Pecan, fruit, and nut Spray Schedule

Homeowners should be familiar with insect pests and diseases, their life cycles and damage. Problems must be identified and proper control methods selected. The situation is often complex because problems vary from one area of Texas to another and from one year to the next. It is important to keep records of pest and disease occurrence to assist in making control decisions such as the timing of pesticide applications.

Plant diseases are most severe during periods of frequent rain or dew and mild temperatures (75 to 85 degrees F). Early-maturing peach varieties are more likely to have brown rot than late-maturing varieties, but late varieties are often damaged more by peach scab.

Cultural Practices

Healthy plants are more able to survive some insect and disease damage than plants already stressed by cultural problems. Optimum tree growth is maintained by following a well-balanced fertility program, selecting adapted disease-resistant varieties, and irrigating and pruning as needed.

Clean-up and residue disposal are important in reducing plum curculio, hickory shuckworm, brown rot of peach and pecan scab. Diseased material that is properly composted can be recycled as mulch or organic material.

Pesticide Safety

Before using any pesticide, carefully read all instructions on the container. Follow instructions such as the need to wear protective clothing during mixing or spraying. Take necessary precautions when applying pesticides to avoid chemical exposure.

Mix pesticides in a well-ventilated area or outdoors. Avoid chemical contact with the skin and do not breathe chemical vapors.

Apply pesticides at the proper rate. Using less chemical then prescribed may result in poor control, while using more than recommended may result in excessive residue on the fruit or in plant damage.

Store chemicals in a secure area away from pets and children. Prepare only the amount required for one application. Properly dispose of any unused, diluted sprays and empty pesticide containers. Store pesticides in original containers.

Spray Equipment

A number of different sprayers can be used to apply insecticides and fungicides.

Compressed air sprayers range in size from 1 to 10 gallons; because of cost and handling ease, most homeowners prefer the 2 1/2- to 3-gallon sizes. Hose-on sprayers are less expensive but require a high volume of water, moderate pressure and a convenient water outlet. Applying wettable powders with a hose-on sprayer is difficult.

Once a sprayer has been used, it is considered a used pesticide container and requires proper handling and storage. Proper cleaning prolongs its life. Do not apply insecticides and fungicides with a sprayer previously used to apply herbicides; this may cause plant damage.

Suggested pesticides are registered and labeled for use by the Environmental Protection Agency and the Texas Department of Agriculture. The status of pesticide label clearances is subject to change, and may have changed since this publication was printed. County Extension agents and appropriate specialists are advised of changes as they occur.

The USER always is responsible for the effects of pesticide residues on livestock and crops, as well as for problems that arise from drift or movement of the pesticide from one’s property to that of others. ALWAYS READ AND CAREFULLY FOLLOW THE INSTRUCTIONS ON THE CONTAINER LABEL.

Organic Disease Management

Peaches, Plums, Nectarines, and Apricots - Use sulfur fungicides throughout the spray program. Decrease application interval to shortest interval allowed. Shortened intervals are important during the late bloom, shuck split and first cover period and again during the preharvest period. These are periods when fruit diseases are most damaging.

Pecans - Copper sulfate is considered an organic fungicide and some formulations are approved for use on pecans to control pecan scab and other foliage diseases. Copper sulfate is highly toxic to fruit trees such as peaches, plums, apricots and nectarines, and to some ornamental plants. Be careful when using this product around sensitive plants if there is a possibility of drift.

General Considerations - Most plant diseases require that the leaf, fruit or nut remain wet for a certain length of time for infection to occur. The following precautions should be taken to reduce the length of time the plant is wet following dew or rainfall: (1) prune trees to allow sunlight to penetrate the leaf canopy; (2) space trees to allow for air circulation; (3) plant trees in an area that will receive early morning sun and where air circulation will not be blocked by buildings or other plants; and (4) avoid wetting the tree during irrigation.

Select varieties that have natural resistance to the major diseases of your area. Resistance does not mean immunity to infections, but fungicide applications are usually more effective on plants with some resistance.

DISEASES (ALL CAUSED BY FUNGI)

• Pecan scab
• Sticky shuck
• Downy spot
• Vein spot
• Brown leaf spot.

INSECTS:

Pecan phylloxera

Causes galls on leaves, trigs and nuts.

Pecan nut casebearer

Fees on nutlets, or later in season, in the chucks.

Hickory shuckworm

Tunnels in and feeds on shucks.

Pecan aphid

Honeydew-producing insects.

Walnut caterpillar

Feeds on leaves, does not produce web.

Fall webworm

Caterpillar encased in a large web, occasionally encasing entire branches.

Obscure scale

Sucking insect found on trunk and limbs. Color much like that of the bark. Difficult to see except on close examination.

There are other pests that do not occur as frequently as those listed, but are usually controlled by spray procedures for the most common pests.

SPRAY SCHEDULE

MID-JANUARY - DORMANT OIL SPRAY for control of obscure scale and phylloxera. Temperature must be 40-70 F.

LATE FEBRUARY - (before buds break) - DORMANT OIL SPRAY for control of phylloxera. Spray all limb surfaces, paying particular attention to the tree trunk. This is where the phylloxera like to overwinter.

MARCH (or when leaves are half-grown, pre-pollination) - Insecticide like X-Ecute (or other suggestions on product information list below). Fungicides like Benelate 50WP or BENOMYL and Zinc Sulphate to feed leaves and control rosette.

LATE APRIL (pre-pollination) - repeat March

MAY (post-pollination when pecan nutlets turn brown and bloom ends) - Repeat March/April applications.

JUNE-SEPTEMBER - Your spray schedule now falls into 15-day cycles (10-day cycle during heavy rain). During periods of rain showers, inspect pecan leaves, nuts and bark for insects, insect egg deposits and indications of fungi.

AUGUST - Regardless of what day your spray application is due, BE SURE to apply insecticide and fungicide along with zinc sulphate on Aug. 15 or as close to this date as possible. This application is necessary to control the hickory shuckworm.

Do not spray any application after pecan shucks splits or during harvest. After harvest, spray schedule may be resumed to control walnut caterpillar, fall webworm and fall foliage diseases. It is important to try to keep your trees disease- and insect-free in order to keep the foliage on the tree as long as possible. Remember, between harvest and normal leaf drop and dormancy, the foliage is manufacturing food for next year's nut production.

PRODUCT INFORMATION:

DORMANT OIL (97% oil emulsion) - Ready available at most nuseries, garden centers and feed stores.

X-ECUTE (dimethoate) - A liquid insecticide made by Pro Tech. Made specifically for pecan trees. Avoid contact with any other vegetation around pecan tree. Also found at most full-service nurseries, solutions stores and feed stores. Other options for insecticide are Cygon 2 EC, Malathion 50%EC, Green Light Double Dursban 12.6%, and Green Light Neem Oil Concentrate for Fruit and Nut Trees.

ZINC SULPHATE - A unique combination of liquid zinc, nitrogen and other compounds. Significantly increases yield and quality and promotes even maturity. More importantly, controls the disease rosette.

DUTER (Triphenyl Tin Hydroxide) - A fungicide that has been effective in controlling certain diseases which have developed resistance to Benomyl.

BENLATE 50 WP (BENOMYL) - Getting harder to find, but still available at feed stores and solution stores. Other options include Benomyl and Green Light Neem Oil. Effective in controlling certain diseases like leaf spot, leaf curl, kernel rot and scab.