Virtually complete elimination of weeds (grass as well as broad- 

 leaf weeds) may be desirable from the standpoint of mouse control, but 

 it is questionable whether this degree of weed control would result in 

 more terminal growth than when considerably less weed control was ob- 

 tained. 



Value of Chemical Weed Control 



In the writer's opinion, there is no substitute for a hay mulch 

 program in newly established apple orchards. Mulch will eliminate most 

 weed competition and enhance the potassium and nitrogen levels in the 

 trees. As the apple trees become older, however, few growers attempt 

 to continue a mulching program other than mowing and letting the grass 

 lie. A chemical weed control program would be of value in these situations 

 to supplement the mouse control program. The treated areas under the 

 trees serve as a barrier between the mouse and its potential food source 



the tree and should provide some protection from mice during late 



fall and winter. With the advent of snow, however, this protection is 

 lost. The snow will provide the necessary cover to allow mice to reach 

 the tree, feed on it, and thus produce damage. 



Recent Label Clearances 



Recent label clearances now make it possible for growers to con- 

 trol a broader spectrum of weeds and to apply an herbicide whenever it 

 is convenient. Because of timing restrictions on herbicide usage and 

 tolerance to most herbicides; bindweed, poison ivy, dandelions and sor- 

 rel became problem weeds where chemical weed control was practiced. 

 The labeling of Ammate X, Dacamine W and dichlobenil (Casoron) has 

 helped solve these problems. Ammate X is available for the control of 

 poison ivy in apple and pear orchards. Dacamine i+D, which has no restri- 

 tions on preharvest interval or frequency of use in apple and pear orch- 

 ards, controls broadleaf weeds such as poison ivy, dandelions, sorrel, 

 field bindweed and hedge bindweed. (These bindweeds are commonly called 

 morning glory by growers.) 



Growers wishing to rely on a fall weed program may use granular 

 dichlobenil in appl^ pear and peach orchards. This material will control 

 a broad spectrum of perennial and annual weeds when applied during the 

 late fall-early winter months. In our tests, dichlobenil has given out- 

 standing control of sorrel, broadleaf plantain, buckhorn plantain and 

 dandelions, which are tolerant to some herbicides. However , this mater - 

 ial should be used on a trial basis only, since further testing of rates 

 of application and tree response to this herbicide is needed . 



Summary 



If used properly, herbicides are a useful tool in orchards. The 

 main benefits derived from their use are the elimination of hand mowing 

 and the aiding of the mouse-control program. Because of label clearances, 

 it is now possible to control a broader spectrum of weeds, prevent the 

 influx of weeds tolerant to some herbicides, and to apply an herbicide 

 whenever it is convenient. 



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