نتایج جستجو برای: wheat fields
تعداد نتایج: 300138 فیلتر نتایج به سال:
Introduction Stand establishment is the first step in producing a good wheat crop, and most producers intend to obtain a uniform stand of wheat. However, intentions are not always the same as reality when it comes to wheat establishment. A study conducted in the early 1990s by the OSU Small Grains Extension Program compared producer perception of wheat seeding accuracy with actual field measure...
Abstract The aim of this research is to present a simulation model for reducing economic damages of mechanized wheat harvesting in the weather conditions of Khuzestan province and similar areas. The simulated model is composed of three sub-models, for determining of the appropriate working hours, grain losses, and economic sub-model. In order to determine the appropriate working hours, a mathem...
Pyricularia oryzae is a species complex that causes blast disease on more than 50 species of poaceous plants. Pyricularia oryzae has a worldwide distribution as a rice pathogen and in the last 30 years emerged as an important wheat pathogen in southern Brazil. We conducted phylogenetic analyses using 10 housekeeping loci for 128 isolates of P. oryzae sampled from sympatric populations of wheat,...
Rainfed wheat (Triticum aestivum L.) is planted each year on 1.5 million ha in the low-precipitation region (150 to 300 mm) of north-central Oregon and south-central Washington. Precipitation occurs mostly (75%) from late autumn (October) to early spring (April) and the amount is highly variable from year to year. Winters are cold and intervals of frozen soil are common. Warm to hot days and co...
"> The present study described the diversity of wheat and barley varieties andlandraces available in farmer’s fields in Syria using different indicators. Analysisof spatial and temporal diversity and coefficient of parentage along withmeasurements of agronomic and morphological traits were employed to explain thediversity of wheat and barley varieties or landraces grown by farmers in Syria.Farm...
From 1997 to 1999, Schizaphis graminum (Rondani), intensity (number per tiller) was estimated on 115 occasions from hard red winter wheat fields located throughout the major wheat growing regions of Oklahoma. A total of 32 and 83 fields was sampled during the fall and spring, respectively. The parameters of linear regressions relating the mean number of greenbugs per tiller (m) and the proporti...
The growth status of winter wheat in irrigated field and rainfed field are obviously different and the field types may have an effect on the predictive accuracy of hyperspectral model. The objectives of the present study were to understand the difference of spectral sensitive wavelengths for leaf area index (LAI) in two field types and realize its hyperspectral prediction. In study, a total of ...
wheat (triticum aestivum) growth and yield are depressed by physical and chemical interference of weeds. recently, wild barley (hordeum spontaneum) population has increased in wheat fields of many provinces of iran. since, little is known about the allelopathic effects of wild barley residues in soil, greenhouse studies were conducted to examine the effects of soil amended residues of wild barl...
Wheat aphids are major pests during the seed filling stage of wheat. Plant lectins are toxic to sap-sucking pests such as wheat aphids. In this study, Pinellia pedatisecta agglutinin (ppa), a gene encoding mannose binding lectin, was cloned, and it shared 92.69% nucleotide similarity and 94% amino acid similarity with Pinellia ternata agglutinin (pta). The ppa gene, driven by the constitutive a...
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