Sistemas de cultivo para a palma forrageira cv. miúda (Nopalea cochenillifera Salm Dyck)

Abstract

The Spineless cactus (Opuntia and Nopalea) is one plant well adapted to the harsh conditions of arid and semiarid zones. However, productivity, mineral content and morphogenesis are affected by the management of crop plant density and levels of organic and mineral fertilizer, among other factors. Thus the study was to evaluate the effect of different management systems on productivity, morphological characteristics and mineral composition of the forage cactus (Nopalea cochenillifera Salm Dyck) cv. Miúda. Two experiments were conducted at the Experimental Agronomic Institute of Pernambuco IPA Station in Caruaru - PE, from June 2011 to June 2013. In experiment 1 we evaluated levels of organic fertilization (0, 10, 20 and 30 t MO ha-1 yr-1), nitrogen levels (0, 120, 240 and 360 kg N ha-1 yr-1) and harvest frequency (one year and two year), in randomized block design with plots arrangement split split, with four blocks. In experiment 2 plant densities were evaluated (10.417; 20.833; 41.666 and 83.333 plants ha-1), harvest frequencies (one year and two year) and cut intensities (preservation of primary and secondary cladodes during harvest). The experimental design was a randomized block with four blocks and a split plot arrangement, where the plot was formed by the different densities of planting / spacing and the split formed by the factorial arrangement between harvest frequencies and cut intensities. The variables were productivity, cladodes number per plant, cladodes area index (CAI), plant height (cm), dead number per plants, N, P, K and Na (g kg-1) and chemical characteristics of the soil at the end of the experiment. Productivity and the N, P and K increased as increased the level of organic fertilization. The number of cladodes per plant, cladodes area index (CAI) and plant height increased quadratically in response to fertilization levels. The number of dead plants reduced quadratically with the increase in the level of organic fertilization. The IAC and plant height were higher in plants with biennial harvest. No effect of nitrogen fertilization for the variables evaluated in spineless cactus cv. Miúda. The increase in plant density caused quadratic reduction in height and width of plants and cladodes number of plants with annual harvest and preservation of primary cladodes and the two cut intensities of the biennial harvest. With the annual harvest and preservation of primary cladodes increased plant density caused linear reduction. The N content was higher in plants with annual harvest the P content was higher with the annual harvest and preservation of primary cladodes for annual harvest and preservation of the side cladodes. The increase in plant density caused quadratic reduction in K content of plants with annual harvest and linear decrease in K content of plants biennial harvest.