INITIAL GROWTH OF Dipteryx alata PLANTS UNDER WATER DEFICIT

ABSTRACT The objective of this study was to analyze the effect of water deficit stress on the growth of Dipteryx alata plants. The experiment was carried out on a bench in full sun at the Goiás State University experimental unit, in Ipameri town, Goiás. Dipteryx alata seeds were collected from native plants in that municipality and sown in four-liter pots containing a mixture of soil, sand and cattle manure at ratio 3:1:0.5, respectively. The experiment was set up following the completely randomized design with five treatments (plants irrigated for 25 days with water volumes corresponding to 0%, 25%, 50%, 75%, and 100% of daily evapotranspiration) and six replicates. Treatments were applied when the plants were 60 days old, and at 85 days the plants were assessed for the following parameters: plant height, stem diameter, number of leaves, foliar chlorophyll concentration (a+b ), total carotenoids, relative water content, transpiration, leaf, stem and root mass ratios, and total biomass. During early development, the Dipteryx alata plants were highly sensitive to water deficit, significantly slowing down vegetative growth. Accordingly, in order to remain alive, the plants drastically reduced transpiration as a result of high stomatal sensitivity