Identifying the key meteorological factors to marketable tuber rate of potato: A 5-year field experiment in North China

Context

Potato is one of the staple food crops in China. Optimized agronomic management could enhance potato yield, while the economic benefits of farmers depend on both the yield and marketable tuber rate (MTR) of potato. The key meteorological factors to the variation of MTR of potato and the relationship between potato yield and MTR remain unclear.

Objective

The study aims to explore the key meteorological factors to the variation of MTR of potato and the relationship between potato yield and MTR.

Methods

A 5-year (20172021) rainfed field experiment with 3-planting date and 3-cultivar maturity of potato was conducted to investigate the optimum combination of planting date and cultivar maturity for both high yield and MTR under different year types and the relationship between potato yield and MTR. The meteorological factors during three growth stages including planting to 10 d before the tuberization, the tuber formation period (10 d before the tuberization to 10 d after the tuber bulking), 10 d after the tuber bulking to maturity were used to identify the key meteorological factors to yield and MTR of potato.

Results

Throughout the experimental period, there were large variations in the fresh tuber yield and MTR of potato ranging between 4.827 t ha⁻¹ and 061 %, respectively. Early- to middle planting of middle maturing cultivars under warm-wet years resulted in higher MTR, yield, and economic benefit compared to other combinations. Under warm-dry years, while early planting of early- to middle-maturing cultivars could achieve higher yield and MTR, farmers still suffer economic losses under most combinations of planting date and cultivar maturity. On the whole, there was a synergistical enhancement between yield and MTR of potato (R²=0.86, P<0.01). The precipitation and growing degree day (GDD) during tuber formation period (TF), precipitation before TF, and the interaction of precipitation and mean air temperature after TF could account for 77 % of the variations in total tuber yield while marketable tuber rate could be determined by the precipitation from planting to 10 d after the tuber bulking, the HDD during TF, and the interaction of precipitation and mean air temperature before TF (R²=0.79).

Conclusions:

Total tuber yield and MTR of potato could be synergistically enhanced by optimizing planting date and cultivar maturity. Compared with total tuber yield, MTR influences economic benefit of potato more significantly.

Implications:

These findings could serve as a valuable reference for determining the optimal planting date and cultivar maturity of potato under different hydrothermal year types to enhance the MTR, yield, and economic benefit of rainfed potato planting and provide an important implication on potato model improvement.