Impact of waterlogging stress on grafted avocado ( Persea americana ) seedlings growth and physiological performance

Abstract

Agricultural fields prone to waterlogging condition induce physiological stress on fruit trees as it affects root respiration and nutrient uptake. However, the information on the growth performance of avocado under waterlogging condition is limited, particularly in terms of morphological and physiological performances. Therefore, this study was designed to evaluate the performance of avocado rootstocks under different waterlogging levels under shade condition. The experiment was conducted using a complete randomized design with factorial arrangement using Ettinger variety as scion that was grafted on Guatemalan and Mexican rootstock races at three waterlogging levels (50%, 75% and 100%) in three replications. The result showed that morphological growth of avocado grafted on Guatemalan race outscored in number of buds, shoot growth, rootstock elongation and scion shoot tip growth compared to the one grafted on Mexican race. Similarly, photosynthesis, transpiration and stomata conductance were significantly affected by the races, waterlogging levels and interaction of the two main factors. The result indicated that the Guatemalan race significantly improved photosynthesis, transpiration, stomata conductance and water use efficiency nearly by 50% in all waterlogging levels as compared to the one grafted on Mexican race. However, the smallest transpiration and water use efficiency were recorded at 100% waterlogging level from the Mexican race. Generally, the study revealed that Guatemalan race used as rootstock gave a strong morpho-physiological performance as compared to the Mexican race. Similarly, waterlogging level at 75% induced strong morphological and physiological performances in Guatemalan race compared to the seedling subjected to 50% and 100% waterlogging. Thus, the finding revealed that the Guatemalan race can be a potential rootstock under waterlogging/saturated soil condition in loamy sand soil texture.