Morphological and nutritional characterization of the cladodes of seven varieties of forage cactus of the genus Opuntia cultivated in Brazil

The plant species of the genus Opuntia are widely cultivated in the Semiarid region of Brazil and are considered as a sustainable technological alternative for coexistence with drought. The objective of this work was to characterize, by order of the cladodes, seven varieties of forage cactus of the genus Opuntia, cultivated under a rainfed regime, through morphological and nutritional parameters. The study was conducted at the IPA Experimental Station in the city of Caruaru-PE. The experimental design used was in randomized blocks, with three replicates. The varieties studied were: Gigante, Redonda, Clone IPA-20, F-08, Orelha de Elefante Mexicana, V-19 and Orelha de Elefante Africana. The number of total cladodes of the plant (NC), cladode length (CL), cladode width (CW), cladode area (CA), cladode thickness (CT), cladode volume (CV), cladode perimeter (CP), total fresh weight (FW), total dry weight (DW), total photosynthetic area (TPA), cladode area index (CAI), plant height (PH), plant width (PW), total fresh matter yield (TFMY), total dry matter yield (TDMY), total water accumulation (H2O), survival (SV), dry matter (DM), mineral matter (MM), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), protein (P), hemicellulose (HEM), nitrogen (N), potassium (K) sodium (Na) and calcium (Ca) were determined at two years of age of the plants. Variability was observed in some of the morphological and/or nutritional characteristics among the order and/or phenological stage of the cladodes within the varieties. The varieties were divergent among themselves in the characteristics, NC, CL, CW, CA, CT, CV, CP, PH, PW, SV, P, N and Ca; and are related to genetic variation among the materials. The knowledge of the variability existing within and among botanical materials of forage cactus serves for the development of technologies aimed at each genetic material.