A survey of stand establishment and in-row spacing uniformity in Washington potato fields

Abstract

Missing plants and non-uniform in-row plant spacing can result in economic loss for potato growers. In-row seedpiece and plant spacing uniformity of 70 Washington potato fields was measured, and factors contributing to missing plants investigated from 2000 through 2002. Ninety-one percent of the fields were planted with cut seedpieces, and the remaining 9% were planted with cut seedpieces, and the remaining 9% were planted with whole, uncut seed tubers. Russet-type cultivars were planted in 79% of the fields, and the remaining 21% were planted with red-skinned and yellow- and white-fleshed cultivars. Seedpiece or plant spacing deviated an average of 25% from the intended spacing mean, with a range of 7% to 43%. Coefficients of variation (CV) for grower in-row plant and seedpiece spacing ranged from 18% to 69% compared with a hand-planted check average of 13%. Based on the growers’ intentions, the average plant population of the 70 fields should have been 44,000 plants ha−1, but averaged only 40,600 plants ha−1. On average, 6% of the grower-intended stand was missing because of planter skips, while less than 1% was missing due to seedpiece failure or decay. There were 1,980 clumped seedpieces ha−1 and each clump typically contained two seedpieces. Twenty-one percent of the fields had at least 700 planter-skips ha−1 where three or more consecutive plants were missing. Despite management efforts, planters were typically unable to place seed uniformly at the intended spacing. Improved planter and seed-cutting-operation management along with new planter technology would likely improve Washington potato stands.