Yield and water use efficiency of cactus pear under arrangements, spacings and fertilizations

Produtividade e eficiência do uso da água da palma forrageira sob arranjos, espaçamentos e adubações

ABSTRACT

Cactus pear is adapted to semi-arid conditions. In this study, the objective was to evaluate the water use efficiency and green and dry mass yields of the cultivar Gigante under different fertilization rates and sources in three production cycles, spacing and planting arrangement. Seventy two treatments, involving two types of arrangements in the plots, three spacings in the subplots and 12 types of fertilization in the sub-subplots were arranged in a split-split-plot scheme, using randomized block design with three repetions. Dry mass content decreases while water use efficiency and green mass and dry mass yields increase from the first to the third cycle. It is feasible to use planting arrangements in triple or quadrupling rows which allow increasing the mechanization index of the crop. Organomineral fertilization with 30 or 60 Mg ha^-1 year^-1 of bovine manure combined with 150-300-600 kg ha^-1 year^-1 of N-P₂O₅-K₂O and 300-300 kg ha^-1 year^-1 of P₂O₅-K₂O, respectively; organic fertilization with 90 Mg ha^-1 year^-1 of manure; and mineral fertilization with 300-300-600 kg ha^-1 year^-1 of N-P₂O₅-K₂O ensure green mass and dry mass yields greater than 200 and 15 Mg ha^-1 cycle^-1, respectively, and water use efficiency greater than 20 kg ha^-1 mm^-1 in ‘Gigante’ cactus pear. It is concluded that yields of this magnitude are ensured with application of about 300-300-300 kg ha^-1 year^-1 of N-P₂O₅-K₂O using organic, organomineral or mineral sources.

Key words:
Opuntia; organomineral fertilization; bovine manure