In complex task domains, such as games, students may exceed their teachers. Such tasks afford diverse means to tradeoff one type of performance for another, combining task elements in novel ways to yield method variations and strategy discoveries that, if mastered, might produce large or small leaps in performance. For the researcher interested in the development of extreme expertise in the wil...

to evaluate general and specific combining ability for resistance to bolting and cercospora leaf spot, 36 hybrids derived from crosses between 9 sugar beet lines along with four checks were planted in safiabad agricultural research center (dezful) in 2008-2009. the experimental design was a triple lattice design with three replications. analysis of variance showed significant differences among ...

abstract low water holding capacity of soilless substrates increases water stress and waste of nutrient solution. irrigation time management can reduce such problems. in this research, responses of hydroponically cultured greenhouse strawberries were evaluated under different irrigation schedules. in first step, plant daily water need was estimated and then delivered to plants through two metho...

rust diseases continue to cause significant losses to wheat production around the world. among them, yellow rust caused by puccinia striiformis f. sp. tritici is an important disease that threatens wheat production in most cool environments. host resistance, especially race- nonspecific resistance, is the most economical way to manage wheat stripe rust disease. in this study, the effectiveness ...

Introduction: The Mediterranean corn borer (MCB), Sesamia nonagrioides, is a major pest of maize, Zea mays, in Mediterranean countries, inflicting significant kernel yield losses. For that reason, it necessary to know the genetic mechanisms that regulate the agronomic and resistance traits. A quantitative trait loci (QTL) mapping study for yield, resistance against MCB attack, and other relevan...

Recently, there have been rapid developments in understanding the costs of disease and pest resistance in model plants and their ecological relevance in wild plants. In crop plants, however, much (although not all) of our current understanding of costs of resistance must be inferred from research on model species. To determine the true costs of resistance in crops and the likely benefit of resi...

resistance of 16 sugar beet cultivars to cercospora leaf spot was evaluated in ghaemshahr region. the experiment was conducted in a complete block design with six replications and disease severity of cultivars was measured two times. as a winter crop the root yield of cultivars and their disease severity compared under natural cercospora infection in dezfoul area in a complete block design with...