جستجوی مقالات مرتبط با کلیدواژه « عملکرد نهایی » در نشریات گروه « زراعت »

The large fluctuations of the final yield of greenhouse cucumber are of great importance in Iran due to its very large cultivated area, so that 76.47% of all greenhouses in the country are under cucumber cultivation. In order to investigate the effect of crop density and variety in the production of greenhouse cucumber (Cucumis sativus), a factorial experiment was conducted in the form of a basic design of randomized complete blocks in 3 replications during 2016 and 2017. Based on this, single-flowered, double-flowered, medium-flowered and multi-flowered cucumber cultivars were cultivated in different planting densities of 37, 42 and 47 cm. The results of the research showed that the highest production productivity was achieved in the planting density of 42 cm between the plants and the selection of    multi-flowered cultivars with a maximum yield of 270 tons per hectare, and the lowest yield was obtained in single-flowered cultivars with a planting density of 37 cm. meter and numerical value of 197 tons per hectare was obtained. Therefore, the main reason for the decrease in cucumber yield in Tehran province was the selection of low-flowering cultivars with inappropriate planting density.

The present research was conducted to evaluate the effect of terminal drought stress on quantity and quality of seeds produced from six promising genotypes of winter rapeseed in East-Azerbaijan Research center for Agriculture and Natural Resources during growing season 2014-15. The factorial experiment based on randomized complete block design was laid out in three replicates including two factors of genotype (six winter rapeseed genotypes called Karaj2, Karaj3, KS7, L5, L146, L210) and water limitation (three levels of water deficit stress viz. full irrigation IW1, irrigation withholding from anthesis IW2 and irrigation withholding from seed set IW3). Imposing water restriction from anthesis caused more loss of silque and seed number and final yield. The least loss of seed yield obtained from L5 and L210 genotypes under drought stress during anthesis. The greatest and lowest fall in seed germinability were recorded in L146 under drought stress from anthesis and L5 and L210 under the same stress level, respectively. Under water limitation from anthesis, the least increase of seed electroconductivity was observed in genotype L5. The greatest length and vigor index of seedling was observed in genotypes L5 and L210 under irrigation withholding from flowering. In general, occurring terminal drought stress especially during anthesis of rapeseed caused significant drop in seed production, both quantitatively and qualitatively. On the other hand, genotypes L5 and L210 had the best yield under stress condition and would recommended for introducing to breeding program of drought stress tolerance.

This study was done because of deficiency of water and necessity in economized water source and other hand in this research performance the positive role of some element such as zinc in decrease the negative effect of drought stress. This experiment was carried out in maize kind Maxima in Fars province Kavar Town. The levels of irrigation containing 8days، 10 days، 12 days and14 days were the main factors and time of foliar application including without foliar application، once foliar application and twice foliar application were the sub factors. The result showed that the period of irrigation 8،10،12 days didn’t make any difference in yield، in situation of 14 days of irrigation there was significant difference in yield، two zinc of foliar application in some characteristics such as leaf area index (LAI) and grain protein content was significant. Interaction of zinc foliar application and period of irrigation، the best grain yield obtain as 9438 kg/ha from two time foliar application with 12 days irrigation. Therefore there is no significant difference between drought stress in 8،10 and 12in period of irrigation in grain yield. In situation of two time zinc foliar application، increasing five and thirteen percent on yield and protein content via control observed respectively and in 14 days and two time zinc foliar application via 8، 10 and 12 period of irrigation in chracteristic LAI، yield component and yield showed increasing significant difference، but in LAI and grain protein content significant difference was observed. So it can be said that the best grain yield obtained from interaction between 12 days period of irrigation and two time of foliar application.