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Abstract
Managing weeds and stewarding pesticides is crucial for agriculture. Research addressing these challenges is essential, thus, 13 experiments and 32 studies were conducted in broccoli, collard, cantaloupe, hemp, cotton, and wheat to assist in farmer sustainability.Glyphosate applied preplant in vegetables facilitates weed-free planting but can cause damage through residual activity. An experiment determined that irrigation of 0.6 cm after application and before transplanting broccoli or collard reduced injury 28 to 48%. Tilling the soil to a depth of 5 cm essentially eliminated glyphosate injury.
Cantaloupe, having a Georgia farm gate value of $13 million, lacks weed management options. In search for new tools, S-metolachlor, pendimethalin, acetochlor, and pyroxasulfone were broadcast before transplanting in mulched or non-mulched systems and were applied overtop just after transplanting. Results indicated unacceptable injury for each herbicide and application approach but identified additional research ideas for these herbicides as row-middle applications and increasing the interval between applications and transplanting.
Floral hemp has few weed management options currently, other than tillage. Research
determined that hemp was tolerant to acetochlor, dithiopyr, flumioxazin, fomesafen, norflurazon,
and pendimethalin applied prior to transplanting and acetochlor, clethodim, pendimethalin, and
S-metolachlor applied after transplanting. Mechanical transplanting reduced preplant herbicide
injury up to 56% when compared to the standard approach of hand transplanting. And while
mulch offers additional weed control, yield was similar in mulched and non-mulched systems.
Detecting pesticide residues when products move off-target is a priority for regulators.
Field studies using dicamba, 2,4-D, and imazapyr defined how sampling method, herbicide rate,
and interval between application and sampling influenced residue detection. The order of
importance in detecting residues was 1) shortened interval between application and sample
collection and 2) higher drift rates. Sampling technique was less influential.
Georgia wheat growers rely on 2,4-D to manage wild radish but crop safety is a concern.
A new herbicide, halauxifen-methyl plus florasulam, was compared to 2,4-D for crop tolerance
and management of radish when applied to wheat preplant, preemergence, 2-leaf, and at 2-tiller.
Halauxifen-methyl plus florasulam controlled wild radish as effectively as 2,4-D while offering a
much wider window of application without crop injury concerns.