Articles
Low-input pruning options in Mini Blues for specialized processed markets reduce production costs while maintaining yield and quality
Article number
1357_14
Pages
93 – 98
Language
English
Abstract
Mini Blues, a small-fruited northern highbush blueberry with uniform, sweet (>16% soluble solids, 0.8 g berry-1), flavorful fruit, is ideal for specialty processed markets and well-suited for machine harvest.
Plants are vigorous and produce many small laterals making typical highbush pruning methods time consuming and costly.
A planting was established in October 2015 to evaluate pruning options for Mini Blues. Pruning removed all fruit for the first 2 seasons; treatments began prior to the third growing season (2018). Pruning treatments were: 1) conventional highbush pruning (HB); 2) removing one or two of the oldest canes per bush (Speed); 3) unpruned from 2017 to 2021 (Unpruned); and 4) hedging immediately after fruit harvest starting in summer 2018 (Hedge). In winter 2019-2020, HB pruning required 423 h ha-1, while speed pruning took 85 h ha-1; the hedge and unpruned treatments required an average of 32 h ha-1 to remove low-growing branches that would interfere with machine harvest.
Hedging was only done in 2018 because it severely reduced yield; it is not a viable pruning method in this region due to insufficient time for growth and flower bud development after hedging.
Harvested yield was not affected by treatment in 2018 or 2020 and was only reduced by hedging in 2019. Berry weight was lower for unpruned plants in 2018 and 2020 compared to HB (0.57 and 0.73 g, respectively in 2020). HB pruning led to a more concentrated ripening period which would reduce machine harvests needed and cost.
However, yield and fruit quality were similar to unpruned and speed pruning and the increase in pruning labor for HB was not enough to compensate for lower harvest costs.
We will continue to study these techniques for long-term impacts on yield, quality, and cost of production, particularly the likelihood of needing to renovate unpruned treatment plants.
Plants are vigorous and produce many small laterals making typical highbush pruning methods time consuming and costly.
A planting was established in October 2015 to evaluate pruning options for Mini Blues. Pruning removed all fruit for the first 2 seasons; treatments began prior to the third growing season (2018). Pruning treatments were: 1) conventional highbush pruning (HB); 2) removing one or two of the oldest canes per bush (Speed); 3) unpruned from 2017 to 2021 (Unpruned); and 4) hedging immediately after fruit harvest starting in summer 2018 (Hedge). In winter 2019-2020, HB pruning required 423 h ha-1, while speed pruning took 85 h ha-1; the hedge and unpruned treatments required an average of 32 h ha-1 to remove low-growing branches that would interfere with machine harvest.
Hedging was only done in 2018 because it severely reduced yield; it is not a viable pruning method in this region due to insufficient time for growth and flower bud development after hedging.
Harvested yield was not affected by treatment in 2018 or 2020 and was only reduced by hedging in 2019. Berry weight was lower for unpruned plants in 2018 and 2020 compared to HB (0.57 and 0.73 g, respectively in 2020). HB pruning led to a more concentrated ripening period which would reduce machine harvests needed and cost.
However, yield and fruit quality were similar to unpruned and speed pruning and the increase in pruning labor for HB was not enough to compensate for lower harvest costs.
We will continue to study these techniques for long-term impacts on yield, quality, and cost of production, particularly the likelihood of needing to renovate unpruned treatment plants.
Publication
Authors
B.C. Strik, A.J. Davis, P.A. Jones
Keywords
blueberry, production efficiency, yield, fruit quality
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