Problems caused by nematodes and Fusarium wilt (Panama disease) on banana plantations are responsible for yield losses and are limiting to its cultivation. In the state of Goias, there is little information about the nematode occurence on this crop, and its relation with the incidence of Fusarium oxysporum f.sp. cubense (Foc). This research had the purpose to identify the occurrence of plant‐parasitic nematodes on banana plantations and to verify its correlation with the Fusarium wilt and with the soil attributes (pH, texture, nutrients). Twelve banana orchards in the state of Goias were sampled in the municipalities of Anapolis, Caiaponia, Goiatuba, Itaguaru, Itumbiara (two areas), Jatai, Morrinhos, Ouro Verde, Palestina, Taquaral and Uruana. All sampled areas, except Morrinhos, revealed contamination with Foc, and all areas had different genera of nematodes either in the soil or in the roots samples. Meloidogyne sp., Helicotylenchus sp. and Rotylenchus sp. were the main genera of plant‐parasitic nematodes found in the samples, with Meloidogyne sp. and Rotylenchus sp. being the most dominant and abundant genera. The presence of Pratylenchus sp. increases the population levels of F. oxysporum. Helicotylenchus sp. is highly correlated with high concentrations of Mn. High population density of Meloidogyne sp. was found in irrigated areas with low concentrations of P, Ca, Mg and soil pH.

Detecção de Meloidogyne enterolobii em mudas de amoreira (Morus nigra L.).Ciência Rural, v.45, n.5, mai, 2015.

Summary Meloidogyne enterolobii is characterised by its aggressiveness and ability to reproduce on plants carrying the Mi resistance gene. However, resistant cultivars and resistance induction may be alternatives to keep the pest population at levels that do not cause economic damage. The aim of this study was to evaluate the reaction of tomato genotypes to M. enterolobii and test the efficacy of resistance inducers in four tomato genotypes. Twenty-one tomato genotypes were inoculated with 2000 eggs of M. enterolobii and evaluated after 35 days of inoculation. All genotypes tested were susceptible to M. enterolobii. Four tomato genotypes were selected and the plants were treated with Bacillus subtilis, B. licheniformis + B. subtilis + Trichoderma longibrachiatum, Acibenzolar-S-methyl (ASM) and extract of Reynoutria sachalinensis. The plants treated with B. subtilis showed higher shoot and root weight. ASM reduced the reproduction factor of M. enterolobii when applied to the genotype ‘PXT 408’. All tomato genotypes tested here are susceptible to M. enterolobii, thus confirming the ability this plant-parasitic nematode to reproduce on resistant plants with the Mi gene. The resistance inducers B. subtilis, B. licheniformis + B. subtilis + T. longibrachiatum and extract of R. sachalinensis did not influence the final nematode population in any of the genotypes used; however, ASM reduces reproduction of M. enterolobii to the genotype ‘PXT 408’.