Evaluation of the efficacy of Eclipse® in reducing sunburn in 'Queen' pineapple of South Africa

Sunburn on 'Queen' pineapples in South Africa can occur any time of the year but is more prominent during the summer months, peaking often during January and February. Temperatures >32 degrees C and no breeze to cool the fruit are often experienced in cases of severe sunburn damage while other factors such as growing conditions (plants/fruit are soft), plant characteristics (ex. long peduncle and translucent fruit), nutritional status of the plant (ex. too much nitrogen) and the surrounding area where fields are planted (surrounding bush prevents air flow), also play a role. Crop losses can be as high as 25%, while in extreme cases damages can reach 70%. Eclipse (R), a calcium carbonate and boron colloidal liquid sun shield film, was applied to a number of fields in trials during January/February 2013 and 2014 to prevent sunburn. Application took place at 4 and 2 weeks before harvest at 18 and 9 L ha(-1) respectively during the first season (2013), while 5 different treatments were applied from 6 weeks to 1 week before harvest during the second season (2014). External sunburn damage was rated according to the degree of severity, namely 1 (slightly damaged - fruitlets show browning; fruit is still marketable), 2 (moderately damaged - fruitlets show more severe browning, sunken skin and often cracking between fruitlets; fruit will be rejected) and 3 (severely damaged - fruitlets show severe browning and cracking between fruitlets, flesh underneath the skin is whitish in colour and often extends to the core of fruit; fruit will be rejected). Severe symptoms provide easy access for diseases. Sunburn in these trials varied between 2 and 27% and the application of Eclipse reduced sunburn to between 0 and 14.4%. Eclipse (R) especially reduced moderate and severe sunburn damage.