Effect of planting depth on yield and tuber set of potatoes

Summary

The results of three years’ depth-of-planting tests with potatoes grown at Shafter on a light sandy soil and of two years’ tests at Davis on a heavy silt loam soil are presented. All comparisons were made when the top of the seed piece was planted 2, 4, 6, and 9 inches below the surface of the ridge.

Four and 6-inch plantings produced higher total yields than did the 9-inch. The total yields from the 2-inch planting were only slightly lower than for the 4- or 6-inch; but the yield of marketable tubers was much lower, because of sunburn.

The percentage of sunburned tubers became less as the planting depth was increased up to 6 inches. The 9-inch plantings differed only slightly from the 6-inch.

The number of tubers per hill became smaller as the depth of planting was increased.

Size of tuber increased along with the depth of planting.

Depth of tuber set also increased with depth of planting. Most tubers tended to develop immediately above the seed piece.

When there was sufficient moisture the plants from shallow plantings tended to emerge first.