Understanding and Manipulating the Interaction of Rootstocks and Constant Nutrition to Enhance the Establishment, Longevity and Profitability of Citrus Plantings in HLB-Endemic Areas

Understanding and Manipulating the Interaction of Rootstocks and Constant Nutrition to Enhance the Establishment, Longevity and Profitability of Citrus Plantings in HLB-Endemic Areas

Report Date: 11/06/2017
Project: 15-013   Year: 2017
Category: Plant Improvement
Author: Jude Grosser
Sponsor: Citrus Research and Development Foundation

Objective 1. (Greenhouse experiment): We reached the 6 month period since the stick grafting and first CRF application, so all CRF nutrition treatments were re-applied using all donated products (all trees), PCR samples were taken from every tree and sent to the Southern Gardens diagnostic laboratory to determine HLB status – hopefully we can report results in the next quarterly report. Composite leaf samples from each nutrition/rootstock combination were sent to Waters Lab for nutritional analysis. Overall, most trees are showing reasonably good health, with only minor symptoms appearing on some trees. The greenhouse and the experiment were not impacted by Irma. Objective 3: To evaluate the effect of complete, balanced and constant nutrition on HLB-affected mature trees (composition, delivery and economics). The third application of fertilizer treatments for the 2nd year was completed at both sites. There were no tree losses due to Irma, but there was some fruit blown off the trees, apparently fairly consistent across the replications within the trial. Ojective 5. (funded by Lee Groves, using donated fertilizer products): Alligator Vernia/Rough Lemon Enhanced Nutrition Experiment � Treatments: 6 tree plots (randomized), 2 plots per treatment � treatments 2 times per year. Trees still look relatively good, no significant impact by Irma. Photosynthesis rates were measured on all trees, and composite leaf samples were taken and sent to Water’s Lab for nutritional analysis.


Your browser does not support pdfs, click here to download the file.