No abstract

Forty-five rice lines comprising of thirty derived hybrid lines obtained from ten tropical Japonica, three Indica and two national checks viz. Pusa Basmati 1121 and Sarjoo-52 were evaluated for selection parameters, yield contributing components and genetic divergence. Fifteen quantitative and three qualitative traits were studied from experimentation with randomized block design during Kharif 2011. The phenotypic coefficient of variability was higher than genotypic coefficient of variability for all of the traits. The highest estimates of broad sense heritability coupled with genetic advance in per cent of mean was recorded for spikelets per panicle, plant height followed by L:B ratio, spikelets per panicle, grains per panicle, biological yield per plant, flag leaf area, days to 50% flowering, plant height which might be due to the additive nature of gene action. Such results indicated that these traits will be reliable for the effective selection. Highly positive and significant correlation was observed at both phenotypic and genotypic level between grain yield per plant and biological yield per plant, followed by panicle bearing tillers per plant, spikelet fertility, panicle length, 1000-grain weight, grains per panicle, panicle weight, flag leaf length, spikelet per panicle, flag leaf area, kernel length, flag leaf width, days to 50% flowering, and harvest index. This relationship reflected that grain yield and aforesaid economic traits can be increased simultaneously in breeding programme to develop high yielding Indica as well as Tropical Japonica rice varieties. Whole genotypes grouped in 8 non-overlapping clusters exhibited maximum genetic diversity between clusters III i.e., TJ- × PB-1. These clusters also stand for early days to flowering, short slender, second highest harvest index and panicle bearing tillers per plant, spikelets per panicle, grains per panicle, spikelet fertility, 1000-grain weight, long bold slender, biological yield per plant, and grain yield per plant. These genotypes showing higher mean performance for aforesaid traits can be exploited for enhancing hybrid vigour of desired New Plant Type with higher number of panicle bearing tillers per plant, spikelet per panicle and grains per spike in Indica as well as Tropical Japonica rice varieties for achieving higher yield.

A field experiment was conducted during two consecutive years of 2015-16 and 2016-17 at Central Potato Research Station, Patna with objective to evaluate theresponse of zinc on potato tuber yield. Significant effect of zinc application was not noticed on plant emergence and plant height of crop at 30 days after planting. However, higher plant height was recorded in the plot which received the zinc as compare to without zinc application. Significant difference in plant height was observed at later stages of crop due to application of zinc at the rate of 6.0 kg/ha along with recommended dose of fertilizers. Similarly, dry matter yield of potato tubers was also recorded consequently higher due to application of higher doses of zinc. Tuber grades of 0-25g and 25-50g were found non-significant irrespective of doses of zinc application in potato. Significant variation in medium and large size tuber yield were recorded due to application of zinc @ 6 kg/ha over without zinc application. About 18.1% increase in marketable tuber yield of potato was found due to application of zinc @ 6.0 kg/ha as compare to without zinc application. About11.3% and 13.7% increase in the total tuber yield of potato was observed due to application of zinc @ 4.5 and 6.0 kg/ha, respectively over without zinc application. However, no significant variation in pooled yield was found with application of zinc up to 3.0 kg/ha over without zinc application. The highest net return (Rs. 36.0×103/ha) and net benefit cost ratio (2.52) was recorded due to application of zinc @ 6.0 kg/ha as compare to without zinc. Application of zinc @ 6.0 kg/ha along with recommended dose of NPK may be found more beneficial for potato cultivation under Eastern Indo-Gangetic plains of India.

The present investigation was carried out during 2016-17 at NDUA&T, Ayodhya to assess the genetic variation and heritability for quantitative traits in rice (Oryza sativa L.) under sodic soil. The experimental materials of rice comprised of 10 genotypes as lines (females) and three testers (males), viz. Pusa Basmati-1, CSR-10 and N.Usar-2009. Each of three testers was crossed with 10 lines during kharif 2016. The genotypes were grown during kharif 2017 and evaluated along with their parents and one check varieties (Narendra Usar-3) in randomized complete block design with three replications. The experiment was conducted at soil having pH 9.2, EC-2.21 dS/m and ESP 43%. The analysis of variance revealed that all the treatments, viz. parents, parent vs crosses, crosses, lines and testers were highly significant for majority of the yield and its contributing traits. The estimates of phenotypic coefficient of variation were higher than genotypic coefficient of variation for all the traits. Estimate of high heritability (broad sense) coupled with high genetic advance in percent of mean were observed for the characters like grain yield/plant, biological yield/plant, grains/panicle, panicle bearing tillers/plant, spikeley's/panicle, chlorophyll content and flag leaf area indicating the involvement additive gene action. The moderate narrow sense heritability with low genetic advance in percent of mean were observed for panicle length and harvest index indicating presence of non-additive gene action suggesting heterosis breeding may be useful for rice improvement in sodic soil.

Among seven small millets, only foxtail millet (Setaria italica) and proso millet (Panicum miliaceum) were found infested with a seed borne nematode, Aphelenchoides besseyi. Basically, the nematode is a serious pest of rice and causes whip tip of paddy, but significant infestation was also recorded in foxtail millet and proso millet. Green foxtail millet (Setaria viridis), crab grass (Panicun sanguinale) and guinea grass (Panicum maximum) were also found infested with A. besseyi. It causes Ear blight or Light ear disease in foxtail millet. Characteristic symptoms of nematode infestation were distortion and spreading of panicles, production of chaffy grains and delayed maturity. Maximum nematode population was recorded in the seeds having black seed coat and abnormal seeds of both the millets. Variation in morphology and morphometric attributes of nematodes was recorded among rice, foxtail millet and proso millet isolates. Amphimictic mode of reproduction was reported in the populations of A. besseyi in foxtail and proso millet. More survival of nematode was found in proso millet as compared to rice. Auxenic culture of Alternaria alternata and Curvularia lunaat supports the growth and reproduction of A. besseyi in proso millet. Number of females over one male was maximum in foxtail millet (5.25) followed by rice (3.41) and proso millet (3.16). Lowest population of nematode was recorded in foxtail millet cultivars