Using processed kaolin is a sustainable and efficient strategy for controlling greening

The use of processed kaolin, a non-toxic and sustainable product, is efficient in reducing the population of the insect that transmits greening and, consequently, also reducing the incidence of diseased plants in orchards. Its use, added to the set of conventional measures recommended for this disease, which is the most serious in citrus farming and has no cure, helps the citrus grower to increase management efficiency.

The application of kaolin for psyllid control diaphorina citri has shown good results in the field, explains Fundecitrus researcher Marcelo Miranda. “In commercial orchards in formation and production, the use of the product has already reduced an average of 40 and 36% of the psyllid population and greening plants, respectively, after three years of experiment”, he adds.

Effect of “camouflaging” plants

Processed kaolin, when mixed with water and sprayed, forms a whitish protective layer on the leaves and fruits that repels the psyllid, acting as a kind of camouflage that interferes with the plant's location. Furthermore, it also interferes with the insect's feeding, consequently reducing the incidence of greening.

Currently, the guidance is for citrus growers to use doses of 2% of the product Surround® WG (the only product with proven efficacy to date), with a biweekly application frequency. “Preferably, use should be done throughout the year, especially in the case of orchards in formation. In adult orchards, it can only be used during periods of greatest psyllid dispersion and vegetative flow emission. However, citrus growers must be aware, as, in recent years (2020/2021), population peaks of the insect occurred throughout the year. Spraying should be directed mainly towards the edges of the orchards, in the first 100 to 200 meters, seeking to reduce the entry of the psyllid into the property”, recommends Miranda.

Greening management requires a combination of actions

Added to other conventional insect control measures, such as monitoring, chemical control, regional management (external actions), kaolin is an efficient option in the long term, considering the protection of younger plants, and also in the short term, when used in more critical areas. Furthermore, it directly contributes to the development of an increasingly sustainable citrus industry.

Research on kaolin continues to be developed, with the evaluation of other products suitable for spraying and also promising studies for its use in controlling other diseases. “Experiments have been carried out by Fundecitrus to evaluate whether doses of 1 to 1,5% are effective in managing the psyllid, which can provide savings for the citrus grower”, adds Miranda.