Cranberry growth: a key stage in fruit development

The cranberry growth stage follows immediately after pollination and fruit set. It is a crucial phase in fruit development. It generally lasts from mid-July to the end of September, depending on weather conditions and the variety grown. During this period, the fertilized ovaries gradually transform into well-formed berries, growing from small green fruits into increasingly larger cranberries.

The enlargement is mainly the result of cell expansion, a process during which the fruit's cells multiply and enlarge due to the accumulation of water, sugars, and organic acids. This stage is influenced by a combination of environmental, nutritional, and physiological factors.

Temperature

Temperature also influences the rate of growth. Moderate to warm temperatures promote photosynthesis and plant metabolism, while extreme conditions, such as intense heat or cold nights, can slow down this process. Although cool nights promote the previous stage of fruit set, we want warmer nights in August to promote fruit growth.

Plant nutrition

Plant nutrition also plays a role. A good balance of nutrients, particularly nitrogen and potassium, supports fruit tissue development and sugar transport. In addition, plant health, especially that of the foliage, is crucial. A canopy with adequate density and good health allows for efficient photosynthesis, providing the energy necessary for fruit growth.

Genetics

Finally, genetics also come into play, as each variety has its own potential for development and growth. In particular, the average weight of a fruit varies from one variety to another, such as Steven compared to Crimson Queen, for example. Moreover, the growth curve will also vary depending on the cultivar, with some reaching their growth plateau earlier than others.

Finally, growth prepares the cranberry for the next stage, ripening, when the fruit acquires its characteristic red color and develops its final organoleptic qualities.