in order to determine the critical period of weed control (cpwc) in corn (zea mays l.), an experiment was carried out in a randomized complete blocks design with 14 treatments and three replications during 2013 growing season in the nahavand climatic conditions. two series of the treatments including weed-free and weed-infested were applied in the regular time distances of 10, 20, 30, 40, 50 an...

l-Ascorbic acid functions as a precursor of oxalic acid in several oxalate-accumulating plants. The present study extends this observation to include Rumex crispus L. (curly dock), Amaranthus retroflexus L. (red root pigweed), Chenopodium album L. (lamb's-quarters), Beta vulgaris L. (sugar beet), Halogeton glomeratus M. Bieb. (halogeton), and Rheum rhabarbarum L. (rhubarb). Several species with...

Effective weed management depends on correct control timing, which seedling emergence dynamics. Since soil temperature and moisture are the two main factors that determine germination, hydrothermal time model can be used to predict their emergence. The aim of this study was estimate base (Tb) water potential (?b) for germination Chenopodium album, Amaranthus retroflexus, Setaria pumila, Panicum...

Weed behaviour in crop fields has been extensively studied; nevertheless, limited knowledge is available for particular cropping systems, such as no-till systems. Improving weed management under conditions requires an understanding of the interaction between residues and seedling emergence process. This study aimed to evaluate influence maize wheat residues, applied three different quantities (...