Postemergence Field Corn Herbicides (Prostko)

Not sure what happened, but the table below was accidently left out of the 2013 UGA Pest Control Handbook.  It should help you address questions about times of application in field corn.

 

Table 1.  Times of Application/PHI for Postemergence Herbicide Labeled for Use in Field.
 

Herbicide	Field Corn Stage of Growth		PHI (DAYS)	Grazing, Feed, Forage, Hay, Silage Interval (days)
	Earliest	Latest
Accent Q	1-2 leaf	20” or V6 20-36” or V10 - drops		30
Aim	spike	V8 V8-14 leaf collars - drops	14 leaf collars	14
Atrazine	PPI/PRE	12”		grazing = 21 forage = 60
Basagran	1-2 leaf	NL		12
Callisto	pre	30” tall or 8 leaf stage	45	45
Capreno	V1	V6 V6-V7- drops		45
Clarity	1-2 leaf	5th leaf or 8” tall 8-36” tall drops
Dual Magnum	PPI/PRE	40” tall		30
ET	Spike	V4 V4-V8 - drops	90	50
Halex GT	Spike	30” or V8	45	45
Impact/Armezon	spike	??	45	45
Laudis	1-2 leaf	V8		45
Liberty	spike	24” or V7 24-36” - drops	70	60
Prowl H20	spike	30” or V8		21
Realm Q	1-2 leaf	20” or V7	70	45
Resolve Q	1-2 leaf	20” or V7		30
Roundup	spike	30” or V8 30-48” - drops	50	50
Sandea/Permit	spike	layby		30
Status	V2	5th leaf or 8” 8-36” or V10 - drops	72	32
Steadfast Q	1-2 leaf	20” or V6		30
Warrant	spike	24” 24-30” - drops		40
Zidua	spike	V4

¹NL = none specifically listed on the label. 

 

Valor Application Method (Prostko)

Not sure what's going on in some counties so here is a friendly reminder that UGA does not recommend that Valor be applied preplant incorporated (PPI) in peanut for 2 very good reasons: 1) Valor is not labeled for this type of application and 2) PPI applications provide significantly less control of of Palmer amaranth than PRE applications (Figure 1).

Gramoxone/Reflex Tank-Mixtures (Prostko)

Over the last few years, growers have experienced a few problems when tank-mixing Gramoxone (paraquat) + Reflex (fomesafen).  In order to prevent these potential compatibility problems, consider the following recommendations developed by Syngenta:

1) When tank-mixing Gramoxone and Reflex, use a non-ionic surfactant (NIS) that contains a minimum of 80% active ingredient.

2) With spray volumes of 10 GPA or more, use NIS at 2 qt/100 gal (0.5% v/v).  Use 1 gal/100 gal (1% v/v) when spraying less than 10 GPA.

3) Mix chemicals in the following order:

a) Add half of the required amount of clean water to the spray tank.

b) Start the sprayer agitation system and continue agitation throughout mixing and spraying.

c) Add the required amount of non-ionic surfactant to the spray tank.

d) Add the required amount of Reflex to the spray tank.

e) Add the required amount of Gramoxone brands to the spray tank.

f) Add the remaining amount of clean water to the spray tank.