- 6 



the applicator and should be considered. The vapor pressure of both 

 materials is low and the vapors are not believed to be of a signif- 

 icant practical hazard. 



These materials may also offer a hazard to the eyes. A farmer 

 in England splashed some di quat-paraquat-surf actant into his eye. 

 He washed the eye. A mild irritation occurred for the next 3 days. 

 A week later he was hospitalized and suffered severe damage to the 

 eye. Thus, care should be taken to avoid splashing of the eyes-- 

 goggles, safety glasses, or a face shield should be worn. 



The present labels for these materials bear a "WARNING" state- 

 ment "DO NOT INHALE", "DO NOT GET ON SKIN", "DO NOT TAKE INTERNALLY. 

 Observation of the use of the material does not indicate that the 

 hazards are realized or the warning followed. 



When using a pesticide--any pesticide--handle it as a highly 

 toxic ma teri al --avoi d becoming a statistic. 



*************** 



RANDOM THOUGHTS ON CHEMICAL WEED CONTROL IN ORCHARDS 



Wi 1 1 iam J . Lord 

 Department of Plant and Soil Sciences 



It is now possible to chemically control a broad spectrum of 

 weeds, prevent the influx of weeds tolerant to some herbicides and 

 to apply an herbicide whenever it is convenient. However, phyto- 

 toxicity to young fruit trees because of excessive dosages of herbi- 

 cides continues to be a problem in some orchards. The injury is 

 generally the result of over-dosage when hand-held spray guns and 

 mechanical spreaders are used. Occasicnally, herbicide drift or 

 direct spray contact on tree foliage and fruit is a problem encoun- 

 tered with tractor-mounted spray booms. To minimize this difficulty, 

 use a coarse spray and avoid applications during windy conditions. 

 The boom should be mounted in front of the driver, so that he can 

 make boom adjustments more easily. 



Paraquat 



Paraquat is worthy of consideration by growers having past 

 difficulties with herbicide injury. This herbicide becomes inac- 

 tive on contact with soil and therefore presents no problem of res- 

 idue. However, at least one repeat application during the summer 

 will be necessary for season-long weed control. Since soil mois- 

 ture is generally more limiting in the late summer than during May 

 and June, the best timing for the repeat application of paraquat, 

 in order to enhance trunk growth and fruit size, and to control 

 annual weeds, is mid-July and later. 



