Al Kovaleski February, 2014 Summer pruning southern highbush blueberries in Florida University of Florida Horticultural Sciences Department
Blueberry summer pruning 2 No removal of flower buds Long growing season in FL Pruning promotes increased vigor More support for reproductive structures
Objectives 3 Determine the effects of timing and severity of summer pruning: Vegetative traits: Regrowth Cane breakage Timing of defoliation Incidence of leaf spots Incidence and severity of stem blight Reproductive traits: Flower bud initiation Fruit set Yield Quality of fruit
Plant material 4 Two cultivars ‘Emerald’ and ‘Jewel’ Seven year old plants Commercial cultural practices PSREU – Citra, FL
Treatments 5 No summer pruning control Prune 30% early June Prune 30% mid-July Prune 30% early June+tip Prune 60% early June+tip Detailed hand pruning control
Treatments 6 30%60%Unpruned
Vegetative traits 7 Canopy volume Regrowth Condition of fall foliage Time of defoliation Leaf spot
Vegetative traits 8 Incidence and severity of Stem Blight
Reproductive traits 9 Re-growth shoots collected to assess timing of flower bud initiation – Late summer until defoliation
Reproductive traits 10 Harvest Period Yield Fruit quality Total soluble solids Titratable acidity Firmness Average berry weight picturesbychristopher.wordpress.com Labmate-online.com
R ESULTS TO DATE 11
Regrowth volume - Jewel 12
Cane breakage - Freezes 13
Leaf spots - Jewel 14
Environmental Conditions
Leaf spots - Jewel 16
Defoliation - Jewel 17 No significant defoliation in ‘Emerald’ until December
Flower bud initiation 18
Flower bud initiation 19
Flower bud initiation 20 Emerald – Sep 8 th Jewel – Oct 20 th
Flower bud initiation 21 Important: Develop management strategies to enhance flowering Regulate fruit load Yield! First sign of transition detectable
Stem blight 22 Jewel was not affected No differences among treatments in Emerald 25% incidence
Berry quality 23 Average weight - Jewel Reduction in the 60%+tip 1.9g 1.4g Others averaged 1.7g pH, acid and sugar content, anthocyanins, firmness No differences
24 Yield - Emerald
Yield - Jewel 25
Yield - Jewel 26
Acknowledgements 27 Dr. Darnell and Dr. Williamson Dr. Olmstead and Dr. Harmon
28 Thank you!