 4.1 0.8 1.1 749.00 280.88 468.12 1.67 T6 3.0 4.2 1.3 1.6 926.41 295.66 630.75 2.13 Highest rice grain and straw yields T7 2.9 4.2 1.3 2.3 940.29 306.29 634.00 2.07 were with interculture twice plus a intrarow hand weeding, followed by Price of produce: Rice: grain - $132.35/t, straw - $14.71/t; lentil: grain - 330.88/t, straw - 21.74/t. Cost of treatments: Land Preparation (1) $8.82/ha, hand weeding (1) $29.41/ha, interculture by hand weeding and chemical control. dryland weeder (1) $7.35/ha, intrarow hand weeding (1) $7.35/ha, spraying of herbicide (1) $4.41/ Highest lentil yield was with ha, butachlor at $13.23/kg ai, prometryn at $13.78/kg ai, and paraquat at $23.85/kg ai. General cost preemergence application of butachlor of cultivation: $214.72/ha. in wet season and prometryn in dry On a pooled mean basis, highest net prometryn following paraquat in lentil season. Interculture was least effective in return was with preemergence (Table 2). both crops. application of butachlor in rice and

Managing other pests Correlation between rodent infestation and bund dimensions. a Hyderabad, India. Crop stage b ( r value) Bund variable Effect of bund dimensions on Seedling (13) Tillering (19) Booting (17) Flowering (21) Maturity (13) rodent infestation in irrigated Width (W) 0.87** 0.79** 0.82** 0.44* 0.77** ricefields Height (H) 0.83** 0.57 0.78** 0.78** 0.63** W × H 0.80** 0.63** 0.78** 0.64** 0.61**

V. K. Sharma and A. M. K. M. Rao, a Significance at the 5% (*) and 1% (**) levels. b Numbers in parentheses indicate sample size. Central Plant Protection Training Institute, Rajendranagar, Hyderabad 500030, India number of live burrows/ 10 m. bund height was significant at all stages We surveyed 83 transplanted irrigated The correlation between rodent except tillering (see table) when rodents ricefields 1987-88 to examine the infestation and bund width was establish themselves. Bund volume relationship between rodent infestation significant at all stages of the crop (height × width) and infestation were and the width and height of bunds. growth; that between infestation and directly related. Rodent infestation was measured as the

Farming systems of Uttar Pradesh. Because currently experiment farm (1,250 m, 29 °36'N, available spring rice varieties have long 79º 40%). The split-plot design had crop duration, cropping cereals and legumes sequence as the main plot and organic Rice-based cropping in rotation is not feasible. The most and inorganic fertilization as subplots, sequences for rainfed popular 2-yr cropping sequence is with four replications. Soil was a sandy conditions in midhills of Uttar upland rice (Mar-Sep) - wheat (Oct- loam with medium fertility. Pradesh May) - finger millet (Jun-Oct) - fallow Rainfed short-duration rice was direct (Nov-Mar), for a 150% cropping seeded in the wet season, followed by V. Prakash, P. Singh, and V. K. Bhatnagar, intensity. wheat variety VL 421, barley VLB 1, Vivekananda Parvatiya Krishi Anusandhan After shortduration (110 d Jun-Oct) pea VL Matar 1, lentil VL Masur 1, and Shala, Almora 263601, U. P., India upland rice variety VL Dhan 163 was rapeseed T9 in the dry season. Rice was released, we evaluated 5 intensive sown the first week of Jun, the winter Spring rice (Mar-Sep) is the cropping sequences for production and crops were planted the third week of predominant upland crop in the midhills return 1985-86 at the Hawalbagh Oct. Organic fertilizer treatment was

40 IRRN 14:2 (April 1989) Grain yield and net return of rice-based cropping systems under rainfed upland conditions. a Almora, India, 1985-86.

Yield (t/ha) Total cost ($/ha) Net return ($/ha) Benifit-cost Protein (t/ha) Carbohydrate Crop sequence Rainy season Dry season (t/ha) OF IOF OF IOF OF IOF OF IOF OF IOF OF IOF OF IOF

Rice - wheat 2.1 2.4 2.5 2.8 377.4 368.4 205.2 290.2 1.5 1.8 0.46 0.50 3.39 3.83 Rice - barley 2.2 2.4 2.2 2.4 373.3 357.8 152.3 215.4 1.4 1.6 0.42 0.46 3.22 3.51 Rice - pea 2.4 2.7 1.9 2.0 337.8 341.8 615.4 682.4 2.8 3.0 0.55 0.59 2.92 3.22 Rice - lentil 2.5 2.7 1.7 1.8 329.5 324.6 527.5 589.1 2.6 2.8 0.60 0.64 2.90 3.10 Rice - rapeseed 2.3 2.5 0.8 1.0 341.6 340.0 207.5 301.7 1.6 1.9 0.33 0.39 1.94 2.16 a OF = organic fertilizer, IOF = inorganic fertilizer.

12 t farmyard manure (FYM)/ ha. (see table). Highest average net return 0.21 t/ha lower than with inorganic Inorganic fertilizer treatment was was from rice - pea, followed by rice - fertilizers. Net return, benefit-cost ratio, recommended NPK for each rainfed lentil; lowest was from rice - barley. and protein and carbohydrate crop. Rice received 60-18-25 kg Benefit-cost ratios were highest (above production were higher with inorganic NPK/ ha. 2.0) for rice - legume and lowest for fertilizers. All dry season crops grew successfully rice - barley. Yields with FYM averaged

Vegetables for high return Gross returns of rice - vegetable cropping systems in coastal Maharashtra, India. and water use efficiency in Yield (t/ha) Gross return ($) Increase irrigated rice- based systems Cropping system (%) Wet season Dry season a Wet season Dry season b Total

B. P. Patil and C. S. Pulekar, Irrigation Rice - rice 3.7 4.5 711.5 865.3 1576.8 – Research Scheme, Central Experiment (150.0) a (5.8) Station, Wakawdi 415711, Dapoli, Ratnagiri Rice - tomato 3.7 49.0 711.5 3769.2 4480.7 184 District, Maharashtra, India (75.0) (50.3) Rice - chili 3.7 10.0 711.5 3846.2 4557.7 189 Opportunities for vegetable cultivation (115.0) (33.4) on rice fallows are increasing with new Rice - watermelon 3.7 30.0 711.5 2307.7 3019.2 91 (30.0) (76.9) facilities for irrigation in coastal Maharashtra (Konkan). Rainfall is high a Figures in parentheses = water use (cm). b Figures in parentheses = gross return ($)/cm water). (2,500-3,500 mm) Jun to Sep with a rain-free postrice season. We evaluated rice - rice (Ratna), rice - tomato for tomato, 36 for chili, and 10 for Increase in gross income was 184% (Sonali), rice - chili (DPL-C-1), and watermelon. Depth of irrigation per turn for rice - tomato, 189% for rice - chili, rice - watermelon (Sugarbaby) for gross was 50 mm for rice, tomato, and chili, and 91% for rice - watermelon (see return and water use. and 20 liters/basin for watermelon. Rice table). Gross returns/cm water used Soil is lateritic with 1.65% organic C, received 100-50-50 kg NPK/ha in both was 8 times higher for rice - tomato, 6 2.3 kg available P/ ha, 242 kg available seasons; tomato, 150-75-50; chili, 150- times higher for rice - chili, and 13 times K/ha, and pH 6.0. Wet season rice was 50-50; and watermelon, 100-50-50. higher for rice - watermelon than for entirely rainfed, planted the first week Protection from pests was need-based. rice - rice. Jul at 20- × 15cm spacing and harvested the second week Oct. Watermelon was planted at 2 × 1 m the The International Rice Research Newsletter invites contributions of concise summaries first week of Nov, tomato at 60 × 60 of significant current rice research for publication. Contributions should be limited to no cm and chili at 60 × 45 cm were more than 2 pages typed double-spaced accompanied by no more than 2 figures, tables, transplanted the first week of Dec, dry or photographs. Contributions are reviewed by appropriate IRRI scientists and those season rice was transplanted the second accepted are subject to editing and abridgment to meet space limitations. Authors are week of Jan. Dry season irrigation was identified by name and research organization. See inside front cover for more scheduled at 25 mm crop potential information about submissions. evapotranspiration (CPE) for rice, 30

IRRN 14:2 (April 1989) 41 Supplementary irrigation Rainfall, a irrigation, and grain yield of soybean under several irrigation methods. Maros, Indonesia, using shallow groundwater 1985. Grain yield (t/ha) ET for soybean after wetland rice Supplemental Effective Total Water use actual b Treatment irrigation irrigation water supply efficiency (mm) Observed Predicted (mm) (t/ha-mm) A. Prabowo, B. Prastowo, and I. U. mm % (mm) Firmansyah, Agricultural Engineering Division, Maros Research Institute for Food Rainfed – 0 – 115 0.6 0.7 188 – Crops, Maros, Indonesia Manual drip 165 116 70 231 1.4 1.4 265 8.62 Sprayed every 233 156 67 271 1.4 1.4 266 6.02 5 d We evaluated methods of irrigation Sprayed every 233 156 67 271 1.3 1.4 25 1 5.52 using shallow groundwater on soybean 14 d Furrow 7.6 cm 274 156 57 271 1.0 1.2 269 3.85 grown after rice. A soybean crop growth pump model (CRPSM) was used to improve Furrow 5.0 cm 274 156 57 271 0.8 1.2 269 2.88 irrigation management and phenology pump clock. a Rainfall received was 144 mm. Effective rainfall (115 mm) = 80%. b Predicted from model. Irrigation methods tested were manual drip, spraying at 5- and 14-d intervals, furrow, and rainfall only. For cropping period totaled 115 mm. 5.0-cm pump the lowest (see table). The furrow irrigation, 7.6-cm and 5.0-cm Minimum water consumption was results indicate that soybean yields can diameter pumps were used. 116 mm. be doubled with supplementary Soybean cultivar Orba was sown 12 Manual drip irrigation produced the irrigation (see figure). Jul 1985. Rainfall received during the highest yield, furrow irrigation with the ERRATA

Influence of P, K, micronutrients, and Effect of azolla green manure on rice Grain characteristics of traditional dolomite on azolla growth, 13:4 (Aug yield, 13:4 (Aug 1988), 29. Soil data in Basmati varieties of northwest India, by 1988), 23. Soil data in column 1, column 2, paragraph 2, lines 2-3 should V.P. Singh, E.A. Siddiq, F.U. Zaman, paragraph 2, lines 2-3 should read read “0.113% total P, 0.0155% Olsen and A.R. Sadananda. 13 (5) (Oct 88), “0.113% total P, 0.0155% Olsen P...” P...” 10-11. Page 11: lines 2-3 should read: “represent group B. HBC-30, 34, 40, 45, 46, 95, 98, and 136; Mohabawali, Kanwali,”. . .

42 IRRN 14:2 (April 1989)