Crop Load Management: Avoid Common Mistakes

Editor’s Note: In this Q&A, Tom Auvil of the Washington Tree Fruit Research Commission shares insight into the role nurseries play in determining crop load management and highlights mistakes to avoid when establishing a new orchard.

Q: What role does the nursery play in crop load management before the grower even plants a tree?

Auvil: The biggest role is the tree quality. The caliper, unheaded tree height, and number of useful “fruiting limbs” under ¼-inch diameter and less than 18 inches long will impact the cropping of second leaf trees. Trees with long, large caliper branches often have severe blind wood issues and are actually detrimental to modern plantings.

Q: What are some of the most common mistakes growers make in regard to crop load management when establishing a new orchard?

Auvil: The most common error is over cropping in the first production year. Some varieties such as Honeycrisp and Fuji need little encouragement to become biennial.

Second leaf cropping can be a huge mistake if the tree volume has not reached 80% of the mature stature. Crop removal in second leaf may be required in many replant sites, regardless of scion cultivar. The third leaf crop should be kept under 40 bins, or 800 packed boxes per acre. With Honeycrisp and Fuji, perhaps the maximum crop should be targeted at 35 bins per acre to reduce the risk of biennial bearing in overcropping-prone cultivars.

Q: What are some of the misconceptions growers have when it comes to crop load management in young orchards?

Auvil: “Early yields have terrible fruit quality and are not worth effort.” Highly vigorous young trees can have poor packouts. The question is, what year will a particular production system have that first crop? Apple systems of less than 500 trees per acre, especially those with free-standing trees with less than 350 trees per acre, will typically have a first full volume commercial crop year in the 10th to 12th season, and also tend to have more challenges with vigor-related issues of bitter pit, poor color, and sunburn.

If the high vigor of growing the new production canopy is maintained into fruit production, the fruit quality can be adversely affected for as long as the tree vigor is excessive of the needs of the crop.

Q: What are the most important considerations growers need to make regarding crop load management in the first year after a tree is planted?

Auvil: The number one priority is to establish a canopy volume large enough to grow 800 packed boxes. Over the next three or so seasons, the crop in the top of the tree should be managed so there is steady expansion of the canopy, without strong shoots/suckers to a crop volume of 1,200-plus packed boxes per acre.

Q: Is there anything you’d like to add?

Auvil: The best results are obtained when all components of a modern orchard system are in sync. Water and nutritional management are inseparably linked. Pruning, limb positioning, and tree support are critical in directing new growth where needed, and crop load management is a tool that ultimately controls the vegetative vigor of the tree, but is also an important part of growing a consistent fruiting wall in new orchards.