- Author: Ed Perry
When you remove young fruit from a limb, the remaining fruits benefit from the reduced competition for mineral nutrients, light, water and plant foods produced by the leaves. By thinning early, you also increase shoot and leaf growth. This results in extra leaves that produce more sugars and other materials necessary for sizing the remaining fruits. Thinning also helps prevent limb breakage caused by heavy crops.
You already thin fruit when you prune your trees, since nearly every pruning cut removes some flower buds. In fact, pruning is the only practical way of thinning cherries and nut crops. However, it is still necessary to hand thin stone fruits such as apricots, nectarines, peaches and plums and pome fruits such as apples and Asian pears. Species that rarely need hand thinning are almonds, avocados, bushberries (such as Boysenberries), cherries, citrus, European pears (such as Bartlett), pistachios and persimmons.
How much to thin depends upon the tree species. With peaches and nectarines, it's important to make room on the branches for each fruit to grow to 2-1/2 to 3 inches in diameter. Thin by pulling off 3/4 to 1-inch long fruit in April and May, leaving one fruit every 6 inches. This results in more fruit on the ground than on the tree, but it's important to produce large, flavorful fruit and to minimize limb breakage.
While it's best to thin early in the season, it is never too late to do some thinning where trees are having difficulty sizing the crop. Removing small fruit from overloaded trees, even shortly before harvest, will pay off in larger average fruit sizes.
Grape varieties such as Thompson seedless may also benefit from fruit thinning. Removing entire clusters after the berries have set helps to enlarge the berries on the remaining clusters. Remove undersized or misshapen clusters first.
Ed Perry is the emeritus Environmental Horticultural Advisor for University of California Cooperative Extension (UCCE) in Stanislaus County where he worked for over 30 years.
When: Tuesday, April 26, 2021 6:00-7:30 p.m.
Where: Harvest Hall Rooms D& E at the Agricultural Center at the corner of Crows Landing and Service Road in Modesto.
Address: 3800 Cornucopia Way, Modesto, CA 95358.
Cost: Free
Instructors: Master Gardeners Heidi Aufdermaur and Denise Godbout-Avant
Questions: call (209) 525-6862
Sign Up online: http://ucanr.edu/bees/2022
- Author: Ed Perry
If you decide to fight them, now is a good time to plan your strategy since the most critical time to protect your fruit from the pest is spring. Warm spring weather causes most of the first generation moths to emerge within a few weeks. The moths may take 6 weeks or more to emerge during a cool spring. Once they have emerged, the codling moths are still affected by temperature. They do not lay eggs or mate when it's below 62°F at sunset or fly when it's 55°F.
The moths emerge from pupae in early spring about the time when fruit trees are in full bloom. Each moth lays 50 to 75 eggs on fruit, twigs, or leaves. Eggs hatch into larvae which tunnel into the young fruit. Inside the fruit, the larvae feed for several weeks, then tunnel to the fruit's surface and search for protected sites such as under tree bark, in branch wounds, weeds, grass or other litter. The larvae changes first to a pupa, then to an adult and repeats the cycle.
You can also trap many larvae under bands. Take a 6-inch wide strip or burlap or corrugated cardboard, wrap it around the trunk several times, then fasten it in place with a loop of wire or twine. If you use corrugated cardboard, the exposed flutes (ridges) must be at least 3/16 of an inch wide and face toward the tree; otherwise, the larvae won't form cocoons in them. Place a band on each tree no later than mind-May. During warm weather remove the band once a week, and during cool weather once every two weeks. Destroy all the larvae and pupae under the band, and then put the band back on the tree. Keep doing this until you've harvested all the fruit.
Insecticidal sprays are usually the most effective means of controlling codling moths. Sprays give best control when you apply them just after a large number of larvae hatch, but before they burrow into the fruit. These times are several days after a period of peak moth flight and vary according to the year and location.
When using any chemical, carefully follow dilution rates and other directions given on the container label. Do not spray within the number of days before harvest indicated on the label. You can read more details about the life cycle of this pest and management, including chemical controls in the UC IPM Pest Notes: Codling Moth.
Ed Perry is the emeritus Environmental Horticultural Advisor for University of California Cooperative Extension (UCCE) in Stanislaus County where he worked for over 30 years.
- Author: Rhonda Allen
There will be many opportunities to learn about pollinators, as well as fun activities for children. A children's scavenger hunt and a ladybug release are planned. The day will start with a children's pollinator costume parade at 10:15, so be sure to dress as your favorite pollinator!
Several local agencies, including the UCCE Stanislaus County Master Gardeners, will feature booths with educational information about pollinators and insects, including insect collections. Learn how to identify native bees and hear a UC Cooperative Extension entomologist speak about the importance of helping local pollinators thrive at 12:15.
Citrus trees are one of the most popular fruit trees grown in California. Not everyone can grow Lemons, limes, kumquats, pomelo, grapefruit, and oranges, just to name a few! The climate has to be just right, and the Central Valley of California is perfect for this crop.
We hope you will join us for an evening learning how to successfully grow citrus in your garden. We will discuss how to properly plant, water, and care for your tree, including when to fertilize, if and when you should prune, and also some of the common pests that cause problems for gardeners.
Where*: On Zoom. You will receive a link the morning of the class.
When: Tuesday, March 29, 2022 6:00-7:30 p.m.
Cost: Free
Register at: http://ucanr.edu/citrus/2022
Instructors: Master Gardener Tim Long and Master Gardener Coordinator Anne Schellman