Strongarm/Peanut Questions (Prostko)

Had a few questions about Strongarm (diclosulam) use in peanuts yesterday that I thought might be interesting to all:

1) In general, what application method is more effective for weed control in peanut (PPI or PRE)?

When averaged over 7 weed species, there was little difference in weed control between PPI and PRE applications of Strongarm (Table 1).  However, in dryland production fields with minimal future rain predictions, PPI applications would be preferred.

 Table 1. Application Method Effects on Residual Weed Control with Strongarm 84WG @ 0.45 oz/A in Peanut.¹

Weed	Control (%)
	Application Method
	PPI2	PRE3
sicklepod	54	44
Florida beggarweed	78	87
bristly starbur	94	97
purple nutsedge	59	73
yellow nutsedge	78	78
morningglory sp. (Ipomoea sp.)	89	99
smallflower morningglory	94	96
All (average)	78	82

¹Source: Grey et al.  2003.  Peanut Science 30:27-34.

²PPI = preplant incorporated.

³PRE = preemergence.

Also very important to remember that Strongarm provides a much broader spectrum of weed control when applied PPI or PRE when compared to POST applications.  However, the following 7 weeds are sensitive to Strongarm when applied POST: tropical spiderwort/Benghal dayflower; common cocklebur; common ragweed; bristly starbur; horseweed/marestail; morningglory sp.; and eclipta.

2) What application method is more effective for the control of tropical spiderwort/Benghal dayflower?

Data collected a few years ago in Grady Co. indicated that POST applications were more effective than PRE applications for the control of tropical spiderwort/Benghal dayflower (Table 2).

Table 2.  Application Method Effects of Strongarm 84WG @ 0.45 oz/A on Benghal Dayflower/Tropical Spiderwort Control in Peanut.¹

Application Method	Control (%)2
	46 DAP3	69 DAP	114 DAP
PRE4	75 cd	68 b	11 e
EPOST5	97 a	90 a	75 abc
LPOST6	88 ab	78 ab	60 c

¹Source: E.P. Prostko and J.T. Flanders, 2003, PE-24-03, Unpublished data.

²Means in the same column with the same letter are not significantly different according to DMRT (P=0.05).

³DAP = days after planting.

⁴PRE = preemergence.

⁵EPOST = early-postemergence, 17 days after planting (2’’ tall, 3 leaf stage).

⁶LPOST = late-postemergence, 31 days after planting (6” tall).

Volunteer Peanut Control in Field Corn (Prostko)

Been getting a few calls about controlling volunteer peanuts in field corn.  Remember that the volunteer peanuts that emerge from seeds that made it thru the winter and rains are some super tough plants.  A couple of thoughts:

Roundup Ready Corn:  Split applications of glyphosate at least 10 days apart.  Glyphosate can be applied over-the-top of field corn up to V8 stage or 30" whichever comes first.  Drop nozzles or lay-by applicator should be used when corn is 30" to 48" tall.

Liberty-Link Corn: Split applications of Liberty (glufosinate) at least 7 days apart.  Liberty can be applied over-the-top up to V6 stage of growth.  For corn 24" to 36" tall, apply with drop nozzles or lay-by rig.

Conventional Corn:  Split applications of dicamba @ 0.25 lb ae/A applied EPOST (8" tall corn) + lay-by (up to 36" tall corn).  These dicamba applications must be separated by at least 14 days.   An alternative treatment would be dicamba (EPOST) followed by Evik (lay-by).

**Atrazine can also be included in any of these EPOST applications as long as corn is < 12" tall.

UPW Meetings – Only 2 left! (Culpepper)

Agents, there are only two more Using Pesticides Wisely meetings left for 2019. Please communicate with your growers/applicators to make sure they have been trained or that they will be attending one of the two final meetings. No additional meetings will be added……….no need to even call and ask! 

2019 Using Pesticides Wisely (UPW) Trainings
Date, Time	County	RSVP # (Max Attendance)	Location and Address
Apr 16, 8:30 am	Pierce	912-449-2034 (125 max)	Pierce County Ext. Office, 705 College Ave., Blackshear, GA 31516
Apr 18, 1 pm	Tift	229-386-3328 (350 max)	Tifton Campus Conf. Center, 15 RDC Road, Tifton, GA 31793

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