Banana frost protection by thermal nets

Most banana cultivars are highly sensitive to chilling and frost damage. In 2013/14-2016/17, banana plantations in Israel were exposed to an unprecedented sequence of four consecutive winters with frost events. Heavy damage, including significant yield loss and plant mortality, was recorded. Thermal nets with various shading levels were tested as a means to protect bananas from frost in two cultivation areas. Frost events occurring in January 2016 and February 2017 resulted in severe visual damage to 'Grand Nain' plants grown under the control net (10% shading), whereas incremental frost protection was observed under the thermal nets with 30, 40 and 50% shading levels. In the first crop cycle, plants under the 50% shading thermal net grew 7 and 4.6% higher than the controls, and bunch weight increased by 23 and 11% in the different locations. Despite the high shading level of the thermal net, there was no delay in time to flowering or time from flowering to harvest. During the frost events, minimum air, ground and leaf temperatures under the thermal net were higher by 1-1.5°C than under the control net. Two months after the frost event, recovery of the photosynthetic system was much better under the 50% shading thermal net compared to the control 10% net. Thermal nets have great potential for the protection of bananas from frost, and will be further tested in the coming winters and crop cycles.