La. Farm Bureau/Radio Network
November 21, 2013
Griffin Reports New Weed Problem
(The following is from LSU AgCenter Weed Scientist Dr. Jim Griffin)
In April of 2013, I visited several sugarcane fields in the Cheneyville area where I observed large broadleaf weeds with flower buds and flowers present and with well-established root systems. The large plants appeared to have survived the winter freezes and were at a population dense enough to affect early season sugarcane growth. Although Weedmaster caused twisting and curling of plants, they were not killed. I later received several calls from other areas of the sugarcane belt concerning the same weed and was informed that atrazine and metribuzin products were also ineffective on established plants.
The plant was identified as eastern black nightshade a weed common to much of the U.S., but not usually observed in cultivated crops in Louisiana. In fact, eastern black nightshade is not even mentioned in the Louisiana Suggested Chemical Weed Control Guide. Eastern black nightshade is generally considered an annual weed which germinates, grows, flowers, and sets seed in a single growing season, but it can also be a short-lived perennial in mild climates where the original plant will survive over the winter and regrow the following year from the original plant. The perennial nature of eastern black nightshade can explain what was observed in sugarcane fields in April. The weed is upright growing and can be identified by leaf shape and red-purple coloration on lower leaf surface .The flowers are white and star-shaped and the fruit is a round berry that can be green, purplish black or dark green at maturity. Each berry can produce 50 to 100 seeds.
The weed may have been present all along but at a very low population level where it was not a concern. With seed production potential of 50 to 100 seed per berry, it would not take long for a light population to become a heavy population. It has been documented that eastern black nightshade seed can be spread by birds, but the infestation level that I have seen is too widespread for that to be the only explanation for its presence.
I re-visited one of the Cheneyville sites on November 12 and observed a few large eastern black nightshade plants with fruit/berries present on the ends of sugarcane rows that had not been harvested. I was most surprised, however, to see a heavy population of 3- to 10-leaf eastern black nightshade plants in sugarcane planted following soybeans. I am inclined to let frost do its job but am concerned based on what I saw in April that plants may not be killed by frost. It should be noted, however, that the winter of 2012-2013 was mild and that eastern black nightshade might not survive under cooler conditions.
Long story short, we now have a new potential weed problem in sugarcane. If you suspect that eastern black nightshade is present on your farm contact your county agent, consultant, or agri-chemical dealer for positive identification. If plants are not killed by frost, 2,4-D plus dicamba (Weedmaster/Brash/ Tricera/others) or dicamba alone (Clarity/Vision/others) can be applied when air temperature is above 65 F. Application in December, January, or early February when eastern black nightshade plants are small and actively growing rather than in March or April should be effective in eliminating early season competition with sugarcane.
Dr. Jim Griffin is with the LSU AgCenter in the School of Plant, Environmental, and Soil Sciences and can be reached at firstname.lastname@example.org or by phone at 225 578-1768.
Wheat Crop Almost Finished
Farmers have planted most of Louisiana's wheat crop. With ideal weather recently, they've been able to plant quickly. "We've had good conditions," said LSU AgCenter wheat specialist Josh Lofton. "The rain has played with us nicely. We've had some showers that helped with germination, but not enough to kick us out of the field for long periods of time." Lofton said planting is around 80 percent complete. He estimates Louisiana will have about 250,000 acres of wheat - about the same planted last year. Wheat prices are down slightly, and acreage could have been lower, but Lofton said because of the good weather, farmers kept planting more acres than expected. He said the Hessian fly, a destructive pest of wheat, could be a problem for growers who planted early. "If growers have gone in and kind of jumped the gun a little bit, that's something they need to start looking out for," he said. Rust disease was a problem on the previous wheat crop. "Those areas that are prone to rust need to start thinking about foliar fungicides to kind of help lock that in check," Lofton said. The LSU AgCenter has helped develop varieties less susceptible to rust, but growers can also use chemicals to control the disease. Lofton stressed the importance of keeping fields weed-free during the growing season. He said warm temperatures or rainfall that would help the wheat grow also would help the weeds.
LSU Homecoming Queen
Emma Arceneaux, former Louisiana Cattlemen's Association Queen, was crowned LSU Homecoming Queen during the halftime of the LSU vs. Furman game on Saturday, October 26th. Emma is from St. Joseph, the daughter of James and Carolyn Arceneaux, and is a biological science senior at LSU.