Physiological responses of coffee plantas cv. Catuaí and Obatã submmited to hydric deficiency and salinity

Abstract

In this research work will assess the role of nitrogen, biometrics characteristics, water relations, gas exchange and biochemical changes in Arabica coffee plants cv. Catuaí and Obatã grown under hydric deficiency (HD) and salinity. The experiments will be conducted in a plastic tunnel with young coffee plants in 5 L pots and drip irrigated. In the first treatment on HD will be compared the effects of three irrigation levels: L1-25%% L2-50 and L3-100% of the water requirement of the crop. Considering that coffee is a perennial crop, will be applied three HD cycles, with two periods of water reconditioning. In the second treatment will assess the effect of salinity induced with NaCl, will be applied when two cycles of salt stress interspersed with a period of reconditioning. The experiments will be done in the hottest months (summer) and repeated at the second year in winter months. The treatments are arranged in a randomized block design with three replications. The evaluations and sample collections will always be performed at the beginning, middle and end of each cycle of stress. The central hypothesis of the experiments is that water restriction and salinity can change the physiology of plants and the nitrogen should take a prominent role in the tolerance of them. Will be evaluated various parameters of water relations, biometrics, gas exchange and biochemical changes related to nitrogen metabolism. In parallel, there will be environmental monitoring greenhouse and nutritional evaluation of the plants. (AU)