Resistência e perdas econômicas de híbridos de coqueiro (Cocos nucifera L.) A Aceria guerreronis KEIFER (ACARI: ERIOPHYIDAE) no município de Moju, Pará.

Abstract

Varied uses of coconut fruits allow it to be of great relevance to the national and intemational markets and especially to producing countries, of which Brazil is the fourth largest coconut producer in the world. However, the attack of the necrosis mite (Aceria guerreronis), one of the main pests, causes damage to fruits with reduced size, liquid and solid albumen and commercial value. The objective ofthis study was to analyze resistance leveis among hybrids, fruit yield losses and economic losses caused by Aceria guerreronis in coconut (Cocos nucifera L.) under conditions of the Eastern Amazon, Brazil. Identifying the average damage severity in six commercial hybrids; degrees of resistance were determined; yield losses were evaluated for the following variables: solid (pulp) and liquid (water), almond, fiber and endocarp albumen; the yields were correlated with the mite attack leveis; as well as the economic analysis of the losses caused by the mite. The experiment was carried out in a commercial arca of SOCOCO S.A. Agroindústria da Amazônia, in the municipality of Moju, in the state of Pará, for five months, in dried coconut fruits, harvest point. The evaluated hybrids were: PB121, PB111, PB141, PB 123, PB 132 and PB113. The design was in randomized blocks. For the quantification of fruits and determination of the percentage of severity index in each levei of attack was adopted the visual scale of grades from 1 to 3. The quantification of losses in production was by weighing the fruits. The analysis of economic losses was based on the estimated gross revenue obtained from the commercialization of solid albumen, water and fiber in damage scores 2 and 3, compared to the lowest score on the visual scale of damage caused byA guerreronis, in each case. month and for each hybrid. The results showed that hybrids have different severity averages over the months evaluated. The hybrids PB 113 and PB 141 were identified with moderate resistance in relation to the others. The hybrid PB 113 stood out with higher albumen and water production compared to the others. Fiber, water and solid albumen yield was higher during November and with the hybrid PB 113 for water and albumen and PB 132 for fiber. The percentage loss of income was 21, 37 and 59% for fiber, solid albumen and water, respectively, when comparing the highest and lowest revenues for each damage grade.