Pruning severity affects yield, fruit load and fruit and leaf traits of 'Brigitta' blueberry

Abstract

Pruning is crucial to balance productivity and fruit quality in blueberry orchards. Slight, conventional and severe pruning treatments were applied on 4-and 5-year old bluberry plants cultivar 'Brigitta' to evaluate their effect on yield, leaf area, gas exchange and fruit load as driver of fruit quality traits. Yield and berries per plant decreased with increasing pruning severity, whereas canopy leaf area increased. The resulting fruit load ranged from 0.2 to 1.4 fruit per cm 2 leaf area. Fruit weight, dry matter, glucose and fructose were negatively related to fruit load, with fruit fresh weight decreasing to greater extent than sugars. Berry weight was restricted by source limitation during the initial cell division and initial cell enlargement fruit growth phases as indicated by decreased relative growth rate. Light-saturated photosynthetic rate diminished with increasing pruning severity indicating a sink limitation of photosynthesis. The strong association between photosynthesis and stomatal conductance shows a high corregulation in the response of carbon and water exchange to sink demand. Our results underline agronomic and physiological factors determining blueberry yield and fruit quality and can be useful for agro-technical management.

Effects of Timing and Intensity of Summer Pruning on Reproductive Traits of Two Southern Highbush Blueberry Cultivars

“…The season average berry weight was also decreased by the heavy pruning treatment compared with other pruning intensities in 2013 and 2014, likely because much of the fruit ripened later in the season, when fruit size was smaller. In contrast to our results where heavy pruning decreased fruit size, Strik et al (2003) and Jorquera-Fontena et al (2014) found that heavy winter hand pruning increased berry weight compared with moderate hand pruning and no pruning in highbush blueberry. However, the removal of inflorescence buds during winter pruning would decrease inflorescence bud number and therefore berry number the following growing season, potentially increasing berry weight.…”

Development of fruit quality traits and comparison of the fruit structure of two Vaccinium corymbosum (L.) cultivars

“…Due to these changes, the skin of the 'Patriot' fruits was substantially thinner than in the 'Earliblue' cultivar. Many researchers report that V. corymbosum fruits are characterised by a double sigmoid growth pattern consisting of 3 stages differing in the length depending on the variety and environmental conditions (Godoy et al, 2008;Jorquera-Fontena et al, 2014). As pointed out by Brady (1987) and Giovannoni (2004), stage I is characterised by rapid cell division and dry weight gain and lasts from 25 to 35 days.…”

Effect of pruning intensity on soil moisture and water use efficiency in jujube (Ziziphus jujube Mill.) plantations in the hilly Loess Plateau Region, China

“…Jujube plants under C 1 pruning intensity had the highest yield, so pruning within a limited range of intensity had a positive effect. Jorquerafontena et al (2014) found that yield and berries per plant decreased with increasing pruning intensity.…”