Twenty rice hybrids developed through a line× tester crossing programme involving five high yielding lines and four superior grain quality testers were evaluated for yield and quality characters. Significant heterosis for grain yield and quality traits were observed in most of the hybrids. Higher magnitude of heterosis against all yield and quality traits were not expressed in a single hybrid combination which varied from cross to cross due to diverse genetic background of their parents. Most of the heterotic crosses for grain yield plant-1 were accompanied by heterosis for two or more component traits. The cross combinations IET 5656×Kalonunia, IET 8002×Dudheswar, IET 5656 × Dudheswar and IR 62×Sambamahsuri were identified for their superior yield and grain quality characters. In general heterosis was found to be low for quality traits as compared to yield and yield components.

Twenty seven mutant lines obtained as advanced generation through selection following physical and chemical mutagenesis of Basmati lines viz., Basmati 370, Saanwal Basmati and Ranbir Basmati were characterized for quality traits. Results revealed that mean values for all quantitative and quality traits deviated more towards positive than towards negative direction. Selections on the basis of mean performance in M3 and M4 generation led to the isolation of six mutant lines. Two of the mutants were from Basmati 370 and four were Saanwal Basmati derivatives. None of the Ranbir Basmati derivative out performed its control parent.

Sixty hybrids developed from crossing four CMS lines with 15 restorers were studied alongwith parents for 13 yield and yield attributing characters. Among the male parental lines, BR-827-35-3-1.RTN-3, IR-46 appeared the best general combiner for grain yield and most of the component characters. The female line IR-58025A was found to be good general combiner for all the traits except’ plant height and L:B ratio of grain. The most promising specific combinations were IR 58025A x XBR-827-35-3-1, IR-58025A x RTN-3 and IR-68885AxRTN-711 for grain yield hill-1.

A field experiment was carried out on summer rice (Oryza sativa L) during 2003 and 2004 using different organic mulches – Azolla, rice chaffy grain, saw dust, subabool (Leucaena leucocephala L.) green leaves and FYM under rotational submergence at 5 days after disappearance of ponded water against continuous submergence. The results revealed that rotational submergence reduced the uptake of N, P2O5 and K2O by 40.2, 49.3 and 33.1% respectively as compared to continuous submergence. However, application of organic mulches in rotational submergence improved the uptake of nitrogen (11.1 - 51.9%), phosphorus (12.7% - 67.6%) and potassium (9.3 - 39.1%) compared to without mulching condition. Among the organic mulches, rice chaffy grain recorded maximum uptake of N and K and FYM recorded maximum uptake of P2O5. Rotational submergence (cyclic stress) reduced the nutrient availability to the extent of 23.8, 17.2 and 2.0% of N, P2O5 and K2O respectively. Organic mulches under rotational submergence significantly improved the nutrient availability to the extent of nitrogen 33.8 - 59.7%, phosphate 28.2 - 61.8% and potash 1.65 - 9.1% and it was even higher than continuous submergence. Soil water stress reduced the oxidisable soil organic carbon status by 5.13% as compared to continuous submergence, whereas, mulching improved the carbon status by 9.5% to 18.2% and increased the grain yield by 20.5-50.7%. Water supply situation and organic mulches significantly influenced microbial population. Among the mulches saw-dust and FYM increased the microbial population by 37-192% over stress control.

A field experiment on diversification of rice-wheat system was carried out from 1999 to 2003 under assured irrigation to identify alternative cropping system with higher productivity and profitability. Sixteen rice based cropping sequences with four dominating varieties of rice viz. short duration (IET-1410), medium duration (PC-19), long duration (Jaya) and Basmati (Basmati-370) were tested. The study revealed that the existing rice-wheat cropping system should be diversified to short duration rice (IET-1410)-cauliflower-french bean which recorded highest rice equivalent yield (REY) of 27.20 t ha-1 year-1, net return of Rs. 105085 ha year-1 and production efficiency of 74.52 kg ha-1day-1. The REY of short duration rice (IET-1410)-potato-wheat, medium duration rice (PC-19)-potato-rajmash and basmati rice (Basmati-370)-potato-okra were next in order. Short duration rice (IET-1410)-toria-wheat had lowest system equivalent yield (11.87 t ha-1year-1). Maximum energy of 77.70 x 106 K calories ha-1year-1 was produced in medium duration rice (PC-19)-pea-maize (cob’s), followed by short duration rice (IET-1410)-potato-wheat and medium duration rice (PC-19)-potato-rajmash. Land utilization efficiency was maximum with rice (Basmati-370)-potato-okra (95%). After five years study, available N and soil organic carbon were found to decline in rice wheat as well as rice-toria wheat cropping sequence, while inclusion of green manuring/legumes/pulses in the system, particularly in summer season markedly improved organic carbon, bulk density as well as available N, P and K content in soil.

Field experiments were conducted during wet seasons of 2004 and 2005 to study the effect of Zn in combination with FYM and/or recommended dose (RD) of NPK on transplanted rice. Application of 10 kg Zn (5.0 + 2.5 + 2.5 kg ha-1) in three splits in combination with RD of NPK (60:13:25 kg ha-1) recorded significantly higher growth, yield attributes, grain (42.5 t ha-1) and straw (46.6 t ha-1) yield and showed additional net return of Rs 1,967 ha-1. However, the benefit : cost ratio was highest (1.72) for the treatment RD of NPK in combination with Zn (2.5 + 2.5 kg ha-1) in two equal splits.

The efficacy of some potent herbicides of sulfonylurea group in conjunction with other traditional recommended herbicides was studied in wet direct- sown summer rice (Oryza sativa) during the dry season of 2005 and 2006 at Cuttack, Orissa. The major weed flora found during the crop growing season were Echinochloa colona (9.6%), Cyperus difformis (21.9%), Fimbristylis miliacea (19.2%), Sphenochlea zeylanica (23.3%), and Ludwigia parviflora (26.0%) at 30 days after sowing (DAS). Bensulfuron methyl (60 g ha-1) applied at 20 DAS was found to be the most effective herbicide in controlling weeds (weed control efficiency 95.2%) and maximizing rice grain yield (5.82 t ha-1). This was at par with hand weeding twice at 20 and 40 DAS in terms of weed control efficiency and grain yield. Other herbicides of sulfonylurea group viz., pyrazosulfuron ethyl (25 g ha-1) applied at 10 DAS, triasulfuran (9 g ha-1) applied at 7 DAS and Almix (metsulfuron methyl + chlorimuron ethyl) + 0.2% surfactant (4 g ha-1) applied at 20 DAS also showed good suppression of weeds with weed control efficiency (WCE) 93.4, 91.7 and 88.6%, respectively. Among the traditional recommended herbicides, pretilachlor + safener (750 g ha-1) performed relatively better with WCE 85.0%. There was more than 46% reduction in the grain yield of rice due to competition with weeds in weedy plots.

Studies on the the effect of green manuring with Dhaincha (Sesbania aculeata) and Sunnhemp (Crotalaria juncea) on physico-chemical properties of soil, nitrogen uptake and productivity of rice indicated that soil pH, organic carbon, available N, available P2O5, available K2O and nitrogen uptake recorded before transplanting, at 20 transplanting and after harvest of rice were affected significantly due to methods of green manuring and nitrogen levels. Soil pH was significantly higher in summer fallow as compared to rest of the methods of green manuring. Organic carbon, available N, P2O5, K2O and nitrogen uptake were higher in Sesbania green manuring at 60 days after sowing. which was at par with Crotalaria green manuring at 60 days after sowing. Summer fallow recorded significantly lowest indices of these physico-chemical properties of soil. Application of N beyond 75 kg ha-1 did not produce significant differences. Nitrogen uptake increased significantly with increase in nitrogen level from 0 to 150 kg ha-1. The number of panicle m-2, grains panicle-1, 1000 grain weight, grain and straw yield of rice were significantly significantly higher under green manuring of Sesbania at 60 days after sowing followed by Crotalaria green manuring at 60 days after sowing.

The available potassium in the rice soils representing six districts of Meghalaya was determined by five chemical extraction methods in order to find out the most reliable soil testing method for predicting response of rice crop to applied K for in the acid soils. Total K in the soils ranged from 1200-3950 mg kg-1 and exchangeable, non-exchangeable and lattice K fractions constituted 5.1, 8.6 and 85% of total K, respectively Distribution of various fractions of K in different soil groups followed in the order: Vertisols > Inceptisols > Ultisols > Alfisols > Entisols. Nitric acid extractable K recorded highest values of available K, ranging from 105 to 748 kg ha-1, whereas the ammonium acetate extractable K varied from 71-403 kg ha-1. Dry matter yield and K uptake widely varied from 13.45-55.77 g pot-1 (30x30cm) and 109-1008 mg pot-1 (30x30cm) with a yield and uptake response of 20 to 110 and 27-247 %, respectively. Water soluble and exchangeable forms of K contributed 65, 68, 44, 66 and 44 percent variation to the extractable K by ammonium acetate, sulphuric acid, nitric acid, hydrochloric acid and calcium chloride, respectively. Water soluble and exchangeable forms of K showed highly significant relationship with K uptake of rice, indicated that these two forms significantly contributed to K nutrition of rice. Ammonium acetate extractable K was found superior to the other extraction methods as it showed highly significant relationship with plant growth parameters, with a critical limit of 194 kg ha-1, below which the crop showed response to the applied K fertilizers. The H2SO4 extractable K was also found equally good as it showed highly significant relationship with plant growth parameters and various forms of K, with a critical limit of 210 kg ha-1.

Investigation on the effect of stem damage by Scirpophaga incertulas (Wlk.) the yellow stem borer on yield contributing characters of 27 deep water rice cultivars indicated that the percent reduction in panicle length, number of grains panicle-1, 1000 grain weight and increase in the chaffy grain percent varied between 8.21 - 16.42, 7.83 - 16.99, 9.09 - 22.57 and 8.8 - 16.5 percent, respectively in plants with stem damage over the healthy ones. Percent reduction in the indices of various yield contributing characters was at higher levels in LPR-56-49, IR-4547-212, TC-6 and Bengdang Kumini. Percent yield reduction (PYR) was lowest in NDGR - 398 followed by NDGR-410, Jalnidhi, NDGR-421, Kariawa and TCA – 4, whereas yield reduction index (YRI) and percent yield loss due to stem damage were lowest in NDGR-398 followed by TCA-4, Jalanidhi, Kariawa, NDGR-410, NDGR-421 and in the higher range in Bengdang Kumini, LPR-5649 and IR-5533-56-1-12 and the highest in susceptible check Jalamagna. The percent yield loss due to 1% damaged stem varied between 0.224 - 0.438 with an average of 0.31 as compared with 0.50 in the susceptible check Jalamagna.

Forty fungal species were isolated from decompsing rice stubbles. Aspergillus flavus, A. niger, Penicillium citrinum, Curvularia lunata, Trichoderma harzianum, Fusarium semitectum and Alternaria alternata were preponderant and present almost throughout the decomposition process while common fungi species like Humicola grisea, P. rubrum, Aspergillus luchuensis, dark mycelium were more frequent and abundant. The species of Duteromycetes were regnant while species of Mastigomycetes, Zygomycetes, Ascomycetes, Mycelia Sterilia were insignificant. Abundance and frequency of species were affected by environmental conditions. Among Deuteromycetes species of the family Moniliaceae and Dematiaceae were dominant.

Ten different chemicals including gibberellic acid (GA3), combinations of , respectively GA3 with other chemicals and control (water spray) were first sprayed at 15% panicle emergence and 24hrs after the 1st spray on female parental lines IR 62829A and CRMS 32A of two promising rice hybrids CRHR 1 and CRHR 5, to find out a suitable substitute to GA3 for better panicle exsertion and seed setting in hybrid rice seed production plots. In general, plant height, panicle length, panicle exsertion, seed setting percentage and seed yield increased significantly over the control with the application of different chemicals. The increase was recorded highest under GA3 application as well as treatments with GA3 combinations as compared to other treatments and control. Though GA3 application was found invariably to be more effective in obtaining higher seed setting and seed yield, GA3 alone could be substituted by GA3 combinations with other chemicals cheaper than GA3 to reduce the cost of hybrid seed production.

Genetics of awnedness and colour of rice husk and pericarp were studied in 231 recombinant inbred lines (RILs) derived from a cross between CSR10 X Taraori Basmati. For awnedness and apiculus colour segregation ratios of 1 (awned):15 (awnless) and 1 (coloured): 15 (colourless apiculus) were observed indicating that they are potentially recessive digenic traits with inhibitors. A ratio of 7 hairy: 9 hairless hull surface indicated a digenic action with complementary inhibitors. Notably, the RILs displayed a broad spectrum of hull colours and pericarp colours, 1 red, 65 golden, 115 straw, 47 dark brown and 3 yellow green and 167 white, 27 light brown, 6 brown, 22 red and 9 green, respectively, which is indicative of the genetic interactions of higher order. 

Eighteen indica/indica hybrids developed by crossing three lines with six testers were screened for various grain quality traits to assess the combining ability of the parents. For head rice recovery, the crosses involving IR 58025A with MTU 9992 and KMR-3, IR 62829A with MTU 9992 and IR 29723 and IR 68886A with IR 40750R and IR 21567 showed significant positive specefic combining ability (sca) effects. For kernel length, IR 58025A and IR 68886A among lines and MTU 9992 and IR 21567 among testers showed positive significant general combining ability (gca) effects. The magnitude of s2gca/s2sca revealed the predominance of non-additive genetic variance for most of the quality characters. For gel consistency, IR 62829A among lines and Ajaya R and IR 40750 R among testers registered significant positive gca effects indicating them to be good general combiners for obtaining hybrids with soft gel consistency. The predominance of non-additive component for most of the quality characters of economic importance offers considerable scope for exploitation of hybrid vigour through heterosis or hybridization and selection.

Field experiments were conducted at research farm of Institute of Agricultural Science, Banaras Hindu University, Varanasi during dry seasons of 2001-04 to find out the suitable age and number of seedling for maximizing productivity of boro rice cv. Gautam. Transplanting of 70 days old Gautam seedlings gave the highest grain yield of 7.0 t ha-1 followed by 60 days old seedlings and both were found significantly superior to transplanting of 80 – 90 days old seedlings. Transplanting of 4 seedlings per hill registered significantly higher grain yield (4.75 t ha-1) than 6 and 2 seedlings hill-1

Field experiments were conducted during wet seasons of 2005 and 2006 at the Crop Research Station, Masodha, Faizabad, Uttar Pradesh in split plot design having three nitrogen levels (30, 60 and 90 kg N ha-1) in main plots and four aromatic rice varieties (IET – 17566, Badshahbhog, Kalanamak and Kanakjeer as local check) in sub plots to find out the suitable variety and optimum levels of nitrogen were evaluated for maximum grain yield under irrigated ecosystem. It was observed that IET- 17566 gave significantly higher grain yield (3.64 t ha-1). The Kalanamk and Badshah bhog were at par (4.04 and 3.06t ha-1). The graded levels of nitrogen significantly increased grain yield and all the attributing characters upto 60 kg N ha-1 (3.37 t ha-1). The N response at 60 and 90 kg Nha-1 (12.33 and 8.66 t ha-1) was higher over the mean grain yield at 30 kg N ha-1.

The effect of integrated management of chemical fertilizers and farmyard manure on crop productivity and profitability in rice-niger cropping sequence was studied at Jorhat, Assam during 2005-2006. Application of 75% recommended dose of fertilizers paste along with 25% N through FYM produced the highest yield and uptake of nutrients for both rice and niger crop. Maximum benefit: cost ratio for the sequence was recorded as 1.95 in treatment receiving 75% recommended dose of fertilizers along with 25% N through FYM and biofertilizer based integrated nutrient management package.

The effect of dual cropping of green manure on productivity of semi-dry rice was studied during 2003 and 2004. The yield attributing parameters viz, productive tillers, panicle length, filled grains and 100 grain weight were significantly superior under paired row sowing (PRS) of rice with Sesbania aculeata under weed free condition. The highest yield (3.53 t ha-1) was recorded with paired row sowing (PRS) of rice with Sesbania aculeata under weed free condition and comparable with normal sowing of rice with herbicide application + hand weeding twice.

Field experiments were conducted during the wet seasons of 2002, to 2004 at Modipuram to find out the most effective weed control method in direct-swon rice. Results indicated that stale seedbed produced higher rice yield (3.58 t ha-1) as compared to traditional seedbed (3.27 t ha-1). Among weed control treatments, herbicide (Pendimethaline at 1.2 kg a.i. ha-1) + one hand weeding ( 5.14 t ha-1) and criss- cross sowing + herbicide + one hand weeding (5.52 t ha-1) produced comparable yield but significantly superior to hand weeding under taken twice. The highest net return (Rs 15556 ha-1) was recorded under criss- cross sowing + herbicide+ one hand weeding.

The effect of natural aging on fatty acids profile in aromatic Pusa Basmati rice was studied. Lipid content and fatty acid profile of the samples were measured at an interval of 30 days. The total lipid content of the samples during the period of six months of natural aging decreased by 2.8% from that of freshly harvested samples. The major fatty acids of rice lipids were oleic acid (18:1), linoleic acid (18:2), and palmitic acid (16:0), myristic acid (14:0), stearic acid (18:0) and linolenic acid (18:3) were the other fatty acids which were also identified and quantified. The results indicated that the fatty acid profiles of rice lipids changed during aging of aromatic rice. The desirable ratio of oleic acid to linoleic acid for all the samples remained within the safe limits.

IR-20, Utrirajapan, Virippu, Daya, Moti, Habiganj, Jeera, Saket-4, IR-48, IR-34 and TN1 were used as differentials to differentiate various isolates of tungro namely Burdwan (West Bengal), Cuttack, Konark, Jajpur, Salipur, Bhadrak (Orissa) etc. Moti was susceptible to Cuttack and Salipur isolates. Saket-4 was susceptible to Burdwan and Jajpur isolates. Virippu cultivar was found susceptible to Konark isolate. Habiganj was susceptible to Bhadrak isolate. All other differentials were found resistant to all the tungro isolates.

One hundred lowland rice cultivars from north and north eastern states of India and one hundred eighty medium land cultivars collected from different parts of Orissa were evaluated for resistance against Scirpophaga incertulas (Wlk.), the yellow stem borer (YSB) under field condition by egg mass implantation method during wet seasons of 2005-2008. The promising entries were further tested in the laboratory by cut stem bioassay. Lowland entries like Nalihazara, OR1898-2, CR580-5, RAU 500-86-4, Kariawa-4, LPR-14, Bazail-65, TCA-282, CR 383-10, NDR-402, TCA-12, Katakipatali, OR1358-RGA-4, LPR-85, LPR-97, LPR56-49, LPR-96, LPR96-10 and Janaki had score-1, whereas among the medium land entries, Chadheinakhi, Daonara Dahijhil, Brahmanbhojni, Litipiti, Ptb-18, GEB-24, Mahalaxmi and CNM-31 had score 1.