in other to evaluate grain yield, rate and effective grain filling period of four barley (hordeum vulgaris l.) cultivars in different planting dates, a factorial experiment based on a randomized complete block design was conducted in the islamic azad university of ardabil research station in 2009. the treatments applied were: three levels of different planting dates (september, 23; october, 16 ...

the crop simulation models are heuristic tools in order to determine optimal of management strategies and analyzing yield stability in agroecosystems. the objective of this study was to evaluate cropsyst model ability for simulating of development, growth and yield of wheat cultivars from golestan province in response to planting date. the results of model evaluation were acceptable so that, th...

this study planed to determine appropriate planting date and proportion of alfalfa and barley in mixed cropping. experiment carried out in khair abad station of agricultural and natural resources research center of zanjan for five years (2004-2007), using split plot design which main plot was planting date (aug .15, sep.26 and oct .6) and subplot contain alfalfa to barley ratio, barley, alfalfa...

Planting date of soybean, Glycine max, influenced winter survival of Pratylenchus brachyurus in microplots at two locations in North Carolina. Delayed planting resulted in a linear decrease (P = 0.05) in the numbers of P. brachyurus at soybean harvest. Effects of planting date on nematode numbers persisted over winter, indicating that survival in the absence of a host is density independent. Co...

 In order to evaluate the effects of cover crops on reduced weed biomass in hybrid sunflower an experiment was carried in the research stations, Natural Resources Medicinal Plants (Samian_Ardabile) with 3 replicates in 1390-1391. The first factor was considered three type of cover crops, winter rye, spring barley, winter wheat with 2 control treatment, second factor was mulch management at two ...

Environ.Entomol.21(2):264-268(1992) ABSTRACT Soybean, Glycine max (L.) Merr., resistance to insects has been shown to vary with planting date and leaf age. This study determined effects soybean genotype, planting date, and leaf age had on feeding behavior of com earworm, Helicoverpa zea (Boddie). Soybean genotypes 'Cobb' (susceptible) and 'GatIR81-296' (resistant) were planted early (29May) and...

weeds in wheat (triticum aestivum l.) fields have always been a big problem in iran and worldwide and must be managed by non-chemical especially cultural methods. a field experiment as factorial based on a randomized complete block design with four replications in a 1000 m2 field in research farm of shirvan college of agriculture was conducted during 2007-2008. treatments included wheat densiti...