Aplicação de calda sulfocálcica no controle de bicho-mineiro (Leucoptera coffeella) em Cafezal de Barra do Garças – MT

Abstract

The coffee miner (Leucoptera coffeella) represents an important coffee crop pest causing losses of up to 80% in production. Different control methods are proposed to reduce its incidence in coffee, from chemical, biological to genetic, however, it remains difficult to control. Thus, the objective was to verify was to verify the incidence, the healthy leaf area and the number of pupae of coffee miner in a coffee plantation located in the rural area of the municipality of Barra do Garças / MT. The evaluations were carried out in a sixyear-old experimental agroforestry coffee area in 2019. The experimental design was a randomized block with three replications in a triple factorial scheme with 2 treatments, 3 positions and 3 cultivars (2 x 3 x 3), where three plants per plot were evaluated. Two treatments were considered, one with application of 1.5% lime sulphur and the other as a control without application and syrup. In each plot, leaf evaluations were made on two pairs of leaves present in the upper, middle and lower positions of each plant. The leaves were photographed to measure the healthy leaf area by the QUANT® software, on two dates, November 22 and December 13, and the identified leaf lesions were classified according to the causal agent. The pupae count took place on three dates 7 and 22 November and 13 December, with an average interval of 15 days between one evaluation and the other, with only the leaves at the bottom of the plants being counted. The evaluated coffee cultivars were: Conilon “Robusta Tropical”, Catuaí Amarelo IAC 62 and Catucaí Amarelo 2SL. Most of the leaf lesions were caused by the coffee miner, with the average incidence by this pest equal to 10.8% and 30.1% in the two evaluations, with no difference in counting between the plots treated with lime sulphur or in the different plant positions. The average healthy leaf area was 99.9% on the first evaluation date, with no difference between the sources of variation in November. In December, the average healthy leaf area was 96.9%, with the lowest value detected statistically occurring in the cultivar Robusta with 93.7% in plots where the lime sulphur was applied. The pupal count had a linear decrease regardless of the sources of variation and may be an indication that some environmental factor, such as increased rainfall, resulted in a decrease in the pest during the evaluation period. In general, there was no effect of the sulfocalsic solution on the control of the coffee miner. However, this inefficiency can be justified by the product's exclusively ovicidal effect and the coincidental natural population decrease due to the beginning of the rains in the analyzed period.