Response of oil palm (Elaeis guineensis Jacq.) genotypes to irrigation regimes at seedling stage

Abstract

This study, which was carried out from March 2010 to April 2011 in Songkhla province, aimed to evaluate the growth, physiological responses, correlation and heritability at the seedling stage of oil palm subjected different irrigation regimes. Five oil palm varieties (hybrid tenera) including Nongped, Golden Clonal Tenera, PSU-139, PSU-140 and PSU-81 were used. The experiment was arranged as a factorial experiment in CRD.  The five oil palm varieties were subjected to 3 irrigation regimes: daily watering, or control; 4-day interval watering;  and 8-day interval watering. The experiment showed that there were some physiological responses of the oil palm seedlings to water deficits in both 4-day and 8-day interval watering treatments, resulting in lower stomatal  conductance, lower leaf water potential, lower the rate of dehydration and lower net photosynthesis compared to the control. The degrees of physiological responses of the five oil palm varieties depended on the magnitude of water stress. The oil palm seedlings which were recorded for vegetative growth showed that those imposed with 4-day interval watering could recover from the dry condition while those imposed with 8-day interval watering had decreased growth rates. The correlation coefficients among the traits were positive at the significance level of P<0.05 or P<0.01. These traits included the number of lanceolate leaves, number of pinnate leaves, plant height, width of bulb and leaf length.