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.

Table. 1 Homeowner’s spray schedule for pecans.

¹Due to variation in the concentration of pesticides in different products, refer to the label for the specific rate per 1 gallon spray solution.

WP = wettable powder
EC = emulsifiable concentrate
DF = dry flowable

Table. 1 Homeowner’s spray schedule for pecans (continued).

¹Due to variation in the concentration of pesticides in different products, refer to the label for the specific rate per 1 gallon spray solution.

WP = wettable powder
EC = emulsifiable concentrate
DF = dry flowable

Table. 1 Homeowner’s spray schedule for pecans (continued).

¹Due to variation in the concentration of pesticides in different products, refer to the label for the specific rate per 1 gallon spray solution.

WP = wettable powder
EC = emulsifiable concentrate
DF = dry flowable

Table. 1 Homeowner’s spray schedule for pecan. (continued).

Table 2. Homeowner’s spray schedule for peaches and plums.

¹Due to variation in the concentration of pesticides in different products, refer to the label for the specific rate per 1 gallon spray solution.

WP = wettable powder
EC = emulsifiable concentrate
DF = dry flowable

Table 2. Homeowner’s spray schedule for peaches and plums (continued).

¹Due to variation in the concentration of pesticides in different products, refer to the label for the specific rate per 1 gallon spray solution.

WP = wettable powder
EC = emulsifiable concentrate
DF = dry flowable

Table 2. Homeowner’s spray schedule for peaches and plums (continued).

¹Due to variation in the concentration of pesticides in different products, refer to the label for the specific rate per 1 gallon spray solution.

WP = wettable powder
EC = emulsifiable concentrate
DF = dry flowable

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)