3. Single-Nozzle Hand Sprayers 



Example: 3-gallon hand sprayer with single nozzle. Mark off an area 5 by 

 20 feet (100 square feet). Fill sprayer with water to 3-gallon level and spray 

 1 00-square-foot area using same speed and pressure that -will be used for 

 spraying weeds. Refill sprayer, measuring accurately the amount of water to 

 refill to original level. The following tabulations gives the ratio of weedkiller 

 to water required to apply 1 pint of weedkiller per acre, based on discharge 

 of the nozzle: 



Nozzle discharge Equivalent Ratio of weedkiller 



per discharge to water to apply 1 pt. 



100 sq. ft. per acre weedkiller per acre 



1/2 pint 27 gal. 1 pt. in 27 gal. water 



1 pint 55 gal. 1 pt. in 55 gal. water"'" 



1-1/2 pints 82 gal. 1 pt. in 82 gal. water 



1 quart 110 gal. 1 pt. in 110 gal. water 



NOTE:- -The volume of water is given to the nearest gallon. 



-"- A mixture of 1 ounce (or 2 standard kitchen measuring tablespoons) of 

 weedkiller in 3 gallons of water is approximately equivalent to an application 

 of 1 pint of ■weedkiller per acre at a nozzle discharge rate of 1 pint per 100 

 square feet. One pint = I6 fluid ounces = 2 cups - 32 tablespoons. 



EFFECT OF WEATHER CONDITIONS ON SPRAYING 



Weather conditions have important effects on results obtained and hazards 

 involved in spraying with herbicides. 



1. Wind 



Winds cause improper distribution of herbicides and greatly increase the 

 hazard of damage from drift to sensitive crops in nearby fields or gardens. 

 Ground applications of herbicides seldom should be made during winds of 

 more than 10 to 15 miles per hour. Applications by airplane should stop when 

 winds become stronger than 6 to 8 miles per hour. 



The herbicide 2, 4-D and other phenoxy herbicides never should be applied 

 when wind of any velocity is blowing across the area to be sprayed toward 

 nearby valuable sensitive plants. 



2. Humidity 



High or moderate humidity increases the effectiveness of most herbicide 

 applications to foliage because it reduces losses of spray from evaporation 

 and aids absorption of the chemicals by weed foliage. Low humidity, on the 

 other hand, reduces the effectiveness of herbicide sprays by increasing the 

 rate of evaporation. The disadvantages of low humidity can be overcome 

 partially by using oil, or oil- water emulsions instead of w^ater as spray 

 diluents. 



3. Temperature 



Moderate temperatures ranging from 70° to 85° F. are favorable for spray 

 applications of most herbicides. Low teniperatures during the week before 



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