WATERMELON RESPONSE TO PLASTIC MULCHING, FERTILIZATION, SOWING AND TRANSPLANTING

Abstract

In this study we determined the yield, water use efficiency and harvest earliness for watermelon (Citrullus lannatus T.) irrigated by drip irrigation (tape) at 60 % of evaporation from a standard “A” type tank, when submitted to three levels of crop establishment (direct sowing, transplant at two true leaves, and transplant at branching onset), with and without black plastic mulching and two levels of N and P₂O₅ fertilization (160N-80P and 240N-120P). The experimental design was completely random with a 3x2x2 factorial treatment design and the comparisons for treatments means were performed with the Tukey test (α=0.05). The highest yield of 68.6 t ha^-1 was obtained by transplanting the crop when plant lets had two true leaves combined with plastic mulching and fertilized with 160N-80P, which also was the treatment with the highest water use efficiency of 14.3 kg m^-3. The yield of this treatment represents an increase of almost 150 % compared to the regional average yield. The increase of soil temperature due to plastic mulching promoted a high yield and allowed to harvest the watermelon one week earlier.