MICROBIAL POPULATION, NUTRIENT AVAILABILITY, AND GROWTH OF UMBU ON SUBSTRATES WITH ORGANIC RESIDUES

Abstract

The umbu is an important fruit for the northeast of Brazil because it is being used in reforestation areas and has great economic potential. However, there is a gap on propagation techniques of this culture that is a crucial step for the successful of plant development. Thus, the objective of the present study was to evaluate the effects of alternative substrate on the growth of umbu rootstock, fertility attributes, and microbial populations of these mixtures.The experimental design was completely randomized with 10 treatments: TA = soil + sand (1:1); A = sand; ECSC = goat manure + Plantmax® (1:3); EBSC = manure + Plantmax® (1:3); ECA = goat manure + sand (1:3); EBA = manure + sand (1:3); ECBSC = manure + goat manure + Plantmax®(1:1:3); ECBA = manure + goat manure + sand (1:1:3); HSC = humus + Plantmax®(1:3) and HA = humus + sand (1:3),with four replications. The addition of residues promoted the quality of the umbu rootstock, especially when mixed with a commercial substrate composed of vegetable organic matter and expanded vermiculite. With multivariate clustering, three groups acknowledged a similarity between the substrate mixtures. The use of humus or goat manure mixed with the commercial substrate is recommended for the production of umbu rootstock.