AGRONOMIC EVALUATION OF OPUNTIA SPP. VARIETIES FOR FODDER PRODUCTION IN THE SEMIARID NORTHEAST, BRA-ZIL

Three field trials were conducted at Petrolina, Brazil: I) From Dec. 1994 to Jan. 1998, 30 varieties at a density of 7,143 pads/ha were established. In November 1996, a visual evaluation of the armored scale insect (Diaspis echinocacti) attack was performed. In the first harvest, the mean yield was 2.46 ±1.86 ton DM/ha/year. Eleven varieties showed similar yield than ‘Palma Gigante’ (PG) (2.85 ton DM), the most cultivated in the region (P>0.05), they showed tolerance to armored scale but PG was susceptible. 1267-Algeria Fodder showed high maintenance of stand even after a drought. II) From Apr. 2000 to Apr. 2004, 20 varieties were evaluated at density of 20,000 plants/ha, (the best eight from the previous study, three local ones, and nine from IPA, a local research institution). In a unique harvest, the mean yield was 6.21 ±2.82 t DM. Again, most varieties yielded more than PG (5.65 ton DM). Two varieties, 1278-Mexico Fodder and 1311-Marmillon Fodder, in addition to high yield (8.71 and 7.59 ton DM respectively), presented shorter diameter (0.88 and 0.78 m respectively vs. 1.05 m for PG) suitable for intercropping; and vertical growth, appropriated for transportation from field to pen. III) From Apr. 2000 to May 2004: COPENA-F1 and COPENA-V1 were compared to four local varieties, including PG, at a density of 20,000 plants/ha. mean yield of one harvest was 6.40 ±2.13 t DM. PG (10.81 t) did not differ (P>0.05) from COPENA-F1 (7.70 tons). These three accessions are promoted for plantation under controlled diffusion.