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2006 Florida Plant Disease Management Guide: Strawberry1
Natalia A. Peres2Alternaria Rot
Alternaria rot, caused by Alternaria tenuissima, occurs infrequently and is usually not important in most strawberry growing regions.This rot affects ripe fruit in the field as well as post harvest. Lesions are irregular in shape and slightly sunken. Older lesions are circular, firm, sunken, and dark green to black due to sporulation of the fungus ( Figure 1 ).
Management
Cultural: Do not leave over-ripe fruit in the field.
Figure 1. Alternaria Rot. Angular Leaf Spot
Angular Leaf Spot (ALS), caused by Xanthomonas fragariae, is an important disease on winter strawberry production worldwide. The disease was first reported in Minnesota in 1960 and since then it has been found in almost all cultivated strawberry areas in the U.S.Symptoms
The first symptoms of ALS begin as small, water-soaked lesions on the undersurface of the leaves ( Figure 2 ). When moisture is high on the leaves, these lesions ooze sticky droplets of bacteria. As the disease develops, the lesions enlarge to form reddish-brown spots that later become necrotic. A practical way to recognize the disease is to place the leaves against a source of background light where the spots are seen as translucent. The tissue with older lesions eventually dies and dries up giving leaves a ragged appearance. If the disease invades the vascular system of the plant, the disease will be difficult to control and affected plants may wilt and die.
Figure 2. Angular Leaf Spot (ALS). Causal organism
X. fragariae is a slow-growing, gram-negative, motile bacterium that is highly specific to wild and cultivated strawberry.
Disease cycle and epidemiology
The primary source of inoculum in a new field is contaminated transplants. Secondary inoculum comes from bacteria that exude from lesions under high moisture conditions. Bacteria can survive on dry infested leaves and tissue buried in the soil for up to 1 year. The pathogen can be spread easily by harvesting operations when wet and cool conditions favor the production of bacterial exudate. The pathogen also can be dispersed by rain and overhead sprinkler irrigation. Little is known regarding the epidemiology of ALS; however, development of the disease is favored by cool days (20°C/68°F) and cold nights (2-4°C/ 36-39°F).
Management
Cultural: The best way to control ALS is to use pathogen-free transplants. Harvesting and moving equipment through infected fields should be avoided when plants are wet. Minimizing the use of overhead sprinklers during plant establishment and for freeze protection may also reduce the spread and severity of the disease.
Chemical: See Table 1 .
Anthracnose Fruit Rot
Anthracnose fruit rot, caused by Colletotrichum acutatum, is an important disease for strawberry production worldwide. Although fruit rot is the most important symptom caused by C. acutatum, the fungus can also attack other parts of the plant including the crown, leaves, petioles, and roots.Symptoms
Symptoms of anthracnose fruit rot appear as dark, sunken lesions on infected fruit. On green fruit, anthracnose lesions are small (1/16 to 1/8-inch across) hard, sunken, dark brown or black.Lesions on ripening fruit are larger (1/8 to 1/2 inch) hard, sunken, and tan to dark brown ( Figure 3 ). During wet weather, the lesions become covered by sticky, light orange ooze composed of millions of spores (conidia) in a mucilaginous matrix. When conditions are favorable for infection, multiple lesions nearly cover the fruit and lesions may appear on petioles. Strawberry flowers are highly susceptible and blighted flowers turn brown and remain attached to the plant, a symptom also produced by the fungus Botrytis cinerea.
Figure 3. Anthracnose Fruit Rot. Causal organism
C. acutatum produces orange masses of conidia that are hyaline, straight and usually with pointed ends. Molecular analysis of C. acutatum revealed that the population on strawberry reproduces asexually and has limited diversity. Other species of Colletotrichum, such as C. fragarie and C.gloeosporioides, cause anthracnose diseases of strawberry but are less frequently involved in fruit rot.
Disease cycle and epidemiology
Infected transplants are a common source of inoculum for production fields. C. acutatum apparently spreads first on the foliage, often without causing visible symptoms. Some conidia are formed on green leaves and petioles, and more are produced as the tissue ages and dies. Conidia are moved from the foliage to flowers and fruit by splashing water and harvesting operations. There, they germinate and infect tissues. As anthracnose lesions develop, abundant spores are formed that may be moved to other plants and new fields on equipment and harvesters. Warm wet weather favors infection and disease spread.
Management
Cultural: Transplants should be obtained from pathogen-free nurseries. Moving personnel and equipment from diseased fields into healthy fields should be avoided without proper cleaning and disinfection. Carmine and Sweet Charlie cultivars are considered relatively resistant to anthracnose fruit rot. Strawberry Festival is moderately susceptible and Camarosa and Treasure are highly susceptible.
Chemical: See Table 1 .
Botrytis Fruit Rot or Gray Mold
Botrytis fruit rot, also known as gray mold, caused by Botrytis cinerea, is one of the most important diseases of strawberry worldwide. B. cinerea is a cosmopolitan fungus that infects a wide range of fruit, vegetable, and weed species.Symptoms
Botrytis fruit rot occurs in the field and after harvest. Infection occurs in the flowers and recently set fruitlets, but the symptoms are commonly observed on green and ripening fruit. Lesions begin as small, light brown spots that quickly enlarge and become covered with white fungal mycelia. Under moist conditions, gray to brown spores cover the lesions and the entire fruit may become mummified ( Figure 4 ). When diseased fruit are disturbed, large numbers of spores are often released and are visible as gray puffs.
Figure 4. Botrytis Fruit Rot. Causal organism
The pathogen produces hyaline, septate hyphae. Single-celled, multinucleated, ellipsoid conidia are produced on conidiophores. Conidia are hyaline individually but appear gray in mass.
Disease cycle and epidemiology
B. cinerea is a common colonizer of strawberry foliage in the nursery, and is also present on dying vegetation around strawberry fields. After runner transplants are planted, spores produced on old dying leaves rapidly colonize new emerging leaves without causing visible symptoms. These spores (conidia) are dispersed by air, water, and harvesters to infect flowers during the main bloom period in January and February. Cool to mild temperatures and prolonged leaf wetness promote spore production, germination, and infection of stamens, petals, and other floral parts. Flower infections often progress slowly, with lesions becoming visible on green and ripening fruit 2 to 4 weeks after infection. Direct infection of fruit by spores is not considered important in the field or after harvest. However, the pathogen also spreads from diseased fruit to healthy fruit by direct contact. As the epidemic progresses, diseased fruit, mummified fruit, and decayed flowers and pedicles become important new sources of inoculum. Botrytis fruit rot is especially damaging in annual production systems with prolonged flowering and fruiting cycles. The disease is favored by cool and wet weather. In Florida, the second crop of fruit that ripen in February and March are more seriously affected than the first crop of fruit that ripen in December-January.
Management
Cultural: Removal of infected fruit and plant debris can be used to reduce inoculum, but is not practical for control of Botrytis fruit rot. Cultivars Camarosa, Carmine and Treasure are less susceptible than Strawberry Festival and Sweet Charlie.
Chemical: Fungicides should be applied at peak bloom.
See Table 1 .
Colletotrichum Crown Rot
Colletotrichum crown rot, caused by Colletotrichum gloeosporioides or C. fragariae, is a serious disease in subtropical production regions. Although crown rot is observed in fields during the winter production season, it is most severe in nurseries in the southeastern United States and is one of the primary reasons that production of transplants for the Florida production season has been moved to higher latitudes.Symptoms
Symptoms caused by C. gloeosporioides and C. fragariae are virtually indistinguishable in the field. Plants infected initially show signs of water stress and may collapse relatively rapidly (2-3 days) under high temperatures. Under cool temperatures, it may take weeks before plants collapse. The internal crowns of infected plants show a reddish-brown and firm rot when cut ( Figure 5 ). Typically there are no lesions on foliage or stolons and symptoms may be confused with those of Phytophthora crown rot.
Figure 5. Colletotrichum Crown Rot. Causal organism
Conidia of C. gloeosporioides are barrel shaped with both ends rounded, whereas conidia of C. fragariae are narrower at one end and have a slightly pointed morphology. Setae of C. fragariae differ from those of C. gloeosporioides in that they function as phialides and conidia can often be observed at the ends.
Disease cycle and epidemiology
Propagation of plants in Canada and northern states for the Florida production season has greatly reduced the incidence of crown rot. However, during the warm months at the beginning and end of the production season crown rot incidences up to 5% do occur on plants in Florida fields. Recent studies have shown that inoculum for crown rot infections in Florida may be coming from non-cultivated hosts. Colletotrichum sp. responsible for crown rot do not appear to survive between seasons in subtropical production systems on plant debris since plants are usually killed immediately after the production season ends in the spring and the fungus disappears from crowns during the hot summer months.
Management
Cultural: Transplants from northern nurseries should be used for controlling crown rot. Reducing water on foliage by using drip irrigation will also limit dispersal of the pathogen. Treasure cultivar is considered highly resistant to crown rot. Sweet Charlie, Carmine and Camino Real have moderate levels of resistance and Festival and Camarosa are highly susceptible.
Chemical: See Table 1 .
Leaf Scorch
Leaf scorch, caused by Diplocarpon earlianum, is a common leaf disease of strawberries grown worldwide.Symptoms
Symptoms on leaves are numerous irregularly shaped purplish blotches that are 1/16 to 3/16 inch in diameter. Clusters of the blotches turn brownish, but never white or gray as in the case of common leaf spot. Dark, glistening acervuli appear in the lesions on the upper surfaces of the leaves. In severe cases, the leaf margins curl upward and the leaves dry to a tan color, progressing from the margins to the midrib, giving the leaf a scorched appearance.
Causal organism
The fungus is limited to species and cultivars of Fragaria although physiological and pathogenic specialization among isolates has been reported.
Disease cycle and epidemiology
Leaf scorch is favored by long periods of leaf wetness (12 h or more), frequent rain, and moderate temperatures (60-78°F). The severity of the disease is usually low in annual production systems.
Management
Cultural: Prolonged use of overhead irrigation should be avoided.
Chemical: See Table 1 .
Leaf Spot
Leaf spot, caused by Mycosphaerella fragariae, is one of the most common diseases of strawberries worldwide.Symptoms
Leaf lesions are initially small, purplish-red and less than 1/8 inch in diameter. The spots may enlarge to 1/4 inch depending on the cultivar. On some, the lesions remain very small and numerous and the leaflets appear "rusty." On others, the lesions increase in size to 1/4 inch or larger and develop white or gray centers with reddish-purple to dark purple borders. Lesions may also form on fruit, calyxes, petioles, and stolons. Severe infection can result in death of leaflets and defoliation of plants.
Causal organism
The fungus is considered to be pathogenic only to species and cultivars of Fragariae although several races have been defined according to their effects on different cultivars.
Disease cycle and epidemiology
Older lesions provide inoculum to infect plants during the season. Conidia are produced during the entire season if weather conditions are favorable (50-86°F) and are splash disseminated by water.
Management
Cultural: Resistant cultivars and disease-free transplants should be used.
Chemical: See Table 1 .
Charcoal Rot
Charcoal rot, caused by Macrophomina phaseolina, was first reported in Florida in 2005.Symptoms
Infected plants wilt, are stunted, and eventually die. The disease affects the plant roots and crown, and it can be difficult to distinguish from other crown diseases. Isolation in laboratory is necessary for proper identification.
Causal organism
Macrophomina phaseolina produces numerous dark oblong sclerotia on the isolation medium after 4 to 5 days incubation. Ostiolate pycnidia bearing relatively large, broadly ellipsoidal, hyaline conidia occasionally developed on host tissue after 8 to 10 days of incubation.
Management
Cultural: Planting should be avoided in fields with history of Macrophomina diseases of other crops.
Phomopsis Leaf Blight and Phomopsis Soft Rot (Phomopsis obscurans )
Phomopsis leaf blight and Phomopsis soft rot, caused by Phomopsis obscurans, can occasionally cause serious problems on strawberry, especially on plants propagated in nurseries from the southeastern United States.Symptoms
Lesions in the foliage are initially small and circular reddish-purple spots. Older spots can coalesce and form large V-shaped lesions with the widest part of the lesions at the leaf margin and the narrow base centered on a vein ( Figure 6 ). Black specks of pycnidia often develop within the central areas of the older lesions. Initial symptoms on fruit are round, light pink, and water-soaked lesions ( Figure 7 ). Frequently, two or more lesions may coalesce into large soft brown lesions with dark fruiting structures (pycnidia) on the surface. The disease may also produce dark, sunken, and elongated lesions in stolons and petioles that are very similar in appearance to anthracnose.
Figure 6. Phomopsis Leaf Blight.
Figure 7. Phomopsis Soft Rot. Disease cycle and epidemiology
Conidia of Phomopsis obscurans are spread by splashing water, harvesting operations, and equipment. The disease is favored by warm, wet conditions and can be the most severe during the summer on plants propagated in Florida and the southeastern United States. In fruit production fields in Florida, Phomopsis leaf blight will develop during the fall and early winter. The fruit rot phase of the disease typically develops in the fall in fields where leaf blight is present, then disappears as the winter weather gets colder and drier. Both the leaf blight and fruit rot caused by P. obscurans are rarely observed later in the season.
Management
Cultural: Transplants should be obtained from northern Canada or the western United States since leaf blight typically occurs on transplants propagated in the southeastern United States.
Chemical: See Table 1 .
Phytophthora Crown Rot
Phytophthora crown rot, caused by Phytophthora cactorum and P. citricola, can be a serious disease of annual production strawberry in central Florida.Symptoms
The disease is characterized by a sudden decline and wilt of plants. Reddish-brown coloration on the internal crown makes symptoms difficult to distinguish from those produced by Colletotrichum gloeosporioides or C. fragariae. Thus, isolation and characterization of the pathogen is important for proper identification.
Causal organism
In Florida, Phytophthora cactorum has historically been responsible for causing the disease, although P. citricola has been the primary cause of Phytophthora crown rot in recent years.
Disease cycle and epidemiology
Infected transplants are the primary source of inoculum for epidemics in Florida. The pathogen produces zoospores that infect strawberry plants under wet conditions. Phytophthora species produce oospores that may persist in infested soil and plant debris, although oospores have not been observed in Florida. Phytophthora cactorum also causes leather rot and the infected fruit may provide a source on inoculum. The disease is favored by warm temperatures and prolonged periods of wetness, conditions that are common during the plant establishment period (October) in Florida.
Management
Cultural: Use of disease-free transplants is the best way to control the disease.
Chemical: See Table 1 .
Phytoplasma Diseases
Several diseases of strawberry are caused by phytoplasmas. Some of the most common are aster yellows, green petal, bronze leaf wilt, and multiplier.Symptoms
Phytoplasma diseases can be recognized by one or more characteristic symptoms, such as phyllody ( Figure 8 ), stunting, and yellowing. Molecular techniques are necessary for detection and identification of phytoplasmas.
The disease is transmitted by grafting and by leafhoppers.
Figure 8. Phytoplasma-green petal. Management
Cultural: Use of disease-free transplants.
Powdery Mildew
Powdery mildew, caused by Sphaerotheca macularis, occurs in most areas of the world where strawberries are grown. The disease is particularly severe on strawberries grown in greenhouses or plastic tunnels. In open fields in central Florida, the disease is typically most severe in November and December and it may reappear in late February and March.
Symptoms
Early symptoms appear as small white patches of fungus growing on the lower leaf surface. These patches can expand and coalesce to cover the entire leaf surface under favorable conditions. In some cultivars, irregularly shaped yellow or reddish brown spots will develop on colonized areas on the lower surface of the leaf and eventually appear on the upper surfaces. The edges of heavily infected leaflets curl upward ( Figure 9 ). The fungus can also infect fruit and may reduce fruit quality and marketable yields.
Figure 9. Powdery Mildew. Causal organism
Sphaerotheca macularis is an obligate parasite that only infects living tissue of wild or cultivated strawberry. The fungus produces chains of dry, hyaline conidia and, occasionally, cleistothecia containing ascospores on infected leaves.
Disease cycle and epidemiology
The fungus readily infects living, green leaves in the nursery. Thus, infected transplants are normally the primary source of inoculum for fruiting fields in Florida. When conditions are favorable, conidia produced on infected plants are wind dispersed. Development and spread of powdery mildew is favored by moderate to high humidity and temperatures between 60° to 80° F. Rain, dew and overhead irrigation inhibit the fungus. Because dry conditions and high humidity are common in greenhouses and plastic tunnels, powdery mildew is typically more severe in protected culture.
Management
Cultural: Disease-free transplants should be used for controlling powdery mildew, although fields can become infected by conidia blown in from neighboring fields. Cultivars differ widely in their resistance to powdery mildew. Unfortunately, some of the most popular cultivars in Florida, Strawberry Festival, Camarosa, and Winter Dawn, are quite susceptible to the disease.
Chemical: See Table 1 .
Rhizopus Rot or Leak
Rhizopus rot or leak, caused by Rhizopus stolonifer, affects fruit and is most serious after harvest or in storage but can also occur in the field.Symptoms
Infected fruits collapse and rapidly leak juice ( Figure 10 ). A loose, cottony growth of mycelium (whiskers) grows over the surface of the fruit. Fruiting bodies (sporangia) appear as black dots scattered throughout the mycelium.
Figure 10. Rhizopus rot or leak. Causal organism
Rhizopus spp. cause rots of various fruit and vegetable crops and physiological specialization has not been established.
Disease cycle and epidemiology
The fungus survives on crop debris and in the soil between seasons. Rhizopus can only infect through wounds. Under favorable conditions of high temperature and moisture, sporulation is rapid and abundant. Spores are disseminated by air and by insects.
Management
Cultural: Fruit should be handled carefully to avoid bruising. When possible, fruit should be picked during the morning, protected from the sun, and cooled rapidly before shipping.
Root Necrosis
Root necrosis, caused by Colletotrichum acutatum, has been observed in Florida since 2000. This fungus is widely known as a fruit rot pathogen, but also infects other strawberry tissues, including the roots.Symptoms
Transplants with infected root systems often grow poorly or fail to become established after overhead irrigation is withdrawn. Few functional roots are found on infected plants even 1 to 2 weeks after transplant. Old structural roots are brown or black with few feeder roots, whereas new roots develop brown lesions, die back from the tip, or fail to emerge from the crown. In severe cases, C. acutatum enters the crown, causing a basal crown rot and eventually killing the plant. Plants in affected fields are stunted or irregular in size, flower late, and produce a poor early crop ( Figure 11 ). Infected plants may recover during the cool winter months and produce normally in February and March, if an outbreak of anthracnose fruit rot does not follow.
Figure 11. Root Necrosis. Causal organism
See anthracnose fruit rot.
Disease cycle and epidemiology
C. acutatum frequently colonizes leaves and petioles of runner plants in the nursery. Obvious symptoms may not be visible in the nursery environment, but if inoculum is allowed to build up and the weather is favorable, lesions may develop on the petioles. Little is known about how or when the pathogen spreads from colonized tissue above the ground to the root system below. However, C. acutatum grows freely in diseased tissues, and has been isolated from the soil around diseased plants. Healthy plants are presumably contaminated by this inoculum during normal digging, trimming, and packing operations in the nursery. Cultivars that are highly susceptible to anthracnose fruit rot, e.g., Camarosa and Treasure, are susceptible to root necrosis disease as well. Early in the season, plant-to-plant disease spread is not thought to occur below ground as the root systems are relatively isolated. However, above-ground spread does occur and may be facilitated by overhead irrigation during establishment.
Management
Cultural: Disease-free transplants should be used.
Chemical: A pre-plant fungicide dip may suppress disease development when the disease is confirmed or when susceptible cultivars are being grown. See Table 1 .
Stem-End Rot and Leaf Blotch
Stem-end rot and leaf blotch, caused by Gnomonia comari, occurs sporadically and may be found in association with Phomopsis obscurans.Symptoms
Fruits can be affected at all stages. Characteristic symptoms on small fruits are irregular brown areas on the surface and cessation of fruit development. On ripe fruits, the disease is characterized by a soft rot that is often invaded by secondary organisms. Leaf blotch lesions on young leaves are purple to brown and occasionally enlarge to form light brown necrotic spots on older leaves ( Figure 12 ). The outer leaves may die resembling the symptoms of Verticillium wilt. Peduncles, petioles, and calyxes may also be affected.
Figure 12. Leaf Blotch. Causal organism
G. comari infects numerous rosaceous species worldwide. Perithecia are globose and beaked, and ascospores are hyaline, straight or slightly curved, and septate.
Disease cycle and epidemiology
Fruit is infected by conidia and ascospores produced on other parts of the plant or other hosts. The disease is spread by frequent rains or overhead irrigation. The fungus generally penetrates through stomata or wounds when humidity is high.
Management
Cultural: Some strawberry cultivars may be resistant but there is no information regarding susceptibility of cultivars grown in Florida.
Chemical: See Table 1 .
Verticillium Wilt
Verticillium wilt, caused by Verticillium albo-atrum and V. dahliae, is an occasional problem in winter annual strawberry production. These pathogens have wide host ranges and isolates that are pathogenic on potato and tomato are also pathogenic on strawberry.Symptoms
Initial symptoms are wilting of the plant and browning of the margins and interveins of older leaves. Younger leaves may remain green, but develop slowly and the plant becomes stunted, declines and ultimately dies ( Figure 13 ). The crown of diseased plants develops necrotic streaking that appears similar to other crown rots. It is necessary to isolate the fungus to confirm its identity.
Figure 13. Verticillium Wilt.
Disease cycle and epidemiology
Infected transplants appear to be the primary source of inoculum for outbreaks of Verticillium crown rot in Florida. Disease spread from plant to plant seems unlikely, but infection may occur through root contact. The pathogen is favored by sudden weather changes such as increases in temperatures or lack of moisture.
Management
Cultural: The best method to control Verticillium wilt is to use disease-free transplants. Strawberry nurseries should avoid areas that were previously used for potato or tomato production. This fungus is likely to be more severe at high pHs, so care should be taken to not over lime the soil.
Tables
Table 1. Fungicides approved for disease management of strawberry in Florida.
- Chemical
Fungicide Group a
Maximum Rate/ Acre/
Applic. Season
Min. Days to Harvest
Pertinent Diseases or Pathogents
Remarks
Abound (azoxystrobin)
11
15.4 fl. oz.
1.92 qt.
0
Anthracnose Powdery mildew
Botrytis (suppression only)
Do not make more than 2 sequential applications and no more than 4 applications per crop year. See label for instructions on dipping transplants
Aliette WDG (fosetyl-Al)
33
5 lb.
30 lb.
12 hr
Phytophthora diseases
Do not tank mix with copper fungicides
Cabrio EG (pyraclostrobin)
11
14 fl. oz.
70 fl. oz.
0
Anthracnose Leaf spot
Powdery mildew
Botrytis (suppression only)
Do not make more than 2 sequential applications and no more than 5 applications per crop year
Captan 50 WP (captan)
M3
6 lb.
48 lb.
1
Anthracnose Botrytis fruit rot
Leaf spot
Rate per treated acre. Special label for FL allows up to 24 applications per season
Captan 80 WDG (captan)
M3
3.75 lb.
30 lb.
1
Anthracnose Botrytis fruit rot
Leaf spot
Rate per treated acre. Special label for FL allows up to 24 applications per season
Captec 4L (captan)
M3
3 qt.
24 qt.
Anthracnose Botrytis fruit rot
Leaf spot
Rate per treated acre. Special label for FL allows up to 24 applications per season
Captevate 68 WDG (captan + fenhexamid)
M3 + 17
5.25 lb.
21 lb.
0
Botrytis fruit rot Anthracnose
Do not make more than 2 consecutive applications
Copper (many brands)1
M1 or M9
varies
varies
1-2
Angular leaf spot
Frequent use of copper fungicides may cause foliar burn
Elevate 50 WDG (fenhexamid)
17
1.5 lb.
6 lb.
0
Botrytis fruit rot
Do not make more than 2 consecutive applications
Nova 40W (myclobutanil)
3
5 oz.
30 oz.
0
Powdery mildew Leaf spot
Leaf blight
Do not plant rotational crops until 30 days after last application
Potassium bicarbonate (many brands)2
varies
varies
1
Powdery mildew
Do not mix with highly acid products
Potassium phosphite (many brands)3
varies
varies
0
Phytophthora diseases
May cause foliar burn if applied with copper based products
Pristine (pyraclostrobin + boscalid)
11 + 7
23 oz.
115 oz.
0
Botrytis fruit rot Anthracnose
Powdery mildew
Leaf spot
Do not make more than 2 consecutive applications and no more than 5 applications per crop
Procure 50WS (triflumizole)
3
8 oz.
32 oz.
1
Powdery mildew
Do not plant leafy vegetables within 30 days or root vegetables within 60 days or rotational crops not on label for one year after application
Ridomil Gold EC (metalaxyl-M)
4
1 pt/trtd.acre
1 ½ qts/trtd acre
Phytophthora diseases
See label for use in drip irrigation
Rovral 4 (iprodione)
2
2 pt.
2 pt.
N/A
Botrytis fruit rot Stem end rot
Phomopsis soft rot
Leaf spot
Do not make more than 1 application per season. Do not apply after bloom initiation
Rovral 75 WG (iprodione)
2
1.33
1.33
N/A
Botrytis fruit rot Stem end rot
Phomopsis soft rot
Leaf spot
Do not make more than 1 application per season. Do not apply after bloom initiation
Scala SC (pyrimethanil)
9
18 fl. oz.
54 fl. oz.
1
Botrytis fruit rot
Do not make more than 2 consecutive applications. Do not use more than 2 of 6 applications in any one season.
Serenade Max (Bacillus subtilis)
3 lb.
0
Powdery mildew Botrytis fruit rot
Anthracnose
Should be used in combination with other fungicides
Sulfur (many brands)4
M1 or M9
varies
varies
1
Powdery mildew
Do not use during hot weather
Switch 62.5 WG (cyprodinil + fludioxonil)
9 + 12
14 oz.
56 oz.
0
Botrytis fruit rot Anthracnose
Do not make more than 2 consecutive applications. Do not plant crops not on the label for 30 days after last application
Thiram 65 WSB (thiram)
M2
5 lb.
25 lb.
3
Botrytis fruit rot
Do not rotate treated crops with other crops for which Thiram is not registered
Topsin 4.5 L (thiophanate-methyl)
1
20 fl. oz.
80 fl. oz
1
Botrytis fruit rot Colletotrichum crown rot
Leaf scorch
Leaf blight
Powdery mildew
Do not use Topsin alone. Fungicides from different chemical groups should be used in spray program for disease resistance management
Topsin M 70 W, Topsin M WSB
(thiophanate-methyl)
1
1 lb.
4 lb.
1
Botrytis fruit rot Colletotrichum crown rot
Leaf scorch
Leaf blight
Powdery mildew
Do not use Topsin alone. Fungicides from different chemical groups should be used in spray program for disease resistance management
N/A - Not available 1 e.g. Kocide, Champion, Champ, Basicop, Cuprofix Disperss, Copper Count-N, Nordox, Nu Cop
2 e.g. Kaligreen, Armicarb, Milstop
3 e.g. Fosphite, Helena Prophyt
4 e.g. Micro Sulf, Enduro, Sulfur 90W, Super-Six, Microthiol Disperss, Wettable Sulfur, Kumulus
a Fungicide group (FRAC Code): Numbers (1-37) and letters (M, U, P) are used to distinguish the fungicide mode of action groups. All fungicides within the same group (with same number or letter) indicate same active ingredient or similar mode of action. This information must be considered for the fungicide resistance management decisions. M = Multi site inhibitors, fungicide resistance risk is low; U = Recent molecules with unknown mode of action; P = host plant defense inducers. Source: http://www.frac.info/ (FRAC = Fungicide Resistance Action Committee). Be sure to read a current product label before applying any chemicals.
Footnotes
1. This document is PDMG-V3-50, of a series of the Department of Plant Pathology, 2006 Florida Plant Disease Management Guide; Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Revised July 2006. Please visit the EDIS Web site at http://edis.ifas.ufl.edu.2. N. A. Peres, assistant professor, Plant Pathology Department, Gulf Coast Research and Education Center, Wimauma, FL; Florida Cooperative Extension Service, Insitute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.
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.
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U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.
Copyright Information
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