What is urea-triazone nitrogen?

Foliar application of nitrogen and other nutrients essential for plant growth and development is an important practice for crop production. Most foliar nutrient N products contained the traditional N sources such as ammonium, nitrate and/or urea before urea-triazone N was available on the market. The traditional N sources have a greater salt index and leaf-burn potential than urea-triazone N. To avoid or minimize leaf burning, urea-triazone N fertilizers can be used instead of the traditional N sources. But growers have concerns about the safety of using triazone N fertilizers for commercial crop production because the fertilizers are still new to them. This 2-page fact sheet provides basic information on urea-triazone-based fertilizer for county faculty, crop consultants and advisors, growers, and students interested in commercial crop production. Written by Guodong Liu and Jeffrey Williamson, and published by the UF Department of Horticultural Sciences, October 2013. http://edis.ifas.ufl.edu/hs1233

Seed germination and seedling dry matter production of canola, barley and wheat as affected by seed-placed KCl and polymer-coated KCl

Seed-placed KCl often adversely affects seed germination and seedling growth because of the high salt index of the material. By coating KCl granules the adverse effect of the KCl can be reduced. Two greenhouse experiments with canola, barley and wheat, and one experiment in the field with barley were conducted to determine if normally adverse levels of seed-placed KCl fertilizer could be reduced when polymer-coated KCl is used. The results show that the number of germinated seeds and seedling dry matter were higher with the seed-placed coated KCl than the seed-placed regular non-coated KCl. Key words: KCl fertilizer, polymer-coated KCl, germination, seedling dry matter

The Flocculation of Dilute Latex by Zinc Sulfate

Within a particular range of temperatures and a particular concentration of rubber, the flocculation of diluted latex by a water-soluble zinc salt is characterized by a critical amount of zinc, termed the salt index, which is necessary and sufficient to destroy abruptly the colloidal equilibrium of the dispersion. In the course of an investigation of a preliminary nature, measurements were made of the changes of the salt index as a function of the concentration and of the initial pH value of different field latexes and of two samples of latex preserved with ammonia. The influence of centrifugation and of buffering agents was likewise investigated. On a theoretical basis, the phenomenon appears to be governed to a major degree by chemical reactions of the zinc with certain substances which are either in solution in the serum or are adsorbed on the rubber particles. From the practical point of view, a systematic investigation is underway to determine whether the salt index as thus defined can be accepted as a new test of the stability of Fresh latex and preserved latex.