BORON DOSES ENRICHED WITH ZINC SULFATE IN THE INITIAL GROWTH OF LETTUCE SEEDLINGS (Lactuca sativa L.)

Abstract

Lettuce (Lactuca sativa L.) is a leafy vegetable belonging to the Asteraceae family and originates 33 from the Mediterranean region and Asia. In Brazil, it was introduced by the Portuguese in the 16th 34 century. It is currently considered one of the most consumed leafy vegetables in Brazil, occupying an 35 area of about 10,775 ha, and having great economic and social importance. Works aimed at preparing 36 the substrate using micronutrients in fertilization for the cultivation of seedlings are scarce. This is 37 one of the most important stages in the development of the species, this work aimed to study the effect 38 of boron (B), enriched with zinc sulfate, on the initial development of lettuce seedlings. The 39 experiment was carried out in a vegetable garden with 35% shade, allocated in a rural property in the 40 municipality of Santana do Araguaia - PA, in a plastic tray of 128 cells where the batavia lettuce 41 seedlings were sown. The experiment was sown on 10/28/2020. When they reached transplanting 42 conditions (25 days after sowing), an evaluation of emergence speed was carried out; length of 43 seedlings and rootlets and dry mass of the different treatments. The experimental design was carried 44 out in a 4 x 5 factorial scheme with 4 replications. The first factor was boron doses at 0.5; 0.75; 1.25 45
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and 1.5 kg ha-1. The second factor was five levels of Zn with doses of 0.0; 0.5; 1.0; 2.0 and 3.0 kg 46 ha-1, with 4 repetitions, totaling 20 treatments. After preparing the doses, they were diluted in 200 ml 47 of water and then homogeneously mixed in the coconut fiber. After mixing, the substrate for each 48 treatment was placed in 4 cells of the tray chosen for the experiment. The data were recorded for 49 statistical processing, where they were entered into the SISVAR program, and the F test of polynomial 50 regression was performed. The combination of Zn and B provided greater IVE, plant growth, and an 51 increase in the dry matter of lettuce plants.