INSECT, PLANT DISEASE, & WEED SCIENCE NEWS [No. 87-7] [May 1, 1987]

In This Issue: HERBICIDE APPLICATION Weed control with herbicides depends on the uniform application of dependable herbicides. A sprayer is needed which will allow for both uniform application and correct droplet size at desired spray volumes. The sprayer should be of sufficient capacity to handle the acreage involved. AGITATION Agitation of most spray solutions is necessary. Any separation will vary the spray concentration. For a simple orifice jet agitator, a flow of 6 gallons per minute for every 100 gallons of tank capacity is usually adequate. SPRAY BOOMS The use of gauge wheels helps maintain the proper distance between the spray nozzle and the target especially on uneven ground, going across terraces, etc. A spray boom where the height and angle of the spray nozzles can be changed is also desirable. The supply lines to and on the spray boom must be of adequate size for even distribution. It is best to have the supply line coming to the center of the spray boom section and distribute from that point rather than coming in on the end of the spray boom and running the chance of less pressure at the far end. Many sprayers, now, are being designed with wet booms and are fitted with assemblies that protrude 1/3 to 1/2 way into the boom which take the spray solution out of the middle of the boom. PVC Schedule 80 makes an excellent wet boom if supported adequately. The wet boom, which takes the spray solution from the middle, will help keep materials like sand and rust in the bottom of the spray boom which can be flushed out of the end of the spray boom when it is cleaned. This requires valves or plugs on the end of the spray boom. Shutoff controls are needed that allow use of 1/3 to 1/2 of the spray boom when necessary