NUTRIENT INTERACTIONS IN CACTUS PEAR (OPUNTIA FICUS-INDICA) AND THEIR EFFECT ON BIOMASS PRODUCTION

There are few reports on the interactive effects of nutrients in Opuntia ficus-indica. The recognition of the importance of nutrient balance in crop production is an indirect reflection of the contribution of nutrient interactions to yield. A field experiment to identify nutrient interactions in cladodes of O. ficus-indica plants cultivated with the objective of biomass production was carried out during three years. N, P, K, Ca and Mg concentrations in one-year-old cladodes and biomass production of three varieties served as dataset (n=108) to identify nutrients and nutrient interactions affecting yield. Cactus pear mineral nutrition is not similar to other fruit, vegetable and forage crops, because nitrogen, phosphorus and potassium are not so important macronutrients as they are in other crops. Significant positive correlations between yield and each of the nutrients K, Ca and Mg imply that yield increase as their concentrations increase in one-year old cladodes. N and P were not correlated with yield. N/P ratio had a significant positive effect on biomass production. Moreover, it is noted that the P/Ca ratio significantly depressed yield in O. ficus-indica.