Plum Curculio

The plum curculio, Conotrachelus nenuphar (Herbst), is an important early season pest of pome and stone fruits.  They can cause considerable damage to apple, pear, apricot, peach, plum, nectarine, cherry, and other fruits.  After codling moth, plum curculio is often regarded as the most serious pest of tree fruits in eastern North America.

Biology and Life History

Plum curculio adults are a type of weevil (or snout beetle), approximately 6 mm (¼”) in length with a mottled combination of brown, …

An Introduction to Hard Cider in the U.S.

By the simplest definition, hard cider is fermented apple juice. In the U.S., unfermented and usually unfiltered apple juice is referred to as cider or sweet cider. In many other countries, particularly in Europe, the fermented product is called cider and the unfermented product is called apple juice. In this article, we use the term cider to refer to the fermented product.

According to Alcohol and Tobacco Tax and Trade Bureau data, production of hard cider in the U.S. has,

Codling Moth

Codling moth, Cydia pomonella, is one of the most serious insect pests of apple in the United States.

Biology and Life History

Adult moths are approximately 10 mm (⅜”) in length, with a wing span of 18 mm (¾”).  Wings are mottled gray with a distinctive copper-colored band at the tip of each forewing (Figure 1)

Female moths lay flat, oval eggs singly on developing fruit or adjacent leaves.  Newly hatched larvae enter fruit, usually through the …

Choosing the Right Cultivar to Plant

gala apple

Several variables should be considered when selecting apple cultivars to plant. Important factors include cold hardiness (some cultivars will not survive extreme winter low temperatures), heat tolerance,  disease resistance, time of harvest, intended uses and time of bloom. Apples require cross-pollination between two cultivars that must bloom at the same time.

Commercial orchardists must consider cultivars for an intended market. For example, processors will pay a premium price for ‘Northern Spy’ for pie filling, but there is little demand for …

Jon Clements

Jon Clements is an Extension educator with 25 years experience in tree fruit production. Located at the UMass Cold Spring Orchard in Belchertown, Massachusetts, Jon is a part of the UMASS Fruit Advisor, whose mission is to assist fruit growers with all aspects of horticulture and integrated pest management.

Contact Information

UMass Cold Spring Orchard
393 Sabin St.
Belchertown, Massachusetts 01007

Email: clements@umext.umass.edu
Blog: http://jmcextman.blogspot.com/

Alan Biggs, West Virginia University

Alan Biggs is a Professor of Plant Pathology and Extension Specialist in Tree Fruit Pathology at the Kearneysville Tree Fruit Research and Education Center in Kearneysville, WV. He has extensive knowledge of major tree fruit diseases and has developed several online resources to assist growers in the West Virginia region. In addition to conducting numerous research projects on apple disease, he also teaches tree fruit pathology to master gardeners and mushroom identification to master naturalists.

Contact Information

WVU-KTFREC
P.O. Box …

How Apple Fruit Size Is Determined and Affected

An apple’s size is determined by the cells that make up the apple. The number of cells, size of each cell, and air space between cells all can play roles in fruit size. An average-sized apple has about 50 million cells. Some apples achieve their larger size by having a larger number of cells, and some achieve their larger size by having larger-sized cells.

Most apple growers strive to produce larger-sized fruit. To achieve this goal, growers should consider the …

Apple Fruit Thinning


Fruit thinning is a management practice that reduces the number of fruits per tree in the current season, resulting in increased fruit size of the remaining fruits and increased return bloom and yield in the next season. Although it can be difficult to achieve, fruit thinning is the single most important management strategy in determining the annual profitability of apple orchards.

Intensity of Thinning

Management of crop load is a balancing act between reducing crop load sufficiently to achieve optimum …

Emily Hoover, University of Minnesota

Dr. Emily Hoover is currently the Head of the Department of Horticultural Sciences, overseeing diverse research, extension, and teaching programs.  Additionally she teaches courses in fruit production and teaching pedegogy. Her research has focused primarily on evaluation of winter hardiness and winter protection/adaptation to enhance profitability, efficiency, and sustainability of fruit cropping systems.

Contact Information

305A Alderman Hall
University of Minnesota
1970 Folwell Avenue
St. Paul, MN 55108

email:  hoover@umn.edu

 …

Timing of Apple Tree Bloom

Apple trees begin visible growth in the Spring of the year after having had their chilling requirement met, measured as chilling hours (800-1200 hours),  followed by a specific amount of warm weather, measured as growing degree-hours (approx.. 300 hours).  The first growth to appear in the Spring is the leaves and the trees will bloom approximately 3-4 weeks later. The date on which apple trees bloom in a location can vary annually based upon fluctuating winter and spring temperatures and …