M.E. Rogers and M.M. Dewdney, Editors R.H. Brlansky, W.O. Dawson, L.W. Duncan, M.R. Estes, F.M. Fishel, S.H. Futch, J.H. Graham, M.E. Hilf, R.N.

Transcription

1 M.E. Rogers and M.M. Dewdney, Editors R.H. Brlansky, W.O. Dawson, L.W. Duncan, M.R. Estes, F.M. Fishel, S.H. Futch, J.H. Graham, M.E. Hilf, R.N. Inserra, J.W. Noling, L.R. Parsons, N.A. Peres, M.A. Ritenour, P.D. Roberts, M. Salyani, T.S. Schubert, B. Sellers, P.J. Sieburth, M. Singh, P.A. Stansly, L.L. Stelinski

2 Page intentionally left blank

3 2015 FLORIDA CITRUS PEST MANAGEMENT GUIDE EFFECTIVE AND SAFE PEST MANAGEMENT STRATEGIES IN CITRUS PRODUCTION FOR USE IN COMMERCIAL GROVES ONLY Before using any pesticide: Read the complete label and the general instructions in this guide. A contribution of the CREC-Lake Alfred crop and pest management advisory group with input from the SWFREC-Immokalee, IRREC-Ft. Pierce, and DOC- Lake Alfred. M.E. Rogers and M.M. Dewdney, Editors Citrus REC-Lake Alfred 700 Experiment Station Road Lake Alfred, FL Institute of Food and Agricultural Sciences Florida Cooperative Extension Service University of Florida, Gainesville Nick Place, Dean and Director Copyright 2015 by the University of Florida, Institute of Food and Agricultural Sciences (IFAS). All rights reserved. Material from this book may be used for educational purposes if full credit is given. Please refer to the EDIS web site at for the most recent updates. COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES, Nick Place, Dean and Director, in cooperation with the United States Department of Agriculture, publishes this information to further the purpose of the May 8 and June 30, 1914 Acts of Congress; and is authorized to provide research, educational information and other services only to individuals and institutions that function without regard to race, color, age, sex, handicap or national origin. The information in this publication is available in alternate formats. Information on copies for purchase is available from the IFAS Extension Bookstore (ifasbooks.com). Information about alternate formats is available from IFAS Communication Services, University of Florida, PO Box , Gainesville, FL This information was published January 2015 as SP-43, Florida Cooperative Extension Service.

4 Page intentionally left blank

5 Table of Contents CHAPTER PAGE GENERAL INFORMATION 1 Introduction Useful Telephone Numbers Fresh Fruit Pesticide Residue Limits Pesticide Resistance and Resistance Management Pesticide Application Technology Best Management Practices for Soil-Applied Agricultural Chemicals Worker Protection Standards Interpreting PPE Statements on Pesticide Labels...29 MITES, INSECTS, AND NEMATODES 9 Asian Citrus Psyllid and Citrus Leafminer Rust Mites, Spider Mites, and Other Phytophagous Mites Soft-Bodied Insects Attacking Foliage and Fruit Plant Bugs, Chewing Insect Pests, Caribbean Fruit Fly, and Thrips Citrus Root Weevils Nematodes...59 DISEASES 15 Phytophthora Foot Rot and Root Rot Brown Rot of Fruit Greasy Spot Melanose Citrus Black Spot Citrus Scab Alternaria Brown Spot Postbloom Fruit Drop Exocortis, Cachexia, and Other Viroids Blight Tristeza Citrus Canker Huanglongbing (Citrus Greening)...97 WEEDS 28 Weeds...99 PESTICIDES 29 Pesticides Registered for Use on Florida Citrus Florida Citrus Pest Management Guide 1

6 Page intentionally left blank

7 2015 FLORIDA CITRUS PEST MANAGEMENT GUIDE: Introduction 1 M.E. Rogers and M.M. Dewdney 2 The objective of the Florida Citrus Pest Management Guide is to assist citrus growers in the identification of pest management options and the selection of appropriate control measures. This publication should serve as a reference once it has been determined that control measures might be warranted. It is not intended to replace pesticide product labels that contain important usage information and should be immediately accessible for reference. Violations of directions for use printed on the label are against State and Federal laws. Care should be taken to select only those treatments best suited for control of the specific pest(s) identified as requiring suppression. Products listed in all tables have been shown to be efficacious, non-phytotoxic to citrus, and relatively safe on non-target arthropods and microorganisms when used as directed. However, it is important to realize that results may not be consistent under different environmental, application, and tank mix conditions. As a supplement to each table of recommendations, we have provided information on which to base a management decision specific to the target pest, weed or disorder. This information will assist the producer in developing management strategies for a particular set of conditions and possibly identify circumstances under which chemical intervention may not be necessary. For specific information on pest identification, biology, damage or non-chemical management techniques, refer to Extension Digital Information System (EDIS) and other IFAS, USDA, and Florida Department of Agriculture and Consumer Services (FDACS) publications. In addition to the authors listed throughout the Pest Management Guide, the citrus specialists and agents listed below can provide assistance with pest management information. Research and Education Centers CITRUS REC 700 Experiment Station Road Lake Alfred, FL (863) Dr. Michael E. Rogers, Interim Center Director / Entomology Dr. Michelle D. Danyluk, Citrus Processing Dr. Megan M. Dewdney, Plant Pathology Dr. Reza Ehsani, Agricultural Engineering Dr. Joseph W. Noling, Nematology Dr. Ariel Singerman, Economics Dr. Tripti Vashisth, Horticulture INDIAN RIVER REC 2199 South Rock Road Ft. Pierce, FL (772) Dr. Peter J. Stoffella, Center Director Dr. Brian J. Boman, Citrus BMPs, Water Quality Dr. Barrett R. Gruber, Horticulture Dr. Mark A. Ritenour, Postharvest Physiology 1. This document is CPMG01, one of a series of the Plant Pathology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date: December Revised: November This publication is included in SP-43, 2015 Florida Citrus Pest Management Guide. Visit the EDIS website at For a copy of this guide, request information on its availability at your county extension office. 2. M.E. Rogers, associate professor, Entomology and Nematology Department; and M.M. Dewdney, assistant professor, Plant Pathology Department; Citrus REC, Lake Alfred, Florida; Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville,

8 SOUTHWEST FLORIDA REC 2686 State Road 29 N Immokalee, FL (239) Dr. Calvin E. Arnold, Center Director Dr. John Dunckelman, Farm Manager Dr. Kelly T. Morgan, Soil and Water Science Dr. Pamela D. Roberts, Plant Pathology Dr. Fritz M. Roka, Economics Dr. Robert E. Rouse, Horticulture Dr. Philip A. Stansly, Entomology TROPICAL REC SW 280 Street Homestead, FL (305) Dr. Christine T. Waddill, Center Director Dr. Jonathan H. Crane, Tropical Fruit Crops Dr. Daniel Carillo, Tropical Fruit Crop Entomology County Extension Agents - Citrus MR. GARY K. ENGLAND Extension Agent III, Multi-County, Fruit Crops Brevard, Lake, Marion, Orange, Osceola, Seminole and Volusia Lake County Extension Service 1951 Woodlea Road Tavares, FL (352) gke@ufl.edu DR. CAMI ESMEL Extension Agent II, Multi-County, Commercial Horticulture Hernando, Pasco and Sumter Sumter County Extension Service 7620 SR 471 Suite 2 Bushnell, FL (352) cami13@ufl.edu MS. ADRIAN HUNSBERGER Extension Agent IV, Urban Horticulture Miami-Dade County Extension Service SW 288th Street Homestead, FL (305) aghu@ufl.edu MS. LAURIE HURNER Extension Agent III, Citrus Highlands County Extension Service 4509 George Boulevard Sebring, FL (863) lhurner@ufl.edu MR. W. CHRIS OSWALT Extension Agent III, Multi-County, Citrus Hillsborough and Polk Polk County Extension Office P. O. Box 9005, Drawer HS03 Bartow, FL (863) wcoswalt@ufl.edu MR. PARKER PLATTS Extension Agent I, Fruit Crops St. Lucie County Extension 8400 Picos Rd., suite 101 Ft. Pierce, FL (772) pplatts@ufl.edu DR. MONGI ZEKRI Extension Agent IV, Multi-County, Citrus Charlotte, Collier, Glades, Hendry and Lee Hendry County Extension Service P. O. Box 68 LaBelle, FL (863) maz@ufl.edu DR. STEPHEN H. FUTCH Extension Agent IV, Multi-County, Citrus DeSoto, Hardee, Manatee and Sarasota Citrus Research and Education Center 700 Experiment Station Road Lake Alfred, FL (863) shf@ufl.edu Florida Citrus Pest Management Guide

9 2015 FLORIDA CITRUS PEST MANAGEMENT GUIDE: Useful Telephone Numbers 1 Frederick M. Fishel 2 National Pesticide Information Center (NPIC) :30 a.m. - 4:30 p.m. Pacific time. Provides general information on pesticide products, recognition and management of pesticide poisoning, toxicology, and environmental chemistry. CHEMTREC CHEMTREC is the Chemical Transportation Emergency Center. It is operated by the Chemical Manufacturers Association to assist in handling chemical emergencies Emergency number providing information to persons having large chemical spills or leaks. The University of Florida/IFAS Pesticide Information Office: Citrus Research and Education Center: Florida Department of Agriculture and Consumer Services Division of Plant Industry: Pesticide Certification/Licensing Office: This document is PI-15, one of a series of the Agronomy Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date: December Revised: September Visit the EDIS website at For a copy of this guide, request information on its availability at your county extension office. 2. Frederick M. Fishel, professor, Agronomy Department, and director, Pesticide Information Office; Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL

10 Page intentionally left blank

11 2015 FLORIDA CITRUS PEST MANAGEMENT GUIDE: Fresh Fruit Pesticide Residue Limits 1 M.A. Ritenour 2 Current production practices often include the use of various pre- and postharvest chemicals, many of which are pesticides. To be used, these materials must be labeled for use on citrus and used only according to label instructions. Chemical residues on the fruit after harvest are a concern to regulators and the public alike because of their potential negative health effects. Therefore, the U.S. and other countries set maximum residue limits (MRLs) on fresh produce for various chemicals. It is unlikely for United States MRLs to be exceeded when label instructions are followed. However, when importing countries MRLs are lower than U.S. MRLs, then use of these pesticides usually must be modified or discontinued to keep from exceeding the country s tolerances. In addition, individual buyers may set their own, more restrictive standards. Similar to buyer-imposed food safety standards, buyer-imposed MRL standards, especially from large buyers, can significantly impact how pesticides are used in the field and packing facility. Table 1 list the MRLs (in part-per-million) for various chemicals used on fresh Florida citrus for the U.S., CODEX, and important export countries. The limit of detection for chemical residues on citrus fruit is often around 0.01 ppm, depending on the testing laboratory and chemical of interest. When no tolerance is stated, any detectable residue will violate tolerances. Violations may lead to rejected loads of product, restrictions on future shipments, and even increased requirements for the entire industry to a given market. Because MRLs change frequently, see the Foreign Agricultural Service (FAS) International Maximum Residue Limits Database ( mrldatabase.com) or the University of Florida s Postharvest Resources Website ( for the most current information. Links to MRL databases for select countries can be found at index/pesticides.shtml. Table 1 and the websites are intended as an initial reference source and no guarantee is made to their accuracy. Always verify these values with other knowledgeable sources within specific markets of interest. TABLE 1. MAXIMUM RESIDUE LIMITS (MRLS) IN PART-PER-MILLION (PPM), BY COUNTRY. ABBREVIATIONS: GRAPEFRUIT (G), ORANGE (O), TANGERINE (T), LEMON (L), PUMMELO (P). Chemical Name 2,4-D (2,4-Dichlorophenoxyacetic acid) Abamectin Trade Names (Examples only, not inclusive) U.S. Citrus Canada Citrus CODEX Citrus EU (G & O only) Japan (G & O only) Taiwan Korea (G & O only) (G & O only) Citrus Fix, Hivol (G); 0.05 (O) Agri-Mek, Clinch, Zephyr, ABBA, Epi-mek, Reaper 0.02; 0.01 (P) Acephate Acephate, Orthene Acequinocyl Kanemite (G); 0.4 (O) 2 1 Acetamiprid Assail Acibenzolar-S-methyl Actigard 0.05 (G; Expires 12/31/15) Azoxystrobin Abound, Graduate A (G); 5 (O) Bifenthrin Brigade, Capture, Telstar, Fanfare This document is HS-1124, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Date revised: November This publication is included in SP-43, 2015 Florida Citrus Pest Management Guide. Please visit the EDIS Web site at For a copy of this handbook, request information on its purchase at your county extension office. 2. M.A. Ritenour, associate professor, Horticultural Sciences Department, Indian River REC, Ft. Pierce, Florida; Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, The use of trade names in this publication is solely for the purpose of providing specific information. It is not a guarantee or warranty of the products named, and does not signify that they are approved to the exclusion of others of suitable composition.

12 TABLE 1. MAXIMUM RESIDUE LIMITS (MRLS) IN PART-PER-MILLION (PPM), BY COUNTRY. ABBREVIATIONS: GRAPEFRUIT (G), ORANGE (O), TANGERINE (T), LEMON (L), PUMMELO (P). Chemical Name CONTINUED TABLE Trade Names (Examples only, not inclusive) U.S. Citrus Canada Citrus CODEX Citrus EU (G & O only) Japan (G & O only) Taiwan Korea (G & O only) (G & O only) Boscalid A component of Pristine Bromacil Bromo, Hyvar (G); 0.05 (O) Buprofezin Applaud, Centaur (G); 2 (O) Carbaryl Sevin Carfentrazone-ethyl Aim Chlorantraniliprole Altacor, part of VoliamFlexi Chlorpyrifos Lorsban, Nufos Cryolite Kryocide 7 7 Cyfluthrin Baythroid Dicofol Dicofol, Kelthane 6 (expires 10/31/2016) Difenoconazole A component of Quadris Top (G); 0.5 (O) Diflubenzuron Micromite Dimethoate Dimethoate, Cygon Diuron Diuron, Direx, Karmex 0.05; 0.5 (L) (G); 0.05 (O) EPTC (S-Ethyl dipropylthiocarbamate) Eptam Fenbuconazole Enable (G, T, O, P); 1 (L) 0.05 (G); 0.2 (O) Fenbutatin Oxide Vendex Fenpropathrin Danitol Fenpyroximate Portal Ferbam Ferbam 4 10 (T); 2 (O) (G); 2 (O) Fluazifop-P-butyl Fusilade (G); 0.1 (O) Fludioxonil Graduate, Graduate A (G); 5 (O) Formetanate Hydrochloride 1.5 (G, O); 0.03 (T), 0.6 (L) Fosetyl-aluminum Aliette Glyphosate Roundup, Durango, Touchdown, & others (G, L); 0.5 (O, T) Hexythiazox Savey Hydrogen cyanide Imazalil Freshgard 700, Imidacloprid Admire, Alias, Provado, Couraze, Nuprid, Pasada, Widow Indaziflam Alion Malathion Malathion, Atrapa, Fyfanon Metalaxyl-M, Mefenoxam Ridomil Gold, Subdue, Ultra- Flourish Metaldehyde OR-Cal Slug & Snail Bait Methanearsonic acid (MSMA) 0.35 (0.7 proposed) 0.5 Methidathion Supracide 4; 6 (T) (Expires 12/31/16) 2 2; 5 (T) Methoxyfenozide Intrepid 2F (G); 3 (O) NAA (1-naphthaleneacetic acid) Fruit Fix (O) Naled Dibrom 3; 0.5 (P) Norflurazon Solicam Oryzalin Oryzalin, Surflan Oxamyl Vydate (G); 1 (O) 5 Paraquat Dichloride Paraquat, Gramoxone, Boa Pendimethalin Prowl, Pendimax Phosmet Imidan Phosphine Piperonyl Butoxide Evergreen EC 10; 8 (O) 8 (O) Propargite Comite, Omite 5 (G, L); 10 (O) Florida Citrus Pest Management Guide

13 TABLE 1. MAXIMUM RESIDUE LIMITS (MRLS) IN PART-PER-MILLION (PPM), BY COUNTRY. ABBREVIATIONS: GRAPEFRUIT (G), ORANGE (O), TANGERINE (T), LEMON (L), PUMMELO (P). Chemical Name CONTINUED TABLE Propiconazole Trade Names (Examples only, not inclusive) Banner, Bumper, Tilt, Orbit, PropiMax U.S. Citrus Canada Citrus CODEX Citrus EU (G & O only) Japan (G & O only) (O) (G); 0.03 (O) Taiwan Korea (G & O only) (G & O only) Pyraclostrobin Headline ; 2 (O) Pyrethrins Pyrellin (+ Rotenone), Evergreen (+ Piperonyl Butoxide) 1 1 (O) Pyridaben Nexter Pyrimethanil Penbotec 10; 11 (L) Pyriproxyfen Distance, Esteem, Knack (G); 0.5 (O) Rimsulfuron Saflufenacil Treevix, Kixor Sethoxydim Poast Plus Simazine Simazine, Princep, Sim-Trol 0.25 (G, O, L) SOPP (2 Phenylphenol, O- phenylphenol, OPP) FreshGard (G); 9 (O) Spinetoram Delegate (O) (G); 0.07 (O) Spinosad Entrust, Naturalyte, Justice, Spintor Spirodiclofen Envidor Spirotetramat Movento (G) 0.5 Streptomycin FireWall 0.4 (G) (Section 18 12/31/15) Tebufenozide Thiabendazole (TBZ) Freshgard 598, Alumni Thiamethoxam Actara, Platinum, part of VoliamFlexi ; 0.5 (O) Thiazopyr Mandate 0.05 (G, O) 0.5 (G); 0.05 (O) Trifloxystrobin Gem Trifluralin Trifluralin, Treflan, Trilin zeta-cypermethrin Mustang ; 0.5 (G, P) Tolerance for unlisted materials=> None 0.1 None None None Florida Citrus Pest Management Guide 9

14 Page intentionally left blank

15 2015 FLORIDA CITRUS PEST MANAGEMENT GUIDE: Pesticide Resistance and Resistance Management 1 M.E. Rogers and M.M. Dewdney 2 Populations of animals and plants possess the ability to respond to sustained changes or stresses in their environment in ways that enable the continued survival of the species. Such environmental stresses include physical factors (e.g., temperature or humidity), biological factors (e.g., predators, parasites, or pathogens) and environmental contaminants. In any population, a small percentage of individuals will be better able to respond to new stresses because of unique traits or characteristics that they possess. Consequently, those individuals will survive and reproduce. This phenomenon is commonly referred to as survival of the fittest. Many pest species, such as the citrus rust mite, are exceptionally well-equipped to respond to environmental stresses because of their short generation time and large reproductive potential. The use of chemical sprays to control insect, mite, and fungal diseases of citrus creates a potent environmental stress. There are now many examples of pests that have responded by developing resistance to one or more pesticides. Pesticideresistant individuals are those that have developed the ability to tolerate doses of a toxicant that would be lethal to the majority of individuals. The resistance mechanisms can vary according to pest species and/or the class of chemical to which the pest is exposed. Resistance mechanisms include an increased capacity to detoxify the pesticide once it has entered the pest s body, a decreased sensitivity of the target site that the pesticide acts upon, a decreased penetration of the pesticide through the cuticle, or sequestration of the pesticide within the organism. The main resistance mechanism for pathogens is a change in the target site so that the pathogen is less susceptible or fully resistant. A single resistance mechanism can sometimes provide defense against different classes of chemicals and this is known as cross-resistance. When more than one resistance mechanism is expressed in the same individual, this individual is said to show multiple resistance. Because the traits for resistance are passed from one generation to the next, continued stress from a pesticide may, over time, create resistance in the majority of individuals in a population. From an operational perspective, this process would be expressed as a gradual decrease and eventual loss of effectiveness of a chemical. Resistance to a particular chemical may be stable or unstable. When resistance is stable, the pest population does not revert to a susceptible state even if the use of that chemical is discontinued. When resistance is unstable and use of the chemical is temporarily discontinued, the population will eventually return to a susceptible state, at which time the chemical in question could again be used to manage that pest. However, in this situation, previously resistant populations may eventually show resistance again. Of the factors that affect the development of resistance, which include the pest s or pathogen s biology, ecology and genetics, only the operational factors can be manipulated by the grower. The key operational factor that will delay the onset of pesticidal resistance and prolong the effective life of a compound is to assure the survival of some susceptible individuals to dilute the population of resistant individuals. The following operational procedures should be on a grower s checklist to steward sound pesticidal resistance management for acaricides, insecticides, fungicides, and herbicides: 1. Never rely on a single pesticide class. 2. Integrate chemical control with effective, complementary cultural and biological control practices. 3. Always use pesticides at recommended rates and strive for thorough coverage. 4. When there is more than one generation of pest, alternate different pesticide classes. 1. This document is ENY-624, one of a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date: December Revised: November Visit the EDIS website at For a copy of this guide, request information on its availability at your county extension office. 2. M.E. Rogers, associate professor, Entomology and Nematology Department; and M.M. Dewdney, assistant professor, Plant Pathology Department; Citrus REC, Lake Alfred, Florida; Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition. Use pesticides safely. Read and follow directions on the manufacturer s label.

16 5. Do not use tank mixtures of products that have the same mode of action. 6. If control with a pesticide fails, do not re-treat with a chemical that has the same mode of action. Reports of resistance have been documented for certain acaricides used to control citrus rust mite and fungicides used to combat diseases in Florida. Resistance to Benlate developed in the greasy spot fungus shortly after the product was introduced about 30 years ago and is still widespread. Benlate resistance also occurs in the scab fungus in isolated situations and is stable. Resistance has been detected in tangerine groves with Alternaria brown spot to strobilurin fungicides (Abound, Gem, and Headline) but no resistance has developed to ferbam. Dicofol resistance in citrus rust mite was detected throughout the citrus industry about 10 years ago, but resistance proved to be unstable and usage of dicofol has continued. Agri-mek tolerance in citrus rust mite is of concern and growers should follow sound resistant management practices when using this product. The following tables are provided to aid in the rotation of pesticides with different modes of action within a season or from year to year. There is a separate table for insecticides/ acaricides, fungicides, and herbicides. The information in these tables was derived from information produced by the Insecticide Resistance Action Committee (IRAC) ( Fungicide Resistance Action Committee (FRAC) ( and the Herbicide Resistance Action Committee (HRAC) ( Each table lists the number (or letter in the case of herbicides) of the group code for each pesticide class, the group name or general description of that group of pesticides, the common name of pesticides used in citrus production that belong to each group and examples of trade names of pesticides for each common name listed. When using the table to rotate between using products with different modes of action, choose products with a different group code than previously used in the grove during the current growing season. In the case of insecticides/ acaricides, many of these pesticides are broken into subgroups. It is unclear whether cross resistance will occur between these subgroups. When possible, it is recommended to rotate with an entirely different group. (Note: The IRAC and FRAC mode of action systems both use a similar numbering system. There is no cross resistance potential between the insecticides and fungicides.) Products with broad-based activity such as sulfur, copper, and oil are not included in this list because the development of resistance to them is not likely Florida Citrus Pest Management Guide

17 TABLE 1. INSECTICIDES AND MITICIDES USED IN FLORIDA CITRUS GROUPED BY MODE OF ACTION. IRAC Group 1 Subgroup Group Name Common Name Trade Name 1 1A Carbamates 1 1B Organophosphates 2 Cyclodiene Organochlorines 3 Pyrethroids 4 4A Neonicotinoids Aldicarb Carbaryl Oxamyl Acephate Chlorpyrifos Dimethoate Fenamiphos Malathion Methidathion Naled Phosmet Endosulfan Bifenthrin Fenpropathrin Zeta-Cypermethrin Acetamiprid Clothianidin Imidacloprid Thiamethoxam Temik Sevin Vydate Orthene Lorsban Dimethoate Nemacur Malathion Supracide Dibrom Imidan Phaser Brigade Danitol Mustang 4C Sulfoxaflor Sulfoxaflor Closer 5 Spinosyns Spinosad Spinetoram 6 Avermectins Abamectin 7 7A Juvenile Hormone Analogues Methoprene Actara, Assail, Admire Pro, Advise, Alias, Belay, Couraze, Imida E-Ag, Impulse, Macho, Montana, Nuprid, Pasada, Platinum, Prey, Torrent, Widow Spintor Delegate 7B Fenoxycarb Fenoxycarb Precision 7C Pyriproxyfen Pyriproxyfen Knack Abacus, Abba, Agri-mek, Clinch, Epi-mek, Reaper, Zoro Extinguish Ant Bait 10 Hexythiazox Hexythiazox Savey 11 Bacillus thuringiensis (B.t.) B.t. var. aizawai B.t. var. kurstaki Various Various 12 12B Organotin miticides Fenbutatin oxide Vendex 12C Propargite Propargite Comite 15 Benzoylureas Diflubenzuron Micromite 16 Buprofezin Buprofezin Applaud 18 Diacylhydrazines Methoxyfenozide Intrepid 21 METI acaricides 23 Tetronic/Tetramic acid derivatives Pyridaben Fenpyroximate Spirodiclofen Spirotetramat Nexter Portal Envidor Movento 28 Diamides Chlorantraniliprole Exirel, Verimark, Voliam Flexi (one component) UN Unknown MOA Bifenazate Acramite Cryolite Dicofol 1 Mode of action based on the Insecticide Resistance Action Committee (IRAC) Mode of Action Classification V7.3 (2014). Kryocide Kelthane 2015 Florida Citrus Pest Management Guide 13

18 TABLE 2. FUNGICIDES USED IN FLORIDA CITRUS GROUPED BY MODE OF ACTION. FRAC Group 1 Group Name Common Name Trade Name 1 MBC - fungicides thiabendazole Many (TBZ) 3 DMI - fungicides 4 PA - fungicides difenoconazole fenbuconazole imazalil propiconazole metalaxyl mefenoxam Quadris Top Enable Many Banner Maxx, Bumper, Orbit, Propimax Ridomil Ultraflourish, Ridomil Gold, Subdue 7 SDHI fungicides Boscalid Pristine 11 QoI - fungicides azoxystrobin trifloxystrobin pyraclostrobin Abound Gem Headline Pristine Quadris Top 12 PP - fungicides fludioxonil Graduate 33 Phosphonates M3 dithio-carbamates Fosetyl-Al Phosphorous acid ferbam mancozeb M1 Inorganic copper Many 1 Mode of action based on the Fungicide Resistance Action Committee (FRAC) Aliette Phostrol, ProPhyt Ferbam Granuflo ManKocide TABLE 3. HERBICIDES USED IN FLORIDA CITRUS GROUPED BY MODE OF ACTION. HRAC Group 1 Group Name Common Name Trade Name A C1 FOPs DIMs Triazine Uracil fluazifop-p-butyl clethodim sethoxydim simazine bromacil Fusilade Prism, Select, Volunteer Poast Princep, Sim-Trol Hyvar, Krovar C2 Urea diuron Direx, Karmex, Krovar D E Bipyridylium Diphenylether N-phenylphthalimide Triazolinone diquat paraquat oxyfluorfen flumioxazin carfentrazone-ethyl F1 Pyridazinone norflurazon Solicam Reglone-Dessicant Gramoxone Galigan, Goal, Oxiflo Chateau, Suregard Aim G Glycine glyphosate Many (Roundup) K1 Dinitroaniline Pyridine oryzalin pendimethalin trifluralin thiazopyr Surflan, Oryza Pendulum, Prowl Treflan, Snapshot Mandate L Benzamide isoxaben Gallery, Snapshot N Thiocarbamate EPTC Eptam Z Organoarsenical MSMA MSMA-6 1 Mode of action of herbicides based on the Herbicide Resistance Action Committee (HRAC) Florida Citrus Pest Management Guide

19 2015 FLORIDA CITRUS PEST MANAGEMENT GUIDE: Pesticide Application Technology 1 M. Salyani 2 SPRAYING TREES: Sprayer Selection Most Florida citrus applications are made with air-carrier ground sprayers. These sprayers may be truck/tractor-mounted, tractor-drawn (p.t.o./ engine-driven), or self-propelled. They may be equipped with a positive or non-positive displacement pump to pressurize the spray liquid and generate spray droplets by hydraulic nozzles, air-shear nozzles, or rotary atomizers. Spray droplets are normally transported by sprayer airflow, generated with one or more axial-, centrifugal-, or cross-flow fans. The air is directed toward the canopy by a series of fixed, adjustable, or moving deflectors (oscillators). Some sprayers use a short or tall tower attachment to discharge a portion of the spray-laden air close to the upper parts of the tree canopy. Sprayers may use mechanical and/or hydraulic agitation systems. The differences in size, shape, design features, and construction material of the sprayers could result in substantial variation in the price of the spray equipment. Nevertheless, a higher price does not necessarily mean a better sprayer or guarantee more satisfactory spray coverage. A pesticide can be expected to be effective if the right material is applied, at the right amount, on the right target, at the right time, with the right sprayer, under the right weather conditions. A cheap sprayer, adjusted and operated properly, may result in better pest control than a sophisticated sprayer used improperly under adverse weather conditions. Sprayer Air Capacity Since air-blast applications depend on the sprayer air stream to deposit the spray on the tree, the air volume and velocity must be sufficient for efficient droplet transport, acceptable penetration inside the canopy, and satisfactory spray coverage. However, air-carrier sprayers have a wide range in air capacities (5, ,000 cfm). While larger sprayers generate much more air volume than the smaller ones, they may not provide any improvement in spray coverage, and in some cases, too much air may adversely affect spray deposition by increasing spray runoff from leaf surface. As the fan power requirement changes with the cubic factor of the airflow rate (fan speed) excessive air capacities dramatically increase the needed horsepower for fan operation. A 10-20% increase in fan speed increases the fan power demand by %, respectively. On the other hand, a 10-20% decrease of the speed reduces the power requirement by %, respectively. Higher energy demand of the fan requires purchasing a larger sprayer or operating the fan at higher rotational speeds. These practices would increase capital investment, fuel consumption, and operating costs. Therefore, smaller fans or lower rotational speeds should be used as much as possible. Using lower air volumes could offer substantial savings in energy expenditure and cost of spray applications. Certainly, small trees and lightly foliated canopies do not require large sprayers. Reduction of fan speed is a practical method for decreasing pesticide waste and application cost in spraying small and low-density trees. It should be noted that sprayers must be re-calibrated if they are used at lower fan speeds. Nozzle Arrangement In Florida citrus applications, it has been a common practice to direct 2/3 of the spray volume to the upper half of the tree and 1/3 to the lower half. However, this practice is no longer recommended when spraying small trees or using large airblast 1. This document is ABE-356 (formerly titled Spray Application Technology ), one of a series of the Agricultural and Biological Engineering Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date: December Revised: October Visit the EDIS Web site at For a copy of this guide, request information on its availability at your county extension office. 2. M. Salyani, professor, Agricultural and Biological Engineering Department, Citrus REC, Lake Alfred, Florida; Institute of Food and Agricultural Sciences, University of Florida, Gainesville, The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition. Use pesticides safely. Read and follow directions on the manufacturer s label.

20 sprayers. The 2/3-1/3 nozzle arrangement has shown no significant improvement in overall spray deposition or pest control as compared to 1/2-1/2 (uniform) nozzle arrangement. The latter may also minimize errors in nozzle selection. Sprayer air deflectors, nozzle orientation and number of nozzles should be adjusted to match the size and shape of the canopy and minimize spray wastage (see Figure l ). Application Rate Adjustment The maximum per acre rate of pesticides, given in this publication, is based on applications to mature citrus trees that have reached containment size (hedgerow status). Smaller trees can be sprayed with the same concentration of agrichemical, but using fewer nozzles (see Figure l). This should provide spray deposition approximately comparable to that of mature trees, with lower spray volume and active ingredient per acre. The spray volume rate can be calculated from Equation 1: VR = (495) x (SO) (GS) x (RS) Figure 1. Recommended nozzle arrangement and spray volume distribution. For low volume rates (less than 100 gal/acre), reducing the number of nozzles and using smaller disc and core sizes rather than spraying at higher ground speeds may improve spray deposition. For high-volume rates (greater than 250 gal/acre), increasing the number of nozzles and spraying at higher ground speeds instead of using fewer large disc and core sizes, may give higher deposition efficiency. Deposition efficiency of mid-volume rates ( gal/acre) is less sensitive to these application variables. Sprayer Calibration Application errors can originate from either incorrect tank concentration of the pesticides (mixing error) or incorrect sprayer output per unit area (calibration error). The latter may be due to travel speed, nozzle pressure, or the use of improper, defective, and worn nozzles. However, by proper matching of the sprayer discharge rate, swath width, and travel speed, calibration errors can be mitigated. Sprayer calibration can be carried out by: a) determining the amount of the tank mix used to spray a known area; b) operating the sprayer in a fixed place and measuring the amount of discharged liquid (water) for a specified time; or c) collecting the nozzle discharge and determining the output for a time period. Application rate is then determined by calculations. If the rate is not acceptable, then sprayer and/or application parameters need adjustment. See UF/IFAS Circular 1435, Calibration of Airblast Sprayers ( AE238), for details. The use of high capacity nozzles at low pressures to achieve low-volume application rates, one-sided calibration of the sprayer for two-sided operations and vice versa, calibration at closed pressure settings and intermittent operation of the nozzles can introduce errors in application rates. Sprayers using positive displacement pumps (diaphragm, piston, etc.) have more potential for application error compared to sprayers using centrifugal pumps, particularly at high volume rates. Equation 1. where: VR = Spray Volume Rate (gal/acre) SO = Sprayer Output (gal/min) GS = Ground Speed (mile/h) RS = Tree Row Spacing (ft) The actual applied rate of pesticides for small trees would be a fraction of the maximum rate per acre, as shown in Equation 2. where: (VRS) x (PRM) PRS = (VRM) PRS = Actual applied rate of pesticides for small trees (pt or lb/acre) VRS = Spray volume rate for small trees (gal/acre) VRM = Spray volume rate for mature trees (gal/acre) PRM = Pesticide rate for mature trees (gal/acre) Equation 2. Further reduction in spray usage may be obtained by shutting the nozzles (manually or automatically) when passing by the gaps between adjacent trees. The above adjustments match the sprayer output with the tree size while providing adequate spray coverage and lowered off-target spray movement. Spray Volume and Ground Speed Lower spray volumes can deposit as much or more pesticide on the canopy than dilute rates. This is because spray runoff from leaf surface decreases and more material remains on the canopy. Lower volumes involve the use of smaller orifice nozzles that provide smaller droplet sizes and more uniform spray distribution on the leaf surface. However, variability of spray distribution within the canopy and drift potential increases as spray volume decreases. With existing spray equipment and for average size trees, a volume rate of about 250 gal/acre may be a good compromise for controlling most pests of economic importance, except some scale insects. The volume rate may be reduced further if higher pesticide concentration is more important than thorough wetting for controlling certain pests (see the label for limitations) Florida Citrus Pest Management Guide

21 Increasing the ground speed can reduce the runoff from leaf surfaces in locations close to the sprayer. This effect can result in increased spray deposition and may be more pronounced with high volume rates and large orifice nozzles. On the other hand, hard-to-reach areas of the canopy may not have enough exposure for adequate spray penetration and deposition. The higher the sprayer air volume, the more potential it may have for high speed applications. However, variability of deposition increases at higher speeds, a ground speed of about 2.5 mph may be a reasonable speed for most citrus sprayers operating under average grove conditions. Weather Conditions The effectiveness and safety of spray applications largely depend on weather conditions during the application. High wind velocities can decrease spray coverage while increasing the variability of deposition and off-target drift. Pesticides should not be applied when wind velocity exceeds 10 mph or when it blows toward an adjacent residential area or susceptible crop. While calm conditions are desirable for spray deposition, temperature inversion may create severe drift problems. Vertical movement of the air during unstable weather conditions can increase the chance of spray drift, but dilution of the drift cloud makes it less serious than concentrated drift clouds generated under inversion conditions. The size of the water-based droplets reduces constantly as they move from the sprayer. The evaporation becomes faster under hot and dry conditions and may become critical for low volume applications. By using larger orifice nozzles and/or lower spray pressures, droplet size can be increased and spray drift decreased. LV/ULV Spray Guidance The U.S. Environmental Protection Agency and the Florida Department of Agriculture and Consumer Services allow the use of a pesticide on an agricultural site in a manner which results in the application of the same or less amount of active ingredient(s) to the site as specified on the product label but with less diluent than is specified on the product label if certain conditions are met: 1. The use of less diluent is not specifically prohibited on the product label, and; 2. All other precautionary statements regarding product mixing, loading, and preparation, application methods, rates, frequency, pre-harvest intervals, tolerances, field re-entry intervals, protective clothing or equipment requirements, product packaging and transportation requirements, and storage and disposal practices are complied with. Typically, pesticide product labels include advisory language encouraging the user to apply the product in a solution of sufficient volume to achieve complete coverage of foliage. Coupled with this language, manufacturers suggest a range of spray volumes necessary to achieve adequate foliage coverage. However, unless the label contains language such as do not use less than x gallons of water volume per acre, it is acceptable for the grove manager to use less volume than suggested by the range on the label. Growers should be cautious, however, and recognize the fact that crop damage occurring as a result of the use of less diluent than recommended on the label is solely their responsibility. Therefore, it is strongly recommended that this use pattern be tested on a small crop area before implementing widespread application. SPRAYING WEEDS: Herbicide Applicators Herbicides are mostly applied with boom sprayers. These sprayers work on the same principles as tree sprayers and consist of a tank, pump, flow (pressure) regulator, agitation system (hydraulic or mechanical), nozzle manifold (boom), and a set of nozzles. However, compared to tree sprayers, herbicide applicators normally are equipped with smaller PTO-driven pumps (centrifugal, roller, or piston) and lower hydraulic pressures (10-50 psi). The pump should be resistant to wear and corrosion. It must have enough capacity (gal/min) and pressure (psi) for both nozzle output and hydraulic agitation. This requires at least 20% greater capacity beyond the combined nozzle demand. Most pump manufacturers recommend not exceeding 70-80% of the pump s capacity for continuous operations. Agitation is more critical for wettable powders and water dispersible formulations. Inadequate mixing of these products could result in non-uniform concentration of the herbicide in the tank, nozzle clogging problems, and over-dose or under-dose output from nozzles. Overdosing of blocks with young trees can result in severe stunting and/or phytotoxicity. Tanks without sharp corners minimize the chance for product settlement. Herbicide applicators equipped with mechanical agitation systems perform better than those with hydraulic agitation but they are more expensive. Regardless of differences in the design and price of the sprayers, the success of weed control largely depends on the choice of herbicide, timing of the application, and proper maintenance, calibration, and use of the equipment. More information on the selection and timing of herbicide application can be found in HS-107 Weeds. The following sections provide information on proper nozzle selection and calibration of herbicide applicators. Nozzle Selection In Florida, nearly all boom sprayers are equipped with hydraulic pressure nozzles. These nozzles are available in many sizes, shapes, and materials and may be color-coded or identified by a number. A typical nozzle assembly consists of nozzle body, strainer (screen), tip (orifice), and cap (tip holder). Strainers vary in mesh size based on the size of the nozzle orifice (opening). Smaller openings (lower capacities) require finer mesh to minimize nozzle clogging Florida Citrus Pest Management Guide 17

22 Nozzles differ significantly in durability, flow rate, droplet spectrum, and distribution pattern. Brass and nylon nozzle tips are the least expensive but are relatively soft and wear rapidly; therefore, they are not suitable for spraying abrasive tank mixes such as wettable powders. On the other hand, ceramic and hardened stainless steel tips are more expensive but have excellent wear life and are very resistant to abrasive and corrosive chemicals. For a given nozzle type, flow rate (capacity) depends on the tip orifice size and operating pressure. In nozzle manufacturers catalogs, nozzle flow rates (GPM) are usually listed for a few selected pressures (PSI). It should be noted that all the tabulations are based on spraying water. When calibrations are based on water, the equivalent GPM of the heavier or lighter solutions should be calculated from Equation 3. where: GPM w GPM s Equation 3. GPM w = GPM s x CF = Equivalent nozzle capacity for water = Desired nozzle capacity of heavier or lighter solution CF = Correction factor for solution density = square-root of specific gravity (SG) Most nozzles perform satisfactorily around 30 PSI; however, recommended pressure of each specific nozzle should be determined from its manufacturer s catalog. If the desired GPM could not be obtained at the recommended pressure, then the pressure should be adjusted. Since nozzle flow rate varies in proportion to square-root of the pressure (Equation 4), only minor adjustment could be achieved by changing pressure. Major adjustments require the use of smaller or larger nozzles. where: PSI 2 PSI 1 GPM 2 PSI 1 = PSI 2 x GPM 2 2 GPM 1 = Correct operating pressure = Recommended pressure = Desired flow rate GPM 1 = Flow rate at PSI 1 Equation 4. Droplet size spectra and distribution patterns of nozzles vary substantially and largely depend on nozzle type, flow rate, operating pressure, and spray angle. Flat fan nozzles generate relatively smaller droplets, whereas drift-reducing nozzles produce larger droplets. Extended-range nozzles adjust the droplet size over a wide range of nozzle pressures. Flooding nozzles produce a wide spray angle and flat pattern. Nozzles with solid or hollow cone spray patterns may also be used in some postemergence herbicide applications. Most of the available nozzles have spray angles ranging from 65 to 140. The nozzle s designated angle corresponds to the rated pressure. Spray angle increases or decreases at higher or lower pressures, respectively. Nozzle wear not only increases the angle and output, but it also distorts spray distribution pattern to some extent. Spray Distribution Unlike tree sprayers, nozzles used on herbicide equipment should be uniform (same type, material, capacity, and spray angle). Using a variety of nozzles on a boom results in uneven distribution patterns. However, herbicide applicators used in citrus may include an off-center nozzle tip (at the end of the boom) to extend the coverage beyond the end of the boom and cover the area around the tree trunk. It is normally mounted on a swivel body, a few inches beyond the last main nozzle. Nozzles that generate tapered edge patterns (e.g., flat fan) need some pattern overlap in order to obtain a reasonably uniform distribution across the spray swath. The amount of pattern overlap depends on nozzle spacing, boom height, and spray angle. Nozzles used on citrus herbicide applicators are normally mounted on inch centers and operated at a height of inches. Smaller spray angles require higher nozzle (boom) height in order to achieve acceptable pattern overlap (usually 30-50%). Some nozzles may require % pattern overlap. Nozzle catalogs normally specify optimum spacing, height, and overlap for each nozzle type. For a given nozzle flow rate, an improper boom height setting or vertical movement of the boom will result in uneven distribution (untreated bands or larger than desired treatment areas) across the spray swath. Herbicide Sprayer Calibration Application rate depends on nozzle flow rate (function of orifice size and operating pressure), number of nozzles, row spacing, and ground speed. Equations 5 and 6 show the relationships among these factors for broadcast and directed sprays, respectively. where: or Equation 5. where: GPA = GPM x 5,940 GS x NS GPA x GS x NS GPM = 5,940 GPA = Application rate (gal/acre) GPM = Flow rate per nozzle (gal/min) GS = Sprayer ground speed (mile/h) NS = Nozzle spacing (in) GPM x NN x 495 GPA = GS x RS NN = Number of nozzles RS = Row spacing (ft) Equation Florida Citrus Pest Management Guide