Climate Change Threatens Apple Harvests Worldwide, Israeli Research Explores Solutions
A new study examining apple production in 13 major growing countries over six decades reveals that rising temperatures and increased rainfall are linked to decreased apple yields globally. While the overall trend is clear, the specific impact of climate conditions varies by country. In nations with higher production, advanced technologies like sophisticated irrigation systems and adapted cultivation methods appear to mitigate the adverse effects of heat.
Dr. Yael Gronwald, a researcher at the Volcani Institute specializing in fruit tree adaptation to climate change, explains that apple trees rely on specific winter chilling periods to regulate their blooming cycle. Insufficient cold can lead to premature flowering, risking frost damage and crop loss. Historically, areas like Israel's Hula Valley, once suitable for apple cultivation, are now too warm, shifting production to higher elevations like the Upper Galilee and Golan Heights. Prolonged summer heatwaves also damage fruit directly on the trees, while increased extreme rainfall can cause root anoxia due to waterlogged soil.
To combat these challenges, new cultivation techniques are emerging. Two-dimensional growing, where trees are smaller and planted densely in narrow rows, increases yield but exposes fruit to more sun, necessitating costly shading nets. Other strategies include precise irrigation, cooling systems, and developing or breeding apple varieties that require less chilling and are more heat-tolerant. The Volcani Institute is actively researching such varieties, aiming to enable cultivation in warmer regions.
Israel faces unique challenges as one of the warmest regions for apple cultivation, with limited precedent for research. Dr. Gronwald notes that while local apples are superior in taste, especially when fresh, Israel imports nearly 50% of its apples, often of lower quality and sometimes a year old. The current domestic production cannot meet market demand, meaning consumers seeking local produce may face higher prices or opt for imported alternatives. Significant research is still needed to fully understand the mechanisms of different apple varieties and adapt cultivation for a changing climate.
