Influence of high tunnel and shade on blackberry yield and white drupelet disorder

E.L. Vinson, J.D. Spiers
Locally produced blackberries have a limited window of availability. Protective structures such as high tunnels or shade structures have been used to protect crops and extend the production growing season. This 3-year study arranged in a split-split-plot design was developed to determine effects of shade and/or high tunnel on yield and incidence of white drupelets on on ‘Kiowa’, a floricane-fruiting blackberry, and ‘Prime Ark 45’, a primocane-fruiting blackberry. Yield, and the number of fruits with white drupelets per 25-berry sample, was recorded. In 2015, yield plant‑1 of both ‘Kiowa’ and ‘Prime Ark 45’ were reduced when grown in full sun compared to those being grown in shade, both inside and outside of the hoophouse. Blackberry yields were generally higher when cultivated inside the hoophouse compared to those grown outside. In 2016 and 2017, blackberries grown in the hoophouse regardless of shade treatment on occasion, tended to have improved yield over those grown in the outside shade and non-shade treatments in general. Conversely, though, shade under the hoophouse encouraged higher yield in ‘Kiowa’, it reduced the yield of ‘Prime Ark 45’. The occurrence of white drupelets was slowest in the shaded treatments in 2015 and 2016. The hoophouse treatment reduced white drupelets in 2015 but increased them in 2016. In 2015, there was no occurrence of white drupelet in ‘Prime Ark 45’ in any treatment. In 2017, ‘Kiowa’ produced significantly more fruit with white drupelets than ‘Prime Ark 45’. ‘Kiowa’ tended to have greater incidence of white drupelets than ‘Prime Ark 45’ in each year. The increase in blackberry yield and reduction in the occurrence of white drupelet was encouraged by the use of hoophouse or shade. Generally, this study showed that the benefits derived from a combination of shade and high tunnel may be cultivar dependent.
Vinson, E.L. and Spiers, J.D. (2024). Influence of high tunnel and shade on blackberry yield and white drupelet disorder. Acta Hortic. 1388, 159-164
DOI: 10.17660/ActaHortic.2024.1388.24
Rubus, protective culture, shade structure, hoophouse, white drupelet

Acta Horticulturae