EFFECT OF NICOSULFURON MIXTURES AND TIME OF APPLICATION ON PEANUT (ARACHIS-HYPOGAEA) CULTIVARS

Field experiments were conducted near Marianna, Trenton, and Archer, F L in 1990 and 1991 to investigate the effect of nicosulfuron mixtures and time of application on five peanut cultivars. Nicosulfuron at 54 g ai/ha was applied alone or in mixture with 2,4-DB at 280 g ai/ha 5 we eks after planting (WAP), 9 WAP, or 5 plus 9 WAP. Injury was greater f rom early and sequential nicosulfuron applications while a single appl ication 9 WAP typically did not cause significant injury or reduce pea nut yield. The 5 WAP and 5 plus 9 WAP applications often caused early visible injury and sometimes reduced peanut yield. When peanut yields were compared, 'Florigiant' was the most sensitive cultivar while 'Sou thern Runner' and 'Valencia' were more tolerant to nicosulfuron. 'Sunr unner' and 'NC-7' were intermediate in tolerance to nicosulfuron. In s everal instances, the addition of 2,4-DB to nicosulfuron reduced initi al crop injury and ameliorated yield losses resulting from nicosulfuro n applied alone.