Effects of Plant Growth Retardants and Root Pruning on Growth and Yield of Tomato Cultured Hydroponically at Hight Temperature during Summer.

Summary

This study investigated the application of plant growth retardants (uniconazole at 1.25 and 2.5 ppm; paclobutrazole at 12.5 and 100 ppm) and root pruning on hydroponically grown tomato seedlings during high-temperature summer conditions in Japan. Growth retardant and root pruning treatments successfully suppressed excessive stem elongation, lowered the flowering node position, and advanced flowering onset, enabling increased nursery bed density. Whilst early harvest of the first fruit cluster was accelerated by treatments, total yield from the first and second clusters was comparable to or marginally higher than controls, with no significant reduction in fruit quality metrics.

Regional applicability

This Japanese study of summer high-temperature hydroponics has limited direct applicability to United Kingdom conditions, which typically experience cooler summers and shorter growing seasons. However, the techniques could be relevant to UK commercial glasshouse tomato production during peak summer months or in heated polytunnels where similar temperature stresses occur, though experimental validation under UK-specific conditions would be required.

Key measures

Plant stem length, flowering node position, flowering initiation date, harvest commencement date for first and second fruit clusters, fruit sugar content (Brix), individual fruit weight, total yield from first and second fruit clusters, early-season yield

Outcomes reported

The study evaluated stem elongation, flowering node position, harvest timing, fruit quality, and yield of hydroponically grown tomato seedlings treated with plant growth retardants (uniconazole and paclobutrazole) and root pruning during high-temperature summer conditions. Outcomes measured included plant height suppression, flowering initiation date, fruit sugar content, individual fruit weight, and cumulative yield from the first and second fruit clusters.

Topic tags