نتایج جستجو برای: weed ecology
تعداد نتایج: 63816 فیلتر نتایج به سال:
Ischaemum rugosum is a competitive weed in direct-seeded rice systems. Developing integrated weed management strategies that promote the suppression of weeds by crop density, cultivar selection, and nutrition requires better understanding of the extent to which rice interferes with the growth of this weed and how it responds to resource limitation due to rice interference. The growth of I. rugo...
The compositions of the germinable weed seedbank and aboveground weed communities in a long-term tillage and rotation study were characterized 4, 5, and 6 yr (2002 to 2004) after the adoption of glyphosate-tolerant corn and soybean. Averaged across rotation, mean germinable weed seed density and diversity were greatest in the no-tillage treatment as compared to the minimumand conventional-tilla...
This study discusses the methodical problems which occur during the process of generating weed distribution maps in geoinformation systems (GIS). Particular attention will be paid to the question of whether or not the weed sampling data and the weed distribution maps for site-specific weed control are sufficiently representative. Manual or image-processing sampling procedures are applied in ord...
This paper demonstrates the framework and methodology how weed population dynamics can be predicted using rule-base fuzzy logic as applied to GIS spatial image. Parthenium weed (parthenium hysterophorus L.) infestation in the Central Queensland region poses a serious threat to the environment and economic viability of the infected areas. Government agencies have taken steps to control and manag...
Whilst it is agreed that climate change will impact on the long-term interactions between crops and weeds, the results of this impact are far from clear. We suggest that a thorough understanding of weed dominance and weed interactions, depending on crop and weed ecosystems and crop sequences in the ecosystem, will be the key determining factor for successful weed management. Indeed, we claim th...
The emerging field of molecular ecology aims to improve the ecological predictability of transgenic crop plants. The most widely cultivated lines are Roundup-Ready plants, which are genetically modified to be resistant to the broad-spectrum herbicide glyphosate. Recent publications demonstrate two ecological effects that were not anticipated: the widespread emergence of glyphosate-resistant wee...
The biotic crisis overtaking our planet is likely to precipitate a major extinction of species. That much is well known. Not so well known but probably more significant in the long term is that the crisis will surely disrupt and deplete certain basic processes of evolution, with consequences likely to persist for millions of years. Distinctive features of future evolution could include a homoge...
Hay fever or pollinosis is the allergic reaction of the human body to allergic pollen grains and is a seasonal phenomenon. Pollen concentrations depend on the climate, geographic features, and vegetation. Trees, grass, and weed pollinosis is frequent in Croatia, common ragweed (Ambrosia artemisifolia L.) pollinosis in particular. Continuous monitoring of pollen air concentrations can provide ti...
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...
Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a) increasing duration of weed interfe...
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