Effect of temperature on seed setting behaviour in rabi sorghum (Sorghum bicolor (L). Moench)

Pollen viability is an important parameter of yield as for as interaction of temperature with seed setting is concerned. Rabisorghum is one of the major cereal crops after rice, wheat and maize. In sorghum seed setting is affected when the floweringperiod coincides with minimum temperature. In this context comparison was made with pollen fertility percentage and seedsetting percentage vs minimum temperature at flowering. The study revealed that the range of pollen fertility percentage washigher than the range of seed setting percentage in all the dates of sowing and temperature regimes. Narrow range of seed set% was observed in BRJ-358, BRJH-129 and R-354.Varieties showed high seed set percentage (79.3) compare to hybrids, Rlines, B lines and stay green lines but mean pollen fertility was still higher than this i.e >90%. In other words, seed settingpercentage is more affected by temperature at all the six dates compare to pollen fertilit

Influence of different temperature regimes on seed setting behavior and productivity traits in rabi sorghum

The experiment was conducted involving 35 rabi sorghum genotypes sown at six different dates of sowing (from Sept Istweek to October IVth week) during 2006-07 to assess the stability for pollen fertility (%), seed setting (%) and otherproductivity traits viz., plant height, days to 50% flowering, number of leaves, length of panicle, panicle weight, paniclediameter, number of primaries/panicle and 500-grain weight. The influence of dates of sowing on different phenotypiccharacters indicated that delayed sowing reduced the expression of all the traits. Flowering was early when genotypes weresown at 3rd date. The grain yield in general was high in the Ist date of sowing compared to the remaining dates. The seed set% (irrespective of sowing dates) was more than 65 as long as minimum temperature was more than 13 ºc where as, it wasdrastically reduced when minimum temperature was dropped down below 10 ºc. Pooled analysis of variance revealedsignificant difference among the genotypes and environments for all the characters indicating genotypes and environmentstested were diverse in nature. The G x E interaction was high and linear for most of the characters indicating significant andlinear response of genotypes to changing environment for these traits. On the basis of stability parameters it was revealedthat the two genotypes viz., DSH 4 and M 35-1 were stable for majority of the characters across the dates of sowing. As faras pollen fertility is concerned M31-2B, BJMS2B, 27B, 101B, BJMS204B, SPV570, BRJ62, RS29, AKR 150, BRJ 358,DSV5, DSV4, M35-1, DSH4, and CSH14 were stable in all the dates of sowing. The genotypes 1409B, 116B, M31-2B,101B, R354, C43, DSV5, DSV4, M35-1, DSH4 and BRJH 129 were stable in seed setting behavior across the dates ofsowing. With respect to grain yield/plant the two genotypes viz., 116B and M35-1 were most stable. In general, the B linesshowed less stability for many characters and the hybrids were found to be more stable across the dates of sowing for manycharacters indicating the scope for development of hybrids for rabi season. Among the hybrid parents R lines exhibitedstability for many characters across the dates of sowing while B lines were found to be not stable indicating the need for thedevelopment of stable B lines for rabi ecosystem. Among the 35 genotypes the lines viz., 296B, AKMS14B, C43, AKR150and B35 were not stable for any of the characters indicating their sensitivity to rabi environment as a whole

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Not AvailableThe Patapur micro-watershed situated in semi-arid region needs effective management of resources for sustainable agriculture. The Soil and Water Assessment Tool (SWAT), a semi distributed physically based model, was chosen and set up in the Patapur micro-watershed for sediment yield modeling. SWAT-CUP (SWAT-Calibration and Uncertainty Programs) was used for model calibration, sensitivity and uncertainty analysis, following the Sequential Uncertainty Fitting (SUFI2) technique. The model calibration was performed for the period (2009–2014), with initial 3 years of warm up (2009–2012), then, the model was validated for the subsequent 2 years of data (2014– 2006). To assess the competence of model calibration and uncertainty, two indices, the p-factor (observations bracketed by the prediction uncertainty) and the r-factor (achievement of small uncertainty band), were taken into account. The results had shown that p-factor for daily, monthly and annual time step were 0.55 (55%), 0.62 (62%), 0.70 (70%), respectively while r-factor for daily, monthly and annual were 0.63 (63%), 0.45 (45%) and 0.37 (37%), respectively, while during the validation p factor and r-factor for daily, monthly and annual were 0.45, 0.72 and 0.75, respectively. Whereas r-factor for daily, monthly and annual time step were 0.73 (73%), 0.38(38%) and 0.34 (34%), respectively. After a rigorous calibration and validation, the goodness of fit was further assessed through the use of the coefficient of determination (R2 ) and the Nash–Sutcliffe efficiency (NS) between the observed and the final simulated values. The results indicated that R2 and NS were 0.68 and 0.68, respectively, during the daily calibration. The validation also indicated a satisfactory performance with R2 of 0.76 and NS of 0.72. The results would be useful to the hydrological community, water resources managers involved in watershed management and soil conservation for efficient design of soil conservation structures.Not Availabl

Genetic control of cowpea seed sizes Controle genético do tamanho das sementes de caupi

Cowpea [Vigna unguiculata (L.) Walp.] is one of the most widely adapted grain legumes in hot regions of Africa, Asia and the Americas. In the semiarid Northeast of Brazil, it is the main subsistence crop, an excellent protein source of low cost, for the poor population. The objective of this work was to estimate genetic parameters to understand the inheritance of seed sizes in cowpea. The parents P1 and P2 and the generations, F1, F2, BC1 and BC2 of the cross TVx5058-09C X Manteiguinha formed the genetic material for this study. These six generates (P1, P2, F1, F2, BC1 and BC) were evaluated in a completely randomized block-design with six replications, in Teresina - PI, Brazil, in 1998. The genetic parameters estimated were: phenotypic and total genetic variance, additive and dominance genetic components of variance and the variance attributed to the environment, heritability in the broad and narrow senses, average degree of dominance and the number of genes controlling the character. The additive - dominance model fitted the data for 100-seeds weight in as much as the midparental value and the additive effect were the more important genetic parameters for the determination of this character. The number of genes that control its expression is five. The occurrence of high values for narrow sense heritability indicates that the selection for seed size can be made in early generations.<br>Caupi [Vigna unguiculata (L.) Walp.] é uma das leguminosas mais adaptadas às regiões quentes da África, Ásia e das Américas. No semi-árido do nordeste do Brasil é a principal cultura de subsistência, por ser uma excelente fonte de proteína de baixo custo para a população mais carente. O objetivo deste trabalho foi estimar parâmetros genéticos que podem explicar a herança do tamanho das sementes de caupi. Os genótipos parentais P1 e P2 e as gerações F1, F2, RC1 e RC2 do cruzamento TVx5058-09C X Manteiguinha, constituíram o material genético utilizado no estudo. As seis populações (P1, P2, F1, F2, RC1 e RC2) foram avaliadas num experimento em blocos casualizados com seis repetições, em Teresina - PI; o plantio foi realizado em março de 1998. Os parâmetros genéticos estimados foram variâncias fenotípica, genética total, genética aditiva e dos desvios de dominância e devido aos efeitos do ambiente, herdabilidades no sentido amplo e restrito, grau médio de dominância e número dos genes que controlam o caráter. O modelo aditivo - dominante ajustou-se aos dados do peso de 100 sementes, visto que a média e o efeito gênico aditivo foram os parâmetros genéticos mais importantes na determinação desse caráter. O número dos genes que controlam sua expressão é cinco. A ocorrência de alto valor para a herdabilidade no sentido restrito indicou que a seleção para o tamanho da semente pode ser realizada em gerações segregantes iniciais

Estimation of population variance in successive sampling

Successive sampling, Class of estimators, Bias and Mean Square Error,