

-»■*'; 





- —OS* >.-- 



Fig. 23. The best control of vegetative growth can be ob- 

 tained by combining mininnal pruning and limb 

 positioning. 



Tree Nutrition 



Fertilizer, either nitrogen (N) alone, a complete fertilizer, 

 or a fertilizer containing N and potassium (K2O) and minor 

 elements, should be applied 3 to 4 weeks prior to bloom 

 and at a rate of 1 /4 pound of ammonium nitrate or its equiv- 

 alent for each year of age. 



Reduce or omit N on young, vigorous Mcintosh trees 

 when they start to bear fruit, if the trees appear very vigor- 

 ous, to avoid excessively large, poorly colored apples. With 

 this cultivar and all other cultivars, start participating in 

 the Leaf Analysis Program when the trees start to fruit in 

 order to determine the fertilizer requirements of the trees. 

 (Information concerning the Leaf Analysis Program and 

 specific details on orchard fertilization can be obtained from 

 your County Extension Service.) 



Boron deficiency is more apt to be a problem with young 

 than older bearing trees. Therefore, boron should be applied 

 as a ground application or a foliar spray once the trees com- 

 mence to fruit if this element is not already present in suffi- 

 cient amounts in the fertilizer being applied annually. Exces- 

 sive N levels are particularly disastrous with bearing Mcintosh 

 trees and low Ca levels are a problem in all Massachusetts 



apple orchards. 



Once every 3 years, take soil samples and send them to 

 the West Experiment Station, University of Massachusetts, 

 Amherst, for determination of soil pH and lime requirements. 

 Directions fortakingsoil samples can be obtained from your 

 County Extension Service. 



Weed Control 



Chemicals (herbicides) are frequently used to control grasses 

 and broadleaf weeds under apple trees. Herbicides should 

 be used in such a manner that they provide early-season con- 

 trol of weeds, but not necessarily control for the entire 

 season. Regrowth of weeds in August and September can be 

 advantageous for the following reasons; 



(1) The weed regrowth will help slow down growth of 

 vigorously growing trees and thereby lessen the 

 chance of winter injury. 



(2) The weeds will provide some protection to the tree 

 roots against low temperature injury. 



(3) They will reduce soil erosion. 



The current recommendations for their use under apple 

 trees can be obtained from your County Extension Service. 

 In addition to chemical weed control, sand or gravel can be 

 applied around the base of trees to reduce weed growth and/ 

 or an area in the vicinity of the trunk can be cleared of weeds 

 in the late fall. 



Calibration of sprayer with tractor-mounted boom. The 

 sprayer can be calibrated by making a trial run over some 

 known area. (One acre contains 43,560 square feet. When 

 spraying a 4-foot swath, you must travel 10,890 feet to 

 treat an area equivalent to an acre.) The easy way to calibrate 

 the sprayer is to fill the tank completely or to some other 

 known level, spray 1/10 of an acre (1090 feet x 4 feet) and 

 then accurately measure how much water is required to refill 

 the tank to the previous level. Multiply the gallons used by 

 10 to get the gallonage per acre. If for example, the sprayer 

 delivered 60 gallons per acre and the herbicide is used at a 

 4-pound per acre rate, 4 pounds of the herbicide should be 

 added for every 60 gallons of water in the spray tank. 



Calibration of granular herbicide applicator Granular appli- 

 cators must be calibrated with the herbicide actually being 

 applied. The best way to calibrate is to operate the applicator 

 over a known area such as 1/100 of an acre (436 sq. ft.). 

 You must catch dichlobenil* while operating over the known 

 area and weigh it. The usual way is to disconnect the spinner 

 and to collect the output from the applicator in a bag or 

 bucket. Weigh the dichlobenil very carefully because the 

 amount collected is quite small. 



When using a hand-operated granular applicator, fill with 

 a known weight of dichlobenil*, operate the applicator over 

 a known area, and then weight the herbicide remaining in 



*The only granular herbicide in common use. 



30 



