Mamoeiro Havaí, biofertilizante bovino e adubação mineral: reflexos no crescimento, produção, nutrição e fertilidade do solo

Abstract

Papaya crop (Carica papaya L.) presents high expenses with agricultural supplies and pesticides showing the necessity of the use of alternative products such as bovine biofertilizers aiming to reduce costs and environmental damages. Therefore, an essay was done during May/2004 to April/2006, in the city of Remígio, State of Paraíba, to evaluate the bovine biofertilizer effects when applied on soil as a liquid and in combination with mineral fertilization with NPK, on the growth, yield, post-harvest quality of fruits, mineral nutrition of papaya and soil fertility. The experimental design was randomized blocks, with three repetitions and four plants per parcel, using 5x2+2 factorial arrangement referring to doses 0.0; 0.8; 1.6; 2.4 and 3.2 L plant-1 of bovine biofertilizer, with and without mineral fertilization with NPK and additional treatments referring to soil without biofertilizer, without limestone and with biofertilizer on medium dose and without limestone. The biofertilizer was applied 30 days before the transplanting and every 60 days until the end of cropping. According to the results, the growths in height and stem diameter were appropriate, showing superiority on soil with bovine biofertilizer and mineral fertilization. Productivity was low, but significantly higher on treatments with organic matter and NPK. Fruits from treatments with biofertilizer and without NPK had highest pulp contend, highest levels of soluble solids, highest firmness and lowest peel mass. Plants in the beginning of fructification were nutritionally balanced in nitrogen, phosphorus, potassium, magnesium, boron and zinc but had deficiency in calcium, copper, iron and manganese. The biofertilizer without NPK, promoted higher increases of pH, organic matter and calcium and accented and greater reductions of aluminum and hydrogen contents on soil, when compared to treatments that received application of mineral fertilization.