Effect of plant spacing and cutting intensity on the morphology andproductivity of forage cactus [Opuntia stricta (Haw.) Haw.]

The forage cactus cultivar Mexican elephant ear (MEE) [Opuntia stricta (Haw.) Haw.] has been widely used in the semi-arid of Brazil because of its resistance to carmine mealybug. Therefore, it is necessary to establish planting and harvesting management strategies for this cultivar. This study evaluated the effect of cutting intensity (preservation mother cladode, and mother + primary cladodes) and different planting densities (55 555; 27 777; 13 888 and 6 944 plants ha(-1)) on the morphology and productivity of the forage cactus cv. MEE, in 10-year-old cultivation under rainfed conditions. A split-plot design was used where planting density was allocated to the main plots and harvesting intensity to the sub-plots. Each treatment combination was replicated four times. The data were submitted to ANOVA, Tukey's test, and principal component analysis at 5% (p < 0.05). Post-harvesting preservation of the primary cladodes promoted greater dry matter production (9.2 t ha(-1) year(-1)), crop water accumulation (86.6 t ha(-1) year(-1)), and rainwater use efficiency (11.4 kg of DM mm(-1)) (p < 0.01). Primary cladodes preservation positively influenced the productive characteristics of the forage cactus, and the planting density of 13 888 plants ha(-1) (0.72 m(2)) favoured the productivity of this cultivar. These findings can guide planting and harvesting strategies for cultivating MEE cactus.