BLIZZARD™ plant growth regulator product (fluthiacet-methyl) is a new harvest aid being developed by Chemtura Corporation and Kumiai America for use in cotton. BLIZZARD™ inhibits the enzyme protoporphyrinogen-oxidase (PPO), inducing the accumulation of protoporphyrins, which leads to irreversible cell membrane damage, and loss of cell function. This mode of action can be used to facilitate cotton defoliation and suppress juvenile foliage growth post treatment to ensure efficient crop harvest and improved lint quality. Typically, no single cotton harvest aid product will satisfactorily remove mature and juvenile foliage, enhance boll opening and suppress juvenile regrowth in cotton for an extended period during the harvest season. Therefore, producers use combinations of different plant growth regulating products and, if necessary, sequential applications to achieve the desired level of defoliation performance.

Field studies were initiated in 2004 and 2005 to evaluate BLIZZARD applied alone in sequential applications, single applications of BLIZZARD tank mixed with COTTONQUIK®, FINISH®, PREP® and other ethephon containing plant growth regulating products, sequential applications of BLIZZARD following BLIZZARD plus an ethephon product, BLIZZARD following DROPP®, sequential applications of BLIZZARD following BLIZZARD tank mixed with DROPP® and BLIZZARD tank mixed with GRAMOXONE®. BLIZZARD use rates of 0.4, 0.5 and 0.6 oz/A were applied depending on location. Crop oil concentrate was added to BLIZZARD treatments to enhance activity. Cotton defoliation, leaf desiccation and juvenile regrowth inhibition was measured post treatment at several locations throughout the Mid-South, Southeast and Texas cotton producing regions. Best defoliation occurred with BLIZZARD following DROPP, BLIZZARD following DROPP plus BLIZZARD and BLIZZARD plus an ethephon product followed by BLIZZARD. Effective regrowth suppression occurred with sequential BLIZZARD applications with or without an ethephon product, BLIZZARD following DROPP and BLIZZARD following BLIZZARD plus DROPP. In west Texas studies, BLIZZARD combinations with ethephon products such as COTTONQUIK, PREP and SUPER BOLL® as single applications and followed by BLIZZARD gave excellent defoliation with minimal desiccation.

Registration of BLIZZARDTM plant growth regulator product for use as a defoliant in cotton is pending at EPA. BLIZZARDTM plant growth regulator product will be formulated as a 0.91 lb/gal emulsifiable concentrate.