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United States Department of Agriculture

Agricultural Research Service

2006 Annual Report

1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter?
Sugarcane is grown on a total of 400,000 hectares (ha) in four states. It has been grown in Louisiana for more than 200 years and is the highest value row-crop in the state with a yearly economic impact of $1.7 billion. Sugarcane is cultured as a perennial crop with a cropping cycle consisting of at least four yearly harvests. The wide range of perennial and annual weeds that occur in the crop, especially in the later years of the crop cycle, can reduce yields 40 to 80% when not controlled. Sugarcane growers presently depend on a few key herbicides applied at high rates to insure residual activity to control problematic weeds. The development of new, environmentally friendlier herbicides for the sugarcane industry by pesticide manufacturers is a low priority because of the small size of the potential national market. Loss of one or two of the currently labeled herbicides could cause a dramatic increase in weed populations. Several species of insects also cause economic damage to sugarcane. Of these, the sugarcane borer is the most important and can reduce yield 10 to 20% when not controlled. Concern for resistance by insects and weeds plus environmental concerns suggest uncertainty for the future of pesticide use to control damaging infestations and places increasing demands for alternative methods of control. Over the last 10 years, the cane sugar industry has seen an increase in farm size, a switch to a chopper harvesting system, and a need to reduce agronomic input (cultivation, fertilization, etc.) costs to remain profitable. Chopper harvesters cut sugarcane stalks into short pieces and its extractor fans remove most of the leafy trash from the cut stalks. The harvester can harvest green or burnt cane. Harvesting burnt cane is more efficient; however, environmental concerns associated with burning are driving the industry to harvest the crop green. The leafy trash removed during green-cane harvesting is deposited uniformly over the field and can be 10 to 12 cm thick and represent 3 to 4 tons of dry matter. The impact of this post-harvest residue and the associated changes in agronomic practices on weed and insect development are not known.

Specific objectives of the project include: .
1)develop new and modify existing production-year strategies for integrated and sustainable weed and insect management in sugarcane; and.
2)measure the long-term impact of changing agronomic and harvesting practices on weed and insect pest development during a 4-year sugarcane cropping cycle.

This project falls within Components III (Plant, Pest, and Natural Enemy Interactions and Ecology) and V (Pest Control Technologies) (35%) and Component VII (Weed Biology), VIII (Chemical Control of Weeds), and X (Weed Management Systems) (35%) of NP 304. The entomology aspect focuses on III.C (Effects of Various Production Practices); V.A (Traditional Biological Control); and V.B (Breeding for Host Plant Resistance). The weed aspect focuses on VIII.D (New Herbicides); VII.E (Weed Biology and Ecology - Growth, Development, and Competition); X.A (Cultural and Mechanical Control); and X.B (Integrated Weed Management in Cropland). The balance of the project (30%) falls within National Program 305, Crop Production.

The research in this project is expected to lead to more effective, efficient, and environmentally friendly weed and insect control systems that reduce herbicide, insecticide, and production inputs. The research is aimed at making the production of sugarcane in the U.S. more environmentally friendly and competitive in a global market. Findings will be used by the Louisiana Cooperative Extension Service (LCES) (and perhaps in Florida and Texas), the USDA National Resources Conservation Service, and various National Estuary Programs as they develop recommendations and Best Management Practices for sugarcane.

2.List by year the currently approved milestones (indicators of research progress)
Year 1 (FY 2005) Objective 1.1. Identify plant-cane sites of the variety LCP 85-384 to determine the degree of weed control that current and alternative cultural and mechanical controls afford and weed species that are most susceptible, and conditions that affect efficacy of control. Infest fields with johnsongrass, itchgrass, or morningglory (at least one study for each weed species).

Objective 1.2. Identify sugarcane fields with existing infestations of bermudagrass, itchgrass, johnsongrass, and morningglory to evaluate and provide efficacy data on new chemistries for selective control of weeds and determine compatibility of new herbicides with currently used herbicidal practices.

Objective 1.3. Initiate studies to evaluate an introduced biological control agent to control season-long infestations of the sugarcane borer. Establish a colony of the introduced parasite Cotesia falvipes. Fabricate cages for containing parasites and sugarcane borer larvae being released in sugarcane in the spring and in johnsongrass isolated on ditchbanks.

Objective 1.4. Complete evaluation of wild sugarcane by cultivated sugarcane cross. Collect stalk and sheath tissue from new wild sugarcanes for evaluation for resistance evaluation in laboratory.

Objective 2.1. Locate two test sites to be planted with the sugarcane variety LCP 85-384 to evaluate the impact of changing cultivation frequencies and the presence of post-harvest sugarcane residues on weed development and competitiveness of johnsongrass and bermudagrass over a complete 4-year sugarcane cropping cycle.

Objective 2.2. Locate appropriate test site to evaluate the impact of late season sugarcane borer infestations in early-planted sugarcane. Sample field for numbers of dead-tops caused by feeding of larvae of sugarcane borer.

Year 2 (FY 2006) Objective 1.1. Initiate cultivation treatments, residue levels, and apply appropriate herbicide treatments. Identify duplicate study sites for repeating experiment.

Objective 1.2. Initiate experiments at alternative sites and begin initial technology transfer at grower meetings and technologist meetings.

Objective 1.3. Repeat releases of sugarcane borer and parasites in young sugarcane and in johnsongrass. Report findings at technologist meeting.

Objective 1.4. Make new crosses with wild sugarcanes and borer resistant cultivated sugarcane. Report findings from evaluation of wild sugarcane by cultivated sugarcane.

Objective 2.1. Apply treatments to the plant-cane crop and collect appropriate yield data at harvest. Locate a duplicate test site.

Objective 2.2. Resample in the spring the field identified the previous year as having high levels of sugarcane borer larvae. Repeat sampling of field to determine the level of stalk damage caused by sugarcane borer larvae feeding and also harvest field. Report findings at crop consultant meeting.

Year 3 (FY 2007) Objective 1.1. Report findings of preliminary data at grower meetings and technologist meetings. Apply treatments to duplicate study.

Objective 1.2. Transfer technology of herbicide efficacy trials and establish a new field for additional trial of new herbicides as they become available.

Objective 1.3. Repeat releases for a third year. If data shows conclusively that young sugarcane is not an appropriate searching environment for the introduced parasite and field releases in johnsongrass does not prove acceptable due to natural infestations, begin greenhouse studies.

Objective 1.4. Plant progeny from crosses of wild sugarcane by resistant cultivated sugarcane made the previous year.

Objective 2.1. Apply treatments to first experiment in the first-harvested crop and collect yield data at harvest. Transfer technology to user groups. Apply treatments to first-harvested crop of duplicate study and collect yield data at harvest.

Objective 2.2. Repeat study of late season infestations in a duplicate study. Begin pit-fall trapping in established experiment to evaluate the impact of crop residue on ground inhabiting insects.

Year 4 (FY 2008) Objective 1.1. Initiate cultivation, residue levels, and herbicide treatments in duplicate study to determine the degree of weed control that current and alternative cultural and mechanical controls afford, weed species that are most susceptible and conditions that affect efficacy of control.

Objective 1.2. Repeat herbicide efficacy studies, initiate new studies, and report findings.

Objective 1.3. Repeat greenhouse studies with johnsongrass and initiate studies with vaseygrass.

Objective 1.4. Evaluate progeny of crosses planted the previous year following one year of over wintering.

Objective 2.1. Apply treatments to second-harvested crop and collect yield data. Apply same treatments to first-ratoon crop of duplicate study and collect yield data from this study.

Objective 2.2. Repeat pit-fall trapping (soil trapping of insects) in a previously harvested crop of the established study. Begin a repeat study in a second experiment. Report findings from previous year's evaluation.

Year 5 (FY 2009) Objective 1.1. Transfer technology from studies to determine the degree of weed control that current and alternative cultural and mechanical controls afford and determine what weed species are most susceptible, and conditions that affect efficacy.

Objective 1.2. Repeat herbicide efficacy studies, initiate new studies, and report findings.

Objective 1.3. Complete greenhouse evaluations of appropriateness of vaseygrass as an alternative host for over wintering parasites. Make final report on the appropriateness of C. flavipes as a beneficial insect for controlling damaging infestations of sugarcane borer.

Objective 1.4. Re evaluate progeny identified as sugarcane borer resistant the previous year and prepare to make germplasm release of those proving to be resistant.

Objective 2.1. Apply treatments to the third-ratoon crop of the first study and the second-ratoon crop of the second study, and collect yield data at harvest of the study to evaluate the impact of changing cultivation frequencies and the presence of post-harvest sugarcane residues on weed development and competitiveness, report findings.

Objective 2.2. Complete pit-fall trapping of the duplicate study to determine the impact of crop residue on ground inhabiting insects. Report findings at technologists meeting and prepare manuscript.

4a.List the single most significant research accomplishment during FY 2006.
NEW HERBICIDES FOR SUGARCANE EVALUATED. Weed control at planting and in the spring during crop establishment is vital in order to attain yields profitable to sugarcane growers. Herbicidal weed control options within sugarcane crops are limited with many acting through the same mode of action, the inhibition of photosynthesis. ARS scientists at the Sugarcane Research Unit (SRU) have continued to evaluate several herbicides applied alone and in mixtures for the control of bermudagrass, itchgrass, morningglory, and johnsongrass when applied as single and sequential applications. Introducing new herbicides for use in sugarcane will broaden the effective modes of action being utilized which has implications for herbicide resistance management and will reduce effective application rates, reducing environmental impact, as these new herbicides are effective at much lower use rates than herbicides traditionally used in sugarcane. In a continuing study, the new herbicide trifloxysulfuron-sodium (Envoke®), in combination with the herbicide asulam (Asulox®), has been shown to improve control of rhizome johnsongrass compared to asulam alone, and for the first time in 2006, the herbicide mesotrione (Callisto®) was evaluated for crop safety of broadleaf weed control in sugarcane. The research conducted by SRU scientists was used by the Louisiana Cooperative Extension Service in the development of weed control recommendations contained in its 2006 Sugarcane Production Handbook. This research addresses NP 304's Action Component Vlll D. (New Herbicides for the Control of Weeds).

4b.List other significant research accomplishment(s), if any.
NEW SUGARCANE RIPENERS EVALUATED. Harvesting of sugarcane in Louisiana begins before the natural ripening of the sugarcane is complete. In order to increase sugar yields, much of the sugarcane is treated with low rates of the herbicide, glyphosate. Glyphosate has been recently shown to negatively impact gross yields in the treated crop and may negatively impact the regrowth of the crop the following year (ratoon crop), especially if harvest is delayed too long following treatment. Currently glyphosate is the only chemical ripener registered for use in Louisiana sugarcane. Several potential sugarcane ripeners were evaluated for their potential use in Louisiana sugarcane, including trinexapac-ethyl (Palisade®), nicosulfuron (Accent®), and imazapyr (Arsenal®), which were all shown to be promising alternatives to glyphosate. This research will be continued and expanded in order to provide new alternatives for sugarcane ripening with greater safety to sugarcane crops. This research supports Action Components I.C. Integrated Production Systems-Sustainable Cropping Systems of NP 305 (Crop Production).

4c.List significant activities that support special target populations.

4d.Progress report.
The project contributes to subordinate project 6435-21000-012-04T with the American Sugar Cane League, Improving Sugarcane Production Efficiency, which is part of the parent project 6435-21000-012-00D, Genetic Improvement of Sugarcane by Conventional and Molecular Approaches. Additional details of research can be found in the reports of the subordinate and parent projects.

5.Describe the major accomplishments to date and their predicted or actual impact.
Sugarcane growers in Louisiana usually spend well over $100/ha annually on herbicides for weed control with additional money being spent on mechanical control of weeds (cultivation). Recent studies by Sugarcane Research Unit (SRU) scientists have shown bermudagrass, not controlled at planting, can reduce sugar yields in the subsequent first production year (plant-cane crop) by as much as 32% even if the bermudagrass is completely removed in March at the start of the growing season. Yield losses in second and third production years (ratoon crops) were less and often insignificant and total sugar yield losses for the three-year crop cycle were as high as 15%. This study shows the importance of eliminating bermudagrass from sugarcane fields prior to planting, as the majority of yield losses occurred during the plant-cane establishment period. The results of these studies will help in formulating recommendations to growers in order to improve management of these problem weeds while showing the impacts of crop residue management and tillage on sugarcane production. This research supports Action Component VII (Weed Biology) with a focus on VII.E (Weed Biology and Ecology - Growth, Development, and Competition) of National Program 304 (Crop Protection and Quarantine).

The sugarcane borer is the most important insect pest of sugarcane in Louisiana and is also an important pest of sugarcane in Florida and Texas. Growing sugarcane varieties with natural resistance to the borer is a viable attribute in an integrated pest management program. Unfortunately, resistance to sugarcane borer is not a primary selection trait in the Louisiana commercial variety development program. Therefore, the resistant category (resistance, intermediate, susceptible) of new varieties must be determined prior to their release to farmers. Scientists at the SRU determined the resistance category of the two most recent varieties released in 2006. One variety, L 99-233, was classified as susceptible and the second, L 99-226, was classified as resistant. Such classification provides farmers and their consultants with information necessary to effectively manage borer control and thus reduce the amounts of insecticides sprayed into the environment. This information is also critical to plant breeders as they make decisions on what bi-parental crosses to make. Crossing resistant varieties to susceptible varieties increases the frequency of borer resistance in progeny and thus increases the probability of ultimately releasing resistance to farmers. This research supports Action Component III (Plant, Pest, and Natural Enemy Interaction and Ecology) with a focus on V.B. (Breeding for Host Plant Resistance) of National Program 304 (Crop Protection and Quarantine).

An additional attribute of a successful integrated pest management system for the control of the sugarcane borer is the presence of natural predators that attach the sugarcane borer especially when it is in the damaging larval stage. Research by SRU scientists and cooperators identified the weak-links in establishing a parasitic wasp (Cotesia flavipes) into Louisiana. The weak-link identified was the absence of overwintering sites followed by an inappropriate searching area when parasites emerge following overwintering. Sugarcane in Louisiana fails to provide either of these two necessary components. However, greenhouse experimentation has shown that native grass species may provide both of these components, plus a third potentially useful component - an alternative host. Ultimately these findings will be of great importance to growers as they will be able to alter their on-farm management practices in a manner that will allow them to establish another beneficial insect with the resulting increase in benefits of biological control. This research also supports Action Component III, but with the focus on V.A. (Traditional Biological Control) of National Program 304 (Crop Protection and Quarantine).

6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
Significant interaction with customer groups occurred at the following meetings in which ARS researchers were invited to speak: Joint Louisiana and Florida Divisions' annual meeting of the American Society of Sugar Cane Technologists at St. Pete Beach, FL (1); LCES sponsored spring (January/February) parish grower meetings (3) and summer (July/August) parish field days (5). Research results were also discussed during LCES-sponsored Research Extension planning meetings in Houma (2) and St. Gabriel (2), LA; and at the Louisiana Ag Consultant Association annual workshop in St. Francisville, LA (2), and its annual convention in Alexandria, LA (2). Research findings were also presented at international meetings. Entomology research was presented at the 6th International Society of Sugar Cane Technologist Entomology Workshop in Cairns, Australia. Weed control research was also presented at a raw sugar factory-sponsored pre-harvest meeting in Thibodaux, LA. The major constraint to the transfer of the agronomic technology is that the development of the technology requires field experimentation over a number of years. The research is slowed further by the fact that the number of variables to consider is great (soil texture, weed and insect pressures, crop age, environments, etc.) and the number of ARS and University scientists involved in this area of research is low.

Review Publications
White, W.H., Adamski, D., Fine, G., Richard Jr, E.P. 2005. Stemborers Associated with Smooth Cordgrass, Spartina Alterniflora (Poaceae), in a Nursery Habitat. Florida Entomologist. 88(4):390-394.

Kimbeng, C.A., White, W.H., Miller, J.D., Legendre, B.L. 2006. Sugarcane resistance to the sugarcane borer: response to infestation among progeny derived from resistant and susceptible parents. Sugar Cane International. 24(3):14-21.

White, W.H., Da Silva, J.A. 2006. Cross resistance in sugar cane to the Mexican rice borer and the sugarcane borer (Lepidoptera: Crambidae)[abstract]. 6th International Society of Sugar Cane Technologists Entomology Workshop, May 15-20, 2006, Cairns, Australia. Available:

Richard Jr, E.P., Dalley, C.D. 2006. Sugarcane response to depth of soil cover at planting and herbicide treatment. Journal of the American Society of Sugar Cane Technologists. 26:14-25. Available:

Dalley, C.D., Richard Jr., E.P. 2006. Efficacy of tank-mix combinations of asulam and trifloxysulfuron on rhizome johnsongrass control in sugarcane. Proceedings of Southern Weed Science Society. 59:61.

Richard Jr., E.P., Dalley, C.D., Viator, R.P. 2006. Ripener influences on sugarcane yield in Louisiana [abstract]. Journal of the American Society of Sugar Cane Technologists. 26:54. Available:

Richard Jr, E.P., Dalley, C.D. 2005. Bermudagrass (Cynodon dactylon) Interference in a Three-Year Sugarcane (saccharum spp.) Production Cycle. Sugar Cane International. 23(4):3-7.

White, W.H., Tew, T.L., Richard Jr, E.P. 2006. Association of sugarcane pith, rind hardness, and fiber with resistance to the sugarcane borer. Journal American Society Sugar Cane Technologists. 26:87-100.

Last Modified: 5/5/2015
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