Agri-Brief: A Balanced Diet Provides Crop Stress Protection

AGRI-BRIEFS
AGRONOMIC NEWS ITEMS

From Agronomists of the
Potash & Phosphate Institute
655 Engineering Drive, Suite 110
Norcross, Georgia 30092-2837
Phone (770) 447-0335

Winter 1996, No. 8

A BALANCED DIET PROVIDES CROP STRESS PROTECTION

Healthy plants, like healthy people, are better equipped to cope with detrimental forces generated by disease, crop injury, extremes in temperature or moisture or with an imbalance of certain inputs. Balanced nutrition is a vital part of this crop stress protection.

Each essential nutrient is directly responsible for at least one major plant function and indirectly for several others. A shortage can increase plant susceptibility to disease or other yield limiting forces. Thus, each nutrient must pull its weight and, at the same time, provide assistance to others if plant growth is to develop to its fullest potential.

Nitrogen...stimulates optimum rate of plant growth for best tolerance to tissue damage inflicted by insects and diseases.
Phosphorus...promotes root growth, improved water utilization and drought tolerance.
Potassium...associated with some 60 enzyme systems, also helps to build root reserves for improved winter hardiness and less plant injury due to severe temperature stress.
Calcium...builds strong cell walls that help in minimizing crop loss from certain diseases and crop loss associated with lodging.
Magnesium...the center ion of the chlorophyll molecule, enhances photosynthesis, enzyme activity and sugar production, all essential for optimum plant development.
Sulfur...is essential for protein formation and nitrogen use efficiency.
Boron...enhances sugar translocation and growth of new plant tissue.
Chloride...improves disease resistance or tolerance in small grains for improved grain yield and quality.

Research continues to document the agronomic and economic importance of nutrient adequacy and balance for crop stress tolerance and/or resistance.

Corn...becomes more susceptible to stalk degradation and yield loss from lodging when potassium is deficient.
Soybeans...experience less moisture stress as phosphorus enhances root system development. Certain seed diseases can be severe when potassium is limiting.
Wheat...response to chloride is reflected in less take-all disease and more grain. Phosphorus helps plants to better tolerate stress from sudden low temperature changes.
Canola...injury from cold temperature extremes is increased when phosphorus is inadequate.
Alfalfa...stands last longer and remain more productive when potassium winterizes the crop and reduces plant injury from heaving.
Turf...tolerance and recovery from nematode injury improves when potassium is properly balanced with nitrogen and phosphorus.
Tomatoes...marketable yield and quality increase when calcium reduces blossom end rot and fruit damage.
Cotton...leaf diseases increase and photosynthetic capacity declines when plant potassium reserves become limiting during the critical boll filling period.
Apples...fruit corking and loss of market value have been traced to inadequate levels of available boron during the growing season.

Yes, a balanced diet of essential nutrients can provide crop stress protection. Start with a good soil test program. Consider specific crop nutrient requirements, crop production objectives, interactions among nutrients and other production practices, and adjustments for climatic influences.