DISASTER PAYMENTS: Dr. Mike Salassi, LSU AgCenter, reported this week that the sugarcane disaster money has been transferred to the mills for payment to producers. This is indeed welcomed news for the industry.

VARIETIES: The final variety survey for 2006 was as follows:

It is anticipated that the new survey for 2007 will show that the area planted to LCP 85-384 will decrease to approximately 50% while HoCP 96-540 will increase to approximately 25%. The remainder of the state’s sugarcane area will most likely be planted to the other newer and older varieties, HoCP 85-845, HoCP 91-555, Ho 95-988, L 97-128, L 99-226 and L 99-233.

In touring the sugarcane belt over the past several days, the crop appears to be off to a good start. There is evidence of ripener (glyphosate) residual in some fields with varying amounts of plants having white-colored or striped leaves. However, this situation is mostly temporary, and the crop should outgrow the symptoms in a few weeks. Most cane has been off barred, and fertilizer is being applied. This is the ideal time to apply nitrogen fertilizer. Many fields scheduled for plough-out are being disked. Although the cane is emerging, there has been limited tillering to this point; however, it appears that the Johnsongrass is off and running.

Dr. Ken Gravois, LSU AgCenter, asked me to stress the need for your growers to keep good maps on their farms as to where the different varieties are planted. With the increase in the number of new and old varieties being planted on many different farms and/or tracts, it is important to have good maps. This should prevent some real head scratching as to variety identification come planting time. Further, Dr. Gravois stressed that growers should be reminded to keep good records and maps as to where their cultured seed cane is planted.

WEED PRESSURE:

Johnsongrass is beginning to show up in many fields. Dr. Jim Griffin, LSU AgCenter, and Drs. Ed Richard and Caleb Dalley, USDA-ARS, SRRC, SRL, have outlined a program for the post-emergent control for Johnsongrass and other weeds in their “Sugarcane Weed Guide for 2007.” The appropriate section dedicated to the post-emergent control of Johnsongrass is as follows:

Asulox/Asulox XP/Asulam PROGRAMS FOR CONTROL OF JOHNSONGRASS & OTHER GRASSES:

Asulox/Asulox XP/Asulam can be applied broadcast, banded, or as a spot treatment. Nonionic surfactant at 1 to 2 qt/100 gal of water or crop oil concentrate at 1 gal/100 gal of water should be added to the spray solution. If water pH is above 9.0, addition of a buffer may be beneficial. At application, average air temperature should be at least 60°F with Johnsongrass 12 to 18 inches tall and actively growing. DO NOT cultivate, fertilize, or otherwise disturb the Johnsongrass root system 7 days before or after Asulox/Asulox XP/Asulam application. With some variation caused by weather conditions, Johnsongrass will be at the recommended treatment size in late March or early April. A 20-hour rain-free period following Asulox/Asulox XP/Asulam application may be needed to maximize control.

• First Application - Apply 4 qt/A Asulox/Asulox XP/Asulam broadcast (or the correct proportion if applying on a band) in 15 to 30 gal of water per acre. If applying on a band, outside nozzles should be mounted on drops and band width should be wide enough to ensure thorough wetting of foliage. Asulox/Asulox XP/Asulam applied at 3 to 4 qt/A also controls browntop panicum, foxtails, goosegrass, and barnyardgrass/junglerice when 6 to 8 inches tall. Itchgrass less than 8 inches tall may be controlled with 4 qt/A. Vaseygrass that is less than 8 inches tall can be partially controlled with Asulox/Asulox XP/Asulam at 4 qt/A, but activity is very slow.
• Second Application - A second application of Asulox/Asulox XP/Asulam at 3 to 4 qt/A plus nonionic surfactant or crop oil concentrate can increase Johnsongrass control, but may not increase yield over that obtained with a single Asulox/Asulox XP/Asulam application in March/April. This may be beneficial in the plant cane or first stubble crop to reduce infestations in subsequent crops. The second application of Asulox/Asulox XP/Asulam should be made to Johnsongrass regrowth, usually about eight weeks after the first application. Sugarcane injury is more likely when Asulox/Asulox XP/Asulam is applied at 4 qt/A to sugarcane stressed from drought, excessive temperature, or flooded soils, especially after June 1. Therefore, the first application should be made as early as possible.
• Spot Application - The most accurate and economical method of spot treating is to use a calibrated sprayer at a constant speed with the operator turning the spray nozzles on and off as needed. If a high-volume “cattle gun” nozzle is used for spot treatment, apply a 2% solution of Asulox/Asulox XP/Asulam (2 gal of herbicide plus 98 gal of water). When using a high volume “cattle gun” nozzle, spray to wet foliage but do not drench as sugarcane injury can be greater compared with spot treating using a calibrated sprayer.
• Aerial Application - Asulox/Asulox XP/Asulam may also be applied by air using the same rates specified above. Spray volume should be a minimum of 5 gal per acre. After calculating the actual sugarcane acreage to be treated, acreage should be increased to account for ditchbanks and headlands also receiving application.

ENVOKE PROGRAMS FOR CONTROL OF JOHNSONGRASS & ITCHGRASS:

• First Application - Envoke 75DF can be applied postemergence overtop to plant or ratoon cane up to 24 inches tall at 0.3 oz/A broadcast (or the correct proportion if applying on a band) or as a directed application at 0.3 to 0.6 oz/A to sugarcane 18 inches tall at layby. As a directed application spray should be directed away from the upper plant parts (whorl) to minimize contact with the crop and to maximize contact with the target weeds. Envoke alone at 0.3 oz/A will suppress but not control of rhizome Johnsongrass or large itchgrass. Combinations of Envoke with Asulox/Asulox XP/Asulam provide complementary broadleaf and grass weed control. Envoke at 0.3 oz/A applied with Asulox/Asulox XP/Asulam at 2 qt/A (half rate) plus nonionic surfactant or crop oil concentrate controls large rhizome Johnsongrass (more than 18 inches) equal to or better than Asulox/Asulox XP/Asulam applied alone at 4 qt/A (full rate). Envoke at 0.2 oz/A applied with Asulox/Asulox XP/Asulam at 2 qt/A has provided control of large itchgrass (more than 6 inches) better than Asulox/Asulox XP/Asulam applied alone at 4 qt/A. Envoke applied overtop of sugarcane can cause some yellowing and white banding on leaves present in the whorl at application as well as slight stunting but recovery is rapid and no negative effect on sugarcane yield has been observed. For ground application use a minimum of 10 gal of water per acre (broadcast basis). Higher spray volume of at least 20 gal per acre should be used for heavy weed infestations to ensure adequate spray coverage.
• Envoke can not be applied aerially: Do not apply Envoke to sugarcane under stress due to drought, standing water, heavy insect and/or disease pressure, or low soil fertility. As specified for Asulox/Asulox XP/Asulam, DO NOT cultivate, fertilize or otherwise disturb the Johnsongrass root system 7 days before or after Envoke application.

NUTSEDGE CONTROL PROGRAMS:

Permit 75DF (halosulfuron) can be applied postemergence prior to planting or after crop emergence anytime during the growing season until row closure. Sugarcane is very tolerant to overtop applications of Permit. No more than three applications can be made per year, and no more than 2.33 oz should be applied per acre per year. Apply Permit at 1.0 to 1.33 oz/A with nonionic surfactant at 1 to 2 qt/100 gal of water or crop oil concentrate at 1 gal/100 gal of water. Activity of Permit is slow, and four weeks may be needed to maximize control. Other herbicides may be applied with Permit for additional weed control. Yukon, a 67.5% DG premix of halosulfuron (the active ingredient in Permit) and dicamba (the active ingredient in Clarity/Vision) can provide control of both nutsedge and broadleaf weeds. A 4 oz/A rate of Yukon is equivalent to 0.67 oz/A rate of Permit and a 4 oz/A rate of Clarity/Vision. Envoke at 0.2 oz/A with nonionic surfactant at 1 to 2 qt/100 gal of water or crop oil concentrate at 4 qt/100 gal of water also provides some control of nutsedge. Application over the top of the crop may not ensure adequate coverage of nutsedge growing under the crop canopy and can result in poor control.

DISEASES:

There have been several reports that brown rust is now appearing in many fields of LCP 85-384 and Ho 95-988 and, to a lesser extent, in fields of the other varieties. Dr. Jeff Hoy, LSU AgCenter, reported that multiple fungicide treatments were identified with the ability to reduce brown rust severity in sugarcane during 2006. A consideration of the yield loss results suggests that some would have provided positive economic returns for growers. Based on the 2006 results, the Headline+Folicur tank-mix treatment was the best treatment. Other fungicides showing promise were Quadris, Quilt and Stratego. Caramba applied alone provided some rust control, so it might be effective in a tank-mix with Headline. The results from one season should not be considered conclusive. Additional fungicide efficacy research will be conducted during 2007. The yield-loss experiment confirmed that rust severity is lower in cane planted in heavy clay soils. However, the estimated yield loss in the 2006 experiment was similar to the losses recorded in the 2004 and 2005 experiments. Dr. Hoy stated that there are no commercial labels for use of any of these fungicides on sugarcane at this time; however, he stated that EPA is considering a Section 18 request on one or more of the fungicides listed above, but no verdict has been rendered as of yet.

Dr. Mike Grisham, USDA-ARS, SRRC, SRL, stated that growers should monitor fields of Ho 95-988 and L 97-128 that may be used as seed cane in the fall for the presence of smut. In most years, monitoring should be conducted between mid June and mid July. The paragraph from the Sugarcane Planting Recommendations & Suggestions guide should continue to be followed. "Cane of any variety containing more than 2% smut-infected shoots should be avoided as a seed cane source..."

INSECTS:

Although it is early in the season, armyworms and the yellow sugarcane aphid have been observed. Dr. Gene Reagan, LSU AgCenter, stated that high numbers of the yellow sugarcane aphid can be a problem on sugarcane at this time of year, and its numbers might justify treatment. He said that Prolex insecticide at ½ the sugarcane borer rate is a good choice. He stressed that one should never consider treating for aphids until you have an average of more than 20 aphids per leaf lasting for longer than 2 weeks at that level (in the 3^rd weekly sampling period).

Dr. Dale Pollet, LSU AgCenter, stated that armyworms are a worry to the cane growers every year. What most of them do not realize is that this is a living herbicide, and they will eat the grass out of the field before they feed on the cane. Even though they eat the cane leaves they do no damage to the cane. Where insecticide treatments have been made in the past, growers were unable to tell the treated blocks from the infested blocks once the cane began to grow. Dr. Pollet told me that if one of your growers has an urge to spend money they can write him a check, and he will hold it until that urge passes or we all have a party. The armyworms are fed on by a small parasite, a wasp that once they mature they leave the worm's body and form a silky blob on the plants and pupate there. If they watch infested fields they will observe this happening. Spraying will only eliminate the parasites and could make for a heavier population of armyworms next spring.

Dr. Pollet also stated that growers need to watch for dead hearts and try to determine the cause. There are four different insects that can produce the dead heart; the sugarcane borer, wireworms, lesser corn stalk borer and the sugarcane beetle. Each has a different method of attack. Borers usually attack from overwintering larvae that feed into the new growth prior to pupating. Wireworms usually enter through the eyes and feed into the mother stalk. Lesser corn stalk borer builds a silken tube on the side of the sprout and bores in just below the soil surface. Sugarcane beetles rip open the shoots and eat the hearts out. Where sugarcane beetles attack, one usually sees secondary shoots come out in a couple of weeks. These usually catch up with the other shoots in a few weeks. The other infestations usually completely damage the bud areas. Management of these pests includes planting clean cane and keeping late-season infestations out of the new growth. Keeping the fields as grass-free as possible will also help with armyworm populations. The treating with labeled pesticides at planting time, particularly in sandy soils, will help greatly to control many of these insects, especially wire worms. Please note that there are no directed sprays for the control of these insects once infestations are detected.

Don’t hesitate to contact me if I can be of further assistance or if you have any questions or comments.

Have a Happy Easter!!!

Benjamin L. Legendre, Ph.D.
Interim Director, Audubon Sugar Institute
Sugarcane Specialist & Denver T.
Loupe/American Society of Sugarcane
Technologists Sugar Heritage Professor
LSU Ag Center Research & Extension
St. Gabriel Research Station
5755 LSU Ag Road
St. Gabriel, LA 70776
Phone: (225) 642-0224
Mobile: (225) 281-9475
FAX: (225) 642-5339