Agronomic performance of lettuce cultivars in an organic production system in Rio Branco, Acre

Abstract

The objective of this work was to evaluate the agronomic performance of lettuce cultivars in an organic production system under the conditions of Rio Branco, Acre. The experiment was installed in an area under organic cultivation since 2008, located in the municipality of Rio Branco, Acre, in the months of June and July 2020. The experimental design was in randomized blocks with six treatments with four replications of 16 plants each. The cultivars evaluated were: Maui, Alaska, Delicia, Malibu, Grandes lakes and Rafaela. In protected cultivation under a greenhouse covered at 3.5 m high with 100 µ additive film and open sides. The beds of height of 0.20 and width of 1.20 m were prepared with a micro tractor and fertilized with 15 t ha^-1 of organic composte. The following were evaluated: total fresh mass, fresh organic commercial mass, fresh head mass, organic productivity, commercial productivity, head diameter, dry mass of the plant, head formation (%) and bolting (%). The Maui and Alaska cultivars showed higher performance, with May total fresh weight, commercial organic fresh weight, fresh head mass and organic and commercial productivities. The percentage of head formation and bolting is the same for Maui, Alaska, Delicia and Malibu cultivars.