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  • Author or Editor: J. D. Gaynor x
  • Journal of the American Society for Horticultural Science x
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Abstract

Four hedgerow types: oblique fan, canted oblique fan, modified central leader, and open center, in a peach (Prunus persica (L.) Batsch cv. Olinda) orchard were evaluated in 1975 and 1977 for their effect on deposition of captan (N-trichloromethyl-4-cyclohexene-l,2,dicarboximide). Within hedgerows captan residues on leaves were generally higher on bottoms than tops of trees but among hedgerows, leaf residues were higher on oblique fan. The higher leaf residues resulted in 10.8% more of the captan applied per tree retained by oblique fan compared to 31.7% intercepted by the other hedgerows. Ground deposits for oblique fan and open center averaged 11.7% but were 6.3% higher for canted oblique fan and modified central leader. Ground deposits did not relate to area below trees or hedgerow type but leaf residues and that unaccounted for related to tree canopy volume. Compared to the standard open center, oblique fan was 41% more efficient at intercepting captan, modified central leader 20% more efficient and canted oblique fan showed no improvement in efficiency. Hedgerows with smaller tree canopy volumes increased captan interception, reduced spray drift and thereby provided economic and environmental gains through more efficient captan use.

Open Access

Metolachlor was evaluated for annual grass and eastern black nightshade (Solarium ptycanthum Dun.) control in processing tomato (Lycopersicon esculentum Mill.). Metolachlor applied preplant incorporated provided excellent (> 88%) control of annual grasses and eastern black nightshade. The metolachlor, metribuzin plus trifluralin tank mix applied preplant and incorporated into the soil provided better annual grass and eastern black nightshade control than the metolachlor plus metribuzin tank mix in two of three years. Nonincorporated and posttransplant treatments of metolachlor provided good annual grass control but failed to control eastern black nightshade. Tomato yield in all herbicide treatments was similar to that from hand weeded controls. Metolachlor dissipated from the soil throughout the growing season so that at the time of harvest <10% of that applied was recovered. Metolachlor residues in the fruit were hydrolyzed to deacylated (CGA 37913) or hydrolyzed conjugated (CGA 49751) metolachlor metabolizes. Analyses of extracts from treated fruits were found to be less than the detection limit of 50 ppb in the whole fruit harvested from selected metolachlor treatments. Chemical names used: 2-chloro-N -(2-ethyl-6-methylphenyl)-N -(2-methoxy-1-methylethyl) acetamide (metolachlor); 2,6-dinitro-N,N -dipropyl-4-(trifluromethyl)benzenamine (trifluralin); 4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-tlriazin-5(4H)-one (metribuzin); 2-(2-ethyl-6-methylphenyl)amino-1-propanol (CGA 37913); 4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3-morphol. inone (CGA 49751).

Free access