Turf

FOLIAR FERTILIZERS Story by Matt Nelson doing more with specialized products Foliar fertilizers can help provide solutions to difficult problems Value-added products offer efficien- cies in many industries and markets. The golf course and sports turf maintenance industries are no exception, and consci- entious managers will actively seek prod- ucts that provide solutions to a multitude of potential problems while delivering exceptional turf performance and playing quality for the golfing customer or ath- lete. This approach is evident in equip- ment innovation, new chemistries that control pests efficiently and safely, soil and turf monitoring equipment that sup- ply turf managers with additional data and information, colorants that mitigate the need for overseeding and reduce oxi- dative stress to turf, and other examples. The science of fertility is no exception to this trend, and is precisely why lead- ing companies invest in independent research projects each year that identify new and innovative approaches to solv- ing difficult agronomic problems with economic efficiency. Integrated Pest Management One of the more exciting areas of fertility research is nutritional IPM (inte- grated pest management). Think of nutri- tional IPM as creating healthy turf plants that require less chemical inputs to with- stand pressure from diseases, nematodes, insects and weeds. While the concept of nutritional IPM is not new to the turf- grass management industry, some of the components included in modern foliar fertilizer formulations are relatively new, including diverse and complete combi- nations of nutrients, plant hormones, amino acids, phosphites and other com- pounds designed to elicit important plant responses. Proper utilization of these materials with regard to timing and pro- gramming can result in better performing turf with reduced cost and risk to the environment. Evolution Foliar fertilizer formulations and tech- nology have evolved in recent decades along with management programs aimed at producing consistent turf health and playing conditions on putting greens. The concept of "spoon-feeding" turf (applying light and frequent applica- tions of nutrient to control growth more effectively) became more refined and easily implemented as improved sprayer calibration and maneuverability facilitated quick and accurate delivery of fertilizer in light amounts. Plant growth regula- tor use and programs further refined this approach to controlled growth, especially with the advent of trinexapac-ethyl. Foliar (those products designed to be absorbed and assimilated into the plant via leaf tissue) fertilizer formulations were designed to provide safety to the turf plants, ease of use and compatibility with other materials for efficient application of multiple products at once. True foliar fertilizers provide an efficient means of both macro- and micro-nutrient uptake, especially when nutrient uptake from the soil may be limited by temperature, pH, compaction, salinity, poor rooting, etc. Other Additives along the way of foliar fertilizer evo- lution there have been many unfounded claims by companies extolling the benefits of questionable and unproven additives, and in some regards this has tarnished the image of many of these products. Other non-nutritional addi- tives, however, have been proven to be very beneficial to turf health and quality in both independent research trials and field observation. This no doubt helps partly explain the widespread use of foliar fertilizers in the turf management indus- try today. For example, amino acids have been shown to be outstanding chelating agents that facilitate very efficient nutri- ent utilization. additionally, topical appli- cation of amino acid products has been shown to improve turfgrass heat stress by limiting oxidative stress (3). early work with cytokinins, a plant hormone found in seaweed extracts, was variable and inconsistent, yet greenkeepers had been using various forms of seaweed in turf management for decades with observ- able benefit. More recent studies have shown that cytokinin applications can recent studies have demonstrated that value-added components of foliar fertilizers can help manage both biotic and abiotic stress to turf.

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