Genotypic Differences in Potato Yield and Starch Content Response to Potassium Fertilization Under Drought Stress

Area of Science:

• Agricultural Science
• Plant Physiology
• Agronomy

Background:

• Drought stress significantly limits potato (Solanum tuberosum L.) yields.
• Potassium (K) fertilization is a potential strategy to mitigate drought stress effects in crops.
• Genotype-specific responses to potassium under drought conditions in potatoes are not well understood.

Purpose of the Study:

• To investigate the impact of potassium fertilization on potato growth and yield under drought stress.
• To evaluate genotype-dependent responses of potato cultivars to potassium and drought.
• To classify potato cultivars based on their potassium use efficiency and drought tolerance.

Main Methods:

• Six potato cultivars were subjected to four treatments: low K with normal irrigation or drought, and adequate K with normal irrigation or drought.
• Measurements included dry matter accumulation, starch content, and final yield.
• Leaf relative water content and stomatal conductance were assessed to confirm stress induction and regulation.

Main Results:

• Drought reduced potato yield by 28.6-52.3%, while potassium application under drought recovered yields by 12.8-41.5%.
• Starch content decreased under drought but was partially restored with potassium application.
• Cultivar SY-2 exhibited the highest biomass and yield, demonstrating strong K-efficiency and drought tolerance, while V7 was most sensitive.

Conclusions:

• Potassium application can effectively mitigate drought-induced yield losses in potatoes, but the benefits are highly dependent on the specific cultivar.
• Potato cultivars can be categorized by their response to potassium under drought, aiding in tailored management strategies.
• Cultivar SY-2 represents a valuable genetic resource for breeding potatoes with enhanced potassium use efficiency and drought tolerance for water-limited environments.