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Diseases
R.E. Baldwin, Extension Plant Pathologist, The home gardener must contend with many of the same diseases confronting the professional nurseryman. But, whereas thenurseryman recognizes the value of disease preventative schedules with regular applications of fungicides, bactericides, ornematicides, the home gardener frequently waits until the disease is rampant and impossible to control with chemicals, or theplant is dead. This guide is intended to assist the nonprofessional to select the proper cultural practice, such as a resistantvariety, proper planting site, purchasing a healthy plant, and using the appropriate chemical to prevent further disease.
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
thoroughly work into the top 2 inches of soil.
ARBORVITAE
Spray at bud break and at 10-14 day intervals.
Cleary 3336-F (4.5 F); 1 tsp; thiophanatemethyl Cleary 3336 should be applied when disease first appears and repeat on a 10-14 day interval.
Cleary 3336-F (4.5 F); 1 tsp; thiophanate Shorten interval during humid, rainy weather.
Mancozeb should be applied on a 7-10 dayinterval.
Fore (80% WP) or Dithane T/O(75% DF) or Dithane WF (4F)or Fore Flowable (4F);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb AZALEA (Rhododendron)
Hand pick infected leaves and remove from plant. Apply mancozeb just before leaves unroll Apply as flowers open. Repeat every 4-6 days Spray Daconil 2787 every 7 days during wet Daconil 2787 (75% WP); 1.5 tbsp;chlorothalonil Spray mancozeb, Zyban or Ziram at 7-10 day intervals when flowers start to show color.
or Fore Flowable (4F);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Zyban (75% WP); 1.5 tbsp; thiophanatemethyl + mancozeb Spray at 10-14-day intervals when disease firstappears.
86 HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Spray at 7-10 day intervals from first sign of Daconil 2787 (75% WP); 5 tsp;chlorothalonil Spray to run off. Repeat at 2-month intervals.
Apply Subdue as a drench using 1 pt/sq ft (soil depth greater than 4 inches apply 2 pt/sq ft).
Apply only once every two months. Read andfollow manufacturer’s directions carefully.
Treat at 4 week intervals as a drench.
Truban (25% EC); 1 tsp/2.0 gal;etridiazole Terrazole (25% EC); 1 tsp/2.0 gal;etridiazole CAMELLIA
Drench soil surface in late December or early Spray at 4-6 intervals while flowers are opening.
Direct spray onto flowers and onto bushesthoroughly.
CARNATION
Spray Daconil 2787 or iprodione at 7-14 day intervals. Remove diseased plants from flowerbed at the end of the growing season.
Daconil 2787 (75% WP); 5 tsp;chlorothalonil Chipco 26019 (50% WP); 1.0-2.0 tbsp;iprodione Begin when growth starts and repeat 7-10 days.
Maneb Plus Zinc F4Fungicide (37% F)1.0-1.5 tbsp of 80 or2.0 tsp of F: maneb Spray at first sign of disease and at 7-14 day Daconil 2787 Flowable Fungicide (500 g/lF); 2 tsp; chlorothalonil Daconil 2787 (75% WP); 5 tsp;chlorothalonil P r e v e n t a t i v e : 1.5-2.0 tsp 50W or 0.5-0.75 tsp
FL when conditions for disease prevail. Repeatevery 10 days during this period.
HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Curative: 2.0-3.0 tsp 50W or 0.75-1.0 tsp FL
for medium to high disease pressure. Repeatevery 10-14 days as needed.
(75% DF) or Dithane WF (4F)or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Triforine EC (18.2%); 0.75 - 1.0 tsp;funginex Triflorine EC (18.2%); 0.75-1.0 tspfunginex CHRYSANTHEMUM
Apply Banner at 0.75 tsp on a 7-day schedule and the 1.0 tsp rate on a 14-day schedule.
Apply first spray of Daconil 2787 just before flower color shows at 7-day intervals or at 10 to14-day intervals with iprodione.
Daconil 2787 (75% WP); 5 tsp;chlorothalonil Daconil 2787 Flowable Fungicide (500 g/lF); 2 tsp; chlorothalonil Apply twice weekly during blooming period.
(75% DF) or Dithane WF (4F)or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Apply first spray of Daconil 2787 just before flower color shows and at 7-day intervals or at10-14-day intervals with iprodione.
Daconil 2787 Flowable Fungicide (500 g/lF); 2 tsp; chlorothalonil Chipco 26019 (50% WP); 1.0 - 2.0 tbsp;iprodione Ornalin (50% WP); 1.5-3.0 tsp; vinclozolin P r e v e n t a t i v e : 1.5-2.0 tsp 50W or 0.5-0.75
tsp FL when conditions for disease prevail.
Repeat every 10 days during this period.
Curative: 2.0-3.0 tsp 50W or 0.75-1.0 tsp FL
for medium to high disease pressure. Repeatevery 10 to 14 days as needed.
88 HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Apply mancozeb twice a week during blooming or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb or transplanting : 3.0-12.0 drops per gallon anddrench at 1.0 pt of solutions/sq ft. Soil depthsgreater than 4 inches apply up to 2.0 pts ofsolution.
Provide good water drainage. Do not plant in sameflower bed in 2 consecutive years. Apply fungicidein sufficient water to saturate the soil. Repeat at 4-week intervals.
Banrot (40% WP) 0.5-1.0 tsp;thiophanate methyl + etridiazole Apply at weekly intervals when new shoot growth begins. Cover lower leaf surfaces completely.
Daconil 2787 (75% WP); 5 tsp;chlorothalonil CRABAPPLE
Spray Daconil 2787 at first sign of disease and at 7-14 day intervals throughout the season.
Daconil 2787 (75% WP); 5 tsp;chlorothalonil Start mancozeb as flower buds open and spray 3 or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Spray Zyban beginning at delayed dormant stage.
Repeat at 2-week intervals during cover period.
Agri-strep (21.2%); 0.5 lb or 1/2 tbsp/gal; Apply at early, mid and late flowering. Prune out HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Apply thiophanate methyl on a 7-10 day interval from bud break until 2 weeks after petal fall.
Spray Daconil 2787 at first sign of disease and at 7-14 day intervals throughout the season.
Daconil 2787 (75% WP); 5 tsp;chlorothalonil Begin mancozeb applications at first sign of disease and repeat at 7-10 day intervals.
or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb CRAPE MYRTLE
Spray as flower buds break. Apply Banner every Spray to run-off when mildew first appears.
Apply Chipco 26019 on a 7-14 day interval and Cleary 3336-F on a 10-14 day interval.
Cleary 3336-F (4.5 F); 0.75 tsp;thiophanate methyl Spray at first sign of disease and repeat at 10 to 14-day intervals throughout the season.
Daconil 2787 (75% WP); 5 tsp;chlorothalonil Banner is applied at 2.0-4.0 fl oz in a 14 dayinterval or at 8.0 oz every 28 days.
Spray to run-off when mildew first appears.
For spot anthracnose and leaf and flower blight apply when buds begin to open. Repeat when bracts have fallen, 4 weeks later and in latesummer after flower buds are formed. Foranthracnose 90 HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
expansion in the spring at 10-14 day intervals.
Fungicides should be used to supplement acultural control program.
Daconil 2787 WDG (90% WDG); 1.25tbsp; chlorothalonil Fore (80% WP) or Dithane T/O(75% DF) or Dithane WF (4F)or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Maneb 80 (80%WP) orManeb Plus Zinc F4 Fungicide (37%F)1.5 tbsp of 80 or 2.5 tsp of 4F; maneb Zyban (75% WP); 1.5 tbsp; thiophanatemethyl + mancozeb EUONYMUS
Spray to run-off when mildew first appears.
GERANIUM
Apply Chipco 26019 on a 7-14 day interval and Cleary 3336 on a 10-14 day interval.
Cleary 3336-F (4.5 F); 0.75 tsp;thiophanate methyl Cleary 3336-WP (50% WP);0.75 tbsp; thiophanate methyl Apply at first sign of disease and repeat at 7-14 Daconil 2787 Flowable Fungicide(500 g/l F); 2 tsp; chlorothalonil P r e v e n t a t i v e : 1.5-2.0 tsp 50 W or 0.5-0.75 tsp
FL when conditions for disease prevail. Repeatevery 10 days during this period.
Curative: 2.0-3.0 tsp 50 W or 0.75-1.0 tsp FL for
medium to high disease pressure. Repeat every10-14 days as needed.
drench at 1.0 pt of solutions/sq ft. Soil depthsgreater than 4 inches apply up to 2.0 pts ofsolution.
Thoroughly drench soil. Reapply at 4-12 weekintervals.
HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Apply at first sign of disease and repeat at 7-14 day intervals throughout the season.
Daconil 2787 Flowable Fungicide (500 g/lF F); 2 tsp; chlorothalonil Fore (80% WP) or Dithane T/O(75% DF) or Dithane WF (4F)or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb GLADIOLUS
Apply Chipco 26019 on a 7-14 day interval and Cleary 3336-F (4.5 F); 0.75 tsp;thiophanate methyl Cleary 3336-WP (50% WP); 0.75 tbsp;thiophanate methyl Apply at first sign of disease and repeat at 7-14 Daconil 2787 Flowable Fungicide (500 g/lF); 2 tsp; chlorothalonil Ornalin (50% WP); 1.5-3.0 tsp; vinclozolin P r e v e n t a t i v e : 1.5-2.0 tsp 50 W or 0.5-0.75 tsp
FL when conditions for disease prevail. Repeatevery 10 days during this period.
Curative: 2.0-3.0 tsp 50 W or 0.75-1.0 tsp FL
for medium to high disease pressure. Repeatevery 10-14 days as needed.
Apply at first sign of disease and repeat at 7-14 day intervals throughout the season.
Daconil 2787 (75% WP); 5 tsp;chlorothalonil appears and increase to 2-3 applications per week during heavy disease or rainy weather. On flower spikes reduce spray concentration by 1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Soak corms for 15-30 minutes at 55-75° F. Stir Soak corms for 15-30 minutes in a warm dip (80- Cleary 3336-WP (50% WP); 0.75 tbsp;thiophanate methyl HAWTHORNE
Apply at first sign of disease and repeat at 7-14 day intervals throughout the season.
Daconil 2787 (75% WP); 5 tsp;chlorothalonil 92 HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Fore (80% WP) or Dithane T/O(75% DF) or Dithane WF (4F)or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb HOLLY (American)
Start spraying in late spring and continue at 10- Cleary 3336-WP (50% WP); 0.75 tbsp;thiophanate methyl HOLLY (Japanese)
Apply as a heavy drench or spray at 1-2 pts per Thoroughly drench soil around roots. Reapply at HOLLYHOCK
Apply at first sign of disease and repeat at 7-14 day intervals throughout the season.
Daconil 2787 (75% WP); 5 tsp;chlorothalonil Start spraying in late May and continue at 10- or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb HONEYSUCKLE
Spray at 7-10 day intervals, from when buds or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb HYDRANGEA
Make 5 applications at 7-10 day intervals starting when leaves are 4 to 6 inches high. Include commercial spreader-sticker or liquid detergent (1/4 tsp/gal water) with Daconil WP or mancozeb.
HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Spray at 7-10 day intervals, from when buds or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Apply Chipco 26019 on a 7-14 day interval and Cleary 3336-F (4.5 F); 0.75 tsp;thiophanate methyl Cleary 3336-WP (50% WP); 0.75 tbsp;thiophanate methyl Apply at first sign of disease and repeat at 7-14 Daconil 2787 Flowable Fungicide (500 g/lF); 2 tsp; chlorothalonil Ornalin (50% WP); 1.5-3.0 tsp; vinclozolin P r e v e n t a t i v e : 1.5-2.0 tsp 50W or 0.5-0.75
tsp FL when conditions for disease prevail.
Repeat every 10 days during this period.
Curative: 2.0-3.0 tsp 50W or 0.75-1.0 tsp FL
for medium to high disease pressure. Repeatevery 10-14 days as needed.
Cleary 3336-F (4.5 F); 1.0 tsp; thiophanate Begin application at bud break and repeat at a 10-14 day interval through the growing season.
Cleary 3336-WP (50% WP); 0.75 tbsp;thiophanate methyl Fore (80% WP) or Dithane T/O(75% DF) or Dithane WF (4F)or Fore Flowable (4F) or1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Thoroughly drench soil. Reapply at 4-week intervals. See under Azalea root rot.
Thoroughly drench soil. Reapply at 4-weekintervals. See under Azalea root rot.
Truban (25% EC); 1 tsp/ 2.0 gal;etridiazole Apply Chipco 26019 on a 7-14 day interval and Cleary 3336 on a 10-14 day interval.
Cleary 3336-F (4.5 F); 0.75 tsp;thiophanate methyl Cleary 3336-WP (50% WP); 0.75 tbsp;thiophanate methyl 94 HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Apply at first sign of disease and repeat at 7-14 Daconil 2787 Flowable Fungicide (500 g/lF); 2 tsp; chlorothalonil P r e v e n t a t i v e : 1.5-2.0 tsp 50W or 0.5-0.75 tsp
FL when conditions for disease prevail. Repeatevery 10 days during this period.
Curative: 2.0-3.0 tsp 50W or 0.75-1.0 tsp FL for
medium to high disease pressure. Repeat every10-14 days as needed.
Spray at 10-14 day intervals after leaves are 3/4grown.
Triforine EC (18.2% EC); 0.75-1.0 tsp;funginex MOUNTAIN LAUREL
Spray when buds break in the spring and twice more at 2-week intervals. Rake up and destroy diseased leaves. Apply mancozeb at 7-10 day Penncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Apply at first sign of disease and repeat at 7-14 day intervals throughout the season.
Daconil 2787 (75% WP); 5 tsp;chlorothalonil NARCISSUS (Daffodils)
PACHYSANDRA
applications at 10-14 day intervals. Purchase Penncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Zyban (75% WP); 1.5 tbsp; thiophanatemethyl + mancozeb PERIWINKLE (
Apply as a drench or heavy spray at 1-2 pts/sq ft.
Cleary 3336-WP (50% WP); 0.75 tbsp;thiophanate methyl HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Apply in sufficient water to saturate the soil.
P H O T I N I A
Cleary 3336-F (4.5 F); 1.0 tsp; thiophanate Spray at 10-14 day intervals starting when newmethyl Triforine EC (18.2%); 0.75-1.0 tsp;funginex Cleary 3336-F (4.5 F); 1.0 tsp; thiophanate Spray at 10-14 day intervals when new leafmethyl PYRACANTHA (Firethorn)
Agri-strep (21.2%); 0.5 lb or 1/2 tbsp/gal; Spray when 20% of the blossoms are open and repeat every 5-7 days during bloom period.
Prune out all diseased limbs.
Begin Kocide at first sign of disease and repeat Cleary 3336-F (4.5 F); 1.0 tsp; thiophanate Apply the first spray at bud break, 7-10 daysmethyl Cleary 3336-WP (50% WP);0.75 tbsp; thiophanate methyl Daconil 2787 Flowable Fungicide(500 g/l F); 2 tsp; chlorothalonil Daconil 2787 (75% WP); 1.5 tbsp;chlorothalonil applications at 10-14 day intervals. Purchase Penncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb RHODODENDRON
Prune out all diseased branches. Do not allowplants to undergo environmental stress.
Tank mix with a registered contact fungicide Cleary 3336-F (4.5 F); 1.0 tsp; thiophanate Start applications in the spring as leavesmethyl expand. During dry weather treat at 7-dayintervals for chlorothalonil. Use 10-day intervalswith Cleary 3336.
96 HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Shorten intervals with all materials during rainy or humid weather. Use sticker. Plant resistantvarieties.
Daconil 2787 (75% WP); 1 tbsp;chlorothalonil Daconil 2787 Flowable Fungicide(500 g/l F); 2 tsp; chlorothalonil Apply first spray early in the spring as growth begins. Make applications at 10-14 day intervals.
Penncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Maneb 80 (80%WP) orManeb Pus Zinc F4Fungicide (37%F);1.0-1.5 tbsp of 80 or2 tsp of F; Maneb Begin when growth starts and repeat 7-10 days Apply Banner at 10-14 day intervals.
Apply Milban at 10-14 day intervals.
Apply Funginex at 7-10 day intervals.
SNAPDRAGON
Spray as soon as rust pustules appear. Repeat Fore (80% WP) or Dithane T/O(75% DF) or Dithane WF (4F)or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Maneb 80 (80% WP) orManeb Plus Zinc F4Fungicide (37%F)1.0-1.5 tbsp of 80 or2.0 tsp of F; maneb Zyban (75% WP); 1.5 tbsp; thiophanatemethyl plus mancozeb HOME ORNAMENTALS: Diseases
Fungicide & Formulation;
Rate/1 Gal (Unless Otherwise
Stated); Active Ingredient
Plant Disease
(g/l = grams/liter)
Apply at 10-14 day intervals. Shorten interval Apply Chipco 26019 on a 7-14 day interval and Cleary 3336-F (4.5 F); 0.75 tsp;thiophanate methyl Cleary 3336-WP (50% WP); 0.75 tbsp;thiophanate methyl Apply at first sign of disease and repeat at 7-14 day intervals throughout the season.
Daconil 2787 Flowable Fungicide (500 g/lF); 2 tsp; chlorothalonil Ornalin (50% WP); 1.5-3.0 tsp; vinclozolin P r e v e n t a t i v e : 1.5-2.0 tsp 50W or 0.5-0.75
tsp FL when conditions for disease prevail.
Repeat every 10 days during this period.
Ornalin FL (4.17 F); 0.5-1.0 tsp; vinclozolin Curative: 2.0-3.0 tsp 50W or 0.75-1.0 tsp FL
for medium to high disease pressure. Repeat
every 10-14 days as needed.
YEW (Taxus)
Thoroughly saturate the soil; reapply at 4-week Apply 1 pt solution / sq ft. For soil depthgreater than 4 inches apply 1.5 - 2.0 ptssolution / sq ft.
Make 4 applications at 7-day intervals starting or Fore Flowable (4F) orPenncozeb (80% WP) orPenncozeb DF (75% DF);1.5 tbs of 80W or 75 DF;2.5 tsp of 4F; mancozeb Make applications on a 7-14 day interval.
Zyban (75% WP); 1.5 tbsp; thiophanatemethyl + mancozeb Triforine EC (18.2% EC); 0.75-1.0 tsp;funginex Daconil 2787 (75% WP); 5 tsp;chlorothalonil Daconil 2787 (500 g/l F); 2 tsp;chlorothalonil Zyban (75% WP); 1.5 tbsp; thiophanatemethyl + mancozeb HOME ORNAMENTALS: Diseases
Nematode and Soil-Borne Disease Control
Nematodes
Controlled
Fumigant
Application Rates
and other soil-borne plant pathogens.
species ofPythium,Phytophthora, andothers Soil Preparation: Before treating, cultivatethe area thoroughly, breaking up clods andloosening soil deeply and thoroughly. Keepthe soil moist, watering if necessary untiltime to treat. Soil temperature should bebetween 60° to 90° F at 3-inch depth.
after application to promote escape ofvapors. Allow an additional 7-9 days beforeplanting on well-drained light- to medium-textured soil; 14 days for heavy clay ororganic soil; and up to 30 days if soiltemperatures are below 60o F.
spaces without adequate ventilation, nor ingreenhouses where growing plants are present. Do not apply within 3 ft of plantdrip line, or to areas underlaid by roots ofvaluable plants. Keep children and petsout of treated area.
(1.0 pt) in sprinkling can, fill with water, andapply to 50.0 sq ft of well-prepared soil.
lb (1.0 qt) to 3 qt of water per 100.0 sq ft.
Continue watering to depth of controldesired.
using 0.795 lb (1.0 qt) in 2.5 gal of waterper 100.0 sq ft in front of tiller.

Source: http://webipm.ento.vt.edu/ipm-www/nipmn/VA-IPM/PMG/home/4aDiseas.pdf