Too Far Gone? Insect Damage and Poor Stand

Agronomy question asked by Travis in Ballard County 6 months ago.

0

After a dry fall seeding, this field had poor germination and establishment riddled with weeds.  It was sprayed with a tank mix of RoundUp, Fungicide, and MustangMax Insecticide, followed by min-till replanting the poor areas at 25 lbs coated seed/ac.

After looking today at about 10 days after planting, the replanted areas have near zero emergence, and the insect (weevil?) damage to the other areas is severe (see pictures).

Is this field just too far gone? Should I continue to try and nurse it can to health and hope that I see more germination and emergence from the replanted areas, and perhaps give another insecticide shot, or just cultivate it all and start fresh?

Agronomy in Ballard County
posted 6 months ago
Travis
Travis H.
Ballard County
Farmer/Producer

2 Answers Posted

1

Surprising there is not more young growth without weevil damage after the spraying, but that could be held back with the few cold nights we have had. The surest bet would be tillage and starting over, but with the amount of weevil damage on a new seeding I'm wondering if there may not be some fertility issues. If fertility levels are low for alfalfa recommendations, then I'd crop this summer and replant next spring after fertilizing, if they are good then you could consider replanting this spring.

Alternatively, wait another week and look at growth and potential emergence from the soil before you make a final decision. Mow off the severely damaged stems ASAP and at 6 inches or so, as long as ground isn't too wet.

answered 6 months ago
Ray
Ray Smith
Jessamine County
Official Public Agronomist (Extension Agent)
1

Agree with Ray about checking the fertility. Given the poor stand and what appears to have been a mild winter, I wonder if you had some sclerotinia damage that took out some plants. I think it would be best to till it and start over as well.

As a point of information, it takes about 4 plants or 20 stems per square foot at a minimum for alfalfa to meet normal yield potential. At this stage, you should be looking at 20 to 30 plants per square foot. 

answered 6 months ago
Jimmy
Jimmy Henning
Fayette County
Official Public Agronomist (Extension Agent)

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