ASHS 2024 Conference

Citrus greening, or Huanglongbing (HLB), poses a severe threat to Florida’s citrus industry, impacting tree health and yield. Due to the lack of a known cure, growers employ various strategies to manage its effects, including increased nutrient application. However, in regions like the Indian River District (IRD), characterized by poor soil fertility and organic matter content, nutrient retention is challenging. Consequently, there is growing interest in using cover crops to enhance soil fertility. Despite this, there is limited published data on their effectiveness in the IRD. To address this gap, a collaborative study was initiated in Ft. Pierce, Florida, involving a commercial grower and the University of Florida. A three-year field trial, employing a randomized complete block design with four blocks, included ‘Star Ruby’ grapefruit trees grafted on ‘US-942’ rootstock, ‘Bearss’ lemon trees on ‘Sour Orange’ rootstock, and ‘OLL’ sweet orange trees on 'US-942' rootstock. Two treatments were applied: conventional (without cover crops) and experimental (with cover crops). Cover crops were planted bi-annually (winter and summer), grown, and terminated at each season’s end. Soil nutrient content, organic matter, microbiome diversity, moisture, and temperature, as well tree and root growth parameters were measured seasonally. After three years of cover cropping, significant differences in soil nutrient content, organic matter, and microbiome diversity were observed between the conventional and experimental treatments, suggesting potential impacts of cover crops on soil characteristics. However, there were no noticeable effects on tree growth or physiology. This study is ongoing and aims to provide a comprehensive understanding of the long-term effects of cover cropping on soil parameters in HLB-affected citrus groves, informing sustainable management practices in citrus cultivation.