Feb 6, 2025

Expert insights on pear orchard practices for healthy winter pruning

Proper winter pruning is essential to maintaining healthy pome fruit orchards. By applying the right pruning techniques, growers can balance tree vigor, reduce disease pressure, and encourage consistent yields. Fruit Growers News spoke with Stefano Misacchi, associate professor, research pomologist, and endowed chair in tree fruit physiology and management at Washington State University’s Tree Fruit Research and Extension Center (TFREC) in Wenatchee, Washington, to learn more about best practices for apple and pear orchard practices during the winter months.

Why winter pruning matters

Musacchi explained that pruning directly connects to tree physiology. “Trees are doing many activities during the annual cycle. The growth cycle includes vegetative growth, fruit development, flower bud formation for the following year’s crop and accumulating reserve,” he said. “If we don’t prune, the trees can easily go out of balance in those activities and be excessively productive.”

Without pruning, trees may produce too much fruit in one year, leading to alternate bearing the following season. “The benefit of winter pruning is the management of the number of flower buds in relation to the tree’s vigor,” Musacchi said.

Annual pruning for apples and pears

According to Musacchi, pruning fruit trees every year is critical to maintaining balance. “Pruning is the key to balancing all the activities the tree is doing in the growing season,” he said. “There is no doubt about that.”

Timing matters as well. Summer pruning can help control excessive vigor if applied carefully. “If you usually prune an apple orchard between the end of June and the first 15 days of July, you will cut and remove the growing apex of a large part of the one-year-old shoots,” Musacchi explained. “This can positively affect the flower bud formation on the remaining portion of the shoot.”

Some varieties, including bicolor apples, may require late-season pruning close to harvest. “A couple of weeks before harvest, people trim out all the long shoots so light can penetrate the canopy and effectively develop the fruit’s overcolor,” Musacchi said.

Pruning as disease management

Winter pruning also plays a key role in disease prevention. “Pruning is one of the most important things you need to do if you get a canker on branches or a fire blight attack,” Musacchi said. He advised heavy pruning to minimize inoculum, cutting at least two feet below the visible infection because bacteria may already exist in apparently healthy wood.

Failing to prune can worsen infection risk. “You increase your inoculum if you don’t prune and remove the infection point,” Musacchi said. “You will have a strong infection when the weather conditions allow the bacteria to grow again.”

Training systems and pruning choices

Musacchi emphasized that training systems dictate pruning strategies. “Every training system has a specific pruning,” he said. “But in general, if you have larger limbs or branches, you need to remove them.” Large limbs often stimulate excessive vigor by producing more carbohydrates than the tree requires, which leads to unwanted shoot growth.

Technology and future orchard systems

As harvesting technology evolves, orchard structures must adapt. “In a spindle system (conic tree), the first scaffold of the branch at the bottom is stronger than the one on the top, so you have branches that are different in size,” Musacchi explained. This uneven structure limits accessibility for new harvesting technology.

To address this challenge, growers are transitioning toward two-dimensional systems. “New 2D systems such as bi-axis have been developed to improve the possibility of reaching the fruit in all the canopy zone,” Musacchi said. “This is the new tendency. We are switching from 3D spindle system to a 2D (planar canopy) that is helpful for assisted harvest, mechanical pruning, and automatization of harvest.”

Applying pear orchard practices year-round

For Musacchi, consistent attention to pruning, training, and disease prevention remains the foundation of orchard success. Whether managing apples or pears, he said the same principles apply: balance vigor, encourage fruit quality, and protect trees from infection.

With research-backed approaches to pear orchard practices, growers can optimize their orchards for healthier trees and more profitable yields season after season.

— Doug Ohlemeier, Assistant Editor