The battle against pigweed is not just one of herbicides and hoes, says Dr. Tom Barber — it also should include practices to deal with the hundreds of thousands of seeds that can be produced by a single Palmer amaranth plant.
“To put it simply, no pigweed should be allowed to go to seed anywhere on the farm or in proximity to the farm,” says the University of Arkansas Extension professor of weed science.
This, he says in a 26 minute webcast, will require that producers “start thinking outside the box,” and that they convince their neighbors to do likewise. Many farmers, he says, have an operational philosophy of “farming one year at a time — but they really need to be thinking four to five years down the road, particularly with a weed as competitive as Palmer amaranth.”
This will require “doing whatever we can do to reduce the number of seeds in the soil, and diversifying weed management practices by using cultural and tillage practices that help reduce the populations that will come up the following year.”
However tough and resilient pigweed may be, Barber says, “It has one specific weakness — seed longevity. So if we can significantly reduce the number of seed produced each year for a three- to four-year period, the populations of Palmer amaranth in the field can be reduced to a more manageable level.”
Management practices include removing pigweed plants manually by hand weeding, physically through tillage and weed seed destruction at harvest, culturally through use of cover crops, and chemically by focusing on use of multiple effective modes of action to allow no plants to go to seed — thus the ZERO TOLERANCE threshold.
“These practices don’t only apply to the cultivated field,” Barber says, “but focus should also be placed on turnrows, ditches, rights-of-way, equipment, and equipment yards.”
He cautions: “This program will not work if only one farmer does it correctly. It will only be successful if the farming community in a specific area makes the decision for everyone to focus on removing pigweeds before mature seeds are produced.”
It’s a thorough, informative webcast, narrated by Dr. Barber, and it will be 26 minutes well-spent to watch it.