Performing Department
Crop & Soil Sciences
Non Technical Summary
Management practices that increase the competitive ability of crops with weeds are important components of integrated weedmanagement systems. Weeds can greatly impact crop yield through direct competition for water, sunlight, and nutrientresources. Practices that affect one factor in a cropping system can impact others. Tillage practices can affect weed speciescomposition, and weed species composition in turn can affect the critical period of weed control in a given crop (Halford et al.2001). Understanding the impact tillage and cropping systems have on weed management will help in determining optimal cropproduction practices. It is important to understand the biology and growth characteristics of plant species that make them strongcompetitors with crops. While biology and ecology are common research areas, weed physiology is an often overlooked area ofresearch in weed research. It is important to understand the effects that environmental factors have on the physiology of weedyspecies. Effective weed management programs that integrate all components of the production system including planting date,crop rotation, tillage regime, soil nutrient amendment application, and weed control measures. Sustainable weed managementpractices will be critical in the success of this emerging crop production area as weeds are one of the most limiting factors inestablishing a healthy competitive crop, especially in perennial crop establishment and production (Fischer et al. 1988; Hall et al.2004). Investigating weed species and their management in row crops and emerging bioenergy crops is important to the NorthCarolina State University mission to secure food and fiber, enhance profitability in agriculture, and providing environmentalstewardship. Developing effective, economical, and environmentally sound weed management systems for North Carolinafarmers will contribute to the fulfillment of the this mission.
Animal Health Component
0%
Research Effort Categories
Basic
10%
Applied
80%
Developmental
10%
Goals / Objectives
1. Identify soybean and wheat varieties with competitive characteristics.2. Develop cultural practices that economically manage herbicide resistant common ragweed or Palmer amaranth.3. Identify at harvest weed seed management practices that reduce weed seed populations in the soil seedbank.4. Determine the impact crop rotation and weed management practices have on long term Italian ryegrass populations in wheat.5. Utilize UAVs and sensors to aid in crop scouting and weed mapping.
Project Methods
Objective 1: Field and greenhouse studies will be conducted to understand the differences in growth characteristics betweenvarious crop cultivars. Studies will investigate early season growth habits, determining factors such as leaf area, growth rate,leaf orientation, and other indices that may enhance competition with weedy species. To determine if these factors affectcompetition, weed species will be grown in competition with the crop species to measure differences where present. Weed species will consist of weeds native to North Carolina including Palmer amaranth, common ragweed, and morningglory species,and annual grass species such as Italian ryegrass, large crabgrass, broadleaf signalgrass, and Texas panicum. Crop cultivarswill be sown according to current recommendations in areas naturally infested with target weed species. Growth measurementswill be taken throughout the growing season, and yields will be taken at the end of the year.Objective 2: Greenhouse studies will be combined with field research studies to screen potential preemergence andpostemergence herbicides programs to manage herbicide resistant weeds. It is suspected that over-reliance on herbicideprograms will lead to the continued development of herbicide-resistant weeds to multiple modes of action. Therefore, fieldstudies will be concurrently conducted to investigate cultural practices on long-term management of resistant species. Todetermine the impact of crop rotation and seed removal on summer annual weed species, at harvest weed-seed removal tacticswill be investigated. Practices such as seed removal, burning, tillage, and grinding will be investigated in continuous soybeanand corn - soybean rotations. Measurements will be taken before and after implementation of management tactics to determineefficacy on weed seeds. Long term evaluation of soil seedbanks and seedling density will also be measure.Objective 3. Various studies investigating narrow wind row burning, chaff lining, and at harvest weed destruction will be investigated in on-farm trials.Objective 4. The experiment will consist of a factorial arrangement of two tillage types, three herbicide treatments for management ofItalian ryegrass in wheat, and two crop rotations. Treatments will be replicated 3 or 4 times at each location. Tillage treatmentswill include no-tillage and vertical-tillage. Herbicide treatments in wheat will include a non-treated check, a singlepostemergence application, and a residual herbicide applied at spike stage followed by a postemergence application. Croprotations for the duration of the project will consist of wheat-soybean double crop or wheat-soybean-corn repeated for 6 years.Fields naturally infested with Italian ryegrass will be used and Italian ryegrass density will be determined periodically with cropsharvested at the end of each season to calculate total grain production and net return of each crop rotation treatment. Toconclude the study, wheat will be planted and Italian ryegrass will be left uncontrolled and the final density of the weed will bedetermined. Corn and soybean will be managed using normal agronomic practices.Objective 5. UAVs and various sensors will be flown in novel configurations to aid in weed identification and mapping practices. These new techniques will be developed through collaborative research projects and as new technologies and uses are identified, they will be disseminated to farmers and crop consultants within the state.