Reduced Chemical Pest Management for Fruit & Nut Trees | UC Master Gardeners of Placer County

January 1, 2026

Author: Chuck Ingels, UC Cooperative Extension, Sacramento County.
Edited by Christine Joshel, Center for Pest Management research & Extension and Mary Lou Flint, IPM Education & Publications, UC Davis.
Publication Number 31-S81 (revised July 2003)

As result of increasing environmental contamination and pesticide safety concerns, we strongly recommend the use of reduced or non-chemical approaches to pest management where possible. Integrated pest management (IPM) emphasizes the use of non-chemical methods first, and the use of chemical pesticides only as a last resort. These methods include proper pest identification, periodic monitoring, appropriate cultural practices, release of beneficial insects if appropriate, applications of lowest toxicity pesticides, and then application of certain pesticides if all other methods fail.

Be sure to thoroughly read all labels to determine if a pesticide is appropriate for a given pest and crop, and always use the protective clothing and gear stated on the label when applying pesticides. If your pest problem is eliminated with a single spray, or in the case of some fungicides if the weather turns dry, no additional sprays may be necessary, even though the label says to use every 7 to 14 days. When spraying, be sure to thoroughly cover leaves and/or branches.

In a few cases, beneficial insects may be purchased through mail order catalogs and released on the trees. Such insects include Trichogramma platneri for codling moth and Aphytis melinus for California red scale. Releasing lady beetles (lady bugs) is usually not effective because they quickly fly away. In most cases, predatory insects will come when the conditions are right.

Tables. The tables on the following pages are intended as a quick guide for managing pests using the least toxic approaches. Products or methods in bold are preferred over others based on efficacy or safety. Some of the products and methods listed may not be as effective as chemical pesticides. For example, codling moth can be very difficult to control using cultural practices. Oil and other low-toxicity insecticides are not effective or require a large number of applications if populations are high. In some cases, applications of Sevin may be the only effective control measure for codling moth.

For more thorough information, several publications are available from your local UC Cooperative Extension office. Some of the information in these publications is more suited for commercial producers rather than backyard gardeners.

Pests of the Small Farm and Garden
Pests of Landscape Trees and Shrubs
UC IPM Pest Notes (free; also on web site - see below): Aphids, Codling Moth, Cottony Cushion Scale, Fire Blight, Leaf Curl, Powdery Mildew, Scales, Spider Mites, Thrips, and Walnut Husk Fly.
Integrated Pest Management publications for: 1) Stone Fruits, 2) Apples and Pears, 3) Citrus, 4) Almonds, and 5) Walnuts.

In addition, the most up-to-date information can be found on the UC IPM web site: https:// www.ipm.ucdavis.edu.

Adapted from Environmental Horticultural Notes #81. January 2000. UC Cooperative Extension, Sacramento County.

Summary of Reduced Chemical Methods of Managing Selected Insect and Disease Pests of Backyard Fruit Trees

-- DORMANT SEASON--

Disease or Insect

Product or Method

Signal

When to Use

Frequency

Comments

Peach leaf curl

(peach, nectarine)

Copper product (e.g., coppersulfate, fixed copper)

WARNING

Late fall and
At bud swell

1-2x /year

Toxic to some soil organisms.

Product must contain at least 50% copper.

Shot hole

(almond, apricot, peach, nectarine)

Lime sulfur

DANGER

Late fall and
At bud swell

1-2x /year

May cause eye damage.

Do not use on apricot.

Not registered for use on almond.

NOTE: Copper or lime sulfur should be applied to peaches & nectarines each year; fall spray maybe adequate except in wet springs. Copper is preferred because it is less hazardous. Do not mix lime sulfur with oil. Use spreader sticker to reduce washing off by rain.

European fruit lecanium (scale)

(decid. fruits/nuts)

Superior/ Supreme Oil

CAUTION

Early dormant season

(by mid-Jan.)

1x per year

Avoid useof products labeled "Dormant oil", it may injure trees.

Do not use within 30 days of sulfur or captan. Can also treat scale with summer oil during crawler stage, but timing is more difficult. Avoid applying oil during dry, warm, and windy periods; best to apply just after rain or fog.

Red mites, aphid eggs, San Jose scale, kuno scale,

walnut scale

(decid. fruits/nuts)

Superior/ Supreme Oil

CAUTION

Late dormant season to bud swell

1x per year

Warning on the Use of Chemicals : Pesticides are poisonous. Always read and carefully follow all precautions and safety recommendations given on the container label. Store all chemicals in the original labeled containers in a locked cabinet or shed, away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock.

Confine chemicals to the property being treated. Avoid drift onto neighboring properties, especially gardens containing fruits and/or vegetables ready to be picked.

Dispose of empty containers carefully. Follow label instructions for disposal. Never reuse containers. Make sure empty containers are not accessible to children or animals. Never dispose of containers where they may contaminate water supplies or natural waterways. Do not pour down sink or toilet. Consult your county agricultural commissioner for correct ways of disposing of excess pesticides. Never burn pesticide containers.

Phytotoxicity Warning: Certain chemicals may cause plant injury if used at the wrong stage of plant development or when temperatures are too high. Injury may also result from excessive amounts of the wrong formulation or from mixing incompatible materials. Inert ingredients, such as wetters, spreaders, emulsifiers, diluents, and solvents, can cause plant injury. Since manufacturers often change formulations, it is possible that plant injury may occur, even though no injury was noted in previous seasons.

-- SPRING AND SUMMER--

Disease	Product or Method	Signal	When to Use	Frequency	Comments
Apple/ pear scab	General comments	Few or no sprays necessary in dry springs. All sprays are preventive only.
	Cultural methods	Remove fallen leaves in winter.
	Wettable sulfur	CAUTION	Green tip Just before petals open	1-3x
	Copper product	WARNING	Green tip Just before petals open	1-3x	Late application may russet fruit.
Fireblight (pears, Asian pears, apples)	General comments	Also attacks quince, crabapple, loquat, and Pyracantha.
	Cultural methods	Cut branches >12" below infection, sterilize shears between cuts.
	Copper product (e.g., copper sulfate, fixed copper) (>50% copper)	WARNING	Bloom period	Every 4-5 days thru bloom	Spray only if fireblight has been a problem in past years. Begin treating when avg. temp. >60F. Late application may russet fruit.
Brown Rot (stone fruits and almonds)	General comments	Few or no sprays necessary in dry springs.
	Cultural methods	Remove mummified fruits. Thin fruit in April for air circulation.
	Copper product (e.g., copper sulfate, fixed copper) (>50% copper)	WARNING	Bud swell Full bloom Petal fall	1-3x	Spray #1 also for peach leaf curl. Spray #2 & 3 during wet springs. Sprays #2 & 3 may russet fruit. Spray #4 if spring infection severe. Sprays after bloom may russet fruit.
	Wettable sulfur	CAUTION	same	1-3x	Do notspray w/in 30 days of oil.
Grape powdery Mildew	Wettable sulfur, dusting sulfur	CAUTION	Budbreak to 2” thru berry softening	Every 7-10 days	Use 10-dayinterval during coldor very hot weather. All sprays are preventive only. Can use wettable in early season, dusting later. Do not use when temperature >90°F.
	Garden Fungicide	CAUTION	same	same	Sulfur +surfactants (Safer brand)
	Neem oil	CAUTION	same	same	Do notspray within 30 days of sulfur.
Bunch Rot (grape)	Cultural methods	Remove leaves around clusters in early June for air circulation. Use two-wire trellising and mid-season hedging of shoots for air circulation. Avoid sprinkling vines. Avoid excess nitrogen fertilization. Remove & destroy infected clusters.