Studies in potato agronomy. II. The effects of variety and time of planting on growth, development and yield

Abstract

1. A factori al experiment involving four varieties (Ulster Chieftain, Arran Pilot, Craig's Royal and Ulster Torch) and three times of planting (28 March, 13 April and 2 May) was undertaken with a view to investigating the effects on growth development and yield of these factors. Only a limited amount of data was obtained in respect of Craig's Royal, because of its extreme variability in the first two times of planting. In addition, data in respect of King Edward and Majestic planted on the second date in an adjacent experiment are discussed.2. In general, yields from Ulster Torch were about twice as great as those from Ulster Chieftain, with the other varieties occupying intermediate positions. The total yield of Ulster Chieftain increased with delay in planting, while in Arran Pilot, Craig's Royal and Ulster Torch, yield was greatest at the intermediate planting date, slightly lower than this at the first, and lowest at the third. Ware yield as a proportion of the total increased with delay in planting.