Show THE COUNTY AGENTS COLUMN by MORGAN P mckay effect of blind und of alfalfa on al beia I 1 conge ae if one wanted to produce large numbers of alfalfa he would choose a 6 thin stand of alfalfa as the ideal breeding ground the weevil multiply much taster faster in a field where the alfalfa plants are aoi iri 10 distance dis apart with bare spots in beb between een than it does where the al falfa is so thick that it completely covers and shades the ground all female weevil seem to be en dove coed ed by nature to lay a large num her ber of eggs heat Is the factor that determines when they lay and how many eggs warm weather promotes egg laying while cold re tards it assume that the temperature ot the aar over an alfalfa field is 75 dagi ea Faren hiet the tempera turf tur on moist gio nd which is shad ed by a heavy stand of alfalfa will be 65 degree F the temperature on the ground anekt next to a large arge bare spot in a thin t alfa will be sa degrees bault Biu alt lt female weevil lives 0 aid and lays her eggs 14 biary r rys stems on the ground and at the base of grow row falfa bems in the fi id of h e re the temperature is 65 degiers F the weevil will be slow in starting to lo lay jay eggs she will perhaps lay a total of eggs only during the season the time required for eggs to hatch Is dependent upon heat the eggs in this feild will take five weeks to hatch into the worms that do damage in the field where there is a light stand of alfalfa with a temperature of 87 degrees down where the adult weevil lives egg la in will all be hastened each fe male weevil will lay about eggs twice as many as she would in the heavy hay where it is colder the eggs will hatch in tow and one halt half to three weeks not much more than half the time required in the other field A little arithmetic applied to the I 1 above figures will show that the weevil damage in a thin stand of al falta falfa where there are only half as many plaats as in a heavy stand stana is not just twice as much but is act bally more than foul fout times as mu h the damage occurs earlier in the thin stand of alfalfa because the hatch earlier the plants are less able to withstand injury than they hey would be later for protection from weevil irjary as well asfor as for higher yields per acre plo plow up the old thin alfalfa fie ds and replace them with young heavy stands |