Source: LOUISIANA STATE UNIVERSITY submitted to NRP
WEED MANAGEMENT STRATEGIES FOR SUGARCANE IN LOUISIANA
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
Reporting Frequency
Annual
Accession No.
1015901
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
May 1, 2018
Project End Date
Apr 30, 2022
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
LOUISIANA STATE UNIVERSITY
202 HIMES HALL
BATON ROUGE,LA 70803-0100
Performing Department
Hammond Research Station
Non Technical Summary
Sugarcane was grown on 439,179 acres in 2017 in Louisiana. Sales of raw sugar and molasses from the 2016 crop resulted in a total economic impact of $819,209,436 for Louisiana producers, processors, and landlords at the first processing level. Sugarcane is a perennial crop, and three to five crops are harvested from a single planting. The top of the sugarcane bed is not appreciably disturbed over the multi-year crop cycle which encourages weed proliferation. The most troublesome weeds in Louisiana sugarcane are johnsongrass, itchgrass, bermudagrass, morningglory, and nutsedge. Periodically, new weed species are introduced to sugarcane fields and current weed management programs are ineffective. Management strategies must be developed to control these weeds in order to ensure economic sustainability of the industry.There continues to be interest in development of herbicides for sugarcane. In order to obtain federal registration of new herbicides, weed spectrum, rate, application timing, and sugarcane tolerance must be determined. Field and greenhouse experiments will be conducted to evaluate new herbicides for the afore mention registration criteria. Managing weeds in a perennial crop is imperative to ensure maximum yield is realized throughout the crop cycle, thus leading to the highest economic returns for producers and landlords.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20520201140100%
Knowledge Area
205 - Plant Management Systems;

Subject Of Investigation
2020 - Sugar cane;

Field Of Science
1140 - Weed science;
Goals / Objectives
To develop effective and economical management programs for the major weed problems in Louisiana sugarcane.To monitor the occurrence of new weed problems and to evaluate management options.
Project Methods
For each of the objectives involving herbicide evaluation, treatments will be applied with compressed air or CO2 using a tractor or backpack sprayers. Plot size and number of replicates will vary depending on the crop and type of study. Typically, plot size will be one, two, or three sugarcane rows 72 inches apart and 40 to 50 feet long with treatments replicated four times.Most field studies will be conducted at the Sugar Research Station. Due to the need for specific weeds not present at the Sugar Research Station, some research will be conducted in farmer fields. Data collected from experiments will include visual ratings for weed control and crop injury using a scale of 0 to 100% with 0= no control or injury and 100= complete control or injury. Injury may also be assessed by determining sugarcane plant population and height. Additionally, weed infestation may be determined by percent ground cover or by actual weed population counts. Where possible, sugarcane will be combine-harvested to determine yield. Samples of randomly selected stalks will be crushed and the juice extracted to determine sugar content using standard methodology.Data for each study will be subjected to the Mixed Procedure in SAS. Years or locations, replications (nested within years or location), and all interactions containing either of these effects will be considered random effects. All other variables will be considered fixed effects. Considering year or location as environmental or random effects permits inferences about treatments to be made over a range of environments. Type III statistics will be used to test the fixed effects and least square means for mean separation at P≤ 0.05. Letter groupings will be converted using the PDMIX800 macro in SAS.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:Target audiences for this project include sugarcane growers, county agents, crop consultants, crop advisors, agrichemical company representatives, extension specialists, and weed management professionals. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Research findings were presented in person at spring parish growermeetings and virtually for field days and other industry meetings due to COVID-19 restrictions. What do you plan to do during the next reporting period to accomplish the goals?Screening of unlabeled and new herbicide chemistries will occur at the Sugar Research Station and within the LA sugarcane industry in order to find weed management solutions. Timely communications with crop advisors, county agents, and sugarcane producers will ensure quick dissemination of newly gathered weed management facts.

Impacts
What was accomplished under these goals? Investigating the Control of Suspected Paraquat Resistant Italian Ryegrass with Paraquat and PSII Tank Mixtures. A study was initiated at the Sugar Research Station in St. Gabriel, LA on February 14, 2020 to investigate postemergence control of a suspected paraquat resistant population of Italian ryegrass (Lolium multiflorum) with tank mixes of paraquat and PSII herbicides. Paraquat was applied alone at 420, 840, 1,680, and 3,360 g ha-1 and paraquat (840 g ha-1) was tank-mixed individually with metribuzin (1,680 g ha-1), atrazine (2,240 g ha-1), diuron (2,800 g ha-1) and ametryn (1,350 g ha-1) and was applied to 1.3-3.8 cm tall (top leaf collar) Italian ryegrass in the tillering stage. Non-ionic surfactant was added to all herbicide treatments at 0.25% v/v. Visual control was recorded at 7 days after treatment (DAT). Ryegrass control averaged 20% for the 840 g ha-1 paraquat treatment. The addition of metribuzin, atrazine, diuron, and ametryn to paraquat provided no improvement in ryegrass control as compared to the paraquat 840 g ha-1 treatment alone and ranged from 15-16% control. The 3,360 paraquat treatment provided the greatest ryegrass control, yielding 56% control. Investigating the Control of Suspected Paraquat Resistant Italian Ryegrass with Increased Rates of Paraquat. A study was initiated in a commercial sugarcane field in Bunkie, LA on February 17, 2020 to investigate postemergence control of a suspected paraquat resistant population of Italian ryegrass (Lolium multiflorum) with increasing rates of paraquat. Paraquat was applied alone at 840, 1,680, 3,360, 6,720, and 13,440 g ha-1. Additionally, an asulam treatment (3,740 g ha-1) was included to evaluate the products efficacy on Italian Ryegrass. Herbicide treatment was applied to 1.3-3.8 cm tall (top leaf collar) Italian ryegrass in the tillering stage. Non-ionic surfactant was added to all herbicide treatments at 0.25% v/v. Visual control was recorded at 18 and 35 DAT. Ryegrass control averaged 5, 23, 41, 73, and 89 % for the 840, 1,680, 3,360, 6,720, and 13,440 g ha-1 paraquat treatments, respectively 18 DAT. At 35 DAT, ryegrass control averaged 4, 17, 29, 49, and 79% for the 840, 1,680, 3,360, 6,720, and 13,440 g ha-1 paraquat treatments, respectively. Control of ryegrass with asulam averaged 27% for the 18 DAT observation, but increased to 75% for the 35 DAT observation. In order to obtain commercially acceptable POST control of the Bunkie, LA population of Italian ryegrass required a 13,440 g ha-1 application of paraquat, which is 16X greater than the highest rate allowed by the current paraquat label. Effect of Paraquat Rate on Sugarcane Yield. A study was initiated in a commercial sugarcane field in Vacherie, LA. Paraquat was applied in the spring of 2020 to second ratoon L 01-299 at the 3-4 leaf stage on March 12, 2020 and at the 7-8 leaf stage on April 13, 2020 at rates of 840, 1,680, and 3,360 g ha-1. Additional treatments included a sequential application of paraquat at 840 g ha-1 (March and April), and pendimethalin + metribuzin (2,240 + 1,860 g ha-1) (March) followed by a sequential application of pendimethalin (2,240 g ha-1) (April). Non-ionic surfactant was added to all paraquat herbicide treatments at 0.25% v/v. A non-treated control was also included for comparison. Plots were hand-sampled (10-stalks) and harvested with a sugarcane chopper harvester on October 26, 2020 then were loaded into a wagon equipped with load cells to gain theoretical recoverable sucrose and sugarcane yield. Sugarcane yield was similar for the paraquat treatments within a given timing, and averaged 99 and 89 Mg ha-1 for the March and April timings, respectively. Sugarcane yield for the sequential paraquat treatment was equivalent to that of a single April application. Sugarcane yield for the pendimethalin + metribuzin followed by an additional pendimethalin treatment and the non-treated control averaged 105 and 108 Mg ha-1 and was statistically similar to the March application of paraquat. Stalk sucrose was similar for all treatments and averaged 114 g kg-1 for the untreated control. Sugar yield per hectare, the product of sugarcane yield and stalk sucrose followed the trend of sugarcane yield. The non-treated control treatment averaged 12,298 kg ha-1 as compared to the average of the three April paraquat treatments of 9,655 kg ha-1. Efficacy of Labeled Sugarcane Herbicides on Preemergence Vaseygrass Control. Twelve labeled sugarcane herbicides were evaluated for preemergence vaseygrass (Paspalum urvillei) control at the Sugar Research Station in St. Gabriel, LA. Vaseygrass seeds were collected from mature vaseygrass plants. Seeds were broadcast seeded to fallow sugarcane beds and the seeds were lightly incorporated. Herbicide treatments included metribuzin (1,680 g ha-1), s-metolachlor (2,600 g ha-1), hexazinone (540 g ha-1) diuron (2,700 g ha-1), pendimethalin (3,330 g ha-1), clomazone (1,390 g ha-1), atrazine (4,500 g ha-1), s-metolachlor + mesotrione + atrazine (3,860 g ha-1), pendimethalin + metribuzin (4,500 g ha-1), sulfentrazone (420 g ha-1), trifluralin (2,240 g ha-1), and terbacil (1,350 g ha-1) and were applied May 29, 2020. Visual control was recorded at 41 DAT. The s-metolachlor, hexazinone, diuron, clomazone, s-metolachlor + mesotrione + atrazine, and trifluralin treatments averaged at least 90% control as compared to the metribuzin, atrazine, and terbacil treatments which averaged no more than 25% control. Efficacy of Trycera and Metribuzin on Bermudagrass. A study was initiated at the Sugar Research Station in St. Gabriel, LA on July 9, 2020 to investigate postemergence control of bermudagrass (Cynodon dactylon) with tank mixes of triclopyr (Trycera) and metribuzin. Herbicide treatments were applied to established bermudagrass growing on buffer rows and included, triclopyr + mertribuzin at 1,010 + 1,680 g ha-1, metribuzin at 1,680 g ha-1, and triclopyr at 1,010 g ha-1. Bermudagrass injury was recorded at 14 and 28 DAT, and the triclopyr + mertribuzin at 1,010 + 1,680 g ha-1 treatment resulted in 79 and 73 % injury at 14 and 28 DAT, respectively. Bermudagrass injury averaged 48 and 33 % for the triclopyr + mertribuzin at 1,010 + 840 g ha-1 and the triclopyr treatments, respectively. The metribuzin treatment provided little to no control of bermudagrass. Efficacy of S-Metolachlor on Preemergence Vaseygrass Control. A study was initiated at the Sugar Research Station in St. Gabriel, LA on July 9, 2020 to investigate preemergence vaseygrass (Paspalum urvillei) control. Vaseygrass seeds were collected from mature vaseygrass plants. Seeds were broadcast seeded to fallow sugarcane beds and the seeds were lightly incorporated. S-metolachlor (Visor S-Moc) was applied at 1,070, 1,600, and 2,140 g ha-1 on July 15, 2020. Visual control was recorded at 22 and 49 DAT. All treatments yielded 100% vaseygrass control 22 DAT and averaged at least 90% control 49 DAT. Tolerance of Sugarcane and Postemergence Control of Itchgrass with Mission Herbicide. A study was conducted in a newly established commercial sugarcane field in Raceland, LA to investigate the tolerance of sugarcane and investigate the efficacy of flazasulfuron (Mission) on itchgrass (Rottboellia cochinchinensis). Itchgrass was 15 to 30 cm at the time of treatment. Treatments were applied on October 5, 2020, and non-ionic surfactant was added to all herbicide treatments at 0.25% v/v. Flazasulfuron was applied at 38 and 50 g ha-1 and was compared with asulam (2,800 g ha-1). Visual control was recorded at 14 and 29 DAT, and averaged 50% for the flazasulfuron treatments at both evaluations. Itchgrass control for the asulam treatment averaged 55% at 14 DAT, and increased to 95% at 29 DAT.

Publications


    Progress 10/01/18 to 09/30/19

    Outputs
    Target Audience:The target audiences for this project are sugarcane producers, crop consultants and advisors, agricultural chemical company representatives, extension professionals, as well as weed management professionals in Louisiana. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Research findings were presented at parish grower meetings, parish field days, and professional conferences (18 events) to sugarcane producers, crop consultants, and county agents. Additionally, two trainings were held for county agents, andcovered many sugarcane topics including sugarcane weed management. Electronic newsletters and Sugar Bulletin articles which focused on sugarcane weed management were also developed and distributed to stakeholders. What do you plan to do during the next reporting period to accomplish the goals?Screening of potential new herbicide chemistries will occur at the Sugar Research Station and within the Louisiana sugarcane industry in order to find new weed management solutions. Meetings will be held with sugarcane producers and crop advisors to stay aware of potential new weed pests.

    Impacts
    What was accomplished under these goals? Efficacy of Experimental Herbicides on Postemergence Ryegrass Control. Three experimental compounds were evaluated at the Sugar Research Station in Spring 2019 to investigate postemergence Italian ryegrass (Lolium multiflorum) control efficacy. Rimsulfuron + thifensulfuron-methyl (32 + 7 g ha-1), thiencarbazone-methyl + tembotrione (30 + 151 g ha-1), and thiencarbazone-methyl + Iodosulfuron-methyl-sodium + dicamba (30 + 7 + 197 g ha-1), was applied to 20-30 cm tall Italian ryegrass on March 11, 2019. Paraquat (840 g ha-1), the industry standard, and an untreated control were also included for comparison. Visual control was recorded at 14 and 29 days after treatment (DAT). The rimsulfuron + thifensulfuron-methyl and thiencarbazone-methyl + tembotrione treatments control 41 and 30% of Italian ryegrass at 14 DAT, and control was increased to 69 and 55% respectively, at 29 DAT. Paraquat, the sole option for controlling ryegrass following emergence in sugarcane provided 75 and 70% control at 14 and 29 DAT, respectively. Postemergence Control of Divine Nightshade with Tank-mixes. A study was conducted in a commercial sugarcane field in Paincourtville, LA in spring of 2019 to investigate the effectiveness of tank mixing herbicides to manage divine nightshade (Solanum nigrescens). Perennial divine nightshade plants averaged 20-30 cm tall and 25-45 cm wide at the time of treatment on March 12, 2019. Treatments included a preformulated mixture of S-metolachlor + atrazine + mesotrione (2100 + 786 + 210 g ha-1) + triclopyr (643 g ha-1) and a preformulated mixture of S-metolachlor + atrazine + mesotrione (2100 + 786 + 210 g ha-1) + triclopyr (1130 g ha-1). Additional treatments included a preformulated mixture of S-metolachlor + atrazine + mesotrione (2100 + 786 + 210 g ha-1) and triclopyr (1130 g ha-1). Control was evaluated at 28 DAT, and the tank-mixes of S-metolachlor + atrazine + mesotrione + triclopyr (643 and 1130 g ha-1) treatments controlled 95 and 98% of divine nightshade, respectively as compared to 85% control for the S-metolachlor + atrazine + mesotrione treatment and 89% control for the triclopyr treatment. Tolerance and Efficacy of Sugarcane to Satellite Flex, KFD-308-01, Coyote, and Tripzin ZC. A study was conducted in a commercial sugarcane field in St. James, LA in spring of 2019 to evaluate sugarcane tolerance and efficacy of several sugarcane herbicide products from the manufacture UPI. These products contained new formulations of molecules labeled for use in sugarcane, unevaluated products, and a preformulated mixture of currently utilized active ingredients. Treatments included Satellite Flex ((pendimethalin EW), EW is formulated as a concentrated aqueous emulsion) (2930 g ha-1) + metribuzin (2100 g ha-1), KFD-308-01 (clomazone) (1260 g ha-1) + metribuzin (2100 g ha-1), Coyote (S-metolachlor + mesotrione) (2630 + 260 g ha-1) + metribuzin (2100 g ha-1), and Tripzin ZC (pendimethalin + metribuzin) (3250 + 1230 g ha-1), and were applied March 22, 2019. Significant sugarcane injury (31%) was noted at 19 DAT for the KFD-308-01 + metribuzin treatment, and sugarcane leaves were chlorotic; however, chlorosis decreased to 6.5% by 32 DAT. All four treatments provided excellent control (>96%) of large crabgrass (Digitaria sanguinalis) at 32 DAT. Efficacy of Experimental Herbicides on Postemergence Vaseygrass Control and Sugarcane Tolerance. Three experimental compounds were evaluated at the Sugar Research Station in Spring 2019 to investigate postemergence vaseygrass (Paspalum urvillei) control and sugarcane tolerance. Rimsulfuron + thifensulfuron-methyl (32 + 7 g ha-1), thiencarbazone-methyl + tembotrione (30 + 151 g ha-1), and thiencarbazone-methyl + iodosulfuron-methyl-sodium + dicamba (30 + 7 + 197 g ha-1), was applied to 45-75 cm tall vaseygrass on April 9, 2019. Asulam (3740 g ha-1) and an untreated control treatments were also included for comparison. Visual vaseygrass control was recorded at 13 and 27 DAT. The rimsulfuron + thifensulfuron-methyl thiencarbazone-methyl + tembotrione, and thiencarbazone-methyl + iodosulfuron-methyl-sodium + dicamba treatments controlled 32, 31, and 45% of vaseygrass at 13 DAT, respectively and control increased to 64, 66, and 64% at 27 DAT, respectively. Asulam, the industry standard controlled 19 and 53% of vaseygrass at 13 and 27 DAT, respectively. The number of vaseygrass seed heads which developed in each plot were counted 27 DAT, and the rimsulfuron + thifensulfuron-methyl, thiencarbazone-methyl + tembotrione, and thiencarbazone-methyl + iodosulfuron-methyl-sodium + dicamba treatments averaged 2, 1, and 1 seed heads per plot, respectively as compared to 7 for the asulam treatment and 17 for the untreated control. No sugarcane injury was noted 13 DAT, but by 27 DAT, a 50% reduction in sugarcane shoot height was noted for all experimental herbicide treatments. Stalk height was measured 90 DAT, and the untreated check and asulam treatments averaged 145 cm. Sugarcane height was significantly reduced by the rimsulfuron + thifensulfuron-methyl treatment by 18 cm. Thiencarbazone-methyl + tembotrione and thiencarbazone-methyl + iodosulfuron-methyl-sodium + dicamba treatments also reduced sugarcane height and was 34 and 41 cm less than the control treatments, respectively. Postemergence Control of Bushkiller Vine. A study was conducted in a commercial sugarcane field in White Castle, LA in spring of 2019 to investigate the effectiveness of auxin herbicides to control bushkiller vine (Cayratia japonica). Treatments were applied on May 23, 2019 and included 2,4-D (2130 g ha-1), a premix of 2,4-D + dicamba (804 + 280 g ha-1), dicamba (1120 g ha-1), and triclopyr (1130 g ha-1) and (1690 g ha-1). All treatments provided >95% control of bushkiller vine 15 DAT. On June 19, 2019, and July 2, 2019, reemergence counts were recorded. At both evaluations, the dicamba treatment had the fewest reemerged bushkiller vine plants per plot and averaged 1 and 4 reemerged plants for the June and July evaluation, respectively. Bushkiller vine reemergence for both triclopyr treatments were similar to the dicamba treatment and averaged 3 and 2 plants per plot respectively for the June evaluation, and increased to 11 and 10 plants for the July evaluation. The 2,4-D treatment had the highest level of bushkiller vine reemergence and averaged 17 and 31 for the June and July evaluations, respectively. Postemergence Control of Least Snout Bean. A study was conducted in a commercial sugarcane field in Loreauville, LA in Summer of 2019 to investigate the effectiveness of herbicides to control least snout bean (Rhynchosia minima). Treatments were applied on June 14, 2019 and included 2,4-D (1060 g ha-1), a premix of 2,4-D + dicamba (804 + 280 g ha-1), dicamba (1120 g ha-1), triclopyr (1130 g ha-1), mesotrione + atrazine (105 + 2240 g ha-1), and sulfentrazone + 2,4-D (280 + 1060 g ha-1). Dicamba and triclopyr controlled at least 99% of least snout bean 27 DAT, whereas the 2,4-D + dicamba treatment provided 80% control. 2,4-D, is an herbicide tool commonly used to control broadleaf weeds after emergence, only provided 11% control at 27 DAT. The mesotrione + atrazine and sulfentrazone + 2,4-D treatments provided poor control of least snout bean as well.

    Publications

    • Type: Journal Articles Status: Published Year Published: 2019 Citation: Orgeron A.J., Spaunhorst D.J., and Gravois K.A. 2019. Exploring the Use of Triclopyr to Enhance Perennial Weed Control in Louisiana Sugarcane. Proc. Int. Soc. Sugar Cane Technol. In Press.
    • Type: Journal Articles Status: Published Year Published: 2019 Citation: Spaunhorst D.J., Orgeron A.J., and White P.W. 2019. Burning Post-Harvest Sugarcane (Saccharum spp. hybrids) Residue for Control of Surface Deposited Divine Nightshade (Solanum nigrescens) and Itchgrass (Rottboellia cochinchinensis) Seed. Weed Technol. doi: 10.1017/wet.2019.65.
    • Type: Journal Articles Status: Published Year Published: 2019 Citation: Spaunhorst D.J., and Orgeron A.J. 2019. Dry Heat and Exposure Time Influence Divine Nightshade and Itchgrass Seed Emergence. Agron. J. doi:10.2134/agronj2019.02.0072.


    Progress 05/01/18 to 09/30/18

    Outputs
    Target Audience:The target audiences for this project include sugarcane producers, crop consultants, crop advisors, agrichemical company representatives, county agents, extension specialists, and weed management professionals. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Research findings were presented at parish growers meetings, parish field days, and professional conferences (12 events) to sugarcane producers, crop consultants, and county agents. Additionally, two trainings were held for county agents, and covered many sugarcane topics including sugarcane weed management. Electronic newsletters and Sugar Bulletin articles which focused on sugarcane weed management were also developed and distributed to stakeholders. What do you plan to do during the next reporting period to accomplish the goals?Screening of potential new herbicide chemistries will occur at the Sugar Research Station and within the Louisiana sugarcane industry in order to find new weed management solutions. Meetings will be held with sugarcane producers and crop advisors to stay aware of potential new weed pests.

    Impacts
    What was accomplished under these goals? Cover Crop Termination Study. Austrian winter pea and hairy vetch was sown onrows and infurrows for newly planted sugarcane in Jeanerette, LA on September 13, 2017. A chemical cover crop termination study was implemented in 2018. A premixed solution of 2,4-D + dicamba (804 + 280 g ha-1) and metribuzin (1680 g ha-1) was applied on January 25, February, 16, and March 8, 2018. Stalk counts and plant heights were collected on July 2, 2018. Significantly fewer stalks were observed for the March termination (88,266 stalks ha-1) as compared to the January and February terminations (105,217 and 99,389 stalks ha-1). Stalk height was reduced by 10 cm when termination was delayed until March, as compared to January termination. Sugarcane and sugar yield will be determined at harvest. Control of Itchgrass with Preemergence Herbicides in Spring. Three preemergence herbicide studies were conducted in ratoon sugarcane in spring to evaluate the ability of current and potential new products to control itchgrass (Rottboellia cochinchinensis). These studies were conducted nearStCharles, LA. In the first study, pendimethalin (2,770 g ha-1) + metribuzin (2,520 g ha-1) and pendimethalin (2,770 g ha-1) + hexazinone (670 g ha-1) controlled 93 and 95% of itchgrass, respectively,three weeks after application (WAA). Metribuzin (2,520 g ha-1) and hexazinone (670 g ha-1) provided poor control of itchgrass, and controlled 42 and 37%, respectively 3 WAA. The second study evaluated the potential new herbicide, indaziflam (Alion) at 55, 95, and 135 g ha-1. Indaziflam at 135 g ha-1 controlled 68% of itchgrass at 3 WAA, but pendimethalin (3,330 g ha-1) provided 94% itchgrass control. The third study evaluated tank-mixes with a premixed formulation of S-metolachlor + atrazine + mesotrione (Lumax EZ) to control itchgrass. Lumax EZ (2060 g ha-1) + pendimethalin (2,770 g ha-1) and Lumax EZ (2060 g ha-1) + clomazone (1,260 g ha-1) provided 91 and 93% control of itchgrass 3 WAA; however, Lumax EZ (2060 g ha-1) + hexazinone (670 g ha-1) provided 59% control. Postemergence Control of Italian Ryegrass. A study was conducted in Cheneyville, LA to evaluate alternative herbicides to manage Italian ryegrass (Lolium multiflorum) after emergence. Pinoxaden (60 g ha-1), ametryn (880 g ha-1), trifloxysulfuron-sodium (26 g ha-1), asulam (3,740 g ha-1), and paraquat (840 g ha-1) were applied to 26 cm ryegrass on March 8, 2018. At 4 WAA, sugarcane injury was noted with the pinoxaden treatment. Ryegrass control was poor for all treatments except paraquat (87% control). Tolerance of Sugarcane to XDE-848 BE. A study was initiated at Sugar Research Station in St. Gabriel, LA to investigate sugarcane tolerance to the experimental compound XDE-848 BE. No sugarcane injury was noted 2 WAA, and grass and broadleaf weed control was poor. Tolerance and Efficacy of Sugarcane to the Experimental Herbicide H1168aa. A study was initiated in newly planted sugarcane to evaluate the tolerance and efficacy of sugarcane to the experimental herbicide H1168aa. L 01-299 was planted on August 24th at Sugar Research Station in St. Gabriel, LA and injury and weed control was recorded 4 WAA. Injury averaged 8.5% for H1168aa (1,046 and 1,490 ml ha-1), and barnyardgrass (Echinochloa crus-galli), crabgrass (Digitaria sanguinalis), browntop millet (Urochloa ramosa), seedling johnsongrass (sorghum halepense), and ivyleaf morningglory (Ipomoea hederacea) control was at least 97% (745, 1,046, or 1,490 ml ha-1). H1168 provided similar grass control as pendimethalin (3,360 g ha-1) and broadleaf control as atrazine (4,500 g ha-1). Mixtures of H1168aa with metribuzin, pendimethalin, hexazinone, or clomazone did not improve weed control, but cropinjury averaged 12% when H1168aa was mixed with clomazone. Control of Itchgrass with Preemergence Herbicides At-Planting. A preemergence herbicide study was conducted in newly planted sugarcane to evaluate the ability of pendimethalin and hexazinone to control of itchgrass near Raceland, LA. 4 WAA, itchgrass plants were counted. Pendimethalin at 2,220, 2,770, and 3,330 yielded an average of 10,675, 11,661, and 8,837 itchgrass plants ha-1 respectively, whereas hexazinone treatments at 504, 740, and 980 g ha-1 averaged 23,996, 20,051, and 21,933 itchgrass plants ha-1. The untreated check averaged significantly more itchgrass ha-1 (40,815) than both herbicide treatments. Impact of Fomesafen on Newly Planted Sugarcane. A study was initiated to evaluate the impact of fomesafen on newly planted sugarcane. L 01-299 was planted on August 21th at Sugar Research Station in St. Gabriel, LA and fomesafen was applied at 198, 395, 790, and 1580 g ha-1. Shoots were counted and % injury was recorded at 27 and 62 DAA. Average shoot height was also recorded at 62 DAA. No differences in the number of shoots were noted among the treatments at 27 DAA, however the 790 and 1580 g ha-1 treatments injured sugarcane 9 and 16%, respectively. Shoots ha-1 were reduced 62 DAA for the 1580 g ha-1 treatment and injury averaged 11%. Shoot height was reduced by approximately 2.5 and 3.8 cm for the 790 and 1580 g ha-1 treatments, respectively.

    Publications

    • Type: Journal Articles Status: Published Year Published: 2018 Citation: Orgeron A.J., E.E. Schilling, L.E. Urbatsch, Q. Ma, and D.J. Spaunhorst. 2018. Solanum nigrescens, a Problematic Nightshade Species in Louisiana Sugarcane. J. Am. Soc. Sugar Cane Technol. 38:23-43.
    • Type: Other Status: Published Year Published: 2018 Citation: Orgeron A. and Spaunhorst D. Divine Nightshade. Louisiana State University Agricultural Center, Publication MISC-257, September 2018.
    • Type: Other Status: Published Year Published: 2018 Citation: Orgeron A. and Spaunhorst D. Divine Nightshade. Louisiana State University Agricultural Center, Magnet Publication MISC-256, September 2018.