Since citrus trees use nitrogen and potassium in the greatest quantities, this combination is highly beneficial in fertigation programs. The presence of nitrates in a nutrient solution also helps limit the uptake of excess chlorides.
Potassium nitrate has been shown to increase a citrus tree’s disease resistance. It reduces the severity of attacks by restricting the pathogen’s food supply and promoting the formation of disease-inhibitory com-pounds such as phenols, phytoalexins, and auxins. This limits pathogen establishment and spread within the plant.
Potassium nitrate also plays a role in the systemic resistance of citrus to Huanglongbing (HLB) bacterial disease, which affects citrus-growing areas worldwide. This severe disease results in bitter, inedible, misshapen fruit and can lead to tree death in severe cases. It is caused by bacterial blockages in the phloem transport system, affecting nutrient and carbohydrate distribution within the plant.
A five-year study (2008-2012) by the University of Florida on a heavily HLB-infected citrus orchard treated with various foliar nutrients found that treatments containing potassium nitrate doubled the citrus yield. The most cost-effective treatment in terms of return on investment was the stand-alone potassium nitrate treatment. The yield improvements were attributed not to any bactericidal properties of potassium nitrate but to its ability to enable the plant to regenerate new phloem vessels to compensate for those blocked by the HLB bacteria.
While potassium is not a pest-control product, it plays a role in plant health and has been reported to increase the efficacy of both insecticides and fungicides in pest and disease control.
Ultrasol® K Plus* and Ultrasol® K Plus Acid** are high-quality potassium nitrate sources that enhance the mutual uptake of nutrients and improve the uptake of calcium, magnesium, iron, copper, and zinc cat-ions, helping the plant in its natural defence system.
Suzette Smalberger, SQM Africa
Reg No K5020 Act 36/1947. Registration holder Sociedad Quimica y Minera (Africa)(Pty)Ltd *
Reg No K6489 Act 36/1947. Registration holder Sociedad Quimica y Minera(Africa)(Pty)Ltd **
Disclaimer: The information herein contained is given to the best of SQM’s knowledge and is believed to be ac- curate. The conditions of your use and application of the suggested recommendations, are beyond our control. No warranty is made as to the accu- racy of any data or statements contained herein. SQM specifi cally disclaims any responsibility or li- ability relating to the use of the recommendations and shall under no circumstances whatsoever, be liable for any special, incidental or consequential damages arising from such use
