Rice requires approximately 3000-5000 liters of water to grow one kilogram of rice traditionally. About 22 million hectares of irrigated dry season rice experience “economic water scarcity” in South and Southeast Asia. Therefore, it was felt that there is a need to save water in rice cultivation, which led to development of alternative methods of cultivation i.e., alternate wetting and drying(AWD), saturated soil culture (SSC) and aerobic rice. Aerobic rice is the latest technology that reduces water inputs by growing rice as any other irrigated upland crop. Selection of physiological traits of aerobic rice using molecular approaches may help in enhancing water use efficiency sustaining the productivity.

Kerala state of India had a very rich diversity of native rice cultivars. A considerable part of it had disappeared from farmers’ fields due to the intervention of modern agriculture. An effort has been made to revisit the hamlets of the traditional farmers of the state and to analyse the extent of variability of native rices available in such areas. Thirty nine cultivars were collected and their genetic variability was studied. The cultivars were found to be very rich in genetic diversity and many of them showed their competence in terms of many agronomic characters. Varieties like Chitteni, Chettadi, Ponmani, Ponnariyan, Arikkinai, Athian, Muttuppatta, Palakkadan, Navara and Kuthiru yielded more than 15 g plant-1.

Five genetically diverse varieties viz., Sanwaal Basmati, Super Basmati, Pusa 2517-2-51-1, P1121-92-8-1-1-3-3 and PAU 2935-16-3-5-2 were crossed with three well adapted varieties, Ranbir Basmati, Pusa Basmati 1 and Basmati 370 in a line x tester design. The preponderance of dominant gene action was observed for plant height, effective tillers plant-1, panicle length, number of grain panicle-1, spikelet sterility, 1000-grain weight and grain yield plant-1. Pusa 2517-2-51-1, Sanwaal Basmati, Super Basmati, Ranbir Basmati and Basmati 370 were found to be good general combiners which can be taken up to generate desirable segregates for further selection. High sca effects were observed in the crosses, Super Basmati / Ranbir Basmati, Pusa 2517-2-51-1 / Pusa Basmati 1, P1121-92-8-1-1-3-3 / Ranbir Basmati and PAU 29-35-16-3-5-2 / Basmati 370. The crosses Pusa 2517-2-51-1 / Pusa Basmati 1, P1121-91-8-1-1-3-3 / Ranbir Basmati and PAU 2935-16-3-5-2 / Basmati 370 found to be the best for grain yield and its components which can be used for exploitation of heterosis for yield.

Effectiveness of plants selected in early segregating F2 and F3 populations was estimated in their corresponding F3 and F4 generation of two rice crosses, Jhona 349 X IET-12944 and Narendra 80 X Lalmati. Both the F2 and F3 selected plants showed consistency in increment of response to selection and realized heritability in their corresponding F3 and F4 generation for grain yield/plant and 100-grain weight, whereas these estimates were inconsistent for spikelets/main panicle and in undesirable direction for panicle/plant. Among intergeneration correlations, the F2 selected plants showed inconsistent significant correlation with their F3 progenies over crosses for all the characters, while F3 selected plants had significant correlations with their F4 progenies for 100-grain weight and grain yield/plant in both the crosses. The higher estimates of selection parameters like response to selection and realized heritability as well as significant correlation for grain yield/plant and 100-grain weight in F4 generation suggested that selection for these two polygenic traits should preferably be started from F3 generation.

Studies were conducted on 47 bold grain rice genotypes with two locally recommended high yielding check varieties namely Ranjit and Monohar Sali of Barak Valley, Assam to assess the genetic variability, correlation and coheritability for five nutritional and seven cooking quality characters. High heritability associated with high genetic advance was found in the cooking quality traits viz. alkali digestion value, cooked rice kernel length, cooked rice kernel lengthwise elongation ratio and water absorption (%); in the nutritional character total soluble sugar content showed high heritability and genetic advance. These characters were predominantly governed by additive gene action. High heritability along with moderate genetic advance was observed in the cooking quality characters gel consistency, cooked rice kernel breadth and cooked rice kernel breadth wise elongation ratio and in the nutritional characters like total soluble protein content and amylose content. Lastly, high heritability with low genetic advance was recorded for starch content and amylopectin content. This indicated that these characters were mostly governed by non-additive gene action (dominance and epistasis). The genotypic correlation coefficient was found to be higher than the corresponding phenotypic correlation coefficient. This indicates a strong inherent association among total soluble protein content and other nutritional and cooking quality traits. The highest positive coheritability of cooked kernel breadth was found with cooked kernel breadth wise elongation ratio (87.93%) followed by water absorption (60.25%).

Experiments were conducted in farmers’ fields during wet (2001 and 2002) and dry (2001-02, 2002-03) seasons in three different irrigation commands (Hirakud, Hariharajore and Pitamahal) in Western Orissa to study the effect of land leveling with and without deep ploughing on productivity of rice. Data revealed that deep ploughing followed by puddling and proper land leveling resulted in significant increase in rice grain yield (ranging from 38.0 to 45.6 q ha-1 in wet season and 42.0 to 44.0 q ha-1 in dry season) in all the locations during both the seasons but it was at par with ploughing with country plough followed by puddling and proper land leveling in Hirakud and Hariharajore locations during kharif. Economic analysis also revealed that net return (Rs. 6127 ha-1 in wet season and Rs.7039 in dry season) and net return rupee-1 invested (0.51 in wet season and 0.64 in dry season) were also the highest in deep ploughing followed by puddling and proper land leveling irrespective of locations. This practice proved more beneficial at Pitamahal where problem of iron toxicity of soil got decreased. However, usual ploughing with country plough followed by puddling along with proper leveling was adjudged to be most cost effective treatment across locations and seasons with a figure of more than Rs.4.00 of additional return per every additional rupee invested.

Integrated nutrient management for rice (Oryza sativa L.) – rice cropping system in the subhumid subtropical climatic condition was studied at Regional Research Sub-Station (RRS), Chakdaha, Nadia, West Bengal. Considering the system productivity, economics of production and soil fertility condition it may be concluded that maximum production (9.26 and 10.37 t ha-1 yr-1 under HYV-HYV and hybrid-hybrid crop sequences, respectively) was obtained when rice crop received 50% recommended doses of nutrients through chemical fertilizer along with 50% recommended doses of nutrients through green leaf manuring during wet season and 100% recommended doses of nutrients through chemical fertilizer during boro season. Under the same treatment combination the net returns/annum were Rs. 24939.25 and Rs. 25875.59 ha-1 yr-1 and the returns rupee-1 investment were Rs. 1.66 and Rs. 1.62 in HYV-HYV and hybrid-hybrid rice crop sequences, respectively. Under similar conditions soil N, P and K content improved over initial value by 1–17%, 1– 5% and 0 –6%, respectively under hybrid rice-hybrid rice crop sequence.

Two components of seed (rice) production system viz.; seed harvest and storage were validated through on-farm trials with an objective to fine-tune existing and/or improved techniques based on location specific requirements. Panicle harvested (PH) seed was compared with that of traditional bulk harvest (BH) using two improved upland rice varieties (Vandana and Anjali) during 2004-05. Despite average yield increase of 6.1% (Anjali) to 14.9% (Vandana) the PH method was not accepted by the farmers due to higher labour requirement of the operation. So, a less labour intensive method of ‘crop area selection’ was evaluated and demonstrated during 2006-07 using the variety Anjali. Improved seeds resulted in significant grain yield increase to the tune of 12.5% (2.36 t ha-1) to 20.3% (2.31 t ha-1) in on-farm and research station trials, respectively. Storage systems used by the farmers (locally termed as; Hatwa/Kothi/Gaza/Tokri) were comparable to hermetically sealed storage systems for seed viability, germination and seedling vigor. Based on the results and farmers’ opinion, the ‘crop area selection’ method followed by traditional method of seed storage was recommended for adoption. However, the farmers were advised to repeat panicle harvest once in 5-6 years, to regain seed purity.

Growth and yield of low land rice genotypes differed significantly due to application of different levels of N, P and K. Uptake was remarkably improved with 120 kg N ha-1. Application of incremental doses of N significantly improved the yield attributes resulting in higher grain and straw yield. Genotype IET-16983 was found significantly superior to other rice genotypes except Radha and IET 15848 in increasing the growth and yield attributes. IET-16983 recorded the maximum grains (3.77 t ha-1) and straw (5.30 t ha-1) yield along with improvement in N, P and K uptake.

On-farm farmers’ participatory trials were carried out during the wet seasons of 2004 and 2005 under rainfed deepwater rice ecosystem in five different villages of Ersama Block in the Jagatsinghpur district of coastal Orissa to evaluate the effect of improved variety and integrated weed management techniques on grain yield and production economics of deepwater rice. The yield improvement due to adoption of improved variety, Durga was 76% more than the traditional variety, Bhaluki. In contrast, the adoption of integrated weed management techniques alone enhanced the grain yield to the tune of 56% over traditional weed management practices. The overall yield enhancement of rice due to adoption of improved variety along with integrated weed management practices was 157% more than cultivation of traditional variety with traditional weed management practices. The highest net monetary return (Rs. 5848 ha-1) and benefit : cost ratio (1.72) was recorded in the plots where improved variety, Durga was grown with integrated weed management techniques.

Asian rice gall midge (Orseolia oryzae Wood-Mason) is a serious pest in most of the rice growing areas in India particularly when high dose of nitrogen is used. In order to know the reaction of popular high yielding varieties (HYVs) and few improved genotypes to gall midge 87 genotypes were screened under natural field condition at 50-62 days after transplanting at zero and 120 kg N ha-1 based on appearance of silver shoot. Few genotypes from early group like Ananga, Annada, Kharavela and Shaktiman showed highly resistant reaction at both the level of nitrogen with 0% silver shoot. Cultivar Jajati and Suraksha showed moderately resistant reaction in mid group and Chaitanya in late group. Other cultivars/genotypes showed high infestation of gall midge as observed from the incidence of silver shoots and are classified as either susceptible or highly susceptible at 120 kg N ha-1 level. Under high N level invariably there was high incidence of gall midge in most of the genotypes than the zero N level.

Influence of two methods of crop establishment viz., direct seeding and transplanting on the incidence of rice blue beetle, Leptispa pygmaea on rice varieties Jyothi (short duration) and Aiswarya (medium duration) were studied during wet and dry season, 2005. A scoring method for the estimation of damage by L. pygmaea was standardized. Transplanting method of rice establishment was observed to suffer more damage by L. pygmaea than direct seeding method in both the rice varieties during the two seasons. Highest damage of blue beetle was observed at the early tillering stage in both direct seeding and transplanting methods with damage ranging from 31.51 to 45.71 per cent in Jyothi and 19.57 to 29.57 per cent in Aiswarya under direct seeded condition and 68.54 to 75.32 per cent in Jyothi and 36.15 to 46.14 per cent in Aiswarya under transplanted crop. Direct seeding resulted in 34-58 per cent reduction of blue beetle damage in Jyothi, whereas in Aiswarya 36-46 per cent damage was reduced by this method.

An attempt was made to decrease the toxic effect of waste soil from a chlor-alkali factory by Sesbania aculeata.Pers. Sesbania cultivated in varying waste/soil combinations for 35 days added about 120.59% more nitrogen and 220.33% more organic carbon to the medium containing 60% of the waste. Alkaline pH of the waste/soil combinations also decreased with time. After 35 days of incorporation of Sesbania, a significant increase in the growth of rice var. IR 36 was reported over that of control set.

Three lowland rice varieties viz. Durga, Gayatri and Sarala were introduced in the submergence prone area of Orissa state and the varieties have spread to 51 percent of the lowland area within three years in the target villages. Durga was adopted much faster than the other two varieties because of its higher submergence tolerance ability. The returns from all the three modern varieties were found to be attractive in comparison to traditional varieties and the additional income generated ha-1 was Rs 4736 from these varieties. The additional employment generation by the cultivation of these modern varieties was found to be 23 man days ha-1. These varieties have added 825 kg of rice ha-1, which has improved the household food security of poor farmers. Due to popularity of the varieties, seed exchange of 1802 kg has taken place among farmers, both within and outside the village.

The present study was conducted in Samastipur district of Bihar where rice variety Rajshree was rapidly adopted which is a superior variety for lowland with water stagnation up to one meter. This variety was adopted by the rice growing community within five years of its release by central variety release committee. The study gives insight in the process of rapid adoption and finds the factor behind it.The superior technological characteristics of the Rajshree variety and education level of farmers that proved crucial in rapid adoption of Rajshree variety over time tested local variety ‘Bakol’ which could not withstand stress due to drought. The curvilinear regression analysis show that about 73.6 per cent change in adoption quotient can be explained by income, lowland area and perception about technological characteristics of Rajshree variety.

The study was conducted to assess the impact of front line demonstrations on rice production technologies on the knowledge and adoption level of rice farmers. A comparison was also made with regard to the knowledge level of non-beneficiary farmers of the same villages. The study revealed that the mean knowledge of beneficiary farmers with respect to all technological aspects of scientific rice cultivation have increased by 44.78 per cent as compared to the non-beneficiary farmers. Maximum change in knowledge was found in aspects like ‘seed treatment with fungicides’ (55.00%). There were some areas where the non-beneficiary farmers also possessed quite enough knowledge namely ‘number of seedlings per hill’ (87.50%), ‘suitable harvesting time’ (85.00%), ‘quantity and application of organic manure’ (80.00%) and ‘proper stages of crop for hand weeding’ (80.00%). In contrast, they were quite poor in knowledge in areas like ‘different considerations at the time of pesticidal applications’ (22.50%), ‘rouging methods’ (27.50%), ‘seed treatment’ (30.00%), ‘nursery management’ (32.50%) and ‘application of NPK in split doses, (30.00%). As many as 68.33 per cent beneficiary farmers were using the recommended seed rate and 63.33 per cent were using all the introduced rice varieties, in contrast, 61.67 per cent beneficiary farmers were not using ‘seed/seedling treatment practice’. ‘Unfavourable climatic conditions’ like dry spell and heavy or erratic rainfall during the major field operations was cited by 91.67 per cent farmers as the major hindrance in adopting recommended practices like nursery management, water management, weeding, fertilizer and pesticides application.

The response of hybrid rice to nutrient application was studied in field experiments during wet season . Both the test hybrids KRH-2 and PHB-71 recorded significantly higher grain yield than the check vareity Jaya. Application of 120:60:80 kg of N, P2O5 and K2O ha-1 recorded significantly higher grain yield (6.11 t ha-1) followed by 120:60:40 kg of N, P2O5 & K2O ha-1 (6.05 tha-1). Among the hybrids, mean maximum nutrient response of 15.57 kg grain per kg nutrients was recorded by PHB-71. Among the nutrients levels, mean maximum nutrients response (17.28 kg grain per kg nutrients) was recorded by the fertilizer schedule of 120:60:40 kg of N, P2O5 & K2O ha-1. Hybrid KRH-2 recorded maximum net return of Rs. 21,111 ha-1 while among nutrients combinations, mean maximum net returns (Rs.23,070 ha-1) was recorded with 120:60:40 kg of N, P2O5 and K2O ha-1.

The efficacy of clomazone alone and tank mix formulation of clomazone and propanil at different concentration against weeds in direct wet seeded rice under puddled condition was studied. The predominant weed species observed in experimental plots were Echinochloa crusgalli, Echinochloa colona, Panicum repens, Cyperus iria, Cyperus difformis, Ischaemum rugosum, Spillanthus calva, Morselia quadrifolia and Molluga sp. The results indicated that tank mix application of clomazone 20 EC and propanil 40 EC at 750 ml ha-1 applied at 15 or 20 days after sowing controlled weeds gave effectively and on par yield with weed free treatment (manual weeding) and recommended herbicide (Pretilachlor + Safener) besides, being phytotoxic to crop.

The effect of nursery management treatments on seedling health and their subsequent effect on crop yield of boro rice were studied. Results revealed that integration of different components of nursery management techniques i.e., addition of organic manure @ 1.5 kg m-2, dusting of ash on seedling leaves at weekly interval, shaking off dew drops from the seedling tips every morning, placement of polyethylene sheet above the seedling at night and foliar spray of multi nutrients solution (multiplex) produced vigorous seedling growth and subsequently higher grain yield compared with non-treated control.