Aplicação exógena de prolina no crescimento, fisiologia e produção da melancieira irrigada com água salina.

Abstract

The área explored with watermelon in the semiarid northeast is irrigated in almost your totality. Irrigation in these regions has been identified as an alternative to the socio-economic development, although when used improperly can promote soir salinization and degradation of water and soil resources. Therefore, the aim of this work to evaluate the effect of exogenous application of proline in the growth, physiology and yield of watermelon irrigated with saline water. The experiment was carried out at the Centro de Ciências e Tecnologia Agroalimentar (CCTA/ UFCG) - Pombal - PB, in the throughout of lO/16/2011 to 12/19/2011, using the hybrid watermelon 'Quetzali'. The treatments consisted of two leveis of salinity of irrigation water (0.3 and 4.0 dS m'l) and ave concentrations of proline (0, 5, 10, 15 and 20 mmol L'l) applied in the leaf in watermelon. The experimental design was a randomized block in factorial scheme 2 x 5, with four replications. The highest values regarding of plant growth, physiological parameters and yield in watermelon are seen in the salinity of 0.3 in relation to 4.0 dS m'l. The supply of proline was effective in reducing stress responses in watermelon caused by salinity of irrigation water up to the concentration of 8.51 mmol L'l proline. The increase in fruit yield provided by the concentrations l0.74 and 8.51 mmol L'l in relation to concentration 0 mmol L'l proline was 31 .08%, when irrigated with normal water (0.3 dS m'l) and 17.03% when irrigated with saline water (4.0 dS m''). In absolute terms we can say that the best performance of watermelon was obtained at concentrations of 10.0 mmol L'l proline for plants irrigated with water of normal irrigation (0.3 dS m'l) and 5.0 mmol L' l of proline for plants irrigated with saline irrigation water (4.0 dS m'1).