How to Manage Pests

Interactive Tools and Models: Dormant Spray Alternatives Calculator

The calculator requires you to specify input values associated with each alternative:

Specify Management Information. Answer the questions and select the input values appropriate for your orchard and situation. The questions are specific to each alternative, even though several are common to a number of the alternatives. As a result, you may see the same questions when exploring the various alternatives.

Specify Cost Information. Supply application rates for products to be applied and the costs of the products or services. For each rate or cost, the calculator supplies a default value reflecting a common practice. If this value is not appropriate for your orchard or situation, change it to reflect your actual rates and costs.

Below is an explanation of each question or option in the calculator.

Specify management information: input variables

Do you employ a paid PCA? Although monitoring is recommended in an IPM program before any treatment action is taken, it is expected that more intensive pest and beneficial monitoring will be required if the OP + oil dormant spray is not applied. This input variable covers the situation where a grower employs a paid PCA and adds this cost to the total cost of the selected alternative.

Does dormant season monitoring indicate the presence of treatable levels of mite eggs or scale—if so would you make a dormant oil spray? If an OP + oil dormant spray is not applied but a selective action is taken to control peach twig borer, it is possible to apply a treatment in the winter to control scales and eggs of the European red mite and brown mite if monitoring indicates that such a treatment is needed. Select "yes" or "no" to indicate whether a dormant season oil treatment for mite eggs or scale is necessary.

Which OP product would you use as a dormant spray? Select the OP product that you would apply with oil in the dormant season. Check the pesticide label to make certain that the specified product may be used on the target crop and at rates provided.

Which non-OP product would you anticipate using for a dormant insecticide application? Select the conventional non-OP product (carbamate or pyrethroid) that you would apply with oil in the dormant season. Check the pesticide label to make certain that the specified product may be used on the target crop and at rates provided.

Which product would you anticipate using for a dormant insecticide application? Select spinosad or one of the listed conventional non-OP products (carbamate or pyrethroid) that you would apply with oil in the dormant season. This question is asked with the pheromone mating disruption alternative. Check the pesticide label to make certain that the specified product may be used on the target crop and at rates provided.

Which application method would you use for a dormant spray? The dormant season application can be made by ground or air. If the application is made by ground, specify whether it is being applied by the grower or by a custom applicator, and whether the application is a dilute (high-water volume) or concentrate (low-water volume) spray. This input variable adds application cost to the total cost of the selected alternative.

Which Bt product would you anticipate using during bloom? Select the Bacillus thuringiensis product which would be used. Check the pesticide label to make certain that the specified product may be used on the target crop and at rates provided.

How many times would you apply the Bt product during bloom? Select the number of applications of Bt that will be made during bloom. It is recommended that at least two applications should be made at this time.

How many of these bloomime Bt sprays would be tank-mixed with fungicide sprays? Indicate how many of the indicated Bt applications will be applied with a fungicide. The cost of applying two pesticides can be reduced if they are applied together as a tank mix. This input variable decreases the cost of any Bt application that is combined with a fungicide spray during bloom.

Because you did not make a dormant OP and oil spray, how many additional in-season applications (over and above those applications you would normally make) for peach twig borer, aphids (plums and prunes), or scale would you anticipate making? With any of the alternatives, it is possible that the practices employed will not be as effective as the OP and oil dormant spray; one or more in-season sprays might then become necessary. Indicate only insecticide sprays being made in addition to those applications that would have been made in any case, whether or not the dormant spray was applied.

Which product(s) would you apply in-season for control of peach twig borer, aphids (plums and prunes) or scale, if monitoring indicates one or more should be controlled? For each of the additional in-season insecticide applications that you indicated, select the product(s) you would use. Check the pesticide label to make certain that the specified product may be used on the target crop and at rates provided.

Which application method would you use for in-season insecticides and miticides? In-season applications can be made by ground or air. If the application will be made by ground, indicate whether it is being applied by the grower or by a custom applicator. This input variable adds application cost to the total cost of the selected alternative. For this calculator, it is assumed that all in-season sprays are made by the same method.

Over and above the spider mite sprays you would normally expect to apply, how many additional in-season miticide applications would you anticipate making if the dormant or in-season insecticide spray resulted in additional treatment for spider mites? It is possible that spider mites will become a problem if certain insecticides and treatment timings are used. An in-season miticide spray might then become necessary. Indicate only miticide sprays that would be made in addition to those applications that would have been made in any case, whether or not the dormant spray was applied.

Over and above the spider mite sprays you would normally expect to apply, how many additional in-season miticide applications would you anticipate making if an in-season insecticide spray resulted in additional treatment for spider mites? It is possible that spider mites will become a problem if certain insecticides and treatment timings are used. An in-season miticide spray might then become necessary. Indicate only miticide sprays that would be made in addition to those applications that would have been made in any case, whether or not the dormant spray was applied.

Which product would you use for mite control if a dormant or in-season insecticide spray resulted in additional treatment for spider mites? For each additional miticide treatment that you indicated, select the product(s) you would use. Check the pesticide label to make certain that the specified product may be used on the target crop and at rates provided.

Which product(s) would you use for mite control if an in-season insecticide spray resulted in an additional treatment for spider mites? For each additional miticide treatment that you indicated, select the product(s) you would use. Check the pesticide label to make certain that the specified product may be used on the target crop and at rates provided.

How many of the additional miticide sprays would be tank-mixed with the above in-season insecticide sprays? Indicate how many of the indicated mite treatments will be applied with one of the indicated in-season insecticide sprays. The cost of applying two pesticides can be reduced if they are applied together as a tank mix. This input variable decreases the cost of any miticide application that is combined with an in-season insecticide spray.

Specify Cost Information: Input Variables

From the management choices you made, the calculator will provide default treatment rates and costs, and management costs. You can easily change these to reflect your actual rates and costs.

It is recognized that some growers will spot spray (treat only a portion) of an orchard based on monitoring which indicates a clumped pest distribution. To handle this situation in the calculator, enter the rate of material applied as the percentage of the total that will be applied across all of the acreage.

Default Products, Rates, and Costs

For some alternatives, the calculator will provide a default product that is commonly used. You can change these default values (including "none" for some management questions) to reflect your specific situation. Default rates are provided for specific products listed in the calculator. You can also change these default rates to reflect your preferences. In any case, you are responsible for checking the pesticide label to make certain that the chosen product may be used on the target crop and at the rates provided by the user.

Costs associated with products, pesticide application, and monitoring were obtained from different sources. Your costs will vary depending upon many factors including farm size, and you will get better results if you replace default values with your own costs. All costs presented have been standardized for a 100-acre orchard. Costs of chemicals are based on average retail prices obtained from the Department of Agricultural and Resource Economics at UC Davis, John Taylor Fertilizers, and Hughson Chemicals. Application costs are based on average prices obtained from the Department of Agricultural and Resource Economics at UC Davis, and from Richard Coviello, UC Cooperative Extension Entomology Farm Advisor in Fresno County who obtained estimates from two different applicators. Monitoring costs were obtained from two private pest control advisors, and represent the average per acre contract cost for almonds and for stone fruits.