Pruning and canopy management are critical cultural practices in berry production, influencing plant health, fruit quality, yield, and ease of harvest. Various pruning techniques are tailored to different berry species, reflecting their unique growth habits and production requirements.
Selective pruning involves removing specific parts of the plant, such as dead, diseased, or non-productive branches, to improve plant health and productivity. This method is essential for all berry types to enhance light penetration and air circulation within the canopy. Selective pruning techniques include:
- Tipping: Common in raspberries and blackberries, tipping involves cutting back the tips of canes to encourage lateral growth, which can lead to more fruiting sites.
- Cane pruning: Involves removing entire canes after they have fruited, particularly relevant for raspberries and blackberries (floricane-bearing). Spent canes are removed to make way for new growth, which will bear the next season’s fruit.
- Renewal pruning: Particularly for blueberries, where older canes are removed to encourage the growth of new, more productive canes. This method ensures the plant maintains vigour and productivity over the years.
- Hard pruning: Used for plants like Cape gooseberries, where significant portions of the plant are cut back to encourage new growth and fruiting. It is crucial for managing plant size and shape, as well as rejuvenating older plants.
A. Application in Commercial Berry Production
Blueberries:
During the first four years, minimal pruning is required, focusing on removing low-growing, non-fruiting shoots. As plants mature, it is essential to remove older branches to stimulate new growth and maintain productivity. The ideal structure includes 8 to 12 healthy canes younger than six years.
Raspberries:
For autumn-bearing varieties, spent tops of primocanes are pruned after fruiting, and all floricanes are removed to encourage new growth. Summer-bearing varieties require thinning of dormant canes and removal of all spent floricanes post-harvest.
Blackberries:
Pruning practices vary with the type. Erect varieties may need tipping of primocanes, while trailing types require trellising and only spent floricanes should be removed. Semi-erect varieties benefit from trellising for support and easier management.
Cape gooseberries:
Hard pruning in spring stimulates new growth for fruiting. Summer shoots are cut back to encourage a bushier growth habit, which facilitates light penetration and airflow within the plant.
Strawberries:
Strawberry plants do not require pruning in the traditional sense (like tree or bush shaping) but do require regular maintenance to ensure plant health and productivity:
- Strawberry plants produce runners (stolons), which can lead to overcrowding and reduced fruit size. Regularly removing these runners helps to concentrate the plant’s energy on fruit production rather than vegetative growth.
- After the harvest, removing old, yellow, or diseased leaves can improve air circulation and reduce the risk of fungal diseases. It also helps in rejuvenating the plants for the next season.
- For June-bearing strawberries grown in matted rows, an annual renovation process is recommended right after the harvest. This involves mowing the foliage down, narrowing the rows, and thinning the plants, followed by fertilisation and irrigation to stimulate new growth.
Tomatoes:
Pruning is an important part of tomato plant maintenance, especially for indeterminate varieties, which continue to grow and produce fruit until killed by frost:
- Suckering involves removing the suckers, or side shoots, that appear in the axils between the leaves and the main stem. Suckering helps to improve air circulation, reduce disease incidence, and focus the plant’s energy on developing fruit rather than excess foliage.
- Removing some of the lower leaves, especially those touching the ground or showing signs of disease, can improve air flow around the plant base and reduce disease risks. However, it is essential to maintain enough foliage to protect the fruit from sunscald and ensure photosynthesis for fruit development.
- Near the end of the growing season, particularly in cooler climates, pruning the top of the plant or removing the growing tips can encourage the plant to focus its energy on ripening existing fruit rather than producing new growth.
Canopy Management for Optimal Growth and Yield
Canopy management in berry production refers to the practices employed to optimise the plant’s leaf area, ensuring efficient light penetration and air circulation throughout the plant structure. This is crucial for maximising photosynthesis, enhancing fruit quality and yield, and reducing the incidence of pests and diseases. Proper canopy management ensures that each part of the plant receives sufficient light and air, critical factors for healthy growth and fruitful production.
A. How Canopy Management is Achieved
Strategic pruning and training are central to effective canopy management. By selectively removing certain parts of the plant, growers can shape the plant’s structure to improve light penetration and air flow. This might involve removing some of the central branches to open up the plant or training the plant on trellises or other support structures. In some cases, reflective mulches are used on the ground around the plants to increase light availability to lower leaves, promoting better growth and fruit development.
Keeping the under-canopy area free from weeds and pests can enhance air circulation and reduce disease risks, contributing to a healthier and more productive canopy.
Managing the number of fruiting sites can influence canopy density. Overburdened plants may have dense canopies that shade lower leaves and fruit, reducing productivity and increasing disease pressure. Proper spacing between plants and rows prevents overcrowding and ensures adequate light distribution and air movement. Row orientation can also be optimised to maximise light exposure throughout the day.
B. Consequences of a Mismanaged Canopy
- A dense, unmanaged canopy can block sunlight from reaching lower leaves, impairing photosynthesis, and reducing the plant’s energy for growth and fruiting.
- Overcrowded plant canopies can restrict airflow, creating humid microclimates that are conducive to the development and spread of fungal diseases and pests.
- Without adequate light and air, fruit set, size, and ripening can be inconsistent, leading to lower overall quality and yield.
- A dense canopy can harbour pests and diseases, making them harder to control and potentially leading to significant crop losses.
- Overly vigorous canopy growth can divert resources away from fruit production, leading to an inefficient use of the plant’s energy and
In commercial berry production, meticulous canopy management is indispensable for achieving optimal growth and high-quality yields. Through careful planning and regular maintenance, growers can ensure their berry plants have the ideal balance of light, air, and space to thrive and produce abundantly.