Abstract
Attaining high-quality potato tubers requires timely on-farm application of harvest-aid herbicides intended to accelerate maturation and improve storability of early-season potato cultivars. Few studies have integrated field and postharvest quality assessments to investigate the influence of canopy desiccation timing on periderm maturation and quality maintenance of potato cultivated under subtropical conditions. Therefore, the effect of desiccation timing interval on canopy desiccation rate, yield, tuber physiology, and postharvest quality maintenance were investigated in early-maturing potato cultivars. Field trials were established during the seasons of 2017 and 2018 in Florida, USA, using a split-block design, including three cultivars ‘Soraya’, ‘Red LaSoda’, and ‘Peter Wilcox’ as the main plot, three application times of diquat, and two rates in each subplot. The overall trend quantified by this study is the potential to improve potato postharvest quality with various desiccation timing strategies with the greatest benefits observed in response to early desiccation, at least 2 weeks before the intended harvest. However, there were no differences between full label rates in a single application and their respective split applications. Another important finding is that cultivar-specific characteristics and environmental conditions were key factors in the progression of maturational changes that affected the observed postharvest physiology. The data presented here demonstrate the importance of managing the trade-offs between tuber yield and postharvest quality when selecting desiccation strategies for early-maturing potatoes grown under subtropical conditions.
