Keywords: potassium, yield, crop quality, photosynthesis, cotton, maize, soybean, wheat, yield components.
Potassium is one of the principle plant nutrients underpinning crop yield production and quality determination. While involved in many physiological processes, potassium’s impact on water relations, photosynthesis, assimilate transport, and enzyme activation can have direct consequences on crop productivity. Potassium deficiency can lead to a reduction in both the number of leaves produced and the size of individual leaves. Coupling this reduced amount of photosynthetic source material with a reduction in the photosyntheic rate per unit leaf area and the result is an overall reduction in the amount of photosynthetic assimilates available for reproductive growth. The production of less photosynthetic assimilates and reduced assimilate transport out of the leaves to the developing fruit greatly contributes to the negative consequences deficiencies of potassium have on yield and quality production. Goals aimed toward increasing crop productivity and improved quality dictate either more requirements for potassium or more efficient use of potassium. Developing plants that more efficiently use potassium might be a worthwhile goal for geneticists.
William T Pettigrew, USDA-ARS, Crop Genetics and Production Research Unit, 141 Experiment Station Road, P.O. Box 345, Stoneville, MS 38776, USA.
18 pages, 93 references.