In today’s Almond Matters, brought to you by Valent, fleabane and marestail are likely to be germinating in orchards after the recent rains. Growers that were able to get a preemergent down prior to the wet weather will be faring better in preventing the weeds from becoming problematic. Field Market Development Specialist with Valent USA, Todd Burkdoll said the weeds can be more difficult to manage once they have had a chance to take root.
“If fleabane or marestail has already come past the cotyledon stage and it’s in the first two to three true leaves, what we call the beginning of rosette, it’s really hard to control at that point. You have to put a burndown with it,” Burkdoll noted. “They’ll sit there in the cold weather and not look like they’re doing anything but actually that root is going down. So once that root is established, it’s hard to kill them.”
There are several burndown materials that can be effective in managing fleabane and marestail. Burkdoll suggests applying an oil-based adjuvant to enhance efficacy in helping the material reach the plant. The waxy cuticle on the leaf makes the weeds hydrophobic, which complicates material absorption. Burkdoll notes that a program that includes Chateau to address preemergent activity, mixed with something like glufosinate can be the most effective in addressing weed issues in orchards.
“That’s probably the best way to tackle it, is staying on it early as far as preemergence. Then stay on it afterwards because if you get any escapes coming through you need to have a secondary program, an escape management program, to come in and pick up whatever did germinate,” said Burkdoll. “If you wait until it gets to the rosette stage, it’s too late. You’re going to have to go in with something like Treevix or glufosinate – a tank mix – to burn it back, to take it out, because Chateau is not going to have any preemergent activity at that point.”
Listen to the report below.