Location: Sugarcane Research
2019 Annual Report
Objectives
1. Develop soil management systems that overcome limitations in soil and nutrient resources and maximize production efficiency.
1.A. Determine the potassium and phosphorus requirements for new varieties on both silt loam and heavy-clay soils.
1.B. Develop practices for the application of phosphorus and potassium that are more accurate and cost effective.
2. Develop crop production practices to increase management flexibility, reduce input costs, and maximize profits.
2.A. Develop mechanized planting methods that increase management flexibility and reduce input costs.
2.B. Develop management systems to replace post-harvest burning of crop residues.
2.C. Develop techniques to estimate yields prior to harvest and maximize production efficiency.
3. Integrate pest management systems into sugarcane production systems including genetic sources of host-plant resistance for greater sugarcane yield, sustainability, and ratoon longevity. Benefits will include an integrated approach to pest and disease control in sugarcane production, enhanced genetic understanding and development of new varieties with host-plant resistance to insect pests and diseases vectored by insects, and increased understanding of integrated pest management in the sugarcane agroecosystem environment for sustainable and profitable production.
Approach
To address the first objective, a series of experiments will be initiated to investigate the response of sugarcane to variations in macro- and micro-nutrients. Results from these experiments will be used to identify critical fertility components and to optimize fertility rates for sucrose production. Initial macro-nutrient experiments will focus on potassium (K), and phosphorus (P), two critical components of a sugarcane fertility program whose costs have risen dramatically. Micro-nutrient experiments will focus on boron, molybdenum, copper, nickel, and cobalt. There is a critical lack of research data for these nutrients in Louisiana and these studies will help to fill this void. All treatments will be arranged in randomized complete block design (RCBD) with six replications. To address the second objective, studies will be initiated to investigate new mechanized planting methods and to develop new management systems that can replace burning of post-harvest crop residues. Finally, scientists will investigate the utility of a newly designed yield monitor and multiband aerial imagery collected with unmanned aerial systems as potential indicators of cane biomass levels and sucrose content.
The sugarcane borer (SCB) and Mexican rice borer (MRB) continue to be the major economic pests in Louisiana sugarcane. In replicated field experiments, sugarcane cultivars will be evaluated for resistance to MRB and SCB. Data collection will include % bored internodes, adult emergence and yield loss assessment. Field experiments will also be conducted to identify control tactics for managing damaging infestations of a four-species hemipteran complex infesting sugarcane (e.g., sugarcane aphid, yellow sugarcane aphid, West Indian canefly, and sugarcane delphacid). These experiments will seek to better refine damage thresholds and ultimately establish action thresholds for initiating insecticide applications. The most effective insecticide formulations will need be to be identified as well as determining their most economical application rates. Ultimately, the findings from these studies will be used to develop improved and sustainable integrated pest management strategies for insect pests of sugarcane primarily in Louisiana, but the findings are generally applicable for sugarcane grown in Florida and Texas.
Progress Report
To consolidate and strengthen complementary efforts in sugarcane research, National Program directed this unit to merge ARS Project No. 6052-12210-003-00D (NP 305), entitled, “New Crop and Soil Management to Improve Sugarcane Production Efficiency,” with ARS Project No. 6052-22000-017-00D (NP 304), entitled, “Integrated Weed and Insect Pest Management Systems for Sustainable Sugarcane Production,” and ARS Project No. 6052-22000-018-00D (NP 303), entitled, “Sugarcane Improvement through Effective Disease Management and Resistance Development.” The new consolidated Project No. 6052-12210-003-00D (NP 305) is entitled “New Crop Production and Protection Practices to Increase Sugarcane Ratoon Longevity and Maximize Economic Sustainability”. This new project is currently undergoing OSQR review.
Sulfur fertilizer recommendations in Louisiana were made when significant sulfur atmospheric deposition still occurred, which markedly reduced the need for fertilizer amendments. However, increased state and federal regulations have significantly reduced atmospheric deposition and sulfur levels in many Louisiana sugarcane fields have decreased. In addition, data from preliminary sulfur trials suggested that current recommendations were too low. It is clear that research is needed to reevaluate sulfur recommendations for the Louisiana sugarcane industry under these new circumstances. ARS scientists in Houma, Louisiana, initiated studies in clay and silt loam soils in commercial plant cane, and first- and second- ratoon sugarcane fields to determine the optimum sulfur requirements for newly released Louisiana varieties. Varieties evaluated in the study included HoCP 96-540, HoCP 09-804,and L01-299. Sulfur was applied to all experiments at rates ranging from 0 to 75 lb S/A using one of three fertilizer sources, 1) elemental sulfur, 2) ammonium sulfate, or 3) ammonium thiosulfate. Leaf samples will be collected for plant tissue analysis and stalk counts and plant heights will be determined in August. Cane and sugar yields will be determined on all trials by harvesting the experiments in October, November, or December--depending on crop age (with plant-cane harvested last).
Research has continued with commercial micronutrient formulations to determine if these formulations could be used as adjuvants at planting and as ripeners. This work was initiated because there is critical lack of research data on micronutrient fertility available in Louisiana. In both plant-cane and first-ratoon fields of HoCP 04-838, a significant increase in both cane and sugar yields was obtained with both cobalt and starter fertilizer. The largest increases were observed when cobalt and starter fertilizer were combined. Significant benefits in sugar yields were observed in a similar second- and third-stubble trials. In ripener trials that evaluated several experimental compounds the best sugar yields were obtained with a boron ripener, which significantly increased tons of cane during the ripening period. Promising results were also obtained when cobalt was combined with the commercial ripener glyphosate. The combined results from these experiments indicate that micronutrient fertilizers can play a vital role in the sugarcane production cycle, beginning at planting and continuing through the ripening of the final harvested crop.
Remote sensing data was collected utilizing an unmanned aerial vehicle (UAV) in a commercial plant-cane field of L01-299. This study was harvested in November 2018 using a chopper harvester equipped with a yield monitor and additional data was collected by weighing select rows with a weigh wagon. The remote sensing data from all experiments was analyzed and compared to actual yield estimates to determine the utility of these methods to estimate yields prior to harvest. Preliminary data indicate that UAV remote sensing data may offer valuable yield estimates that could help growers determine harvest schedules to optimize both cane and sugar yields. Additional studies are planned for the 2019 harvest season with UAV imagery collection to begin in late July 2019 and harvest to occur in mid November 2019.
Accomplishments
