Doenças em alface (Lactuca sativa L.) hidropônico na região do sudeste paraense

Abstract

Lettuce grown in hydroponic systems accounts for about 80% of Brazilian production and this is due to the high efficiency in the use of water and fertilizers and the low incidence of environmental problems. Despite this, in some regions of Brazil, there are reports of high loss rates caused mainly by the incidence of diseases that, in general, are associated with the choice of cultivar and inadequate management practices. In the southeast of Pará, the municipality of Marabá is the largest producer of lettuce in the region, followed by Nova Ipixuna and Tucuruí. However, there are no further studies on lettuce cultivation in this region. Therefore, the objective of this work was to carry out a survey on the lettuce cultivars produced in hydroponic systems in the southeast region of Pará, to identify the main diseases that cause losses and to provide alternatives to reduce these losses. The lettuce cultivars most produced in the region of the southeast of Pará are: SVR 2005, Roxa, Caipira, Americana and Lirice. The main diseases of lettuce in hydroponic systems are Cercosporiosis, Burning of the skirt and Soft rot. These diseases present 100% of incidence in the cultivars produced from all the inspected vegetable gardens. Other fungal diseases no less important also stand out, such as, for example, the tumbling or "damping-off" (Pythium spp. and Rhizoctonia solam); wilt or black rot (Thielaviopsis basicola); cercospora spot (Cercospora longissima) rhizoctoniosis or skirt burn (Rhizoctonia solani) and fusarium wilt (Fusarium oxysporum). The use of more adequate structures, such as greenhouses with arches and agricultural film covering could improve the quality of the plants and reduce the incidence of diseases in the main lettuce cultivars produced by the hydroponic system in the southeast region of Pará.