ADUBAÇÃO NITROGENADA E POTÁSSICA NA FISIOLOGIA E PRODUTIVIDADE DO JERIMUM CABOCLO (Cucurbita maxima).

Abstract

The culture of Jerimum is widely cultivated in the Northeast, most often by small producers, generally produced in consortium with other crops, which plays an important economic and social function. This study aimed to evaluate the effect of nitrogen and potassium fertilization on physiological parameters, production and fruit quality of Jerimum Caboclo. The experiment was conducted in monkeys site located in the municipality of Remigio in the state of Paraiba. The treatments were arranged in design BOX Center headquarters, in a factorial 5 x 5, relating to 5 levels of nitrogen fertilization (0, 26, 90, 154 and 180 kg ha-1) and 5 potassium fertilization levels (0, 13 , 45, 77 and 90 kg ha-1), the beating was used 2 x 2 between plants and lines, were placed 3 seeds per hole, irrigation was by drip tape, being held every day, it was applied all phosphorus in the cultivation along with 20% N and 20% H + 80% remaining was divided into two application 40%. The following parameters were evaluated: Soil fertility (P, Ca2 +, Na +, Mg + 2, K +, organic matter, pH, CEC, SB, V%, Al + H), Chlorophyll a, b and total fluorescence initial, variable and maximum transpiration, stomatal conductance, net photosynthesis, stem diameter, plant yield, productivity, pulp yield, titratable acidity, vitamin C, sucrose, glucose and starch. The potassium x nitrogen interaction influenced the increase of chlorophyll b ratio to greater than 9.5, fruit length and sucrose content, potassium also had isolated effect on the mass of the fruit with a reduction of 23% due to the increasing the dose, the calcium content was reduced due to the potassium dose had a reduction of 36%, nitrogen promoted the 37% increment in the production per plant, also promoting increased productivity by 37, 2% to the dose 90 kg ha-1, glucose level showed a desiccome 12.7 to 90 kg-1 there. The nitegogenio stimulated the number of fruit and yield per plant, potassium promoted the decrease in calcium content, nitrogen and potassium stimulated sucrose content and length of the fruit.