Flowering Bud Induction Advisory #4
Current Condition: Current observations indicate that most citrus‑producing regions have accumulated very high flower bud induction hours, and flower bud differentiation has already begun. The table below summarizes induction hour totals estimated around each FAWN station in the region.
Based on the current models, the first wave of flowering from the early differentiation event was expected to occur in mid‑February. However, the recent freeze conditions across many areas of Central and Southwest Florida likely damaged or burned the more advanced flower buds. As a result, groves that experienced freezing temperatures during the past three weeks will probably show a very light bloom in February.
Temperatures across the citrus belt remain below seasonal averages, and the forecast for the next 10 days indicates continued highs below 70 °F for most areas. Under these cooler conditions, we anticipate that flower bud differentiation will temporarily halt.
Given the current weather patterns, the first economically significant wave of bloom is now expected between the last week of February and the first week of March across most of Central and Southwest Florida. The freezing temperatures from early January have potentially contributed to a more synchronized flowering by weakening the first wave of bloom.
Season Forecast: This winter and spring (2026) are predicted to bring a weak La Niña, which means Florida will experience warmer-than-normal temperatures and lower-than-normal rainfall. However, the freeze events have been unpredictable and have slowed the bud differentiation. Moreover, drought conditions have been evident in many citrus-growing areas and are likely to persist. This has made this season challenging.
We are currently working on updating the old DISC website, and we apologize for any inconvenience as it may be intermittently unavailable. In the meantime, a comprehensive list of all FAWN stations along with accumulated induction hours will be published every Monday until the website becomes fully accessible to everyone.
Contact Dr. Tripti Vashisth (tvashisth@ufl.edu) for any questions or concerns.
Flowering related management considerations for HLB-affected trees:
- DO NOT drought stress HLB-affected trees even though drought stress promotes flower induction and suppress vegetative growth, you should not risk current crop due to additional drought stress. Drought stress can exacerbate fruit drop. Daily, lower volume irrigations to minimize fall drought stress is suggested, especially when the weather is warm,
- Flowering enhancing fertilizer to increase the number of flowers are NOT suggested for severely HLB-affected trees as they are very unlikely to benefit because of 2 reasons: (1) HLB-affected trees have more dead wood therefore, there are fewer buds available to become flower, interestingly a good branch of severe HLB trees has same flowering potential as mild HLB trees. So additional flowering promoting fertilizer is not needed. (2) High twig dieback and low fruitlet retention is the main concern with severe HLB trees in regards to fruit set. Only 2% of the total flowers turn into harvestable crop; therefore, pushing trees to flower more is not advisable as that is likely to waste trees’ energy and resources in extra flowers.
- Gibberellic acid suppresses flowering, but the window to apply for GA seems to have passed. DO NOT apply GA for flowering manipulation.