Mulchfolien mit inkorporiertem Atrazin zur Unkrautbekaempfung in Zuckermais.
1989
Pfister G. | Bahadir M.
A new method of weed control in sweet corn cultures, grown with plastic mulch films, was tested in field trials lasting over three vegetation periods. The method is based on the homogeneous incorporation of atrazine in mulch films made of suitable polymers mainly ethylene-vinylacetate copolymers (EVA). The herbicide was released by diffusion out of the polymer over a period of 2-4 weeks. At the beginning of the field tests, however, the films with higher concentrations of atrazine (0.2 per cent - 1.0 per cent) showed considerable "blowing-out" of the active ingredient on the film surface which caused a faster release at rainy weather conditions. A herbicide concentration in the films of nominal 0.025 per cent equal to 0.18 kg/ha already was so effective against weeds and indicator plants that a further reduction of the herbicide inventory of the films seems to be possible. The conventional application of comparable amounts of atrazine usually had a similar herbicidal effect. In the year 1985 trial, however, there were indications for a higher efficiency of the film application. The yields of corn cobs were very uniform in each vegetation period independent of the kind of herbicide treatment, but they were always significantly higher than in the control treatments without mulch films. Residues of atrazine were not found in the corn samples. In soil samples, residues were detected in the range of 5 mug/kg up to 175 mug/kg corresponding to the different amounts applied. The formation of residues seemed to be less when herbicidal films had been applied.
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