For fruits other than apples there is less information avail- 

 able on foliar applications of Mg . Epsom salts (10 to 15 lbs. per 

 100 gallons dilute rate) have been suggested for use on pears and 

 peaches, and, at lower rates (2 lbs, per 100 gallons plus a casein 

 spreader) on plums, prunes and apricots. Manufacturer's suggested 

 rates should be followed in trials with magnesium chelates. 



Boron (B) sprays are commonly used on apple orchards. Rates 

 suggested are usually in the range of one-half pound to one pound 

 of Solubor or Polybor per 100 gallons of dilute spray equivalent 

 in one or two post-bloom sprays. Spray timings most often suggested 

 are first and second cover sprays. Applications at the one-half 

 pound rate at tight- cluster or pink have been found to increase 

 pollen germination in some tests and might be suggested where leaf 

 samples collected the previous year indicate boron to be low. B 

 sprays may be used in conjunction with soil applications as follows: 



Leaf 



B (ppm dry wt . ) Boron treatment 



35 to 50 Continue present program 



(Satisfactory) 



25 to 35 Ground application of 201 fertilizer grade borate 



(approximately 10 to 15 lbs/acre) or apply 1 or 

 2 sprays of Solubor or Polybor (2 to 3^ lbs per 

 spray) during the period from petal fall through 

 second cover. 



below 25 



Ground application of 201 fertilizer grade borate 

 (10 to 15 lbs per acre) plus Solubor or Polybor 

 at tight cluster or pink (one-half pound per 

 100 gallons) plus Solubor or Polybor at first 

 to second cover (one lb/100 gallons dilute rate). 



With pears, a post-harvest application of Solubor or Polybor 

 (one to two lbs. per 100 gallons dilute rate) has been reported to 

 be more effective than early spring applications in avoiding a 

 temporary boron deficiency during bloom. Additional trials are needed 

 to determine the value of this treatment under our conditions. Foliar 

 sprays of B are not recommended for peaches because of their sensi- 

 tivity to this element. 



Zinc (Zn ) is best supplied to tree fruits in dormant or foliar 

 sprays. Do rmant sprays of Zn sulfate (35''o zinc sulfate monohydrate) 

 at rates oT^lO to 20 lbs per 100 gallons as a dilute spray ( do not 

 concentrate above 2X) have been generally recommended for all decid- 

 uous tree fruits. Dormant sprays (before green tissue appears) have 

 resulted in injury to buds and spurs of apple trees if frost occurs 

 within 24 to 48 hours of the application or if oil sprays are used. 



