Controle alternativo de Helicotylenchus multicinctus na cultura da bananeira

Abstract

The search for phytopathogen control agents that have little impact on the environment and that are viable and efficient in the most diverse agroecosystems has been increasing.This work aimed to evaluate the effectiveness of the alternative control of Helicotylenchus multicinctus in banana crop as an alternative to the use of chemical nematicides and its limitations, such as high cost, unsatisfactory control levels and environmental contamination. Tests were carried out under greenhouse and field conditions with soil naturally infested with nematodes and tested the following agents: papaya seed meal (FSM); Pumpkin Seed Meal (FSA); Trichoderma asperellum and Bacillus methylotrophicus (TB); Pochonia chlamydosporia (PC) and Carbofuran. Distilled water was used as a control. All control agents were solubilized in 15L of distilled water and applied to the soil via watering can. The application of each treatment was performed in an area of 16 m², containing 4 bananas trees of approximately 4 years of age. A randomized complete block design (DBC) was used for the field conditions test. In the test under greenhouse conditions, a completely randomized design (DIC). In both trials 6 treatments and 8 replicates were used in total (each plant represented one replicate).The seedlings were obtained from tissue culture in culture medium. These were removed from the culture medium for the assay with 70 days old. On the same day the soil sampling and the evaluation of the initial population of nematodes were carried out. After 75 days of the application of the alternative control agents, soil and roots samples were taken for quantification of the final nematode population and, from the evaluation of the development of the seedlings: dry weight of aerial part, fresh weight of aerial part and roots, height and length of roots. In field conditions, no statistical difference was observed in relation to the control for any control agent tested, in soil and root, for the nematode population. In greenhouse the FSM was superior to the other treatments for fresh weight of the aerial part, fresh weight of the root and dry weight of the aerial part. For the soil nematode population, PC was superior to the combination of TB and the control with 99.2% relative control, while FSA was superior only to the control (88.3%). The other treatments did not present statistical difference for soil and root populations. FSA and TB were able to reduce infestation in roots by 100% in relation to the control, although they did not differ statistically from the other agents.