DDD Conference

Dr. Or Shapira

Optimization of Rootstock-Scion Interactions in Almonds to Improve Food Security

Volcani Institute, Agricultural Research Organization, Israel

Forecasts point to extreme climate changes that will lead to a deterioration in the growing conditions for many plants. Among other things, changes in rainfall regime and an increase in temperatures are expected, which will lead to an increase in the transpiration and water consumption of plants. The effect of these climatic changes is likely to harm crop physiology and yields. Almonds are an important crop globally, known for its high nutritional and health value. Almonds are grown in diverse climatic and soil conditions in many areas. Like other fruit trees, almonds are grown as commercial varieties (scions) grafted onto selected rootstocks. The successful rootstock-scion interaction is crucial for ensuring high yield, excellent crop indices, and profitability. It is most likely that specific rootstock-scion interactions regulate tree responses to the environment and affect crop yield. Currently, rootstock-scion compatibility for crop production is being studied in orchards, which requires large areas, long years of research and large investments. With Climate-change there is an urgent need to develop a rapid screening system for rootstock-scion compatibility. In this study we combined a detailed physiological study using a mature almond orchard, composed of two cultivars (Shefa/Um-El-Fahem) grafted on five rootstocks (Felinem, Hansen-563, Nickels, Viking and G.F677). Additionally, 6 month old Um-El-Fahem and Matan (new self-fertilizing cultivar) grafted on three rootstocks (Hansen-563, Cornerstone, and G.F677) were analyzed in a high throughput lysimetric system. Our study showed that different rootstocks have specific effects on the physiological performance of different scions. Excitingly, a correlation between stomatal conductance, photosynthesis and almond yield was found at the orchard level. Meanwhile, our lysimetric-based system showed that the water consumption of Matan cultivar doubled when grafted on Hansen compared to all other rootstock-scion combinations, but only under well-watered conditions. Rootstock-scion compatibility in relation to water-balance and yield will be discussed.

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