Growth dynamics and accumulation of forage mass of forage cactus clones as affected by meteorological variables and water regime.

[Display omitted] • Multivariate analysis assisted to plan the cultivation of forage cactus. • Irrigation affects growth dynamics and forage accumulation of forage cactus. • Growth dynamics and forage accumulation are affected by the semiarid climate. • Opuntia stricta Haw. (Haw.) is more sensitive to semiarid climatic conditions. Comprehending the relation between climatic variables and the productive and morphological characteristics of the forage cactus is essential to the adjustment of the management of its production in different agro-climatic areas. The aim of this study was to evaluate the interrelationship between the meteorological variables and the water regime with the growth dynamics and accumulation of forage mass of three different forage cactus clones. We submitted the clones Miúda–MIU; Orelha de Elefante Mexicana–OEM and IPA Sertânia–IPA to three water regimes (40 %ETc, 80 %ETc and 120 %ETc), plus the non-irrigated condition (0 %ETc), during 18 months, in the municipality of Serra Talhada, Pernambuco, Brazil. Morphological, structural, and productive characteristics of the plants, and environmental variables were supervised throughout the experimental period. Pearson's correlation, multicollinearity test, canonical correlation and path analysis were applied to these data. It was observed that the minimum air temperature, the relative air humidity, and the irrigation were the variables that affected the growth dynamics and the accumulation of fodder mass of the forage cactus clones the most. The clone OEM presented more sensitivity to the environmental conditions (climate and irrigation) in comparison to the other clones MIU and IPA. The environmental conditions affected the growth dynamics more than the productivity of the clone from the genus Nopalea. It was determined that the species of forage cactus presented differentiated morphological and productive responses among themselves, under semiarid conditions in Brazil. [ABSTRACT FROM AUTHOR]