Corn
Diseases
Since 1995, Mississippi producers have planted more acreage of corn than previous years. Corn is a very good rotational crop to control plant diseases (e.g. Reniform nematode (Rotylenchulus reniformis), Soybean cyst nematode (Heterodera glycines), Verticillium wilt, and Seedling disease) and it adds a high amount of crop residue (3 tons per acre) to the soil. This is a sound agronomic and economical practice that producers are adopting. However, corn is subject to many diseases and can reduce corn yield in Mississippi. The following diseases were occurred in several corn fields in Mississippi: Downy mildew (Sclerophthora macrospora) in 1996, Common rust (Puccinia sorghi) in 1997 and Aflatoxin (Aspergillus flavus) in 1998.
Frequently Asked Questions
What are the chemicals labeled
for corn seed treatment?
The table below shows chemicals labeled for corn
seed treatment:
| Chemical |
Pathogen |
|||||
|---|---|---|---|---|---|---|
| Common name |
Trade name |
Percent a.i. |
Rate per 100 lbs. |
Fusarium |
Pythium |
Rhizoctonia |
Bacillus subtilis |
Epic |
2.75 |
0.25 - 1.0 oz. [field, sweet] |
|||
Bacillus subtilis |
Kodiak |
2.75 |
0.1 - 0.5 oz. [field, sweet] |
|||
captan |
Captan 300 |
28.70 |
1* fl.oz. [field] 3* fl.oz. [sweet] |
|||
captan |
Captan 30-DD |
28.70 |
1* fl.oz. [field] 3* fl.oz. [sweet] |
|||
captan |
Captan 400 |
37.40 |
1* - 2 fl.oz. [field] 2 - 4 fl.oz [sweet] |
|||
captan |
Captan 400D |
37.40 |
1* - 2 fl.oz. [field] 2 - 4 fl.oz [sweet] |
|||
captan |
Captan 75 |
71.70 |
1* oz. [field] 2 oz. [sweet] |
|||
carboxin |
Vitavax-34 |
34.00 |
2 - 4 oz. [field] |
|||
carboxin + thiram |
Vitaflo-280 |
14.90 + 13.20 |
8.5 - 11.5 fl.oz. [field] |
|||
metalaxyl |
Apron FL |
28.35 |
0.75 - 1.50 fl.oz. [field, pop, sweet] |
|||
metalaxyl |
Apron 25W |
25.00 |
1 - 2 oz. or 4 oz. [field, pop, sweet] |
|||
metalaxyl |
Apron 50W |
50.00 |
0.5 - 1 or 2 oz. [field, pop, sweet] |
|||
oxadixyl |
Anchor Flowable |
29.50 |
0.75 - 1.50 fl.oz. [field, pop, sweet] |
|||
quintozene (pcnb) |
RTU-PCNB |
24.00 |
3 fl.oz. [field] |
|||
thiram |
42-S Thiram |
42.00 |
3 fl.oz. [field], 5 fl.oz. [sweet] |
|||
thiram |
Thiram 50WP Dyed |
50.00 |
3.0 fl.oz. |
|||
What are the levels of Aflatoxin
(Aspergillus flavus) in Corn?
Presently, the Food and Drug
Administration (FDA) will commence enforcement actions if aflatoxin levels
in corn exceed the following limits: 20 ppb for human use, dairy feed,
or feed for immature animals 100 ppb for breeding cattle, swine, or mature
poultry 200 ppb for finishing swine (i.e. more than 100 pounds body weight)
300 ppb for feedlot cattle.
What are the plant parasitic
nematodes affecting corn in Mississippi?
Root-knot nematode (Meloidogyne
incognita) can cause an economic damage to corn in sandy to sandy
loam soils in Mississippi. However, so far we have not seen any damage
to corn by the root-knot nematode in Mississippi. Other plant parasitic
nematodes are not a problem in Mississippi.
Does reniform nematode affect
corn?
No. Corn is not a host of reniform
(Rotylecnhulus reniformis) nematode. Therefore, planting one year
of corn to reniform nematode infested soils will reduce the nematode
population.
