Nursery plant production controlled by prohexadione-calcium and mechanical treatments in strawberry cv. ‘Honeoye’

Abstract

SummaryResponses to an inhibitor of gibberellin biosynthesis, prohexadione-calcium (Pro-Ca) at 0.01% (w/v), applied at three different times during nursery plant production, was tested in June-bearing strawberry (Fragaria ananassa Duch.) cultivar ‘Honeoye’ under cool-climate, long-day conditions. The effects of mechanical manipulation, detaching runner plants from the mothers, were also tested on the same dates. The treatment dates were 12 August, 24 August and 2 September 2004 which corresponded to day-lengths of 16, 15 and 14 h, respectively. After lifting on 11 November, and sorting into size categories, the plants were cold-stored and their performance was subsequently investigated under greenhouse conditions. Mother plant growth was decreased by the first two Pro-Ca treatments. A Pro-Ca application on 12 August also decreased the number of runners, and the total number of daughter plants was reduced by 30%.This reduction was highest in the smallest plant category, which was the most abundant.All Pro-Ca treatments increased the dry mass of the crown and the roots of plants in the smallest size category. The Pro-Ca treatment on 12 August enhanced crown-branching in the largest size category, and increased the number of inflorescences in these plants when grown in the greenhouse. All Pro-Ca treatments increased the number of flowers in inflorescences of plants in the smallest size category. In contrast, plant production did not benefit from the detachment of runners from mothers, suggesting that this nursery practice has no advantageous consequences.