Desenvolvimento do sorgo forrageiro (Sorghum bicolor(L.) Moench) submetido a diferentes dosagens de adubação com manipueira

Abstract

In the Semi-arid region of the Northeast, goat breeding and sheep farming are relevant activities in socioeconomic aspects for rural families. However, the inadequate management of chemical fertilization in this region has added serious environmental problems, and consequently, forage production has been hampered by misapplication of mineral fertilization in production systems. Thus, the objective of this research was to evaluate the response of two genotypes of forage sorghum submitted to different doses of manipueira.The experiment was carried out in the Statistical Unit of Serra Talhada, installed in randomized blocks, in a 4x2x4 factorial scheme, composed of four blocks of two sorghum cultivars and four doses of manipueira (0.0, 12.0, 24.0 and 48, 0 m3ha-1), totaling 32 experimental units. The evaluated characteristics were stem diameter (DC); plant height (AP); number of live leaves (NFV); number of dead leaves (NFM); weight of the green mass (PMV) and weight of the dry mass (PMS). In the interactions obtained by the ANOVA of the data, it can be observed that, of the growth parameters evaluated were significantly altered by the use of manipueira doses, for these variables we observed a quadratic behavior as a function of plant height (AP), the evaluation period (mL / pot) for the two sorghum cultivars IPA 2502 and BRS Ponta Negra, at the height of the IPA 2502 plant the dose of 168.34 mL / pot provided a maximum height of 67cm at 62.51 days , and for BRS Ponta Negra it reached a maximum height of 85 cm, with a dosage of 104.76 mL / pot at 68.65 days, in Figure 2 (a) and (b). For the variable diameter of the stem (DC) Figures 3 (a)and (b), the dose of 168.06 mL / vessel provided the IPA 2502 maximum diameter of 11.82 mm at 49 days, while for the BRS Tip The dose of 101.71 mL / pot provided a maximum diameter of 13.69 mm at 64.29 days. There was no influence of the different dosagesof manipulation for the number of live and dead leaves, total green mass and total dry mass of the leaves. cultivars IPA 2502 and BRS Ponta Negra. The use of manipueira in the conditions established in this research did not promote increases in the production of sorghum forage, however, further evaluations are necessary with new studies on the influence of this fertilizer, since the plants were conditioned to water stress.