Blue mold hits late tobacco crop

Long rainy spells punctuated the planting season in many of the South's tobacco-growing areas. As aresult, much of the leaf crop was set out late, and there was a wider-than-normal gap between the oldest and most recently planted crops.

As if that weren't enough, tobacco blue mold broke out in earnest in southern Pennsylvania in June, and infections were found in North Carolina and Tennessee.

The North Carolina infection was found in a burley field in the Belews Creek community near Winston-Salem on June 26. It appeared limited to the single field. This was in the Piedmont of western North Carolina, one of the hardest hit by the weather, and much of the crop was way behind normal in development.

“As late as June 23, tobacco was still being planted here,” said Tim Hambrick, Extension tobacco agent in Forsyth County. “That is very late for use.”

There was much concern about a late crop in the North Carolina Piedmont, since last season 5 percent of the flue-cured was lost when it couldn't be harvested before frost.

“We sure hope this crop doesn't go as late as last year,” said a flue-cured grower from Gibsonville, N.C., near Greensboro. “Even the growers around here who didn't lose any tobacco to the frost were butting right up against it when they finished harvest last season.”

As July began, most of the tobacco in his neighborhood was at the layby stage, he said.

“We are about two weeks late, because we had trouble getting the crop planted. I am not too worried about it if we get enough rain in the next six weeks.”

But there was still considerable apprehension about the possibility of a late crop.

Planting got off to a rocky start in the Piedmont of Virginia too, said Virginia Tech University Extension Tobacco Specialist David Reed.

“It was dry early, then we got a lot of water,” he says. “A lot of our soil wasn't plowed the way we wanted. Now we have a shallow-rooted crop that will be susceptible to drought.”

He estimates that 85 percent to 90 percent of the Piedmont crop was planted in a timely manner. “But that last 10 percent to 15 percent was spread out. Some was even planted the week of June 26,” he says.

But if the weather is good, this crop could recover and do well, says Reed. “Tobacco here that has been irrigated has become more uniform. In Brunswick County, in the eastern part of our tobacco area, we have some very good quality tobacco. But toward Danville, to the west, there are more problems.”

Joseph French, superintendent of the Upper Piedmont Research Station in Reidsville, N.C., says, “It was wet here when we planted tobacco, so some of it wasn't planted until about two weeks late,” says French. “Now, our tobacco looks good, but it is definitely behind.”

The lateness may weigh heavier on the Piedmont burley crop than on its flue-cured. At the Reidsville, N.C., station, French says he is concerned about what impact the late start might have on the yield of the burley grown on his station.

“One thing we have learned about growing burley in the Piedmont in the three years we have grown the type is that it is very important to get it planted as early as possible,” he says. “Burley does not grow well in heat, so you want to get it grown as much as you can before it gets hot.”

That's why this crop could be vulnerable to a hot spell.

A leaf dealer traveling in western Kentucky and Tennessee in early July said about 65 percent of the burley appeared to have been planted close to the desired date. But about 25 percent was planted so late he expects it to come off in late September or early October, or even later.

But because of all the rain, timely planting wasn't always an advantage, he added. “Much of the soil between the rows is hard as asphalt, and we had winds that twisted the tobacco around on the hill. A lot of it looks very tough.”

But there was still plenty of time for the tobacco to recover if the weather cooperates, he says.

In the areas the dealer had visited, the major commercial greenhouses had run out of plants by July 1. So he doubted any burley was planted after that.

Extension Agent Hambrick, who is stationed in Winston-Salem, says conditions through July 1 didn't favor a good yield of tobacco of any type.

“We don't want a light crop,” he says. “Companies want a heavy crop that will store correctly. We have thin leaf so far. But it may be able to catch up.”

But that will be difficult if blue mold continues to spread. The fungal disease had been found earlier in June in Pennsylvania, both in beds and fields. By July 1, it was rampant in the field, especially on late-planted tobacco, says Pennsylvania State University Extension Tobacco Agent Jeff Graybill.

“It has been at least 10 years since we have had blue mold this bad,” says Graybill. It appeared in some cases to be systemic, he says.

Some fields had been destroyed by the end of June. Earlier, many infected beds were destroyed, so many that there was an extreme shortage of plants. Some fields couldn't be planted because plants weren't available.

As July began, there was another confirmed case of field blue mold on burley, this time in Greene County, Tenn. Here too, the incidence was in a single field.

The Extension Service suggests sprays with a mix of Forum and either Manzate ProStick or Penncozeb DF. Complete coverage, including the underside of the leaf, is crucial for good control. Use a high-pressure sprayer with drop nozzles between rows, and hollow-cone nozzles.

If you need to control target spot too, use Quadris when plants meet in the row middles. Quadris provides good control of blue mold also if you apply it before infection has occurred. You can apply Quadris more than once, but it must be alternated with some other treatment.

TAGS: Tobacco
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