Nutrition and irrigation: towards a practical solution for cherry cracking

Fruit cracking in sweet cherries is an economically significant problem for growers world-wide and is associated with late season rainfall. Building resilience into fruit from an early stage in order to withstand rapid excess water entry without cracking, is important.

This trial assessed calcium (Ca) levels and fruit characteristics of sweet cherry fruit produced under three different irrigation volumes, following on previous research suggesting low irrigation increased cracking susceptibility. In the present study, higher irrigation volumes also resulted in reduced cracking levels at harvest.

Given the structural role of Ca in plant cells and that Ca is xylem mobile, it was hypothesised that higher irrigation volumes may favour the uptake and incorporation of Ca into fruit cells. While Ca concentration increased with increased irrigation levels at harvest (when cracking occurs) Ca concentration was not significantly different between treatments. Both the high and low irrigation treatments resulted in fruit with increased firmness and skin puncture force compared to the medium (commercial orchard practice) irrigation level. This provided information about building resilience to cracking in sweet cherry fruit, highlighted the importance of both nutrition and irrigation in managing risk and applies the knowledge to provide solutions to a very real dilemma.

The findings will be important for the development of future cherry fruit cracking management strategies, which may need to be considered early, rather than later during fruit growth.