2006 Annual Report
Specific objectives of the project include: .
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.
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.
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).
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: http://www.issct.org.entoabstracts06.htm.
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: http://www.assct.org/journal/journal.htm
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: http:www.assct.org/journal/journal.htm
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.