Due to climate change, fruit trees are flowering increasingly earlier, making them more vulnerable to late frosts.
A new study conducted by the research team led by Dr. Wiebke Kämper from the Department of Agroecology and Functional Agrobiodiversity shows that flowering in some sweet cherry cultivars can be deliberately delayed.
The treatment had a particularly clear effect on the 'Kordia' cultivar: although a large proportion of the untreated flowers had already opened, many more treated flowers were still at an earlier stage of development.
At the same time, the results show that the effect strongly depends on the plant species, cultivar, timing and dosage. Further trials over several years and in different regions are needed before recommendations for agricultural practice can be made.
Climate change increases the risk of late spring frosts, which damage flowers and developing fruit in tree crops. Ethephon, a plant growth regulator, can delay flowering and potentially reduce frost damage.
We investigated the effects of ethephon on flowering and fruit set in two sweet cherry cultivars (Bellise and Kordia) and two apple cultivars (Elstar and Kanzi). Treatments involved two ethephon concentrations (500 and 750 ppm) applied in early or late autumn.
Ethephon significantly delayed flowering in the Kordia sweet cherry cultivar, but not in the Bellise cultivar, with a lower percentage of Kordia flower buds in bloom in two of the four treatments compared with the controls.
Specifically, on April 9, 88% of the flower buds on the control trees were in bloom, compared with 56% and 63% on trees treated with high concentrations of ethephon in early autumn and low concentrations of ethephon in late autumn, respectively.
No significant delay in flowering was observed in the apple cultivars. Initial and final fruit set were generally unaffected, although Kordia showed a reduction in final fruit set from 16% to 6% following the late high-concentration treatment.
Our results indicate that ethephon can effectively delay flowering without causing significant yield losses, providing a practical tool to mitigate spring frost damage in the context of climate change.
However, its effectiveness was found to depend on the crop and cultivar.
Read the full article at: https://lnkd.in/eQVhZ2my
Image source: Stefano Lugli
14 Apr 2026
A FAO study in Uzbekistan analyzes the life cycle of apple, cherry and grape orchards, showing a negative carbon balance but critical issues in water use and eutrophication. Drip irrigation and solar energy improve sustainability, productivity and environmental impact.
15 Oct 2024
Cherry Growers Australia, an association that gathers Australian producers from all six cherry-growing areas of the country, organized a webinar to discuss the season, as Queensland, New South Wales, and Australia in October, and soon after, Victoria, prepare to harvest.
21 Oct 2026
A study of greenhouse-grown Sunburst sweet cherries in Beijing, China, compares hand pollination, growth regulators and honey bees. Hand pollination raises fruit set to 71.68% while maintaining good fruit firmness. Costs and results across seasons still need assessment.
21 Oct 2026
Cherry irrigation and fertilization: practical guidance on water, nutrients and root growth. Learn how irrigation frequency, calcium and nitrogen applications, soil inspections and compaction management can support fruit quality, healthy roots and productive orchards.
