Picos em plantas de Citrus spp. infestadas por mosca negra dos citrosarâmentros fisiológ

Abstract

Aleurocanthus woglumi provides reduction in the physiological performance of the plant due to the damage it causes. This study aimed to evaluate physiological changes in citrus plants in response to infestation A. woglumi in greenhouse and field conditions. The experiment was conducted in a greenhouse on the premises of the Postgraduate Diploma in Agroecology Program - PPGA, Sao Luis - MA. 16 seedlings tangerine Ponkan and 16 lima-ácida Tahiti seedlings grafted on Rangpur lime were used. The seedlings were placed in iron cages covered with “voile” (two plants/cage). Released were about 50 adult insects of A. woglumi in each cage for development life cycle. They were assessed physiological parameters: Biometrics plant, estimated chlorophyll content, photochemical efficiency and gas exchange. The experiment conducted in the field was installed in an orchard of citrus crops in the municipality of Lumiar Palace - MA. 32 citrus plants were used, 8 plants of each of the following varieties: lima-ácida Tahiti, tanjarine Tanjaroa, tangerine Nissey and tanjarine Ponkan. We selected four plants at random from each variety with the presence of A. woglumi and sooty mold. At the same time, they were kept 4 plants to free chance of plague action. They were determined two evaluations during the rainy season and two in the dry season for the following physiological parameters: estimate of chlorophyll content, determination of photochemical efficiency and gas exchange. In the greenhouse the Tahiti plants performed better as the biometric parameters. The Tahiti and Ponkan varieties when infested by A. woglumi showed an increase of chlorophyll content. In photochemical efficiency of Tahiti and Ponkan plants showed photoinhibitory damage under pest infestation. The photosynthetic assimilation of CO2 has been reduced by 65% in plants Tahiti and in Ponkan infestation A. woglumi. In the field of citrus plants under infestation A. woglumi showed physiological changes as photosynthetic CO2 assimilation, stomatal conductance, instant sweating, VPDleafair and performance index in the rainy and dry seasons. Plants of Tahiti, Tanjaroa, Nissey and Ponkan under pest infestation, showed high values of SPAD index and photoinhibitory damage in rainy and dry season. The photosynthetic assimilation of CO2 has been reduced by 70% during the rainy season and in more than 70% during the dry period infestation of plants under A. woglumi