¿BONUS-NPK¿ - HIGHLY CONCENTRATED, ENRICHED POTASSIUM NITRATE, AN OPTIMAL BOOSTER FOR YIELD AND QUALITY OF CITRUS FRUITS

Bonus-npK is a new fully soluble, crystalline formulation of potassium nitrate that has been specifically developed for foliar feeding of a large variety of crops. It is sprayed at concentrations of up to 10% for intensive foliar nutrition and for a prolonged effect, without any phytotoxic effects. Bonus-npK is potassium nitrate enriched with soluble phosphates and a special adjuvant. The moderately acidic pH (4.5-6.0) of the spray solution enables tank-mixing it with numerous pesticides. Foliar feeding with Bonus-npK has achieved the following results in citrus crops: in ‘Shamouti’ (“Jaffa”) oranges a single application of 9-10% (w/v) Bonus-npK, when fruits were 18-22 mm in diameter, increased percentage of fruit above 75 mm in diameter by 75%, consequently, total yield increased by 14 ton ha^-1. Foliar K in dry matter (D.M.) increased by 0.47%. Shelf life of stored fruit was also significantly enhanced due to a marked increase in potassium content of the rind by 0.44% (in D.M.). In ‘Newhol’ navel orange (Citrus sinensis Osb.), a single application of a 10% solution significantly increased total yield by 19%, fruit above 75 mm in diameter increased by 28%, foliar K in D.M. increased by 0.33%. In Nova tangerine (Citrus reticulate Bla.), a single application of a 10% solution significantly increased total yield by 30%, mean fruit weight – by 38.3 g and reduced the incidence of rind creasing by 20%. These results verify that Bonus-npK is an ideal preparation for intensive potassic feeding that considerably increases total yield, primarily by increasing the size of individual fruit units. Bonus-npK provides its maximum benefit to the grower when the market pays high premiums for larger fruit units.