Use of Water Mist to Protect Tree Fruit from Spring Frost Damage

View the project final report

Commodities

• Fruits: apples, cherries, general tree fruits

Practices

• Production Systems: general crop production

Climate variability and change have been  major threats to global food security historically and will almost certainly continue to be threats in the future given the sensitivity of agricultural production systems to their surrounding environment. Recent changes in temperature and seasonality have significantly impacted commercial fruit production in the Great Lakes region. Michigan's tart cherry and apple production in 2012 was reduced by about 90% and 88% respectively compared to the previous year’s production due to a series of spring freeze events.  The onset of phenological development in the spring is a key factor in determining potential cold damage risk, as the vulnerability of vegetation to freeze injury increases rapidly with the stage of development. Application of water prior to the onset of growth has been used in the past to delay early vegetative development of temperate fruits like cherry and peach. This approach reduces the plant tissue temperature through evaporative cooling, effectively slowing the rate of plant growth and leaving it less vulnerable to freezing temperatures.  However, there are several significant drawbacks to the approach, including the quantities of water needed, nutrient leaching and potential increases plant disease risk.             The proposed study examines the application of water mist via a new plant management technology, the solid set canopy delivery system (SSCD), to suppress the temperature of cherry trees in the spring season to delay phenological development and limit potential frost damage. The study aims to identify the timing and discharge rate of mist applications on cherry and apple trees necessary to delay early crop stages such as blooming by a week or more. The study will be carried out at four cherry orchards in Michigan and in a growth chamber to address the broad question: Is it possible to reduce frost damage risk for tree fruit with proper water management? This research will utilize advanced automated instrumentation and data acquisition at all sites and growth chamber to control the water mist flow rate based on environmental conditions. If successful, the approach is expected to directly increase economic benefits of cherry growers by reducing the vulnerability of freeze damage. Moreover, the research results will be relevant to other states within the region that experience similar conditions and problems. The research has the potential to significantly increase the economic viability and sustainability of the region’s fruit industry.

Our long term goal is to develop an effective, environmentally friendly method to protect cherry and apple buds and flowers from spring frost damage, and to delay bloom by cooling the buds once the dormancy has been broken.

Specific short term goals include:

1) Determining the potential delay in early vegetative development of cherry and apple buds by evaporative cooling using solid set canopy delivery system.

Further ahead, intermediate term goals include:                                 

2) Identification of optimal water application rates based on ambient temperature and humidity relative to the effective rate of cooling and associated delay in phenological development.

3) Estimates of tree growth and development based on internal tissue temperatures.