Description of the subject. Weed pressure is a main biotic constraint in tropical agriculture. Cover crop mixtures have increased popularity to limit weed growth through competition for resources, but relationship between cover diversity and suppression still under debate. Objectives. This study aimed assess impact increasing (one four species) on control during two growing seasons (tropical su...

Variability of weed infestation needs to be assessed for site-specific weed management. Since manual weed sampling is too time consuming for prctical applications, a system for automatic weed sampling was developed. The system uses bispectral images, which are processed to derive shape features of the plants. The shape features are used for the discrimination of weed and crop species by using a...

Allelopathic substances can be used to develop weed control alternatives based on natural products. The objective of this study was to compare the phytotoxic activity of aqueous leaf extracts of Rapanea umbellata with the toxicity of a synthetic herbicide on the germination and growth of weed species. The weeds species barnyard grass (Echinochloa crus-galli), wild poinsettia (Euphorbia heteroph...

in order to evaluation of relation between weed dynamic and utilization of nitrogen in weed as influence of integrated fertilizer management in different weed densities, a field experiment was carried out in experimental farm of agricultural faculty of shahid chamran university of ahvaz at 2011-2012 growing season. experimental design was based on a split-plot with three replications .main plot...

OBJECTIVE: Because the prevalence and pattern of IgE-mediated hypersensitivity to inhalant allergens may vary between different European regions, our goal was to evaluate ragweed aeroallergen sensitization in allergic rhinitis patients from the central part of the Romanian Plain, located in the southern part of the country. MATERIAL AND METHODS: In a two-year period we recruited patients with a...

AIM To compare final height in two groups of low birth weight children examined for short stature: the first group untreated because of normal growth hormone (GH) secretion, the second treated with human growth hormone (hGH) because of abnormal secretion. METHODS A total of 49 subjects born at term of birth weight below the 10th centile were consecutively examined for idiopathic short stature...

Redroot pigweed is one of the injurious agricultural weeds on a worldwide basis. Understanding of its interference impact in crop field will provide useful information for weed control programs. The effects of redroot pigweed on cotton at densities of 0, 0.125, 0.25, 0.5, 1, 2, 4, and 8 plants m(-1) of row were evaluated in field experiments conducted in 2013 and 2014 at Institute of Cotton Res...

Weedy and invasive plants cost Americans billions of dollars annually in crop damage and lost earnings. Various Western states have reported annual weed control costs in the hundreds of millions of dollars. Herbicides account for more than 72 per cent of all pesticides used on agricultural crops. $4 billion was spent herbicides in the US in 2006 and 2007 (Grube, et al, 2011). The USDA Economic ...