Tillage-Live 2011: Weed control in trash conditions
Choosing pendimethalin formulation carefully could help growers achieve better weed control in minimum tillage situations, new research suggests.
Trials at the Silsoe Spray Applications Unit by NIAB TAG’s spray application specialist, Paul Miller, show that up to 50% of the applied spray can be locked up by straw trash in extreme conditions with an EC formulation of pendimethalin.
In contrast, about 20-30% extra pendimethalin was available when the newer micro-encapsulated formulations were tested in the same conditions, where the spray was applied in 200 litres/ha water volume to trays containing soil and wet straw.
Similar differences in performance were seen in better conditions when the herbicide was applied in 100 litres/ha to trays with dry straw.
“The trial was pure chemistry, but it should mean that growers can get 30% more active in the soil, where it needs to be, by selecting the right formulation,” said Prof Miller.
Separate experiments also showed it was much easier to clean containers filled with micro-encapsulated pendimethalin formulations, such as Stomp Aqua from BASF and Cinder from Makhteshim-Agan, than the older formulations.
Potentially, there could be a 50% reduction in loading time by using one of those formulations, with Stomp Aqua taking only a minute to open, pour and rinse into a spray, compared with 90 seconds for Cinder and the EC formulation and over two minutes for Stomp 400SC.
Rinsing was a significant part of that time, he pointed out, which lengthened if growers also had to wash jugs. “My advice would be not to get too hung up about water volume and try to avoid splitting packs, if at all possible.”
