Scorching Heat Hits Yilan: 'Red Guavas' Fear Sunburn, Farmers Use Bags to Combat Heat Damage

Extreme heat is hitting Yilan, Taiwan, posing a significant threat to the region's "red-fleshed guava" crop as it enters its crucial fruit expansion stage. With temperatures frequently soaring above 35 degrees Celsius, the delicate guavas are vulnerable to sunburn and heat stress, prompting farmers to adopt innovative protective measures.

Farmers in Yilan's main growing areas, including Yuanshan and Toucheng, are particularly concerned about the "sunburn" risk, which is highest from late June to late August. When temperatures exceed 35 degrees Celsius for 2.5 hours, traditional plastic bags can trap heat, causing temperatures inside to spike above 45 degrees Celsius. This can lead to hardened flesh, unsightly brown patches, and even fruit cracking and dropping, resulting in significant losses for growers.

To combat these harsh conditions, farmers are turning to new agricultural techniques promoted by the Hualien District Agricultural Research and Extension Station. They are using a "new type of guava bag" featuring a patented sun-proof material on the side facing the sun, inspired by Tyvek. This advanced material can reduce the temperature inside the bag by up to 13.8 degrees Celsius. The other side of the bag remains transparent, aiding in the fruit's color development.

Trials by agricultural authorities indicate that these new bags not only reduce sunburn damage by approximately 60% but also increase fruit weight and sugar content. Furthermore, the bags are reusable, offering high economic efficiency. Beyond physical protection, guavas, being shallow-rooted, are sensitive to soil moisture changes. The Hualien station also advises farmers to manage irrigation carefully, avoiding large, infrequent watering after prolonged drought and opting for smaller, more frequent applications to stabilize root systems. During continuous high temperatures, irrigation should be increased, and after heavy rains, waterlogging must be prevented to avoid root oxygen deprivation. Practices like grass cultivation or ground cover can also help reduce water evaporation and ground temperature.