The repellence of Aristolochia aff. orbicularis root, a native of Xochipala, Guerrero, Mexico, to the corn borer Sitophilus zeamais (Coleoptera) was investigated. The essential oil was isolated from the aromatic root and its repellent effect was assessed. About 40 components of the oil were identified using gas chromatography-mass spectrometry and other spectroscopic methods. The repellence of ...

Different techniques for estimating seasonal water use from soil profile water depletion frequently do not account for flux below the root zone. Shallow water table contribution to supply crop water use may be important in arid and semi-arid regions. Development of predictive root uptake models, under influence of shallow water table makes it possible for planners to incorporate interaction bet...

Natural selection is a phenomenon, which allows nature to select at any point in time the structure and number of organism living in a particular habitat [1]. This competitive tendency has been shown and reported by several authors Bonner [2], Grummer et al. [3], Evenari (1961), Whittaker [4], Putman and Duke [5], and Fischer et al. [6]. Allelopathic behaviour can best be described as direct or...

Natural selection is a phenomenon, which allows nature to select at any point in time the structure and number of organism living in a particular habitat [1]. This competitive tendency has been shown and reported by several authors Bonner [2], Grummer et al. [3], Evenari (1961), Whittaker [4], Putman and Duke [5], and Fischer et al. [6]. Allelopathic behaviour can best be described as direct or...

Development of an autonomous weeding machine requires a vision system capable of detecting and locating the position of the crop. It is important for the vision system to be able to recognize the accurate position of the crop stem to be protected during weeding. Several shape features of corn plants and common weed species in the location were extracted by means of morphological operations. Eff...

Field studieswere conducted in 2003 and 2004 to determine the effects of grassyweeds, postemergence grass control, transgenic rootworm-resistant corn, Zea mays L., expressing the Cry3Bb1endotoxin andglyphosate herbicide tolerance (Bt corn), and the interactions of these factors on western corn rootworm, Diabrotica virgifera virgifera LeConte, damage and adult emergence. Three insect management ...