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Root knot nematodes are among main problems in cucumber production, mainly in protected cultivation. The utilization of resistant cultivars is the most efficient and cheapest method of control. The objective of this research was to study the genetic inheritance of resistance to Meloidogyne incognita in cucumber. A cross between a inbred line obtained from Tsuyataro hybrid (L1), moderately resistant, and another from the Yoshinari hybrid (L2), susceptible to M. incognita race 2 was done. Population F1 (L1 x L2) between these two lines, generations F2 and F1BC1 were obtained for both lines (F1BC1L1 and F1BC1L2). Six treatments (two parental lines, generations F1, F2, F1BC1L1 and F1BC1L2) were evaluated in a complete block design with five replications. Plants were inoculated with the nematode (5,000 eggs per plant) after transplantation. At 60 days after inoculation gall and eggs mass index in root and reproduction factor (FR) were determined. Statistical-genetics analyses were performed according to the segregation obtained in generations F1, F2 and backcrossings to estimate the resistance of inheritance observed. The FR observed for line L2 (Yoshinari) was 7.21, more than twice of the observed for line L1 (Tsuyataro) that was 3.28. The partial resistance to M. incognita race 2 in 'Tsuyataro' cucumber is quantitative, with predominance of additive effects, with three main genes conditioning it. [ABSTRACT FROM AUTHOR]

Variations on the physical and biological soil properties resulting from harvest and vinasse application were evaluated in a sugarcane cultivated area in the municipality of Goiana, Pernambuco, Brazil. Evaluations were based on soil humidity and density, porosity, granulometry, particle density and nematode community trophic structure characterization, carried out before and after both sugarcane cut and vinasse application. Horizontally, samples were colleted in 42 points within a 60×50 m square. Vertically, in each point, samples were colleted 0-10, 10-20, 20-30, 30-40, 40-50 cm deep. Within the physical variables soil humidity, porosity and density were influenced by harvest and vinasse application. Harvest affected Mononchidae and Cephalobidae directly, but Xiphinema and Criconemella, inversely. Vinasse decreased Dorilaymidae and Meloidogyne density, in contrast to the increase on Rhabditidae and Cephalobidae. Plant parasitic nematodes were the most abundant community in all sampling periods. [ABSTRACT FROM AUTHOR]