POMCRACK

The Operational Group led by FRUILAR, together with TORNAFRUITS, as relevant producers in the sector, and AFRUCAT at the helm of coordination, and with the participation of IRTA as a technology centre, are participating in the innovative POMCRACK pilot project, carried out by an Operational Group. The aim is to mitigate one of the main problems affecting the production of two of the apple varieties most valued by consumers, Fuji and Pink Lady.

The “Fuji” and “Pink Lady” apples are among the varieties most valued and accepted by consumers for their organoleptic quality. Despite the agronomic difficulties involved in growing these varieties, especially Fuji, apple producers see them as varieties that provide them with an economic return if they can achieve a minimum yield. For many years, these minimums have not been achieved because a high percentage of the fruit is unmarketable due to various defects that make its production practically unviable.

One of these defects is fruit cracking. Cracking is a phenomenon that greatly limits quality and yield and reduces marketability. Fruit cracking begins with microcracks in the apple skin, a protective layer covering the flesh and formed by a cuticle made of cutin and wax. Microcracks form when the fruit expands faster than the skin cells and cuticle can keep up. This usually occurs around 30 days after full bloom and can continue until harvest. Throughout the growing period, these microcracks can become deeper and reach the pulp, drying it out and helping pathogens/fungi to penetrate the pulp and rot the fruit.

In order to address this problem, this project proposes, on the one hand, to identify the possible causes of cracking in Pink Lady and Fuji apples and, on the other hand, to find strategies to mitigate cracking in Pink Lady and Fuji apples. To this end, technological tools based on plant sensors will be used. Specifically, the water status of the apple tree was continuously monitored using microtensiometers (Florapulse, Davis, CA, USA) and sensors to assess hourly fluctuations in fruit growth with dendrometers, and based on this information, different irrigation strategies will be adopted.

The overall objective of the project can be broken down into the following specific objectives:

• Evaluate the effect of irrigation monitoring on cracking.
• Benchmarking of the water status of plots with cracking problems.
• Evaluate different strategies to mitigate cracking with hormonal products and cuticle protectors.
• Effect of nutrition on the appearance of cracking.

Action of the Strategic Plan of the PAC 2023-2027 co-funded by: