If you are trying to control Fairy Ring, Ferbam can be applied at 9 lb/100 gal water through July 31. Do not apply after July 31. You can only do one application of Ferbam. This goes out as a soil drench at a rate of 1 gal/sq ft. Treat 3 ft beyond the advancing ring and 2 feet within the line.
If you are using Stinger for control of asters or legume weeds (like wild bean), wait until after fruit set to apply. Vines are very sensitive to Stinger prior to bloom. Use the lowest effective rate. Spray only to wet the leaves, not to run-off. Minimize drift/contact of Stinger with cranberry vines. Recovery from Stinger injury can take several years.
In general, if you can avoid spraying herbicides during bloom, that is a good approach. However, sometimes to get the best results, you have to apply based on what the WEED is doing compared to what the VINES are doing. Select applications must wait until fruit set; IntensityOne and Poast have no timing restrictions during the bloom period. However, always be careful when using crop oil, especially when bloom is out and when the temperatures are high. IntensityOne uses a NIS whereas Poast uses a crop oil.
My general guideline is to add up the temperature and the relative humidity. Totals over 150 indicate that the risk of crop injury is higher than if the number is below 150. Again, this is a “seat of the pants” guideline but can help steer you away from applying on hot humid days.
Clarification on the use of adjuvants with Proline. The use is recommended for some crops as a possible additive and it’s recommended to use the lowest possible rate. However, there is no specific language that recommends adding an adjuvant for cranberries (listed as the “berry” group). On the other hand, the label does not prohibit the use. At this time, the take-home would be you do not have to add an adjuvant with Proline, but you can if you feel it improves the efficacy.