Dallemole-Giaretta, R., Freitas, L. G., Cavallin, I. C., Marmentini, G. A., Faria, C. M. R., and Resende, J. T. V.
The fungus Pochonia chlamydosporia is currently one of the most studied biological control agents for its great potential in management of root-knot nematode. The objective of this study was to evaluate the efficiency of a biological product, at the development phase, based on the fungus P. chlamydosporia, isolate Pc-10, for the control of Meloidogyne javanica on lettuce and carrot at the field level. Rizoflora Biothecnology Inc. had the special temporary registration for field application of Pc-10 isolate for agronomic efficiency tests. The experiment was arranged in a randomized block design with eight replicates per treatment. Each experimental plot was 2 m2. The treatments consisted of the doses 0.0, 3.0, 3.8, 4.5 or 9.5 g of rice colonized with P. chlamydosporia and dried, /m2 of experimental plot. Fifteen days after the incorporation of the product 21-d-old lettuce seedlings of the cultivar 'Babá de verão' were transplanted into each experimental plot, and the experiment was conducted for 50 d. The doses of 3.8 and 9.5 g of the product reduced the number of galls in 46.0% and 38.9% on the roots, and the number of nematode eggs in the soil by 52.3% and 53.1%, respectively. All treatments enhanced the development of the lettuce plants, compared with the control treatment. After the lettuce harvest, doses of 0, 25, 50, 75 and 100 g of product /m2 were applied, with the plot position of the new doses, lowest to highest corresponding with the doses in the previous experiment. After 15 d, the plots were seeded with carrot 'Nantes superior'. At all of the doses, including the control treatment, low numbers of galls were observed on the roots of the carrots, without significant differences between the treatments. No statistical differences were observed for the development of plants. [ABSTRACT FROM AUTHOR]