The influence of different irrigation levels, both with and without mulching, was evaluated for the growth variables of productivity, production components and water use efficiency, in a castor bean crop (Ricinus Comunnis) cv. BRS Energia, in a Fluvic Neossol of the semiarid in the Brazilian state of Pernambuco. The experimental design used was completely randomised in a factorial of 4 (irrigation levels) × 2 (with and without mulch), with four replications. The irrigation levels were based on the evapotranspiration of the crop (ETc), with L1 = 60% ETc, L2 = 80% ETc, L3 = 100% ETc and L4 = 120% ETc. All growth variables showed significant differences to the mulch at 120 days after germination. The number of racemes per plant, percentage of bark, and water use efficiency responded significantly to the presence of mulch on the ground, while length of racemes, fruit yield and berry yield responded significantly to the isolated effects of the irrigation levels and ground cover. Levels L3 and L4 improved the performance of the crop, with an average productivity of over 2,360 kg berries ha-1.
Irrigation; Growth; Production components
