Management strategies in a semiarid environment for forage cactus cultivation to balance growth, development, forage productivity and indicators of water efficiency and economics

Abstract Different cutting intervals can influence crop development. Therefore, knowledge of the interaction between growth factors and soil-plant-atmosphere conditions can contribute to the efficient cultivation of forage cactus. The objective of this study was to evaluate morphophysiological characteristics, production and water and economic indicators in forage cactus clones subjected to different cutting interval. The study was conducted in Serra Talhada, Pernambuco, in a 3 × 4 factorial arrangement, with three forage cactus clones (‘Orelha de Elefante Mexicana, OEM’ – Opuntia stricta ; ‘Miúda’ and ‘IPA Sertânia’ – Nopalea cochenillifera ) and four cutting intervals (6, 9, 12 + 6 and 18 months) in randomised blocks, with four replications. Biometric and productive measurements were performed to determine the phenophases and cutting times. The components of the soil water balance (SWB) were considered at a depth of 0.60 m and the indicators were analysed. The Absolute Growth Rate – AGR and Relative Growth Rate – RGR were higher for the OEM clone at a interval of 18 months. The highest productions of fresh mass (FM) (286.4 Mg/ha) and dry matter (DM) (21.4 Mg/ha) occurred in the OEM clone regardless of the cutting interval. The MIU clone presented three phenophases. The water use efficiency indicator (*WUEc, 1.5 kg/m 3 ) and crop water productivity (*WPc, 1.3 kg/m 3 ) were improved in treatments with the OEM clone, as well as the gross economic productivity of water via irrigation (PBEAi, 2.98 US$/m 3 ). It is recommended to cultivate the OEM clone of forage cactus, regardless of the cutting interval, to provide greater productivity and economic benefits.