Crescimento e eficiência fotossintética em duas gramíneas Tifton 85 e Gramão irrigadas sob diferentes águas.

Abstract

Water scarcity in the northeastern semiarid is a problem that requires a response priority. Its cause is related to low rainfall and irregular rainfall. region and a geological structure that does not allow satisfactory accumulation of water in the underground. This research aims to analyze the influence of different types of water on the (height, absolute and relative growth rate) and efficiency photosynthetic (photosynthesis, transpiration, stomatal conductance, internal concentration CO2 and relationship between internal CO2 concentration and environmental concentration) Tifton 85 and Gramão forage species, planted in pots filled with soil Abrupt Plutic Eutrophic Yellow Argisol. The experimental design used was completely randomized, arranged in a factorial scheme (3x2) with twelve repetitions, totaling 72 experimental units whose factors were: three types of water and two varieties. The cultivation was carried out in a protected environment located at Embrapa. Semolina, Petrolina, PE, from October 2010 to January 2011. The following Grasses were grown in pots irrigated with different waters (water supply, well and fish pond), with watering shift every two days. Analysis results show that fishpond water promoted higher plant height for both varieties. The best absolute and relative growth rates, were observed in plants irrigated with fish and poco nursery waters. In In general, the plants responded better to irrigation with water from the Fishpond.