Damage caused by Meloidogyne javanica and Pratylenchus zeae to sugarcane cultivars

AUTOR(ES)
FONTE

Summa phytopathol.

DATA DE PUBLICAÇÃO

10/07/2019

RESUMO

RESUMO Nematoides são importantes parasitos da cana-de-açúcar, reduzindo significantemente a produtividade e a longevidade da cultura. Os danos causados por eles variam com a suscetibilidade da cultivar, razão pela qual é importante para os produtores conhecer a resposta dos novos genótipos, a fim de direcionar as medidas de controle. Assim, o objetivo do presente trabalho foi avaliar o dano causado por nematoides a cultivares de cana-de-açúcar recém lançadas para plantio comercial. Dois experimentos foram conduzidos em áreas infestadas por Meloidogyne javanica e Pratylenchus zeae. Ambos os ensaios foram conduzidos segundo o delineamento de blocos ao acaso, com parcelas subdivididas. As cultivares foram plantadas nas parcelas e duas doses de carbofuran 350SC, 0 and 7 L ha-1, foram aplicadas às subparcelas (tratada e não tratada). Na média, subparcelas tratadas com nematicidas produziram 10 % mais que as não tratadas, sugerindo que os nematoides reduziram a produtividade das cultivares em pelo menos 10%, mas a redução atingiu 22 % na cultivar IACSP97-7569, no experimento 1 e 17 % na CTC20, no experimento 2. O dano foi insignificante nas cultivares CTC9001, CTC9002, IACSP93-3046, IACSP95-5094, IACSP96-3060, IACSP97-4039 e RB975952, no experimento 1 e nas cultivares IACSP97-4039, RB867515 e RB966928 no experimento 2. Essas cultivares podem ser consideradas tolerantes M. javanica e P. zeae.ABSTRACT Nematodes are important parasites of sugarcane, significantly reducing the yield and the longevity of the crop. Damage caused by them varies with the susceptibility of sugarcane cultivars; thus, it is important for growers to learn the reaction of new genotypes in order to better direct control measures. The objective of this study was to evaluate the damage caused by nematodes to cultivars newly released for commercial planting. Two experiments were conducted in fields infested by Meloidogyne javanica and Pratylenchus zeae. Both experiments were arranged in split-plot randomized block design. The cultivars were planted in the plots, and two carbofuran 350SC levels, 0 and 7 L ha-1, were applied on two subplots (treated and non-treated subplots). On average, the subplots treated with the nematicide had their yield increased by 10%, compared to non-treated subplots, suggesting that nematodes reduced the yield of cultivars by at least 10%, but such a reduction reached 22% for cultivar IACSP97-7569 in experiment 1 and 17% for CTC20 in experiment 2. Damage was insignificant for cultivars CTC9001, CTC9002, IACSP93-3046, IACSP95-5094, IACSP96-3060, IACSP97-4039 and RB975952 in experiment 1 and for cultivars IACSP97-4039, RB867515 and RB966928 in experiment 2. These cultivars can be considered tolerant to hpsMhpshps. javanicahps andhps P. zeae.hps

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