Management of perennial grasses in wild blueberry (Vaccinium augustifolium Ait.) fields

Abstract

Weeds are a major yield limiting factor, and perennial grass has become an increasingly serious weed problem in wild blueberry fields. Herbicides are still the primary means of weed control in wild blueberry fields. However, the availability of herbicides for perennial grasses in wild blueberry fields is limited, and some native perennial grasses have developed resistance to several herbicides. Multiple experiments were conducted to introduce new herbicides (foramsulfuron, glufosinate, and flazasulfuron) and develop new herbicide use patterns to limit spread and negative effects of perennial grasses in wild blueberry fields. Our results indicated that foramsulfuron can be an alternative to fluazifop-p-butyl or sethoxydim in controlling tickle grass and bluegrass, and the foramsulfuron efficacy was not affected when tank mixed with mesotrione. Non-bearing year fescue suppression with spring foramsulfuron was generally higher when applications were preceded by fall applications of dichlobenil or glufosinate verses just the fall herbicide applications alone. The glufosinate and terbacil tank mixture, followed by foramsulfuron, provided efficacy similar to propyzamide, and so could be an alternative treatment to propyzamide to suppress hair fescue in the non-bearing year. Among all experiments, dramatic recovery of fescue occurred in the bearing year in all treatments lacking a fall non-bearing year propyzamide or flazasulfuron application. Additional research should be conducted to determine alternative treatments for fall non-bearing year fescue grass management in wild blueberry.