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The study assessed the effect of crop rotation with economically important plant species on Pratylenchus zeae damage to sugarcane. Two experiments were conducted, one in October 2011 and another in January 2012. The experiments followed a completely randomized design with 10 treatments, which included three rice genotypes (Ana 9001, Iapar 9, and Ecco CL hybrid), millet cv. AMN-17, crotalaria, cotton cv. IPR 140, sunflower cv. Syn 045, fallow, sugarcane cv. RB 72454 and the hybrid maize BRAS 3010. Sugarcane was cultivated for 90 days and followed by different rotation crops for 90 days. Next, the plants were cultivated for 180 days to finish their growth cycles. The plants were inoculated with 2,000 P. zeae. Sugarcane root mass, root population of P. zeae, nematode population in 100 cm3 soil, total nematode population, and Reproduction Factor (RF) were assessed at the end of the experiment. Among all species and cultivars, crotalaria and rice cultivar Ana 9001 had the lowest nematode RF. None of the economically important crops were recommended for use in rotation systems with sugarcane because all of them had RF values similar to those of sugarcane and maize. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of a crop succession using plant species of economic importance on a population of Pratylenchus brachyurus in soybean. Two experiments were carried out at different times of year by means of a fully randomized arrangement, with nine treatments and four replicates consisting of three rice genotypes (Ana 9001, Iapar 9, and hybrid Ecco CL), millet cv. AMN-17, Crotalaria juncea, cotton cv. IPR 140, sunflower cv. Syn 045, fallow, and maize cv. BRAS 3010 as the check. First, soybean cv. BRS 284 was cultivated for 60 d, followed by the various plant species (treatments) and finally the soybean cv. BRS 284 once again completed the succession. The experimental units consisted of 1-L pots containing two plants cultivated in sandy soil initially inoculated with 2,000 P. brachyurus per pot. At the end of the experiment, the weight of soybean root, the number of specimens of P. brachyurus per gram of root and per 100 cm3 of soil, and the final total population were evaluated. There was no significant difference among the treatments for the fresh weight in experiment 1 and the number of nematodes in 100 cm3 soil in the experiment 2. All treatments showed reproduction of P. brachyurus when compared to the check. Of the species studied, Crotalaria juncea and rice cv. Iapar 9 exhibited lower reproduction of the nematode. If these two plant species are to be used in succession with soybean, the population of the nematode in the area should be monitored. [ABSTRACT FROM AUTHOR]