PHYSIOLOGY OF EX VITRO PINEAPPLE PLANTS (ANANNAS COMOSUS L. (MERR) BRS IMPERIAL) SUBMITTED UNDER DIFFERENT LEVELS OF NUTRIENTS.

Abstract

Pineapple (Ananas comosus L. Merr) a specie of Bromeliaceae Family is one of the most commercially important fruit. In Amazon, specifically on Tapajós Basin is largely cultivated in family agricultural contexts with high productivities. However, in the last years, the fusariosis on Pérola cultivate culminated to reduce local productivity of pineapple, associated with water stress. In this context, a new cultivar of pineapple, BRS IMPERIAL (EMBRAPA) that is resistant to fusariosis was introduced in a region. The objective of this work was to evaluate the physiological behavior of ex vitro pineapple BRS IMPERIAL throw nine variables, 1. Photosynthetic rate (A), 2. Stomatal conductance (GS); 3. Evapotranspiratory rate (E); 4. Leaf Temperature (^o C), 5. Total dry matter (MS); 6. Leaf Dry Matter (PA); 7. Root dry matter (SR) 8. PA / SR ratio; 9. Specific Leaf Area (AFE) under different levels of nitrogen, phosphorus and potassium (NPK). The Multivariate Analysis results showed a high similarity (Phi= 88%) between the physiological behavior based on the parameters of photosynthetic rate, stomatal conductance and evapotranspiration in pineapple ex vitro leaves when submitted to three different cultivation substrates as demonstrated by the high maximum coefficient (p <0.0001). The leaf temperatures were lower (38.6 ^o C) in control treatment (without NPK), compared to high leaf temperatures (46.0 ^o C) observed in NPK treatments, suggested that the metabolism CAM must acting on plants with significative levels of NPK. High plasticity on physiological behavior on ex vitro pineapple BRS IMPERIAL was observed and suggested the turn C3/CAM metabolism in young plants.