Growth and yield of seed potatoes after application of gibberellic acid to the tubers before planting.

Abstract

The influence of GA on growth and yield of potato seed tubers (size 28-45 mm) was studied in field experiments on sandy soil in the late cv. Alpha. Different GA conc. were applied to seed tubers with or without sprouts by both dipping and spraying. The main purpose was to find a more suitable method of preparing seed tubers than the laborious presprouting in light method. This other method would allow mechanical planting, should not be laborious and should give a high yield of seed tubers. The application of GA accelerated emergence. GA also significantly increased the yield of the seed tuber fraction, probably by increasing the number of stems and thus the number of tubers/plant. GA accelerated tuberization, decreased the total tuber yields in one experiment, whereas in the other experiment an increase occurred. The best results were obtained if sprouted tubers were treated and under favourable growing conditions. Spraying was equally effective as dipping also in the 'spraying just before planting' treatment after heat shock. This means that application during mechanical planting seems to be possible, on the understanding that the GA conc. is not too high to prevent the occurrence of phytotoxic effects (45 mg GA/l caused small leaflets with yellow discolouration). The application of GA to seed tubers seems to be attractive especially in slowly emerging cv. or in cv. with a high proportion of large tubers. (Abstract retrieved from CAB Abstracts by CABI’s permission)