ASHS 2024 Conference

Based on six years of research at the University of Arkansas, the rotating cross-arm (RCA) trellis has been shown to improve several aspects of blackberry production such as yield and fruit quality. Through this research, a new training method coined the ‘fan’ method was developed with the potential to maximize canopy fill and decrease labor. A trial was conducted from 2022 to 2024 at the University of Arkansas Fruit Research Station (UAFRS) in Clarksville, AR to verify the ‘fan’ method and test new cultivars not used in previous trials. The blackberry cultivars ‘Ponca’, ‘Von’ and ‘Caddo’ were planted in 2021 on a 33m row of t-trellis and a 33m row of RCA trellis in a randomized complete block arrangement. The plants were spaced 0.76 m apart in four plant plots replicated three times per trellis treatment. The ‘fan’ training method (primocanes tipped at 30 cm and laterals trained upward and fanned out on the long arm) was implemented on the RCA trellis treatment for all plants. The t-trellis was tipped at the top wire following practices standard for the region. Blackberry yield, fruit quality, and physiological data were collected during 2023 and 2024. Preliminary results from 2023 showed the ‘fan’ method on the RCA can achieve similar yields to the T-trellis but offer the opportunity to protect the crop from severe cold events and reduce the incidence of fruit quality disorders for some cultivars. All the varieties evaluated were found to be suitable for use on the RCA with the fan method however differences in cane vigor were noted and cultivar can be the biggest determinant of yield and fruit quality regardless of trellis type.