in order to study the weed damage and to determinate the influence of weed species and multiple weed species competition in corn (zea mays l.), a field experiment was conducted based on interval mapping at the agronomy research field of ferdowsi university of mashhad during 2009-2010. treatments consisted of four density level of crop (5, 6, 7 and 9 plant.m-2) and four type of weed management (...

chickpea (cicer arietinum l.) is a dry pulse crop commonly used from old time. the chickpea yield is lower as compared to maximum potentials of the cultivars. the gap could mainly be attributed to the weed competition in addition to other production constraints. although chickpeas are traditionally grown on residual soil moisture, weeds competition pose major problem in many situations. in orde...

In this study, we reviewed weed seed bank dynamic and main agriculture operations to come up with the management modeling designed increase crop productivity by removing competition. Weed contributing 10% loss of total global grain production. regulate five demographic processes seedling recruitment survival, production, dispersal survival in soil. The that interference are rotation primary til...

In northern Laos, rapid population growth and government policies to reduce the area under slash-and-burn systems have resulted in increased cropping intensity, which has increased weed pressure and reduced yields of upland rice. Promising alternative cropping systems include the use of weed-suppressing and multi-purpose legumes as short-term fallow crops. In this study, Stylosanthes guianensis...

Variations in climate are widely recognized as central factors governing the competitive balance in mixedspecies plant communities. In agricultural systems, highly variable patterns of crop yield reduction as a function of weed density have been documented across sites and among years at the same site for several crop–weed combinations. This variation is typically attributed to contrasting envi...

Weed interference in annual cropping systems can be highly variable from year-to-year, as well as spatially heterogeneous. These factors have confounded efforts to develop simple methods for predicting competitive outcomes early in the growing season. A 2-year study was conducted with maize in competition with four annual weed species (Setaria faberi, Abutilon theophrasti, Chenopodium album and...

Weed control through crop rotation has mainly been studied in a nonspatial context. However, weed seeds are often spread beyond the crop field by a variety of vectors. For weed control to be successful, weed management should thus be evaluated at the landscape level. In this paper we assess how seed dispersal affects the interactions between crop rotation and landscape heterogeneity schemes wit...

Concerns exist that transgenic crop x weed hybrid populations will be more vigorous and competitive with crops compared with the parental weed species. Hydroponic, glasshouse, and field experiments were performed to evaluate the effects of introgression of Bacillus thuringiensis (Bt) cry1Ac and green fluorescent protein (GFP) transgenes on hybrid productivity and competitiveness in four experim...

Post-Conservation Reserve Program (CRP) land may provide an excellent opportunity to satisfy certified organic crop production requirements. However, conversion of CRP or long-term pastureland to certified organic production will require tillage because the use of herbicides is prohibited in organic production. Our objectives were to evaluate stand establishment, weed competition, yield, and gr...

Evolutionary theory can be applied to improve agricultural yields and/or sustainability, an approach we call Evolutionary Agroecology. The basic idea is that plant breeding is unlikely to improve attributes already favored by millions of years of natural selection, whereas there may be unutilized potential in selecting for attributes that increase total crop yield but reduce plants' individual ...