Influence of genotype and soil tillage on regrowth in Jerusalem artichoke (Helianthus tuberosusL.)

Abstract

Regrowth in the secondary crop is a major obstacle for the large scale production of Jerusalem artichoke (Helianthus tuberosus L.). The objective of this study was to determine the significance of genotypes on the extent of harvest loss, the effect of post‐harvest soil tillage treatments on the distribution of tubers in the soil and the emergence of volunteer plants in the course of time. Ten genotypes contrasting in size, shape and knobbyness of tubers were chosen. The plots were dug with a potato harvester. The distance between elevator bars was 20 mm. Tubers lost during machine harvesting were collected by hand. Post‐harvest soil tillage treatments were performed immediately after harvest. In relation to the respective totals, the fresh matter tuber yield loss ranged from 13 to 62% and that of tuber number ranged from 31 to 76%. The proportion of tubers located in the upper 5 cm of the soil were 82% without tillage, 86% for spring‐tine cultivator and 78% for rotary harrow. After ploughing 70% of the tubers were recovered in a depth of 10 to 20 cm.