Chapter 2 Temperate fruits
by Christine Schmitz with support from the former team members Anton Milyaev and Eduardo Fernandez
2.1 Materials
To prepare for class, please watch the following four videos: (You need the module password from eCampus to access these files.)
As supplementary material, we also offer two videos on sweet cherry bloom and apple varieties recorded by our HortiWood team:
2.1.1 Questions
- In a few lines, describe the main difference between the fruit production systems for pome and stone fruits. Link the process occurring inside the fruit and the changes that farmers could see.
- What are the types of sunburn usually observed in apple orchards? How could farmers avoid this problem?
2.2 Instructions
We’ll be going for a walk with you. Depending on weather conditions, the ground may be wet or muddy, and it may be raining/snowing/windy etc. Make sure to dress appropriately!
2.3 Literature for discussion
This week we will discuss the following paper: Reher et al. 2025. Agrivoltaic cultivation of pears under semi-transparent panels reduces yield consistently and maintains fruit quality in Belgium. Agron. Sustain. Dev. 45, 25
Read the paper and discuss: 1) What aspects of the paper do you find particularly strong or interesting? 2) What are your main points of criticism regarding the study? 3) Which additional measurements or data would you have liked the authors to collect? 4) If you were a fruit grower, would you decide to invest in an agrivoltaic (AV) system for pear production based solely on the results of this study? If not, what additional information would you need before making such an investment decision?
2.4 Term paper topics
Current research on foliar fertilization in pome fruit production
Foliar fertilization is a widely used practice in pome fruit production. However, some experts argue that its benefits are often overestimated. In this term paper, provide a brief overview of the principles of foliar fertilization, including the mechanisms of nutrient uptake through leaves and the nutrients that are commonly applied as foliar sprays. Subsequently, review and summarize current research on foliar fertilization in pome fruit production. Describe the foliar fertilization strategies that have been investigated and the effects that have been observed on trees and fruits. How consistent are the reported results across different studies? Finally, critically discuss the practical relevance of the research findings for commercial fruit production.
Fruit doubling in stone fruits
Double fruits may appear attractive at first glance when observed in the orchard, but they are not marketable and therefore represent a major challenge in stone fruit production. In this term paper, provide a brief overview of the physiological background of fruit doubling in stone fruits. Explain how double fruits develop and which factors (e.g., environmental conditions and cultural practices) contribute to their formation. Which management strategies can help fruit growers reduce the incidence of double fruits, and how effective and feasible are these strategies under commercial orchard conditions?
Factors influencing consumer preferences and apple purchase decisions
Consumer preferences play a crucial role in the success of apple varieties on the market. While growers and breeders often focus on yield, disease resistance, and fruit quality, consumers ultimately decide whether a new variety will be successful. In this term paper, you should provide an overview of the factors that influence consumer preferences when purchasing and consuming apples. Review and summarize current research on consumer preferences for apple fruit quality, including sensory attributes such as sweetness, acidity, texture, juiciness, aroma, and appearance, as well as non-sensory attributes such as origin, sustainability, production system, and branding. Discuss whether consumer preferences differ among countries, cultures, or consumer groups. Finally, evaluate how consistent the research results are and which characteristics breeders and fruit growers should prioritize to improve the market acceptance of new apple varieties.