The recent development of coated fertilizers by industry offers a promising new tool to regulate the availability of minerals for the nutrition of plants. The new controlled-availability fertilizers cannot be expected to replace the liquid-fertilization techniques now widely used in the production part of the ornamentals industry. However, they will be useful in promoting the rapid start of seedlings and cuttings, as a supplement to liquid-fertilization programs, and for producing short-term crops. It is now possible for the pottedplant producer to incorporate enough fertilizer in his mix to grow a 3-month crop to maturity with no further fertilizer additions. Likewise, landscape contractors will benefit from the new materials, which will assure adequate nutrition to new plantings for a prolonged period. Longevity of nutrient supply and a high degree of safety from injury by excess application should be important for home-grounds maintenance. Another possible benefit is to minimize the large flushes of growth associated with the use of soluble nitrogen sources on turfgrass.

The above progress report is based on Research Project No. 1469.