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Uniformity of Promalin response on the tree. The L/D ratio of fruits will vary considerably 

 on a tree. This is due to the location of the fruit on the tree and their origin within the 

 blossom cluster. The L/D ratio distribution of fruits from untreated and Promalin-treated 

 trees is similar (Figure 2). This indicates that a Promalin application increases the L/D 

 ratio of all fruits on the tree equally. Therefore, a grower can expect to find some rather 

 flat-looking Delicious on Promalin-treated trees at harvest time although there should 

 be fewer than on check trees. 



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Figure 2. The L/D ratio distribution of fruits from trees receiving a 25 ppm dilute spray 

 of Promalin and from Control trees. 



Variable Promalin response. It has been observed that the L/D ratio following Promalin 

 application is sometimes less than expected. We believe that there are at least two 

 reasons for this. Weather, and especially high temperature during and following the 

 bloom period, can influence fruit shape. Undoubtedly, part of the diminished response 

 can be attributed to high temperature during and following Promalin application. It 

 is known that temperature during and following bloom can have a direct effect on cell 

 division and expansion in the calyx end of fruit. Based upon several experiments over 

 several years where Promalin was placed directly in the calyx of fruit it is concluded 

 that Promalin always elongates fruit. Promalin promotes at least 2 independent processes: 

 fruit elongation and fruit thinning. In situations where a diminished response is observed, 

 Promalin may be thinning from the cluster the fruit that have been elongated. 



