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Show IS AC LABORATORY APPROVES EARLY j SPRING ALFALFA WEEVIL CONTROL Early spring treatment of alfalfa for weevil control developed by enfomoligists of the U S Legume Seed Laboratory at Logan, has proved to be a most effective method and is being recommended to growers. This is the information from Frank V. Lieberman, entomologist entomolo-gist of the laboratory, who is the authority on alfalfa weevil. He is stationed at Utah State Agricultural col- , dieldrin have been tested sufficiently suffi-ciently to be recommended. lege. ' Whether the field is used for hay or seed, or hay followed by seed, early spring spraying is an outstanding method of weevil control. Crop protection is excellent ex-cellent with this method, said Mr. Lieberman. It's the kind of protection from alfalfa weevil weev-il that seed growers need. Hay growers are freed of concern over poisonous residues or rigid cutting schedules. Early spring treatment will prevent retardation retarda-tion of the second crop as well as damage to the first growth. ! The treatment Mr. Lieberman ! recommended is spraying of the field with chlardane or dieldrin. Its purpose is to kill most of the adults that have overwintered overwint-ered in the field and to do it before the females have oppor-tuntiy oppor-tuntiy to lay many eggs. The spray should be applied when the shoots of the first growth are one to two inches long. Usually Usu-ally this means between March 15 and April 15, depending on the season and the locality, according ac-cording to Mr. Lieberman. The spray should contain IV2 to 2 pounds of technical chlordane or Vi pound of technical dieldrin per acre. When 'applied by ground sprayers at least six to eight gallons of water should be used. There are indications, however, continued Mr. Lieberman, Lieber-man, that use of more water, that is 15 to 20 gallons, will give better results. Dusting has not given satisfactory results and is not recommended. Many growers who have already al-ready tried this latest method of weevil control delayed it past the recommended time. Such delay will usually result in failure fail-ure to prevent crop damage despite de-spite the fact that a check of a treated field will show most of the adult weevils were killed, warned the entomologist. In this case, the weevil were killed too late. This mistake will generally gen-erally be avoided if the egglay-ing egglay-ing habits of the alfalfa weevil are understood. As a general rule, a few of the female which have survived the winter begin to lay eggs soon after the snow cover melts in the spring, Mr. Lieberman explained. ex-plained. At this time there is no growth on the field. For the next few weeks more and more females become sexually mature ma-ture and begin to lay eggs. At first these are laid only in fragments of dead stems on the ground. After the spring growth is six inches tall, the beetles gradually shift their egg laying to the- growing stems. Neverthe-Tess, Neverthe-Tess, most of the eggs are laid in dead stems, and the number laid increases rapidly after the alfalfa al-falfa shoots are two inches long. Therefore, when early spring spraying is delayed for even a short time, the beetles usually succeed in laying eggs to assure later crop damage by the larvae. Few insecticides will kill enough adults at this time of year to make the method work. Of these, only chlordane and |