A Comparison of an Unhooded and Hooded Sprayer for Pesticide Drift Reduction

Management of drift from pesticide applications is important for human and environmental health concerns. It is also necessary to ensure adequate dosage of the pesticide meets the target species(s). A variety of factors can affect the drift potential of a pesticide application, including nozzle selection, solution chemistry, and application equipment. In the present study, a comparison of two ground sprayers, one with a hood and one without a hood, is made using three common ground nozzles in the US. The hooded sprayer reduced the drift potential of the pesticide application for all nozzles tested. In addition, higher spray coverage under the boom was measured when using the hooded sprayer. The results of this study indicate that incorporating a hood will lead to reduced drift potential from a pesticide application

Corn Disease Update

Goss\u27s Bacterial Wilt and Blight ... Symptoms ... Management ... 2011 Survey ... Literature Cited Gray Leaf Spot Seedling Diseases and Stalk/Crown Root Diseases More Resource

Corn Disease Update

Goss\u27s Bacterial Wilt and Blight ... Symptoms ... 2011 Survey results ... New alternate hosts identified ... Goss\u27s Wilt Management Strategies ... More Resources ... Literature Cited Aspergillus Ear Rot and Aflatoxin Contaminated Grain ... Table 1. FDA Action Levels for Aflatoxin in Feed and Food ... Testing for Aflatoxin ... High risk factors for aflatoxin contamination in corn ... Scouting for Aspergillus Ear Rot ... Harvest and Storage ... More Resources Stalk Rot Diseases ... Scouting for Stalk Rot Diseases ... Management ... More Resource

Four Common \u3ci\u3eSetaria\u3c/i\u3e Species Are Alternative Hosts for \u3ci\u3eClavibacter michiganensis\u3c/i\u3e subsp. \u3ci\u3enebraskensis\u3c/i\u3e, Causal Agent of Goss\u27s Bacterial Wilt and Blight of Corn

Goss’s bacterial wilt and blight, caused by Clavibacter michiganensis subsp. nebraskensis (Cmn), has reemerged as an important disease of Zea mays (corn) in the U.S. Midwest. Results from a 2011 multistate survey indicated that Setaria spp. (foxtail) were often present in corn fields with a history of Cmn. The objective of this research was to determine if Setaria spp. that are common in the Midwest are susceptible to infection by Cmn. In the greenhouse, seedlings of four Setaria spp., including S. viridis (green foxtail), S. faberi (giant foxtail), S. verticillata (bristly foxtail), and S. pumila (yellow foxtail), and Zea mays (Golden Cross Bantam sweet corn, GCB) were inoculated with a suspension of 1.0 × 107 bacteria cells. The trial was arranged in a randomized complete block design and repeated once. Percent of symptomatic leaf area was visually estimated eight days after inoculation. S. faberi exhibited the highest levels of disease among the four Setaria spp., with disease incidence similar to what was observed on Z. mays. S. viridis was the next most susceptible. Symptoms were also observed on S. viridis, S. verticillata, and were lowest for S. pumila. Bacterial streaming was confirmed microscopically and Cmn was reisolated from the four Setaria species. Results indicate that these four Setaria spp. are susceptible to Cmn, thus serving as potential sources of inoculum

Comparison of water-sensitive paper, Kromekote and Mylar collectors for droplet deposition with a visible fluorescent dye solution

The study was conducted at the University of Nebraska Pesticide Application and Tech-nology Laboratory in North Platte, Nebraska in July 2015. Two application volume rates (100 and 200 l · ha−1) and three nozzle types (XR, AIXR, TTI) were selected at two flow rates (0.8 and 1.6 l · min−1) and at a single application speed of 7.7 km · h−1. Each collec-tor type [Mylar washed (MW), Mylar image analysis (MIA), water-sensitive paper (WSP), and Kromekote (KK)] was arranged in a randomized complete block design. Each nozzle treatment was replicated twice, providing six cards of each collector type for each nozzle treatment. A water + 0.4% v/v Rhodamine WT spray solution was applied, given the fluo-rescent and visible qualities of Rhodamine, which allows it to be applied over all the collec-tor types. MW had the highest coverage at 18.3% across nozzle type, followed by WSP at 18%, KK at 12% and lastly by MIA at 4%. MW resulted in a 58% increase in coverage, WSP in a 56% increase, and KK only an increase of 39% when the volume rate was doubled from 100 l · ha−1 to 200 l · ha−1 across nozzle type. MW coverage was similar to KK for half of the nozzles (XR 11002, XR 11004, AIXR 11002). Droplet number density fixed effects were all significant for nozzle type and collector type (p \u3c 0.001) as was the interaction of nozzle type and collector type (p \u3c 0.001). Results from this study suggest a strong correlation to data produced with WSP and MW collectors, as there was full agreement between both types except for the TTI 11004. Using both collector types in the same study would allow for a visual understanding of the distribution of the spray, while also giving an idea of the concentration of that distribution

Particle drift potential of mesotrione and rimsulfuron plus thifensulfuron-methyl tank mixture in a low-speed wind tunnel

Particle drift happens during herbicide application when droplets travel outside the intended site. Different nozzles produce various range of droplets, so they play a very important role in coverage and drift occasions. When nozzles produce small droplets, the potential for off-target movement is very high. Another important factor determining particle drift is the distance between crops. Wind velocity gives the energy to herbicide particles to move away from the target place. Therefore, a drift simulation of herbicide (mesotrione and rimsulfuron plus thifensulfuron-methyl mixture) was done in a wind tunnel, using different nozzles Extended Range (XR) and Turbo TeeJet Induction (TTI). The wind speed was set at 4.4 m/s, representing the least favourable conditions where applications are possible. In the wind tunnel, eight crops (cantaloupe, cotton, green bean, pumpkin, soybean, sunflower, wheat, and watermelon) were positioned at 4, 6, 9, and 12 m downwind distances from the nozzle, and drift was simulated. Following treatments, plants were returned to a greenhouse for 28 days, and biomass reduction was recorded. Artificial collectors (Mylar cards) and water sensitive cards were positioned alongside plants. According to obtained results, spraying with XR nozzle influences higher injuries than TTI nozzle. Tracer deposition was higher at all distances when XR nozzle was used. Accordingly, droplet numbers, covered area, Volume Median Diameter (VMD), and deposition were higher on water sensitive cards when spraying were done using XR nozzle. As a consequence, higher biomass reduction occurred using the XR nozzle. The most sensitive crops were cantaloupe, pumpkin and sunflower, while the most tolerant were soybean and wheat

Comparison of an ultra-low volume (ULV) sprayer against a conventional sprayer, for foliar fertiliser and fungicide applications in turfgrass

Two field studies (I and II) at the University of Nebraska-Lincoln: John Seaton Anderson Turfgrass Research Facility near Mead, NE, USA, were conducted to determine if a new ultra-low volume (ULV) sprayer can apply foliar nutrient, growth regulator, and fungicide treatments, in a manner similar to that of a conventional sprayer. Treatments were applied over creeping bentgrass ‘L-93’ (Agrostis stolonifera L.) managed as a fairway at 561 l · ha−1 and 47 l · ha−1 with the conventional and ULV sprayer, respectfully. Data were collected for chlorophyll content with a chlorophyll meter, and for the normalised difference vegetation index (NDVI) with a turf colour meter. Each plot was harvested for biomass at 21 days after treatment. Study II compared the ULV sprayer and a conventional sprayer, for the control of brown patch (Rhizoctonia solani Kuhn) in creeping bentgrass. The treatments were propiconazole and azoxystrobin. Spray volume was 561 l · ha−1 for the conventional sprayer, and 19 l · ha−1 for the ULV sprayer. Statistical differences in turf quality or dry weight reductions between the conventional and ULV sprayer were not detected. Brown patch control was also similar between the two sprayers, but azoxystrobin provided better control than propiconazole. Even with a 30-fold decrease in application volume, the results indicated that the Kamterter ULV sprayer may be a useful and effective management option for foliar fertiliser and fungicide applications in turfgrass