PHYTOTOXICITY OF HERBICIDES TO TRANSGENIC MAIZE VARIETIES AND ROTATIONAL CROPS.

With the advent of transgenic maize (Zea mays) varieties newagronomic problems might be placed to agricultural ecossystems. A greenhouse study was conducted to evaluate the behaviour of genetic modified (GM) maize varieties (‘96096’ and ‘96097’) tolerantes to the herbicide glufosinate in relation to atrazine, bentazone, bromoxynil, isoxaflutol, nicosulfuron, prosulfuron and glyphosate. Also effects of GM maize straw after cultivation on rotational crops chick-pea (Cicer arietinum), sugar beet (Beta vulgaris) and wheat (Triticum aestivum) was studied. Conventional variety ‘Cecilia’ was used as reference. No significant differences in selectivity of both GM maize varieties and the reference for the herbicides were observed. However, a higher level of sensitivity was shown to glyphosate, suggestting the possibility of using such herbicide to control volunteer GM maize plants on our fields. A significant reduction in fresh weight was observed on chickpea (17%) growing in a substrate composed of ‘96096’maize straw treated with glufosinate, compared to the reference. However, the same result was not obtained for variety ‘96097’ which had an increase of about twice the reference. No significant reduction was observed on the fresh weights of sugar beet and wheat.