Effects of nematicides on nematode population densities and crop yield in a turnip-corn-pea cropping system

Nous avons évalué quatre systèmes de conduite de cultures lors d'une étude de 6 ans afin de lutter contre les nematodes dans un système annuel de production de navet-maïs-pois sur des parcelles de sable loameux Tifton naturellement infestées par les Meloidogyne spp. (environ 90 % de M. incognita et 10 % de M. hapla), les Pratylenchus spp. (environ 65 % de P. scribneri, 25 % de P. brachyurus et 10 % de P. zeae), ainsi que par les Paratrichodorus minor et Criconemella ornata. Le navet (Brassica campestris subsp. rapifera) a toléré de faibles quantités de tous les nematodes. Le maïs (Zea mays) 'Pioneer 3369A' a toléré de plus importantes quantités de tous les nematodes que le maïs 'Funks G-4507'. Les densités de population de juvéniles (J2) de Meloidogyne spp. ont été abaissées en deçà de 80 par 150 cm3 de sol par un mélange composé de 98 % de bromure de méthyle et 2 % de chloropicrine et par 20% de methyl isothiocyanate combiné à 80% d'hydrocarbones C3 chlorinés sur le navet et le maïs. Ces populations de nematodes ont augmenté rapidement chez le pois (Vigna unguiculata) 'Pinkeye purplehull' mais ce ne fut pas le cas chez le cultivar Worthmore. Les densités de populations des autres nematodes n'ont pas été affectées par le cultivar de pois ou par le nématicide, en l'occurrence l'ethoprop. Le fenamiphos a été plus efficace que l'ethoprop en abaissant les densités de nematodes. Les augmentations de rendement du système intensif de conduite des cultures se sont échelonnées de 4% à 52 % par rapport aux témoins non traités.Four management systems were evaluated in a six-year study to control nematodes in a turnip-corn-pea annual cropping System on plots of Tifton loamy sand naturally infested with Meloidogyne spp. (about 90 % M. incognita and 10% M. hapla), Pratylenchus spp. (about 65% P. scribneri, 25% P. brachyurus, and 10% P. zeae), Paratrichodorus minor and Criconemella ornata. Turnip (Brassica campestris subsp. rapifera) supported low numbers of all nematodes. 'Pioneer 3369A' corn (Zea mays) supported greater numbers of all nematodes than 'Funks G-4507'. Population densities of Meloidogyne spp. juveniles (J2) were suppressed below 80 per 150 cm3 of soil by 98 % methyl bromide + 2 % chloropicrin and 20 % methyl isothiocyanate + 80 % chlorinated C3 hydrocarbons on turnip and corn, and increased rapidly on 'Pinkeye purplehull', but not on a resistant cultivar, 'Worthmore' pea (Vigna unguiculata). Population densities of other nematodes were not affected by cultivar of pea or the nematicide, ethoprop. Fenamiphos was more effective than ethoprop in suppressing nematode population densities. Increases in crop yield in the intensive management system ranged from 4% to 52% over untreated controls

A GROSS MARGIN COMPARISON OF RETURNS TO NEMATICIDE TREATMENT IN CONTINUOUS AND ROTATION TRITICALE-SOYBEAN PRODUCTION

A study of irrigated strip-till soybean production compared gross margins over nematicide expense for a continuous triticale-soybean system versus a two-year rotation system alternating triticale-soybean with triticale-cotton. Half of the replicated plots under each system received nematicide treatment. Gross margins were calculated using recorded yields and Georgia average market prices by marketing years. Mean gross margins for untreated plots were not significantly different between crop-sequence systems. Within each system, however, mean gross margins were significantly higher for plots not receiving nematicide treatment versus treated plots, even when treated plots produced greater yields

A GROSS MARGIN COMPARISON OF RETURNS TO NEMATICIDE TREATMENT IN CONTINUOUS AND ROTATION TRITICALE-SOYBEAN PRODUCTION

A study of irrigated strip-till soybean production compared gross margins over nematicide expense for a continuous triticale-soybean system versus a two-year rotation system alternating triticale-soybean with triticale-cotton. Half of the replicated plots under each system received nematicide treatment. Gross margins were calculated using recorded yields and Georgia average market prices by marketing years. Mean gross margins for untreated plots were not significantly different between crop-sequence systems. Within each system, however, mean gross margins were significantly higher for plots not receiving nematicide treatment versus treated plots, even when treated plots produced greater yields.conservation tillage, gross margin, irrigation, Meloidogyne incognita, root-knot nematode, rotation, soybean, triticale, Crop Production/Industries,