《植物化学保护》课程教学资源（英文讲稿）Considerations on Foliar Applications and Volume of Pesticides

Considerations on Foliar Presentation Outline Applications and Volume of Pesticides review Considerations 573-634 mes Quinn Wayne Peterson Most veggie sprayers Parts of a hydraulic spraye ·Hydraulic 。Tank sprayers ·Agitato, ·Low pressure ·High pressure ·Pump 。Droplet size ·Gauge ·Fine-better ·Strainer coverage ·Pressure ·Large-better regulators penetration 。Hose Nozzles Air assist/air blast sprayers Regular flat-I&H,low p Flooding flat-common* Hollow cone-good p* Rain drop-p varies praPagteforlowvo Nozzle material- Brass ant amo Nylon -Hardened SS Greater risk of drift,esp.at high p

1 Considerations on Foliar Applications and Volume of Pesticides James Quinn 573-634-2824; QuinnJa@missouri.edu & Wayne Peterson 660-783-0006; midwestgrower@sbcglobal.net Presentation Outline • Quick sprayer review • Discussion on some of the most common sprayers used with vegetable crops￾small & large • Checklist for operation and maintenance • Water volume for complete coverage Considerations • Systemic products vs contact • Impact of nozzle pressure • Two approaches for adjusting spray volume due to plant size • How much to apply given a range (e.g. 5 to 9 oz/acre Most veggie sprayers are. • Hydraulic sprayers • Low pressure • High pressure • Droplet size • Fine- better coverage • Large- better penetration Parts of a hydraulic sprayer • Tank • Agitator • Pump • Gauge • Strainer • Pressure regulators • Hose Nozzles • Regular flat- I&H, low p • Flooding flat- common* • Hollow cone- good p* • Rain drop- p varies • Nozzle material- – Brass – Stainless steel (SS) – Plastic – Nylon – Ceramic – Hardened SS * Greater risk of drift, esp. at high pressure Air assist/air blast sprayers • Fan aides distribution • Used in fruit production • Compatible for low volume spraying • Pros – Reduced runoff – Reduced use of pesticide and water • Cons – Need constant ground speed – Extra care for calibration – Application errors easier because less total gallonage applied

On pressure and volume Shielded sprayers ·5 ow press5ure- ·50 gallons per (.tm coverage vares and its size take 300 Sprayers for small areas Sprayers for small areas Modified ATVs Sprayers Operation and maintenanc Available as a kit Small tank for spraying or smal add a hose and gun 2

2 On pressure and volume • Low pressure- 5 to 60 psi • High pressure￾greater then 100 • Volume required for complete coverage varies greatly by crop, and its size • 50 gallons per acre is common • 100 g/acre may be required for upright crops (e.g. tomatoes) • Tree fruit may take 300 g/acre Shielded sprayers Sprayers for small areas Sprayers for small areas Modified ATVs Sprayers • Available as a kit • Small tank for stability • Good for spot spraying or small areas • Can add a hose and gun Operation and maintenance Before • Fill & pressurize • Check for leaks • Review nozzle type, size & angle • Check strainers and screens • Look at boom height/nozzles for uniform application • Calibrate!! During and after • Pressure should stay same- check • Adjust speed to limit swaying/bouncing • Avoid in field repairs if possible • Flush after use • Thoroughly clean when switching between pesticides and/or when doing repairs or maintenance

Systemic product or contact? Implications of nozzle type and pressure Systemic Contact/protectant he iny of th mos ninplant nray nre ed hpeedegarenc phids/mi Implications of nozzle type Adjusting spray volume for and pressure.comments smaller plants/lesser area Nozzle angle smeith othe products te am area higneteracan inch crop stature al The recommended range of middle pray volume por acre fo e acre r ana-5.8 to 9 2.6to6.4 3

3 Systemic product or contact? Systemic • Translaminar • Localized systemic • Systemic￾distribution in plant is (usually) less with foliar application then when soil applied (e.g. drench) Contact/protectant • Many of the most common products • Only effective where lands • Complete/uniform coverage very important, esp. for diseases & pests like aphids/mites Implications of nozzle type and pressure • Study from 97 to 99 at Purdue looked at chlorothalonil on melons • Used flat or hollow cone nozzles and 3 spray pressures • No differences between treatments • Conclusion￾emphasize the timing of fungicide applications and choice of chemicals over how those fungicides should be applied • Good uniform coverage is essential Implications of nozzle type and pressure.comments • Nozzle angle • May not be the same with other products • Other factors can influence, e.g. environmental & crop stature Adjusting spray volume for smaller plants/lesser area Reducing area of application • When plants are small, pesticide could be banded over the plants • Less area is treated (less product) • Pesticide ‘strength’ is the same on a given area • Example- using one 1 nozzle for an 18 inch wide band. If rows were on 6-ft. centers, spraying an 18-inch strip over the row would mean that for every acre of field sprayed, only 1/4 acre (1.5 ft. / 6 ft.) would actually be treated Adjusting spray volume for smaller plants/lesser area Volume based recommendation • First determine the maximum spray volume per acre for your sprayer for fully-grown plants • Then mix the acre rate for a given product in the maximum spray volume that it takes to cover an acre. • Much less ‘volume’ will be used on smaller plants • For example, mancozeb products (Dithane DF, Manzate, Penncozeb, etc.) are labeled at 3 lbs per acre. If the maximum spray volume is 100 gallons per acre for your sprayer when plants are full grown, then mix the mancozeb product at the rate of 3 lbs per 100 gallons of spray. At the start of the season, it may take only 25 to 30 gallons per acre to obtain full coverage. The volume of spray per acre is then increased as plants grow and spray nozzles are added until the maximum 100-gallon volume per acre is reached at full plant growth. The recommended range of pesticide on the label- apply the high, middle or lower amount? • Can vary greatly￾examples (cucumber beetles on cucurbits) – Asana- 5.8 to 9 fl oz/acre – Capture- 2.6 to 6.4 fl oz/acre • What rate to use? • Higher/lower depending on pest pressure? • Depending on the pest? • Experience? • Or always use the max?

IRAC (not Irag)FRAC Conclusions Good working order Understand impact o uniform coverage key systemic vs contact ·Understand reduced volume based ·e hmna5ea品8 ae Each sprayer has its approach When the label rate Rotate to a different number consideraioareS d options ·IRAC and FRAZ

4 IRAC (not Iraq!) & FRAC • Number is prominently displayed on pesticide label; phased in voluntary addition to label • Rotate to a different number • If same number, choose a different letter • Pyrethroid class has limited options Conclusions • Good working order, uniform coverage key • Nozzle type and pressure may not be limiting factor • Each sprayer has its advantages and limitations • Understand impact of systemic vs contact • Understand reduced area application vs volume based approach • When the label rate of product/acre varies, considerations. • IRAC and FRAC