Invasive Pest Updates, Brown Rot on Peach
October 11, 2013
In this Issue:
Fruit Tree Management - Just The Basics
Expanded Coverage - Insect and Disease Information
SPOTTED WING DROSOPHILA UPDATE
Lori Spears, USU Coordinator for the Cooperative Agriculture Pest Survey (CAPS) program, reports that the first spotted wing drosophila (SWD) trap catch of 2013 in Utah occurred on September 25. Spears is monitoring 14 traps in 5 locations in Davis County, and on that date, she found 5 flies in backyard sites and at the USU Kaysville Experimental Farm. To date, her traps have captured 22 flies.
Utah is fortunate to continue to have very low numbers of this potentially serious pest. In 2012, a total of 17 flies were captured, in 2011, it was 25 flies, and in 2010, 73 flies. Compare these numbers to other western states that capture close to 100 flies/trap per week at this time of year.
Spears and colleagues are considering investigating exactly what SWD is doing in Utah: is it overwintering here, or are these new introductions each summer; is it reproducing in wild hosts; etc. To date, infested fruit have not been reported in Utah.
Elsewhere, SWD maggots feed in a wide variety of fruit, including cherry, blackberry, raspberry, strawberry, grape, blueberry, and peach. Cherries and small berries are the prime hosts, but all overripe fruit is fair game.
Even though SWD populations are low in Utah, it is still important to take precautions to prevent any possibility of infestation by picking fruit before it is overripe, removing fruit from trees after harvest, and removing or mowing/shredding fallen fruit.
Below are links to more information about monitoring and treatment for spotted wing drosophila, and images of damage to fruit (click on orange link):
BROWN MARMORATED STINK BUG UPDATE
The Utah CAPS program is also surveying for the brown marmorated stink bug this year. BMSB was first identified in fall 2012 from a Salt Lake City residence. This season traps placed in 10 Salt Lake City locations have captured a total of 3 stink bugs. An additional, single specimen was detected in another CAPS trap in Utah County (not in an orchard).
The BMSB has devastated a variety of crops (apple, peach, tomato, and others) in eastern U.S., and populations are marching westward. They have become established as nuisance pests in locations in California, Oregon, and Washington.
Click here for more info.
NEW PEACH WEBSITE
Fruit Report (ucanr.edu/sites/fruitreport) is a new website from University of California, compiling 30 years of research, images, and publications on establishing and managing fresh market peach, plum and nectarine orchards. The website contains numerous topics of interest to Utah growers including information on rootstocks, varieties, pruning and training, nutrition, fruit thinning, and irrigation strategies. There are also many links to other sites covering stone fruit production with an emphasis on peaches.
Fruit Tree Management - JUST THE BASICS
APPLE & PEAR
PEACH/NECTARINE & APRICOT
EXPANDED COVERAGE - Insect and Disease Information
APPLE & PEAR
Apple- and Pearleaf Blister Mites
Preventing Split Pits
This season, like last year, resulted in many peach fruits with split pits. The problem can happen about 3 weeks after bloom, or during the pit hardening stage when the fruits make their final swell.
When the fruit flesh expands before the pit has fully hardened and the bond between flesh and pit is still tight, internal forces pull on the pit, causing it to break along the suture. Sometimes the problem is not noticed until after storage or when the fruit is opened and the cavity is a gummy mess. The splits can allow insects to enter, introducing rot fungi.
The real issue with split pits lies in the balance of carbohydrates between the canopy and roots. This balance is upset by winter injury, high heat, freeze injury to fruit in spring, excess soil moisture in spring followed by dry soils in summer, excess vigor, or trunk damage.
Practices such as heavy thinning and excess irrigation or fertilizer applications close to harvest can lead to pit splitting. If this is a problem you find every year, develop a balance between fruit size and losses through the following practices:
Precautionary Statement: Utah State University Extension and its employees are not responsible for the use, misuse, or damage caused by application or misapplication of products or information mentioned in this document. All pesticides are labeled with ingredients, instructions, and risks. The pesticide applicator is legally responsible for proper use. USU makes no endorsement of the products listed herein.