Pre-Emergent Chemical Usage
Resistance to post-emergent herbicides has resulted in an increased reliance on pre-emergent herbicides, particularly products like Trifluralin and Boxer Gold. Achieving the best results from these products requires an understanding of how the products work, label guidelines and use restrictions. Following are guidelines for the use of Trifluralin, Boxer Gold and Avadex Xtra:
Trifluralin
Volatilises (becomes a gas) if left exposed on the soil surface
Binds well to soil particles once incorporated
Binds tightly to stubble and trash
Absorbed primarily through plant roots
Best results are achieved:
Through application to bare soil
By incorporation within 4 hours
Using high water rates and large droplets when stubble is present
When applied separately to Glyphosate
Crop damage is minimised through:
Sowing good quality seed
Ensuring seed is sown below the layer of soil treated with chemical
Minimising soil throw into adjacent rows, when using a knife point presswheel seeding system
Boxer Gold
Can be applied up to 7 days prior to incorporation
Does not bind well to soil, so can wash into furrows easily resulting in crop damage
Doesn’t bind to stubble as tightly as Trifluralin
Taken up through the roots and coleoptile of the germinating plant
Foliar uptake is possible, but weed control is compromised
Best results are achieved:
Through application to bare soil
When sufficient rainfall occurs within 10 days of application to wet the top 3-4 cm of soil
When thorough incorporation is achieved
Crop damage is minimised through:
Sowing good quality seed
Ensuring seed is sown well below the layer of soil treated with chemical
Minimising soil throw into adjacent rows, when using knife points and presswheels
Not sowing into water logged soils
Not sowing if heavy rain is forecast within 2 days of application
Avadex Xtra
Should be incorporated within 6 hours when applied to moist soil, or 24 hours if applied to dry soil
Taken up through the coleoptile of the germinating plant
Requires thorough incorporation
Requires moisture to be activated
Best results are achieved:
Through application to bare soil
When thoroughly incorporated in the top 3-4 cm soil
When rainfall occurs post sowing to activate the chemical
Crop damage is minimised through:
Sowing good quality seed
Ensuring seed is sown below the layer of soil treated with chemical
Minimising soil throw into adjacent rows, when using a knife point presswheel seeding system