Crescimento do sistema radicular da Opuntia ficusindica (L) Mill (palma forrageira) em função de arranjos populacionais e adubação fosfatada.

Abstract

The research was conducted in the Nucleus of Searches for the Semi-arid, CSTR/UFCGPatos-PB, during the period of January- 2007 to January- 2008, to evaluate the effect of phosphorus levels and variable spacing on the root development of cactus pear. The experiment was installed following the randomized block design in a factorial 4 x 4, with four doses of single superphosphate (10; 15; 20 and 25 g.SS.plant-1 ) and four spacing between plants (10; 15; 20 and 25 cm) with three replicates. Soil samples were collected on line and between planting, at depths of 0 to 10 cm and 10 to 20 cm, in three different seasons. Evaluations were conducted in length and density of roots. In determination of the lenght of roots, the Tennant method was used. The data analyzed showed that: the highest concentration of roots in the cactus pear occurred in the surface layer of soil; the spacing and doses of single superphosphate didn’t interfered in the root distribution, in the line between planting, respectively; the interaction between spacing and doses of single superphosphate didn’t influence the root distribution, the distribution and seasonal variation in the amount of roots of the cactus pear presented characteristics closely related to the ability to adapt to water stress.