Using marker-assisted selection in a backcross-breeding program, four bacterial blight resistant genes namely Xa4, xa5, xa13 and Xa21 have been introgressed into the popular hybrid rice parental lines KMR3, PRR78, IR58025B, Pusa 6B and a popular variety Mahsuri. Only foreground selection was done using markers. Conventional breeding strategy was adopted for background selection. The pyramids showed very high level of disease resistance to 10 highly virulent isolates of Xoo. Grain quality parameters of the pyramids were on par with that of the original genotype. This work demonstrates the successful application of marker-assisted breeding for pyramiding four BB resistant genes into multiple backgrounds, simultaneously. These lines can be used directly or can be used as donors of bacterial blight (BB) resistance breeding.

Forty one promising rice varieties of eastern India were evaluated for physico- chemical and cooking characters to study the diversity pattern among the genotypes. The genotypes were grouped into ten clusters. Maximum 11 genotypes were grouped in cluster IV followed by ten in cluster I. The clusters VI, VIII, IX and X are represented by single genotype namely Gayatri, Hanseswari, Satyakrishna and Saket-4 respectively indicating high degree of heterogeneity among the genotypes. The intra cluster distance is highest in cluster IV(D=13.41) followed by cluster V(10.16), cluster II(10.05) and lowest in cluster VII(D=7.31). The coefficient of variation was highest in water uptake(10.1) and volume expansion ratio (6.97)and lowest in hulling%(1.26) The cluster mean for Kernel length and Kernel length after cooking were highest in cluster V. Highest cluster mean was reported in cluster VI for Hulling% and Kernel breadth. Percentage of contribution towards total divergence is highest in alkali spreading value (33.05) and lowest in milling recovery(0.0).Alkali spreading value, kernel length after cooking, amylose content and kernel breadth together accounted for 83.78percent to the total divergence. So these characters should be considered during hybridization programme.

Molecular characterization and diversity analysis of thirty-two rice genotypes using 11 SSR primers were undertaken in order to further utilize these lines in the breeding programmes. The results revealed that 7 primers showed distinct polymorphism among the genotypes consistently. A total of 33 amplification products were obtained with all the selected seven primers. The number of alleles varied from 3 to 7 with a mean of 4.71. The PIC values of 7 primers varied from 0.1986 to 0.3038 with a mean of 0.2625. Cluster analysis based on SSR data revealed that the genotypes MTU-2077 and JGL-1798 were clustered at the two extremes based on their similarity coefficients. This information could be used in hybridization programmes for the improvement of rice.

A field investigation was carried out, to study the effect of integrated nutrient management practices on dry matter production, nutrient uptake and yield of wet seeded rice and cotton under sequential cropping system, during summer seasons of 2001 and 2002. The study was undertaken at the Central Farm, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Killikulam. Eleven treatments were imposed in wet seeded rice viz., pre sowing of Sesbania aculeata @ 50 kg seeds ha-1, in situ incorporation at 45 days after sowing+100 % recommended dose of fertilizer (RDF) (150:50:50 Kg NPKha-1), pre sowing of Sesbania aculeata @ 75 kg seeds ha-1, in situ incorporation at 45 DAS+75 % RDF (112.5: 37.5:37.5 Kg NPK ha-1), intercropping of Sesbania aculeata @ 25 kg seeds ha-1 and incorporation at 40 DAS + 100 % RDF, intercropping of Sesbania aculeata @ 37.5 kg seeds ha-1 and incorporation at 40 DAS +75 % RDF, GLM (Glyricidia maculata) @ 6.25 t ha-1 +100 % RDF, GLM (Glyricidia maculata) @ 9.75 t ha-1 + 75 % RDF, FYM @ 12.5 t ha-1 + 100 % RDF, FYM @ 18.75 t ha-1 + 75 % RDF, 100 % RDF alone (150:50:50 Kg NPK ha-1), 75 % RDF alone (112.5: 37.5:37.5 Kg NPK ha-1) and control. Four nutrient management practices were adopted viz., 100 % RDF (60:30:30 kg NPK ha-1), 75 % RDF (45:22.5:22.5 kg NPK ha-1), 50 % RDF (30:15:15 kg NPK ha-1) and control in succeeding cotton crop. Application of FYM @ 12.5 t ha-1 + 150:50:50 kg NPK ha-1recorded significantly higher dry matter production (10.90 t ha-1) and nutrient uptake (154.2:24.8:171.6 kg NPK ha-1) at harvest stage, grain yield (5538 kg ha-1) and straw yield (8693 kg ha-1) than inorganic fertilizer alone and control and it was on par with pre sowing of Sesbania aculeata @ 50 kg seeds ha-1, in situ incorporation at 45 DAS +100 % RDF (150:50:50 kg NPK ha-1). In succeeding cotton also, application of FYM @ 12.5 t ha-1 + 150: 50: 50 kg NPK ha-1 to rice exerted more residual effect and significantly improved the dry matter production (3.93 t ha-1) and nutrient removal (85.6:15.4:105.6 kg NPK ha-1) at harvest stage, seed cotton yield (1.29 t ha-1) and stalk yield (2.78 t ha-1). Direct application of inorganic fertilizer to residual crop/succeeding cotton at 100 % RDF (60:30:30 kg NPK ha-1) also significantly enhanced the dry matter production (4.18 t ha-1) and nutrient removal (101.0:17.6:114.5 kg NPK ha-1) at harvest stage, seed cotton yield (1.40 t ha-1) and stalk yield (2.87 t ha-1) than application of 75 % RDF (45:22.5:22.5kg NPK ha-1) and 50 % RDF (30:15:15 kg NPK ha-1).

The beneficial effect of intercropping of cereal (rice) and legumes (Green gram) with suitable row ratios studied under lateritic acidic soil condition of Visva-Bharati, West Bengal. Sole rice and green gram (Panna and PDM-84-139) recorded the maximum plant height, yield attributes and crop yields. Among the intercrops, rice crop sown with green gram at 2:1 row showed better performance than in other row ratios. The highest rice equivalent yield was observed at 2:1 ratio of rice+green gram cv. Panna but 1:1 ratio showed the highest benefit cost ratio. A minimum of 43.9% higher rice equivalent was observed under rice+PDM-84-139 green gram at 2:2 row ratio than rice alone. Competitive functions like relative crowding co-efficient, Land equivalent rati monetary advantage, area time equivalent ratio and relative value total were found maximum at 2:1 ratio of rice + green gram and green gram was found dominant crop in the intercropping systems.

Multi-location field experiments under Directorate of Rice Research during wet season 2002-03 and 2003-04 on responses of hybrids and inbreds to applied N, P and K revealed that the differences among hybrids/high yielding cultures and fertilizer treatments were significant at substantial number of locations while the interactions viz., varieties x fertilizer treatments were significant at majority of the centers. The paired t-test revealed that hybrids had a significant yield advantage of 0.82 t ha-1 during 2002 and 1.01 t ha-1 during 2003 over high yielding cultures indicating superiority of hybrids. With respect to responses of applied N, P and K nutrients, hybrids were found significantly superior to high yielding cultures for N responsiveness while response to P and K responses was not significant between hybrids and high yielding cultures. A significant positive relationship (R=0.51 to 0.57) between P availability in soils and response to applied N could be established irrespective of factors like variety and soil textural conditions and soil pH. Based on data from 9 locations in clay loam soils, no significant relationship between soil pH and response to N could be observed, while a negative relationship between soil pH and response to N could be established in clay soils. However, similar response was observed with hybrids and inbred rice varieties to applied P and K.

The performance of Azophos with different levels of NPK fertilizers on the rice variety PMK 3 was assessed under irrigated, semidry and rainfed field conditions. Growth and yield of rice were more by the application of recommended dose of NPK fertilizers, than those for the Azophos inoculation under irrigated condition. However, Azophos effected more growth, yield, nutrient content of PMK 3 than those of the recommended doses of NPK fertilizers under semidry, and rainfed condition i.e. under the water stress situations. The results concluded that Azospirillum produced growth hormone and Phosphobacteria increased root biomass through phosphorus solubilization, which gave drought tolerance to the plant under stress conditions.

Rate of decreasing levels of total sugar and starch content in rice plants during complete submergence could be considered as an indicator of submergence tolerance as revealed through repeated experiments with two submergence tolerant and two susceptible varieties. Younger the seedlings (7 days), quicker are depletion than in older seedlings of 10 and 15 days. Drastic reduction is thus prominent under prolonged submergence period (15 days) than 7 or 10 days of complete submergence. Susceptible varieties show maximum decrease in starch and sugar content than resistant varieties.

The influence of combined application of Azospirillum, Penshibao (a biochemical product) and growth regulators (Triacontanol, GA3 and Kinetin) on growth characters (plant height, number of tillers m-2 , LAI, Chlorophyll content and DMP) and yield parameters (number of panicles m-2, total number of grains panicle-1, number of filled grains panicle-1, thousand grain weight, grain yield-ha and straw yield-ha) were studied. Among the several treatments, seed soaking with Azospirillum (1200 g ha-1) and Penshibao 100ppm+foliar spray of Penshibao 100 ppm at 30 DAT+Miraculan (Triacontanol) 500 ppm+GA3 5 ppm at 45 DAT significantly increased the growth characters and yield attributes. This was followed by seed soaking with Azospirilum (1200 g ha-1) and Penshibao 100ppm+Miraculan (Triacontanol) 500 ppm+GA3 5 ppm at 45 DAT. The increase in grain yield was up to 50.52% over control.

Pest incidence on five aromatic rice varieties was recorded during wet seasons of 2001 – 2006. Maximum numbers of pests were observed during 2001 followed by 2005 and 2006. Varietal reaction did not play a prominent role for the high or low pest incidences. Analysis of weather parameters indicated that they play a major role in creating the variation in pest prevalence. Temperature and relative humidity remaining conducive during the cropping season in different years, wide variation was recorded in the amount of rainfall and its distribution in different months along with the variation in sunshine hour. High rainfall during June-July, with low sunshine hours in August, followed by gradual decrease of rainfall with increase in sunshine hours towards September and October resulted in more pest incidences than initial dry spell during June, July with high sunshine hours or less amount of total rainfall.

Biology of the rice tarsonemid mite Steneotarsonemus spinki was studied under laboratory at 28 ± 2.1°C temperature and 88 ± 5.9 per cent relative humidity during September 2003.Both the sexes passed through three stages viz. egg, larva, and adult and a short resting period known as quiescent stage. The egg stage lasted on an average 3.32 ± 0.55 days. Average larval period for male was 1.23 ± 0.44 and for female 1.52 ± 0.52 days and quiescent period was 0.53 ± 0.22 day for male and 0.66 0.24 day for female. Adult period was 5.28 0.54 days for male and 6.68±0.98 days for female. The total life cycle was completed in 12.20 ± 1.47 days and 13.75 ± 1.17 days for male and female, respectively. The pre-oviposition, oviposition and post-oviposition periods were 1.40 ± 0.39, 4.50 ± 1.20 and 1.65 ± 0.47 days, respectively. The female laid average 20 ± 5.03 eggs during its life span. The sex ratio (female:male) was recorded 1:1.5 and 1:2.8 in laboratory and field conditions, respectively.

The present study assesses the risk and profitability of rice seed production in the Union Territory of Puducherry. The percentage analysis and linear discriminant functions were used to analyze the data. The findings of the study indicated that seed production was profitable but a risky venture. A few farmers withdrew from the seed production programme in the initial stage due to non-availability of seeds, poor rainfall, poor germination, grazing and admixture. During the final stage of production, farmers faced the risk of rejection due to presence of other distinguishable varieties and germination failures. The farmers also faced the problems of late payment made by the purchasing agency, late release of subsidy, timely non-availability of seeds. The analysis on economics of seed production indicated that the expenditure on miscellaneous items like drying, marketing, registration and field inspection charges contributed towards the differences between the seed and commercial production. The cost of cultivation was higher in seed production as compared to the commercial production. The total return was higher in seed production than commercial crop production. The discriminant analysis indicated that there were significant differences in the gross return between seed production and commercial rice production.

The present experiment was conducted to screen the already adapted high yielding short duration rice varieties and pre release cultures for two critical sodicity sensitive phases of rice crop, viz., early seedling phase and reproductive stage. It was concluded that the rice genotypes, TRY2, ASD 16, MDU 5, CO 47 , IR 64, TR 2000-3, TR 2003-25 and TR 2004-08 were more suitable for sodic soils.

Productivity of rice in waterlogged area/deepwater area is very low due to submergence and at times prevailing water level of 1.5 to 2.0 m. In order to increase the economic return from these areas in wet season water chestnut along with fish was tried and high yielding rice varieties were grown during dry season in farmers’ field in Jaleswar area of Balasore district, Orissa. Black gram was grown in summer utilizing residual moisture of dry season crop. Three years experimentation in framers’ field indicated that the net benefit per hectare was increased from Rs.22,300 to Rs.42,050 when water chestnut was grown in wet season followed by rice in dry season. When fish component was added with chestnut the net return was increased to Rs1, 33,750. It is recommended that in deepwater/waterlogged area water chestnut may be grown with fish in wet season and rice in dry season. Black gram can be taken after dry season whenever moisture was available.

The efficacy of selected herbicides along with mulching for weed control in transplanted rice was evaluated under temperate conditions of Kashmir during wet seasons of 2006 and 2007. All the weed control treatments were superior to weedy conditions. Butachlor (1kg a.i. ha-1 3-5 days after transplanting) + brown sarson (Brassica campestris) straw mulching and pretilachlor (1 kg a.i. ha-1 3-5 days after transplanting) + brown sarson straw mulching had a mean grain yield of 9.3 and 9.2, respectively and were significantly superior to herbicide combination treatments viz. butachlor (1 kg a.i. ha-1) followed by (fb) 2,4-D ( 0.5 kg a.i. ha-1 20 days after transplanting) or pretilachlor (1 kg a.i. ha-1) 2,4-D (0.5 kg a.i. ha-1). All the weed control treatments resulted in higher uptake of nitrogen. Among weed control combination treatments, butachlor (1kg ha-1) + brown sarson straw mulching and pretilachlor (1 kg a.i. ha-1) + brown sarson straw mulching proved most profitable with net returns of Rs 35,813 ha-1and Rs 35,294 ha-1and benefit: cost ratio of 1.63 and 1.60, respectively.

The efficacy of new insecticides and combinations viz., Bifenthrin (10 EC), Flubendiamide 36% + Fipronil 30% (66 WG), Imidacloprid 40% + Ethiprole 40% (80 WG) and Monocrotophos (Check) (36 WSC) @ 10, 33, 100 and 500 g a.i. ha-1, respectively against major insect pests of paddy viz., whorl maggot and leaffolder during wet seasons of 2007 and 2008 evaluated at the Rice and Wheat Research Centre, Malan revealed that Flubendiamide + Fipronil @ 33g ai ha-1 was found to be effective for the control of leaffolder with 1.95 % damaged leaves (DL) as against 10.66 % DL in untreated control. Bifenthrin was found promising against whorl maggot (3.21 % DL) followed by Imidacloprid + Ethiprole (3.41 % DL) and Flubendiamide + Fipronil combination (3.58 % DL) as compared to untreated control (13.65 % DL).