The big challenge in the cassava production is to produce tuberous roots long, uniforms, and with easy cooking. Various production factors can interfere in this process, including mineral plant's nutrition. The nutrients phosphorus (P) and calcium (Ca) despite having a positive effect on the root growth of crops, also appear to interfere with the cooking of cassava roots. Thus, this research is being conducted in order to evaluate the effect of liming and phosphate fertilization on plant growth, yield and cooking of tuberous roots of cassava. The experiment is being conducted under field conditions on experimental design of randomized blocks, in scheme of splitplot, with four replications. The plots are represented by four lime rates, 0, 1.5, 3.1, and 4.8 t ha-1, in which they tried to reach the base saturation levels (V%) of 12, 30, 50, and 70%, respectively. The subplots are represented by the lower, medium and high P levels, which corresponding to the supply of 0, 80, and 160 kg ha-1 of P2O5, respectively. Each plot has 7 m wide and 12 m long. Each sub plot consists of 5 cassava lines of 4 m long, spaced 1.0 m apart (5 m wide). The following variables will be evaluated: a) Ca, P and V% of the soil before planting; b) leaf diagnosis of cassava; c) number and diameter of the stems, number of leaves per plant and plant height; d) final plant population; e) accumulation of dry matter (DM) in the shoot, cutting and the tuberous roots; f) yield of tuberous roots; g) firmness of tuberous roots; h) moisture content of tuberous roots; i) content of Ca, P, and P/Ca ratio in the storage roots; j) cooking time of tuberous roots. The data will be submitted to analysis of variance. Means of P levels will be compared by LSD test (pd0,05). The effects of limestone rates will be assessed by regression analysis (pd0,05).
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