Foliar fertilizers

The principal function of Zn in plant nutrition is the activation of enzymes at least nine of these have been identified thus far. Soil application of Zn is the most common and generally successful method used for crop fertilization. Foliar application is generally used as a temporary emergency measure, or as an amendment to soil application. 

MantrDon . [BASF AC] Liq. manganese fertilizer foliar fertilizer for agric. crops, vines, fruit... 

Methods of Mo application include soil application of Mo fertilizer alone or with phosphorus (P) or nitrogen-phosphorus-potassium (NPK) fertilizers (molybdenized fertilizers), foliar sprays, dusts, and seed treatment. 

In addition to borax, which can be applied directly as a fertilizer, special borate products are manufactured for fertilizer use. These include granulated beads for blending with other common fertilizer products and soluble borates for application as liquid foliar sprays. Boron fertilizers are typically applied at a rate equivalent to about one to two pounds elemental boron per acre, depending on the specific crop and soil conditions. As with most fertilizers, excessive application can have adverse results. Borate fertilizers are phyotoxic at high levels and are sometimes used as non-selective herbicides. 

As a fertilizer, urea is a convenient form for fixed nitrogen and has the highest nitrogen content (46% by weight) available in a solid fertilizer. It is easy to produce as prills or granules and easily transported in bulk or bags with no explosive hazard. It dissolves readily in water and leaves no salt residue after use on crops and can often be used for foliar feeding. 

Biuret is undesirable for some industrial applications and in fertilizers used as foliar sprays. Prilled urea normally contains more biuret (0.8% - 1.5%) than granular urea because prilled urea goes through an extra evaporation step. 

The following foliar fertilizers can also be used if there is demonstrable deficiency ... 

Another new method of spray application which may improve foliar deposition is called air-assist spraying (10). This application system involves spraying air along with the pesticide to enhance penetration of crop canopies. With more spray impacting the plant, not only is environmental impact reduced but the performance of insecticides, fungicides, foliar fertilizers, and growth regulators is vastly improved. 

A number of changes took place in the Sixties that will influence the marketing of agricultural chemicals in the Seventies among them are the expansion of the number of producers, many of whom are in both pesticides and fertilizers, the decline in the number of farms and the increasing size of the farm enterprise the expansion of services to the farmer by retail outlets. Opportunities in the product area include selective systemics to replace products that have become ineffective, new systemic soil nematocides, new systemic foliar fungicides for cereals and fruits. Sales of basic toxicants at the manufacturers9 level will reach 700 million in 1968, over 1 billion by the mid-Seventies. 

Foliar Nitrophoska . [BASF AG] Liq. compound fertilizer for foliar applic. 

Humiplex. [Western Nutrients] Neutralized complexed foliar fertilizeR containing humic acids. 

Vitousek and Sanford (1986) grouped lowland forests according to the underlying soil fertility and showed that forests growing on moderately fertile soils (about 15% of the total moist tropical forest area) tend to have foliar N, P, K, Ca, and Mg concentrations higher than do those growing on the more common oxisol or ulti-sol soil types of moderate to low fertility (63% of the total moist tropical forest area). Forests on the latter tend to have foliar nutrient concentrations not very different from forests growing on the very low-fertility spodosol or psamment soil types (7% of the total moist tropical forest area Sanchez, 1976 Vitousek and Sanford, 1986). 

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