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 33 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?