New technology protects pineapples from sun damage, boosting harvest

Pineapple farmers in Kenya are set to benefit from a new technology that protects the fruit from heat stress and sun damage responsible for 30-50 per cent of crop losses.

The initiative currently on trial could be a silver bullet to farmers in the horticultural industry growing tomatoes, oranges, lemons and apples, which are also susceptible to heat damage.

Purshade is a calcium-based product scientifically engineered to protect fruits, vegetables, and other crops from harmful sun and water stress using a system called Advanced Reflectance Technology (ART).

ART reflects harmful wavelengths of solar radiation such as ultraviolet (UV) and infrared (IR) away from the plant, while still allowing the transmission of sufficient sunlight for photosynthesis.

Laboratory results show Purshade reflects as much as 85-95 per cent of harmful UV radiation and has been shown to keep plant surfaces three to six degrees cooler than untreated plants, improving water use efficiency, reducing the incidence of heat stress, and enabling basic physiological processes to continue in high temperatures when they would normally shut down.

The liquid formulation is easy to mix, can be applied with standard spray equipment, and is designed for easy wash off once the fruits are harvested. It is available in a wet suspension concentrate and is sprayed directly on the plant surface.

The concentrate forms an even film of millions of microscopic “prisms,” or mirrors, which are responsible for deflating the harmful sun rays and help reduce heat from building up on the fruiting structures and plant leaves.

The concentrate is applied throughout the growing season.

The breakthrough comes at a time when pineapple farmers, both small and large scale, are grappling with costly and labour intensive sun protection systems, with heat damage now surpassing pest attacks as a cause of pineapple damage.

Growers have tried various solutions, including chemical-laden kaolin clay and overhead cooling, to protect crops from solar damage, all with unsatisfactory results.

Grown in hot, tropical climates, pineapples are susceptible to heat stress and sun damage, which has been shown to limit plant production as well as deteriorate or discolour tissue that can render the fruit unsellable.

Last year, Mukurweini pineapple farmers in Central Kenya lost more than 300 kilogrammes of pineapples set for export to heat damage after making a maiden attempt at pineapple farming.

The rudimental and cost prohibitive sun protection practices they have adopted since then, which include wrapping of individual pineapple with newspapers, has further chewed into their earnings.

Trials in Dominican Republic, Ghana, Mexico, Australia, Costa Rica, the Caribbean, and US suggest that Kenyan farmers who embrace the Purshade stand to double yields, with farmers already using the technology recording a 207 per cent increase in yield compared to untreated fruit, while reducing cullage by 50 per cent.

Tomzo Pineapple Farm in Kandara area Thika is among the farms trailing the new product on their 10 acre pineapple farm, with astounding results in their recent harvest.