Location: Sugarcane Research
2017 Annual Report
Objectives
The main objectives proposed in this Project Plan are to develop and improve sustainable management strategies for weeds and insects. Effective integrated pest management (IPM) programs are vital to a sustainable cropping system. Over the next 5 years, the project will focus on the following objectives:
Objective 1: Evaluate newer herbicide chemistries (i.e., 4-hydroxyphenylpyruvate (HPPD) inhibitors, cell wall biosynthesis inhibitors, etc.) for efficacy of weed control in sugarcane and crop safety, as well as older, currently registered herbicides to improve weed management (tank-mix combinations, timing of application, use of spray adjuvants, etc.).
Objective 2: Evaluate cultural control methods for reducing weed interference in sugarcane including, but not limited to: varietal differences in competitiveness of sugarcane, inter-row tillage timing, type, frequency, and rotational crops (including green manure cover crops) that could be used during fallow season compared with chemical fallow, and site-specific management.
Objective 3: Enhance the role of plant resistance in managing damaging infestations of stem borers (i.e., sugarcane borer and Mexican rice borer) in sugarcane.
Sub-objective 3.A: Characterize fiber among commercial sugarcane cultivars resistant to the sugarcane borer and Mexican rice borer.
Sub-objective 3.B: Identify borer resistant progeny in high sucrose bi-parental crosses.
Objective 4: Identify control tactics for managing damaging infestations of a hemipteran complex (e.g., sugarcane aphid, yellow sugarcane aphid, West Indian canefly, and sugarcane delphacid) to include the role of soil health on these infestations and new insecticides for controlling the complex.
Approach
The approach to meeting the objectives of this project plan will be primarily in the form of replicated field experiments. Some of these field experiments will also be supported by laboratory analyses. New herbicide chemistries, when they become available, will provide the potential for greater efficacy in weed control; however, determining appropriate application rates, application timing, and application methodology will require replicated field experimentation that are repeated in multiple years. Results from these experiments will be used for obtaining labeling by EPA and ultimately in formulating extension recommendations to sugarcane growers. Cultural controls provide opportunities for reducing weed pressure by planting sugarcane varieties with greater competitiveness resulting in more efficient tillage practices (i.e. fewer cultivations). Planting rotational crops (e.g. soybean and sweet sorghum) will provide an additional income stream to growers while also aiding in suppressing weed infestations. To develop these improved cultural practices will also require a series of field experiments. The results from these studies will also be used to develop extension recommendations for sugarcane growers. Enhancing the role of plant resistance in controlling the sugarcane borer and Mexican rice borer will require a more in-depth knowledge of fiber composition in commercial sugarcane varieties. A replicated field experiment consisting of sugarcane varieties with known reaction to sugarcane borer and Mexican rice borer will provide plant tissue for detailed fiber analyses. Ultimately a fiber profile will be qualified and quantified that will allow selection for stem borer resistance in the absence of the insect pest. Finally, field experiments will be conducted to identify control tactics for managing damaging infestations of a four-species hemipteran complex infesting sugarcane. 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 this Project Plan will be used to develop improved and sustainable management strategies for weeds and insects pest of sugarcane primarily in Louisiana, but the findings are generally applicable for sugarcane grown in Florida and Texas.
Progress Report
Ten studies were established in February of 2017 with sugarcane varieties
HoCP 96-540 and L 99-299 to determine the effects of several new herbicides and herbicide tank-mixtures on crop injury, weed control, and cane and sugar yields. Herbicide treatments were applied in the spring of 2017 and crop injury and weed control ratings were recorded throughout the spring. In certain studies, weeds were counted and harvested for biomass measurements. Sugarcane stalk counts and heights were measured in August and cane and sugar yields will be recorded in November or December 2017. Four of the studies were located at cooperators’ fields in Terrebonne and Pointe Coupee Parish, Louisiana.
Soybean and sweet sorghum were planted at the Sugarcane Research Unit’s (SRU) research farm near Houma, Louisiana, to study the effect of potential allelochemicals from these crops on subsequent cane and sugar yields. Soybean and sweet sorghum emergence was poor following the first planting attempt in mid-April, but the second planting attempt in early-May was successful. Soybean and sweet sorghum will be harvested in September 2017. Plots will be cultivated, beds re-established, and sugarcane varieties HoCP 04-838, HoCP 09-804, HoCP 96-540, and L 99-299 will be hand-planted. Soil samples will be taken prior to cultivation to determine the presence of potential allelochemicals. Cane and sugar yields will be measured by harvesting the plots in the fall of 2018. This will be the second run of the study. Plant cane from the first run of the study will be harvested fall of 2017.
In the fall of 2016, a study was planted with sugarcane varieties HoCP 85-845, HoCP 04-838, Ho 07-613 and HoCP 00-950 to determine how the fiber components of the four varieties changed during the growing season. This data will then be related to borer infestation data from separate yield reduction studies. The plots were sprayed with insecticide to maintain the plots free of sugarcane borers in the spring and summer of 2017. Stalks were collected on a monthly interval from June through September for fiber component analysis and stalk counts were determined in August of 2017. All plots will be harvested in the fall of 2017 to determine cane and sugar yields.
A field has been identified to determine the efficacy of selected sugarcane insecticides on the levels of hemipteran pests present in a commercial field of L 01-299. Insecticide treatments were applied in late June 2017. Insect counts were completed prior to insecticide application and then at 3, 10 and 20 days after treatment. Yield data will be collected from all plots in the fall of 2017 to determine cane and sugar yields. In July 2017, a large field (2-5 ha) infested with hemipteran pests were identified for a grid mapping study. Hemipteran pest numbers will be determined at selected grid sample points throughout the field to determine their distribution and density in the field. Soil and leaf samples will also be collected at each sample point to determine if the pest numbers can be related to soil and plant nutrient levels. Cane and sugar yields will be determined by harvesting selected rows of the field in the fall of 2017.
Accomplishments
