QUALITY OF FOLIAR FERTILIZERS

Many new applications of foliar fertilizers have been recommended and implemented in the practical agriculture and horticulture. This development encouraged the progressive production of foliar fertilizers in many countries for local use as well as for export.There is a real chaos in the market. For example in Egypt, during the period 1990 – 1995, 554 new fertilizers were registered. Out of them 285 are indicated as foliar fertilizers and over two hundred soluble fertilizers for drip irrigation, which are partially used as foliar fertilizers. Quality control of foliar fertilizers is a much more difficult issue than quality control of soil used fertilizers. The efficiency of foliar fertilizers is depending on much more different measures than soil fertilizers, thus agreeing on quality criteria is much more complex. Major quality factors related to foliar fertilizers are given. Looking around to the products, and the different legislations, we can generalize that most countries do not have special articles in their legislation specifically related to foliar fertilizers and thus, there are no special quality criteria for this kind of fertilizers. It is highly recommended that ISHS takes the lead and assign an ad hoc committee to study the situation and legislation in some developed and developing countries and make proposals about the quality criteria which should be considered by the registration of foliar fertilizers in different regions, and which should be made clear to the customers.