Experience In Massachusetts has shown that CaCl„ can be com- 

 bined with pesticide sprays. However there is limited evidence 

 that the combination of Captan or Guthion (azinphos methyl) 50 WP 

 and CaClj may increase foliar burn. DO NOT MIX CaCl^ AND SOLUBOR 

 SPRAYSl Always dissolve the CaCl„ in a pail of water and add this 

 last and when the spray tank is nearly full. 



Foliar CaCl„ sprays may be applied dilute (300/acre) or up to 

 lOX concentration (30 gallons /acre) . In our research, flesh calcium 

 was increased more by concentrated than by dilute sprays. In 1977, 

 foliar CaCl sprays at 6X and lOX concentration were equally effect- 

 ive for increasing Mcintosh flesh calcium. 



CaCl sprays can cause 

 more serious on Mcintosh than Delicious. Apple leaves are less 



burn of leaf margins. Foliar injury is 



pple ; 



susceptible to CaCl burn after mid-July. Mcintosh growing on M7 

 may be more susceptible to foliar burn than ones on standard root- 

 stock. Weak or injured trees may be more susceptible than healthy 

 trees. Do not repeat a foliar calcium chloride spray unless at 

 least 1 inch of rain has fallen since the last application. 



Foliar CaCl„ sprays should be continued until the apples are 

 harvested. Growers using alternate row pest control, should apply 

 CaCl„-water sprays in those rows that were missed. 



CaCl„ is not a substitute for a sound soil-liming program. 

 Lime orchards to pH 6.5 with a Ca-Mg/limes tone containing 5-7% MgO. 



*********** 



SUPPRESSING WEED GROWTH UNDER FRUIT TREES 



Will iam J . Lord 

 Department of Plant and Soil Sciences 



Growers have become concerned, particularly due to the root- 

 injury on apple and peach trees last winter, about the absence of 

 sod under their trees because of annual use of a contact herbicide 

 such as Paraquat CL* (paraquat) plus a soil sterilant (terbacil, 

 diuron, or simazine). Of more concern is the occurrence of soil 

 erosion and in some instances tree heaving. Therefore, growers 

 have expressed interest in re-establishing sod and then suppressing 

 grass and weed growth rather than eliminating this growth. 



Dacamine*, Dacamine 4D*, paraquat or Dowpon*M (dalapon) appear 

 to be the logical herbicides to use for re-establishment and main- 

 tenance of sod under apple trees. Where heaving of trees has occur- 

 red applications of mulch and re-establishment of the sod may help 

 prevent it. In peach orchards, many of which are relatively small, 

 it might be feasible to substitute mulch for herbicides or use para- 

 quat or dalapon alone. 



Trade name 



