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Effect of Promalin on pollinizers. Delicious is not the only cultivar that can be elongated 

 with Promalin. If pollinizers are located within the rows of Delicious being sprayed you 

 can expect elongation of these fruit also. Increased length of such cultivars as Mcintosh 

 and Cortland in most cases would not be desirable. Therefore, when applying Promalin 

 attempts should be made to avoid spraying pollinizer trees where increased calyx-end 

 length is not wanted. 



Suggestions for Promalin use 



1. Calibrate your sprayer. Thinning due to Promalin has often been traced to 

 overapplication because of improper sprayer calibration and nozzle adjustment. The 

 margin of error with Promalin is not great. The label suggests that Promalin should 

 be applied in 100-200 gal/acre. Therefore, an error in application of only 50 gal/acre 

 can result in a 50% increase in the amount of Promalin applied. 



2. Do not apply more than \i pts/acre of Promalin. 



3. Do not apply Promalin when the temperature exceeds 85° F. Excessively warm 

 temperatures may increase the thinning response without a corresponding increase 

 in the shape response. 



4. Do not apply Promalin on young trees. A good rule-of-thumb is not to apply this 

 growth regulator on any tree until it is bearing heavily enough to consider chemical 

 thinning. 



5. Apply Promalin as soon after opening of the king blossom as weather permits. This 

 is earlier than we have suggested in the past. It is our feeling that the reduced leaf 

 surface at this earlier timing may reduce the possibility of thinning. 



6. The addition of surfactants or spreader stickers increases both the fruit shape and 

 thinning response to Promalin. On trees where bloom is heavy and the use of a chemical 

 thinner is anticipated, the addition of a surfactant or spreader sticker is suggested. 



7. Promalin may thin as well as accelerate the normal fruit abscission process. Therefore, 

 before using a chemical thinner on Promalin-treated trees, check initial set to see 

 if additional thinning would be desirable. It is possible that no chemical thinner is 

 needed on Promalin treated trees. If a thinner is used on Promalin-treated trees 

 it is unlikely that thinning will be excessive. 



8. Leave a few untreated and representative trees in the Promalin-treated block. Initial 

 fruit set, subsquent drop and fruit shape are never constant from year to year. 

 Therefore, the only way to accurately assess the performance of Promalin in your 

 orchard is to leave a few untreated trees in the same block to indicate what would 

 have happened in the absence of the Promalin spray. 



