The Rain Shelter Improves The Water Productivity Of Sweet Cherries

In the past two decades, the global production of sweet cherries has significantly increased due to high consumer demand for high-quality fruits. New cultivation techniques have been adopted, such as using new varieties/rootstock combinations (e.g. low cooling varieties and dwarf rootstocks), new tree systems (e.g. KGB, Y-shaped), and protective cultivation systems (e.g. greenhouses and plastic canopies). Climate change is currently affecting horticulture, and extreme events such as drought, flood, heat wave, rainstorm and hail have become more frequent and serious. The greatest impact in Mediterranean and semi-arid climates will be a decrease in irrigation water usage due to an increase in frequency and intensity. Agriculture is the world's largest water user (accounting for 70% of freshwater), and horticultural practices must consider sustainable irrigation strategies to improve water productivity. Sweet cherry production may be negatively affected by climate change, especially in areas where water resources continue to decrease. On the other hand, sweet cherry fruits are sensitive to rain induced fruit cracking, leading to commercial losses before harvest. The use of plastic canopies has rapidly increased as an effective alternative method to reduce fruit cracking caused by rainfall. The plastic protective layer prevents rainwater from coming into contact with the fruit surface (i.e. the physical barrier of rainwater), allowing for production under more extreme weather conditions and potentially expanding the commercial landscape. Among all plastic covering alternatives, plastic canopies and greenhouses are the most popular in high-yield areas. The canopy is a plastic covered hoop structure, similar to an unheated and passively ventilated greenhouse. Some researchers have reported the effects of rain shelters on the agronomic and physiological responses of sweet cherry trees. The use of canopies in sweet cherry orchards can affect changes in leaf area (LA), yield, fruit quality, and harvest period. The commercial harvest under plastic canopies is 5 to 15 days earlier than under outdoor conditions, resulting in higher returns. The greatest impact in Mediterranean and semi-arid climates will be a reduction in irrigation water usage due to an increase in drought frequency and intensity. In terms of sweet cherries, most growers continue to use the same amount of water as in open field conditions. Research has shown that under plastic canopy conditions, using different irrigation strategies can reduce water supply by 25% to 38% without reducing fruit yield and quality. Therefore, rain shelters may have altered environmental conditions and increased water productivity in sweet cherry management.