-11- 



Calcium (Ca) : The use o£ calcium chloride (CaCl2) sprays to 

 increase the flesh Ca content o£ our apples is rapidly becoming a 

 standard practice in commercial orchards. Our suggestions for their 

 use in 1979 are as follow: 



Apply foliar sprays of CaCl2 starting about 3 weeks after petal 

 fall and repeat at 2-week intervals, totalling 6 or 8 applications. 

 Apply 6 to 8 pounds CaCl^/acre/spray until mid-July. After mid-July, 

 apply 10 pounds/acre/spray. Use a technical grade CaCl2 such as Allied 

 Chemical Flakes, 77-801 CaCl^- Other brands may be equally suitable. 



Experience in Massachusetts has shown that CaCl2 can be combined 

 with pesticide sprays. However, there is limited evidence that the 

 combination of Guthion (azinphosmethyl) 50 WP and CaCl^ may increase 

 foliar burn. Do not mix CaCl- and Solubor sprays. Always dissolve 

 the CaCl^ in a~p^ail of water and add this last and when the spray tank 

 is nearly full. 



Foliar CaCl^ sprays may be applied dilute (300 gallons/acre) or 

 up to 6x concentration (50 gallons/acre). In our tests, flesh calcium 

 has been increased more by 6x concentration than by dilute. In 1977 

 the effectiveness of foliar CaCl^ sprays at 6x and lOx was compared on 

 Mcintosh. The concentrations were equally effective for increasing 

 flesh calcium, and foliar burn was not excessive. 



CaCl^ sprays can cause burn of leaf margins. Foliar injury usu- 

 ally is more serious on Mcintosh than on Delicious. If foliar injury 

 occurs, do not apply again until 1 inch of rain falls. Foliar burn 

 was more severe from dilute sprays than when applied at 6x at the 

 Horticultural Research Center in 1976, but the opposite occurred in 

 1977. This appears to indicate that CaCl, injury varies with season 

 because of such factors as rainfall and temperature. 



Boron (B) : B can be supplied to apple trees either by foliar or 

 soil applications . Use the most economical and convenient method. How - 

 ever , it is safest to apply all elements as a fertilizer except in 

 emergency situations . 



Soil applications of boron should be applied to orchards every 



3 years. The rate of application per tree vary with tree age and size. 

 In low density orchards, apply 1/4 pound of borax (11.11 actual B) or 

 its equivalent under young trees coming into beari ng, 1/2 to 3/4 pound 

 to medium age and size trees and 3/4 to 1 pound to. large or mature trees 

 Be sure to note the percent actual B in the fertilizer being used to . 

 supply this element . B- containing fertilizers vary from approximately 

 11 to 211 actual B. 



In medium and high density orchards (115 trees/acre or higher) , 

 it might be best to apply B on an acre basis. We suggest the following 

 rates per acre of borax (11.11 actual B) or its equivalent: (a) trees 



4 to 7 years of age - 12 lbs; (b) trees 8 to 15 years of age - 12 to 

 24 lbs; and (c) trees 16 to 30 years of age - 24 to 48 lbs. 



When the soil application of B is followed by a wet spring, it 

 may be advisable to apply 2 foliar applications of B.the following 

 year . 



