By Clint Thompson
Specialty crop producers need to be wary this spring of supply issues with regards to Oryzalin, a popular herbicide. None is being manufactured, according to Wayne Mitchem, N.C. State Extension associate and Southern Region Small Fruit Consortium coordinator. He discusses the impact that a lack of the product will mean for some fruit farmers.
“The thing about Oryzalin is, it’s very key on certain crops. It’s something that we use in grapes quite a bit and definitely in newly planted blackberries and newly planted blueberries. Those are the two crops where it’s going to impact the most,” Mitchem said. “We also use it in tree fruits, and it’s a good tank mix partner with other things. It’s a product that we’re definitely going to miss. It’s going to be missed more in some crops than others.”
Growers can consider Prowl H20 as an alternative. It is in the same herbicide family as Oryzalin. But it needs rainfall within 10 days to remain 100% effective.
“Prowl H2O is an alternative for grapes and tree fruits, but it’s not an alternative for blackberries or blueberries,” Mitchem said. “If you get rainfall within seven to 10 days at equal rates, you probably can’t tell (the two herbicides) apart. If you have to wait on rainfall for three weeks, generally the Orazylin or Surflan will wait on rainfall longer without having any reduction in herbicide (effectiveness).
“Depending on what pre-emergent herbicide it is, the amount of time it will lay there on the surface to wait on rainfall without becoming less effective varies from active ingredient to active ingredient. Pendimethalin, which is in Prowl, just won’t wait on rainfall quite as long as Oryzalin will without losing some efficacy.”
