Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824
Performing Department
Horticulture
Non Technical Summary
Michigan is the second most diverse state in the agriculture sector followed by California. More than 30 different types of fruit and vegetables are produced here in Michigan. Profitable production of these crops requires effective management of the land, plants, and pests that might otherwise reduce quality and yield. Weed control is a continuous challenge for production of these specialty crops.Weeds not only directly compete with crop plants for nutrients, water, space, and light and reduce yield and quality, but can also indirectly affect crop growth by harboring insects and pests, reducing the harvest efficiency,and causing inhibition in general crop maintenance practices such as setting up irrigation and sprayer applications. Season-long weed interference can cause in an average of 50 to 100% yield loss depending on type of crop and weeds.In addition, several herbicide resistant weed species have been identified in Michiganand are increasing exponentially in vegetables and fruits.New weed species are being introduced into Michigan that may not be effectively controlled with existing herbicides. Therefore, there is a continuous need to explore new weed management tools to provide sustainable and economic production of fruit and vegetables.More research is required to improve current methods and to develop economic, effective, and environment-friendly weed control strategies by combining both chemical and non-chemical practices. Therefore, the overall aim of this project is to provide research based integrated weed management (IWM) solutions to the edible specialty crop growers which will lead to effective weed control and ultimately good quality crops with higher yields and profitability. This project will focus to understand the herbicide resistance in important weeds in Michigan vegetable and fruit production systems. Having an understanding of the types of resistance present in the field will help to plan future weed management strategies, thus helping farmers preserve and use wisely the weed control tools they currently have.This project will examine the biology and management of the newly emerging pigweed species, purple amaranth, in Michigan vegetable production systems. Understanding the biology and management of target species in the specific environment where they are growing is critical knowledge necessary to implement integrated pest management strategies. This project will also focus on evaluating precision sprayer technology, evaluate new and emerging weed management tools (e.g. electrical weeder), and involve an IR-4 project to generate data related to crop safety and/or product performance/efficacy, and residue for registration of pesticides in these various fruit and vegetable crops.
Animal Health Component
60%
Research Effort Categories
Basic
10%
Applied
60%
Developmental
30%
Goals / Objectives
Michigan is the second most diverse state in the agriculture sector followed by California. More than 30 different types of fruit and vegetables are produced here in Michigan. Weed control is a continuous challenge for production of these specialty crops.More research is required to improve current methods and to develop economic, effective, and environment-friendly weed control strategies by combining both chemical and non-chemical practices. Therefore, the overall aim of this project is to provide research based integrated weed management (IWM) solutions to the edible specialty crop growers which will lead to effective weed control and ultimately good quality crops with higher yields and profitability.OBJECTIVES:1. Screen for herbicide resistance to key weeds, including pigweeds, horseweed, large crabgrass, and common ragweed in fruit and vegetable production systems2. Assess the spread of purple amaranth in Michigan, develop extension material for awareness, and design management strategies for its control.3. Evaluate the best fit for electricity-based weed control in IWM systems for carrot, squash, and pickling cucumber4. Evaluate a vision-guided, precision sprayer with respect to weed control efficacy and crop safety as compared to traditional broadcast applications5. Obtain phytotoxicity, efficacy, and residue data to support potential new uses and registrations of herbicides on fruit and vegetable crops (IR-4 Project)
Project Methods
Objective 1.Seed collected from cooperating farms will be used to better understand the scope of resistance issues across Michigan vegetables. Samples will be screened for resistance to six to eight herbicide modes of action at two rates (1x and 4x field rates) to examine the suspected resistance issues and to look for cases of multiple resistance.Objective 2a.To help with the identification of purple amaranth, our plan is to develop a fact sheet "Purple amaranth in Michigan: Keys to Identification" and share with growers through various means. Extension articles will be published on a regular basis to encourage growers to contact us for correct identification and seed collection of purple amaranth. A data sheet along with sample collection instructions will be developed and shared with growers through MSU extension news articles, at various extension talks, and events to spread the news about this emerging new weed species. With the help of regional extension educators, we will also reach out to the various growers to scout their fields for purple amaranth infestation and seed collection. Objective 2b.The collected seed samples of purple amaranth will be screened for potential herbicide resistance by using a whole plant assay, and then a dose response assay will be performed to characterize the level of herbicide resistance. Objective 2c.Germination studies will be conducted to determine whether seed germination of purple amaranth is influenced by temperature, light, pH, osmotic potential, and depth of burial. For all assays other those examining burial depth, fifty seeds of purple amaranth will be placed evenly in a 9-cm-diameter petri dish lined with two pieces of filter paper. Germination will be recorded every 2 d for a period of 14 d.The effect of constant temperature will be evaluated by placing Petri dishes in growth chambers at 5, 10, 15, 20, 25, 30, and 35 C during a 14-d period. To assess the effect of photoperiod, seeds will be incubated under 5 different light/dark regimes of complete dark, 0h/24h, 8h/16h, 12h/12h and 16h/8h. The effect of a pH buffered solution on germination will be evaluated by incubating seeds in dishes containing solution of pH 4-10. To evaluate the effect of water stress on purple amaranth seed germination, seed will be placed in solutions with osmotic potentials of 0, -0.2, -0.4, -0.6 and -0.8 Mpa (megapascal) which will be prepared by dissolving 0, 112.38, 172.41, 218.13, and 256.13 g of polyethylene glycol (PEG6000) in 300 ml of distilled water. The effect of seed burial depth on seedling emergence will be investigated in a greenhouse by planting purple amaranth seeds at soil depths of 0, 2, 4, 6, 8, and 10 cm in plastic pots. Objective 2d. Additive studies will be conducted to investigate purple amaranth competitive interactions with various vegetable crops.Purple amaranth will be planted at varied density in pots along with either celery or carrot or pickling cucumbers to assess the impact of purple amaranth density on crop growth. Growth measurements including plant height (distance between base and terminal leaf), number of primary branches, and plant biomass will be recorded at the maximum vegetative stage.The total leaf area will be determined using a leaf area meter. Objective 2e.Greenhouse studies will be conducted to evaluate the effectiveness of various pre- and post-emergence herbicides to control purple amaranth. The potential herbicides may include: glyphosate, glufosinate, halosulfuron, pendimethalin, ethalfluralin, metribuzin, prometryn, linuron, oxyfluorfen, flumioxazin, fomesafen, s-metolachlor, pyroxasulfone, mesotrione, indaziflam. At the time of postemergence herbicide application, purple amaranth plants will be 10 to 12 cm tall. Percent control and biomass data will be collected at 4 weeks after treatment (WAT). For preemergence herbicide application, 50 seeds of purple amaranth will be planted in each pot using field soil and then covered with a thin layer of soil. One day after sowing, preemergence herbicide will be applied, and after that pots will be sub-irrigated on a saucer plate to avoid any leaching. Seed count data will be collected at a weekly interval for four weeks.Based on the greenhouse screening, pre-and postemergence herbicides will be selected to evaluate in field for celery production systems. Objective 3.Carrot, squash, and pickling cucumber will be selected to evaluate the electricity-based weed control in IWM systems. These crops are selected due to their economic importance for Michigan, limited availability for weed control methods, and short crop canopy. These trials will take place on commercial grower-collaborator farms (Oomen farm, Hart, MI). Treatments will include either no pre-emergence or traditional pre-emergence herbicide-based weed management programs. Escaped weeds will either be allowed to remain (weedy control) or controlled with either hand-weeding (weed-free control), weed zapping, post-emergence herbicides, between-row cultivation, and combinations thereof.Data will be collected for weed control as a visual estimate on a scale of 0 (no control) to 100% (complete control) and weed counts by species. At the end of the season, weeds will be harvested to determine weed seed production. A subsample of seeds will be tested for germinability. Seeds within the subsample that fail to germinate will be subjected to viability testing to approximate the percentage of dormant seeds. Crop injury from incidental contact with the weed zapper will be documented. Crop yields will be recorded. Objective 4.To examine the efficacy of vision-guided sprayer, trials will be conducted in apple, grapes, and blueberry.The treatments will include POST herbicide applications made using a vision-guided sprayer or traditional broadcast sprayer.Post-emergence active ingredients to be tested include: glyphosate, glufosinate, paraquat, carfentrazone, Pelargonic acid, tiafenacil (new PPO burndown herbicide from ISK; not registered to use in any fruit or vine crops), and several organic products (caprylic plus capric acid, clove oil, citrus-based concentrate, and acetic acid).Key data to be collected include: weed control as determined by changes in weed cover and density; differential performance with respect to species identity (i.e. management escapes); off-target particle movement and degree of crop contact; crop injury; pesticide use, labor requirements (and associated costs); costs of equipment purchase/maintenance. Kromekote papersmart phone application, SnapCard (SNP),will be used as samplers to quantify spray coverage, deposits, and deposit density in the target and nontarget areas. Objective 5.Each year, at least 10 replicated trials will be conducted to collect data related to the efficacy and phytotoxicity in various fruit and vegetable crops in representative locations in Michigan to support new herbicide uses and registration. Annual and perennial horticultural crops will be treated with various herbicides and combinations of herbicides to determine effective use rates and timings. The treatments will be evaluated for crop injury, crop yield, and weed control by species. In addition to traditional herbicides, several new herbicides and herbicides with labels being expanded will be tested. These include florpyrauxifen, tiafenacil, tolpyralate, pyroxasulfone, pendimethalin, and indaziflam, quinclorac, and saflufenacil. Field residue trials (10 to 12 trials each year) will be conducted by following the Good Laboratory Practice (GLP) requirements mandated by EPA. These residue trials play an important role to establish the tolerance level for pesticides in various fruit and vegetable crops. Overall, the phytotoxicity, efficacy, and residue data collected from Michigan will be the part of the multistate data which plays a paramount role for product registration and recommended for MRL at IR-4.