Tobacco disease and insect update

By David Dugan
Extension Educator, 
Agriculture and Natural Resources
Ohio Valley Extension Education Research Area
Adams/Brown/Highland Counties

The drought like conditions that we have dealt with, for most of the growing season, has kept the disease pressure pretty low for most crops, including tobacco. There has been an increase in the disease possibility with the recent rains that most of the Tri-County area has had during the last two weeks of July and the beginning of August.

There has been no report of blue mold in any fields in the United States to my knowledge.

At this point, most of the crop is beyond the stage of growth where blue mold would be a concern. Black Shank did show up in some patches during the peak of the heat and dry period. Measures should be taken to reduce this soil borne problem from getting to other parts of the farm with this crop including equipment and stalks. Using a 10% bleach solution to clean equipment is recommended.

At this point the biggest disease concern is most likely to be damage from target spot. Target spot is often confused with blue mold, however this disease seems to be found much more often and can result in significant yield loss.

Target spot often shows up in the lower leaves once the crop gets some size and reduces air flow. The name target spot should help identify this disease. The round like spots that turn brown do resemble a target, you should be able to see rings. With the reduced airflow, and now plenty of moisture in some areas, this could become an issue.

The fungicide Quadris does a good job on preventing this problem. The best time to use Quadris is at layby, but a later application may be necessary. In most plots that I have seen in Kentucky and that we have done here locally, 8 fl. Oz, /A at lay-by has been all that is needed.

If you have not applied Quadris, and the tobacco is at or even beyond topping stage, drop nozzles would provide much better coverage. If Quadris was used at lay-by, and another application is needed, remember you are required by the label to use another product before using Quadris again.

Some things to keep in mind, Quadris should be used in the morning or late evening. Applications made during the heat of the day will increase the risk of burn to the crop.

Also, tank mixes are not recommended. Never mix Quadris with foliar fertilizers, sucker control materials, surfactants, liquid Dipel, or pesticides formulated as emulsifiable concentrates. These mixes will cause crop damage. Other products like Orthene and Warrior have been used, but there have been instances where crop damage has occurred with these mixes, too. Follow the label and use caution.

As far as insects, I have talked to producers who have used systemic products for both aphid and worm control that have reported very good control. Some producers have reported minimal damage to severe damage that has warranted rescue spraying where systemic products were not used at the time the crop was set in the field with a barrel application.

Watch for information about a Tobacco Field Day in the next couple of weeks. A date has not been set at this time.

Chance to Scrap Old Tires

Adams/Brown Recycling is offering Scrap Tire Amnesty days in Ripley on August 11, in Georgetown on August 18 and in Fayetteville on August 25. The times are from 9:00 a.m. until 2:00 p.m. each day. Call for details at (937) 378-3431 or (513) 403-2495. There is a limit of 10 tires per household.

Options for Drought Stressed Corn

The entire area has crops that have been stressed by the extreme heat or lack of rain fall at critical times this year. In some cases crops were hit with both at that critical time and the results are not good. Most producers that I have talked to recently are all over the place with expected yields as a result of yield checks. Planting time and spotty showers have resulted in producers have yields in corn that will not reach 50 bushel to the acre on one farm and just a couple miles away the same producer may be looking at 150 bushel plus.

Soybeans seem to have come through this much better than the corn. There will be some loss in soybeans, but not as much as some of the corn. I have talked to farmers from all three counties that say their soybeans are looking better and better. They are continuing to grow, and some have set a good number of pods and are still flowering. This is not the case everywhere, depends on the amount of rainfall for the most part.

For those with corn that may not able to reach 50 bushel per acre, this may help give you some insight when it comes to your options. The question came to someone in extension and the answer was pretty complete, so I thought it was worth sharing.

This appeared in the Beef Blog last week. You can get this information, and more like it on the OSU Beef Team page at http://beef.osu.edu or send me an e-mail and I will add you to the mailing lists that I send information to on a regular basis. My e-mail is dugan.46@osu.edu.

The first issue for most corn producers may be protecting farm program and crop insurance benefits. It is our understanding that regular farm program payments will be received regardless of how the corn is used. But silage has been eligible for LDP in the past, while grazing has not been eligible.

Of course, not much LDP is available for a 0 bushel grain crop! Federal disaster eligibility still is a totally different question that you need to check into before you do anything. Corn can be harvested as hay (much like cane hay, with a thick, slow-drying stalk), as silage, or grazed. It has the potential to solve some of the forage/feed shortage caused by drought, although getting corn forage to the animals or bringing animals to the forage remains a logistics challenge.

Challenges for hay include:

• Mechanics of harvest (especially cutting): Bale integrity often is less desirable than for other forages (especially in round bales).

• Nitrates: Testing is a must, and cutting at taller stubble heights will help.

• Feed value/feeding: Grinding may be needed to limit refusal and waste of stems. Silage is an excellent choice for reducing nitrate problems; an average of one-third to one-half of nitrates are neutralized during fermentation.

Standing corn will remain too wet for a long time due to stalk retention of moisture. Waiting until crop dries to desired 65% moisture, windrowing and field wilting to reduce moisture, or mixing wet chop with dry feeds like corn grain or chopped hay can overcome the moisture problem. Silage does not transport well, so it makes for a poor cash crop unless livestock are near.

If you consider grazing as an option for using your drought corn field, make sure you fill the cattle up on hay before you turn them out. Most deaths to cattle because of nitrates are of cattle that are hungry and are allowed access to a feed that has nitrates.

Grazing will have some nitrate concerns, depending on how completely animals are forced to eat the lower stalks. Bigger challenges are fencing and water because most fields do not have these resources. But many are winter grazed using temporary fencing and hauled water, so this problem can be overcome. Grazing management, such as strip grazing, will be needed if efficient use is desired; otherwise cattle will trample and waste a huge portion of the crop.

Again, do not force cattle to graze the lower 8 inches of the stalk where most of the nitrates will accumulate. If animals are given the opportunity to selective graze, they will select the leaves first, followed by the upper portion of the stalk, and these parts of the plant typically do not pose nitrate concerns. Nutritionally, drought-damaged corn easily should be close to adequate for beef cows, dry or with suckling calves, and replacement heifers. Salt should be supplemented, and a mineral containing some phosphorus is likely needed through the breeding season.

Dates to Remember

• Ohio Valley Antique Machinery Show – August 9-12 just west of Georgetown on S.R. 125;

• Southwest Ohio Corn Grower Field Day – August 14 just northwest of Washington C.H. on S.R. 38

• Ohio Tobacco Festival – August 23 – 26 in Ripley.