جستجوی مقالات مرتبط با کلیدواژه « وزن تک دانه » در نشریات گروه « زراعت »

Growth characteristics, phenological stages, and yield components of crops are affected by environmental conditions and can affect seed yield. The present study evaluated the duration and rate of seed filling at three layers of upper, middle, and bottom, seeds number per plant, and seed yield of five rapeseed genotypes (RGS003, Dalgan, Zabol10, Hyola401, and Hyola4815) in 6 planting dates of fall (7-Oct, 17-Oct, and 27 Oct) and winter (9-Feb, 19-Feb, and 1-Mar). Two separate experiments were performed in autumn and winter as split plots in a randomized complete block design with three replications at the research field of Seed and Plant Improvement Institute, Karaj, Iran in 2015-2016 growing seasons. In each experiment, planting dates and rapeseed genotypes were considered as the main plots and sub-plots, respectively. The results of this study showed that the values of seed yield, single seed weight, seed filling duration, and seeds per plant decreased with delay in planting, especially in winter planting dates. The number of seeds per plant was more effective in final yield formation than the single seed weight, seed filling rate, and seed filling duration. The Dalgan genotype, although having a moderate single seed weight, seed filling rate, and seed filling duration, had the highest seed yield due to its greater number of seeds per plant. Also, the rapeseed genotypes produced the highest grain yield in Oct 7 and Feb 9 planting dates in the fall and winter seasons, respectively.

In order to determine the phenological differences of some improved rice cultivars in Iran for applying in crop simulation models, an experiment has been conducted in the research farm of the Rice Research Institute of Iran (Rasht) in 2020 as a randomized complete block with three replications. The experimental treatment consist of six rice cultivars (Rash, Anam, Gohar, SA1, SA6 and M7). Results show that the highest development rate can be observed in development rate in juvenile phase and grain filling phase in Anam cultivar. The minimum and maximum time required to start emergence with 3 and 6 days are in Anam and Gohar cultivars, respectively. The maximum time required to achieve maximum flowering and physiological maturity is obtained with 71 and 103 days in Gohar cultivar. The highest flowering period with 19 and 20 days is obtained in late maturing Rash and Gohar cultivars, respectively. The highest growth degree days (GDD) in beginning of grain filling to maturity stage is observed with 401 GDD for M7 cultivar. The highest growth-day for pre-flowering with 1208 GDD belongs to Gohar cultivar. The highest harvest index is obtained with 50.91% in Gohar cultivar. The results also show that the single grain weight under ideal growing conditions with 0.030 g is observed in Gohar and M7 cultivars. The highest plant height belongs to cultivar M7 with 150 cm and the highest total nitrogen uptake is observed in the plant at maturity of Anam cultivar. Overall, the estimated genetic coefficients in different models differ between cultivars and the coefficients vary in the range defined in the model for different groups of maturity. To accurately calculate the genetic coefficients, it is suggested that this experiment should be repeated over several years and in different ecosystems under rice cultivation.