Opportunities After Hurricanes
Behind every hurricane is a silver lining. Carbohydrate levels in citrus leaves, the amounts of sugars and starches, are very important in determining tree growth, flowering and fruit set. Since carbohydrates only come from leaf photosynthesis, growth of new leaves, roots and the fruit crop must compete for limited supplies of these sugars and starch. Understanding how this competition works will lead towards better management practices and enhanced yields. After the multiple hurricanes in 2004 blew off leaves and fruit, many trees immediately flushed new leaves and some flushed more than once. Since this leaf replacement had to come from carbohydrate reserves, we hypothesized that levels of sugars and starches in leaves and roots should be at an unprecedented low this fall. To take advantage of this opportunity, in October we sampled trees on the Ridge and in the Indian River area that had sustained varying levels of defoliation to evaluate carbohydrate levels in different aged leaves and roots. By comparing these data to carbohydrate levels in the winter and spring, we should gain insights into threshold levels of carbohydrates required to support flowering and fruit set. We hope to incorporate information from this hurricane opportunity into long term studies of carbohydrate relationships and citrus productivity.