Manitoba Agriculture, Food and Rural Initiatives
Saskatoons - Insect Control
Preharvest Intervals for Insecticides
Preharvest intervals are listed on the labels of many pesticides registered for use on food crops. The time period given indicates that the crop should not be harvested for that time interval after application of the chemical, in other words the minimum number of days which must pass before fruit is picked. If the crop is harvested before the indicated interval has elapsed there could be unsafe or unacceptable residues of the pesticide remaining in or on the harvested fruit.
When pesticide applications are being considered, take note of the required preharvest interval and allow for that time period before harvest.
The following table gives the required preharvest intervals for insecticides listed in this guide. The preharvest intervals are also listed under the Restrictions section of individual product descriptions.
Insecticides: Required Preharvest Interval in Days
After application of a pesticide do not pick fruit for the number of days indicated on the table.
| Product | Saskatoons |
| Decis | 21 |
| Orthene | For use on non-bearing plants only |
Insect Control for Saskatoons
The crop year has been divided under headings according to appropriate time to spray.
Check for the insect of concern under the "Time to Spray" heading and apply the
product listed in the pesticide column. See the Comments column for information on time to
spray and when specific insects are likely to occur. Check the product description at the
end of this section for rates, restrictions and any special cautionary notes.
Time to Spray: See Comments
Insects |
Materials |
Comments |
|
Saskatoon bud moth Tarnished plant bug Lygus bug Sawfly Apple curculio Hawthorn weevil |
|
Apply a maximum of three applications per season, once prior to flowering, once at early flowering, and once after petal drop, observing the preharvest interval of 21 days. Growers are encouraged to apply Decis EC when the insect pest of concern first appears in sufficient numbers to cause economic damage. Not all pest species will appear every year, therefore producers are encouraged to scout regularly. The insect species controlled will appear at different times of the growing season. Saskatoon bud moth, lygus bug and tarnished plant bug will often first appear at the time of inflorescence bud break (green tip) to tight bud cluster. Sawfly will often first occur at 25% bloom and apple curculio and hawthorn weevil will often appear within five to ten days after petal fall. |
| Wooly elm aphid |
|
This treatment is for new non-bearing orchards only, for application in the first three years of establishment. May be applied once per season only, in mid-July or early August. Must be applied by soil injection. |
|
Note: Insecticide application during the bloom period could cause fruit loss due to the
impact on pollinating insects. Special Note: Some crop stage and timing information is different from that included on the current Decis label. The revisions have been suggested to and reviewed by the manufacturer. |
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Links:
- Early Season Saskatoon Insects
- Chemical Resistance in Insects and Diseases
- Pesticide Safety
- Pesticides and Bees
For further information, contact your GO representative.
