Produção de porta-enxerto de cajueiro anão precoce com águas salinizadas e doses de matéria orgânica.

Abstract

In Brazil, most of the cashew orchards are located in the semi-arid tropics, where water resources are scarce and present salinity problems. In view of the socioeconomic importance of cashew trees in the northeastern region of Brazil, as well as the difficulties related to water scarcity and water quality for irrigation, the objective of this work was to evaluate the effects of the use of different doses of organic matter combined with waters of different saline levels In the production of cashew rootstock. The experiment was carried out in a greenhouse (protected environment) of the Center for Science and Technology Agro-Food of the Federal University of Campina Grande (CCTA / UFCG), located in the municipality of Pombal-PB. The experimental design was a randomized complete block design, in a 5 x 4 factorial scheme, with the treatments referring to five levels of electrical conductivity of ECw irrigation water of (0.3, 1.0, 1.7, 2.4 and 3, 1 dS m-1 ) in interaction with four organic matter doses OM (2.5, 3.5, 4.5 and 5.5%). Three replicates were used, with two useful plants per plot, where the precocious dwarf cashew clone CCP 06 was evaluated. The variables of stem diameter, number of leaves and leaf area were evaluated at 20 and 30 days after application of the treatments (DAT), absolute and relative growth rate of plant height and stem diameter in periods of 10 to 30 DAT, fresh and dry stem, leaf and shoot biomass, dry root phytomass, total dry matter and Quality of Dickson at 30 DAT. Increasing doses of organic matter did not attenuate the effect of irrigation water salinity on the variables studied in the present study. The transpiration, stomatal conductance and the net photosynthesis of the CCP 06 cashew rootstocks decrease with the increase of the salinity of the soil saturation extract. Increasing OM masses do not reduce the deleterious effect of irrigation with salinized waters on phytomass and physiology Of CCP 06 cashew tree rootstock. ECw water irrigation of up to 2.49, 0.90 and 1.01 dS m-1 in the production of CCP 06 cashew rootstock promotes acceptable growth reduction (diameter, Leaf area and TCRap), physiology and phytomass at 30 DAT of 10%, respectively. The organic matter dose of 2.5% presented the best results for the studied variables.