جستجوی مقالات مرتبط با کلیدواژه « آنالیز رشد » در نشریات گروه « اکولوژی »

In order to evaluate different irrigation amounts and salicylic acid spraying and determination of principal components in water use efficiency of sesame (Sesamum indicum L.), maize (Zea mays L.) and common bean (Phaseolus vulgaris L.), a split plots experiment based on RCBD design with three replications was conducted in 2014-2015 growing seasons, in Ferdowsi University of Mashhad, Iran. Irrigation levels (50 and 100% of water requirement) and application and non-application of salicylic acid assigned to main and sub plots, respectively. The result showed that in sesame and maize, the highest seed yield obtained in conditions of salicylic acid application. Variables analyzed to 3 factors in sesame and 2 factors in maize and bean. In sesame, first factor included variables of dry matter yield, plant height, leaf erea index and soil phosphorous, variables of seed yield, seed weight per plant, crop growth rate and water use efficiency were in second factor and variables of EC, soil nitrogen and pH had the highest load in third factor. In maize, variables of seed yield, dry matter yield, seed weight per plant, plant height, crop growth rate, leaf erea index and water use efficiency were on first factor and variables of soil nitrogen, EC, pH and soil phosphorous had the highest load in second factor. In bean, variables of seed yield, dry matter yield, seed weight per plant, crop growth rate, soil nitrogen and phosphorous, EC and water use efficiency were in first factor and second factor included variables of leaf erea index, plant height and soil pH. In general, in all three plants, water use efficiency and effective variables in seed yield were in same factor, therefore it seems that any change in these variables will result in a direct change in water use efficiency.

In order to investigate the impact of the sowing date on yield, yield components and physiological growth indices of grain maize (Zea mays L.) cultivars, a field experiment was conducted at the Faculty of Agriculture of the University of Lorestan in 2011 as a randomized complete block design with factorial arrangement of treatments and three replications. Treatments consisted of two sowing dates (21st May and 13th June) and six maize cultivars, namely T.V.C.767 and S.C.704 from a late maturing group, cultivars T N.S640 and Maxima from a mid maturing group, and cultivars Koppany and D.C.370 from early maturing group. Results indicated that the main effects of the experimental factors were statistically significant in terms of 1000-kernel weight, number of kernels per ear, number of kernels per row, number of rows per ear and harvest index. The interaction between sowing date and cultivar was only significant in the case of biological and grain yields, ear length and plant height. In the first sowing date the highest and lowest grain yields belonged to cultivars S.C.704 and D.C370 (12.7 and 7.5 t ha-1, respectively). In the second sowing date, N.S.640 from mid maturing group was ranked first in this regard (13.37 t ha-1). Higher grain yield in S.C704 and N.S640 compared to other cultivars, could be attributed to their higher leaf area index, leaf area index duration and crop growth rate. In total, planting late maturing group cultivars is not recommended for the second sowing date.

To investigate the effect of various levels of nitrogen fertilizer and different plant density on nitrogen use efficiency (NUE) and growth analysis of corn, a split plot experiment based on randomized complete blocks design with three replications was conducted in Ardabil Agriculture Research Station in 2005. The factors were nitrogen fertilizer at three levels in main plots (0, 75 and 150 Kg N ha-1) and plant densities in subplots (7, 9 and 11 plants m-2). The results showed that NUE was significantly affected by plant density and nitrogen levels. Maximum rate of NUE was obtained in application of 75Kg N ha-1. There was no significant difference between 75 and 150Kg N ha-1. With increasing plant density, the NUE was decreased, and maximum NUE was also obtained in density of 7 plants m-2. With increasing plant density and nitrogen levels, total dry matter, crop growth rate and grain yield were increased. Grain yield per plant decreased with increasing plant density. With increasing nitrogen levels and decreasing plant density the number of kernel per row, and number of kernel in ear were increased. Numbers of kernel in ear were only affected by nitrogen levels, and was decreased with increasing nitrogen levels. Number of ear per plant and weight of thousand grains wasn’t affected by levels of the experimental factors.