Effects of a Sprayer-Passed Ridge on Soil Clods and Green Potato Production and Yield of Potato.

Abstract

Reducing the sorting of soil clods and green potatoes on the potato harvester is effective in reducing labor in potato harvesting. In this study, we focused on the passage of tractors and sprayer wheels and their soil compaction during spraying as factors in the production of soil clods and green potatoes. In conventional spraying practices, the tractor and sprayer wheels pass through the valley positions between ridges, and wheel passage lines affect four ridges (sprayer-passed ridge) on both sides of the wheels. In Experiment 1, we investigated the sites of frequent soil clod occurrence during harvest. The results showed that the sites of frequent soil clod production were the sprayer-passed ridges. In Experiment 2, we investigated the effect of improving the tractor and sprayer-passed lines on soil clods and green potato production. Improved passage lines were not set on planted rows to widen the distance between the tractor runway and the improved ridges. The potato yield of the processing standard and the quantity of the soil clods and green potatoes in both ridges were compared with that in the control ridges (no effect of passage). The quantity of soil clods and green potatoes in the sprayer-passed ridge plot increased significantly compared to the control ridge. In contrast, those in the improved ridge plots were not significantly different from the control plots. These results suggested that the improvement of the tractor and sprayer-passed lines was effective as a cultivation method for reducing the quantity of soil clods and green potatoes. Moreover, the yield of potatoes suited for processing standard in the sprayer-passed ridge plot was significantly lower than that of the control plot, whereas the yield of the improved ridge plot was significantly higher.