2018 ASHS Annual Conference

Supplemental foliar nutrient products are applied by some berry growers to improve sugar content, fruit quality and yield. However, there is not sufficient evidence that these applications improve fruit quality or increase crop yield. Virginia growers have limited information on two new thornless, primocane bearing blackberry cultivars- PrimeArk® Freedom and PrimeArk® Traveler. Both primocane cultivars are considered compatable for USDA hardiness zones 4-8. A study was conducted at the Hampton Roads Agricultural Research and Extension Center, Virginia Beach, VA (USDA zone 8A) with thirty-six PrimeArk® Freedom and Traveler plants each that were established on raised beds covered white woven polyethylene and supported by T-post trellis. The objective of this study was to determine if supplemental foliar treatments showed increases in total soluble solids (TSS) content, yield and fruit size. Three sources of foliar nutrient treatments were applied using recommended label rates of: AgGrand (4-3-3); Sugar Express (40-10-40); K-Ace (0-0-25). An untreated control that received no supplementary nutrient was included in the study. Six foliar applications treatments were applied (April 17, May 5, May 27, June 11, June 25 and July 16 in 2017) at various growth stages from pre-bud to bloom through harvest. There were no significant differences between control and those that received foliar treatments, on crop yield, TSS content, or overall fruit size. The study will be repeated in the 2018 growing season.