RESPOSTA DA ALFACE CRESPA ADUBADA COM DIFERENTES DOSES DE TERMOFOSFATO

Abstract

The objective of the present study was to evaluate the effect of different doses of rock powder on fresh weight, commercial weight, diameter, number of leaves and dry mass on the performance of the Vanda variety cultivar under cultivation (Lactuca sativa L.) field directly in flowerbeds. The experimental design was a randomized block design, with four replications and six treatments. The treatments were as follows: No fertilization (T1), conventional fertilization recommended (T2), fertilization with thermophosphate as recommended (T3), fertilization with 50% less than recommended thermophosphate (T4), fertilization with 50% recommended (T5) and fertilization with thermophosphate 100% more than recommended (T6). Harvesting took place on the 45th day after transplanting and were taken to the laboratory for evaluation of the diameter, analytical weighing and leaf count per lettuce. After this process, they were taken to the oven, at a temperature of 65oC, until reaching a constant mass. The averages obtained with conventional fertilization were higher than the means with thermophosphate that were statistically equal to each other. The treatments used to provide the phosphorus necessary to grow lettuce were not promising and obtained less than conventional responses to the evaluated characteristics. Probably because the crop is short cycle and the product used is a fertilizer of low solubility, requiring a longer period in the soil to make the phosphorus available.