| 1570144 |
Research |
Dose response curve (radial growth inhibition of Penicillium digitatum due to imazalil) using actual Petri plates for data points. Yellow line is of a sensitive strain. Red line is a strain resistant to imazalil. May 1990 |
| 1570153 |
Culture |
A single sector has overgrown the original colony of Penicillium digitatum. Sectoring is a common phenomenon in P. digitatum. |
| 1570837 |
Research |
Life-size graph using actual Petri plates from bioassay to plot the dose-response of Penicillium digitatum to the fungicide imazalil. July 1994 |
| 1570826 |
Research |
Spreading a spore suspension of Penicillium digitatum onto an agar plate using a bent glass rod and turntable. June 1994 |
| 1570771 |
Research |
Imazalil resistance assay showing colony reverse. Both plates were exposed for 30 seconds to air near the dump at a lemon packinghouse. Left: agar contains 0.1 ppm imazalil; right: no fungicide. March 1994 |
| 1570772 |
Research |
Imazalil resistance assay. Plates were exposed for 30 seconds to air near the dump at a lemon packinghouse. Left: no-fungicide; center: agar contains 0.1 ppm imazalil; right: agar contains 0.4 ppm imazalil. March 1994 |
| 1570769 |
Research |
Imazalil resistance assay. Both plates were exposed for 30 seconds to air near the dump at a lemon packinghouse. Left: agar contains 0.1 ppm imazalil; Righ: no fungicide. March 1994 |
| 1570770 |
Research |
Imazalil resistance assay showing colony reverse. Both plates were exposed for 30 seconds to air near the dump at a lemon packinghouse. Left: agar contains 0.1 ppm imazalil; right: no fungicide. March 1994 |
| 1570143 |
Research |
Dose response curve (radial growth inhibition of Penicillium digitatum due to imazalil) using actual Petri plates for data points. Yellow line is of a sensitive strain. Red line is a strain resistant to imazalil. |
| 1570194 |
Research |
In planta bioassay for fungicide resistance in Penicillium digitatum. Lemons are dipped for 30 seconds in a solution containing 1000 ppm imazalil, injected with a spore suspension of P. digitatum (see 1570164) and incubated at 25oC for 7 days. March 1991 |
| 1570767 |
Research |
Imazalil resistance assay. Both plates were exposed for 30 seconds to air near the dump at a lemon packinghouse. Left: agar contains 0.1 ppm imazalil; right: no fungicide. March 1994 |
| 1570789 |
Research |
See 1570790 for row and column labels. May 1994 |
| 1570790 |
Research |
Single- and triple-resistant Penicillium digitatum. See 1570789 for same photo without labels. May 1994 |
| 1570797 |
Culture |
Color variation in Penicillium digitatum growing on 15 ppm OPP. May 1994 |
| 1570148 |
Culture |
Growth inhibition of Penicillium digitatum on imazalil-amended potato dextrose agar. Note that the fungus is growing in the inoculum plug (no fungicide), but not on the fungicide-amended medium. |
| 1570794 |
Fruit(s) |
Lemon completely covered with sporulation by Penicillium digitatum. May 1994 |
| 1570805 |
Research |
Procedure used to wash spores of Penicillium digitatum off of infected fruit. Moldy fruit placed in jar filled with sterile water + surfactant. See 1570813 for result. May 1994 |
| 1570809 |
Fruit(s) |
Green mold of lemon 5 to 7 days following inoculation and storage at 15C. Note the different zones of disease progress: sporulation at center and advancing mycelium. Little to no watersoaked host tissue in contrast to blue mold. May 1994 |
| 1570810 |
Fruit(s) |
Green mold of lemon prior to sporulation. May 1994 |
| 1570813 |
Research |
Procedure for washing spores of Penicillium digitatum from fruit. See also 1570805. May 1994 |
| 1570814 |
Research |
Measuring the proportion of resistance in a population of spores after passage through one disease cycle. Imazalil-sensitive isolate (top row) and mixture of imazalil-sensitive and imazalil-resistant isolate (bottom row) on non-amended agar (left column) and imazalil-amended agar (right column). May 1994 |
| 1570833 |
Research |
Rotted lemon in mason jar for spore harvest. July 1994 |
| 1570834 |
Research |
Harvesting spores from rotted lemon in mason jar. July 1994 |
| 1570836 |
Research |
Spore harvest from rotted lemon in mason jar. July 1994 |
| 1570178 |
Culture |
Preparing a spore suspension of Penicillium digitatum. Left: slant culture of P. digitatum on potato dextrose agar. Center: dense spore suspension after washing spores from surface of slant and filtering through cheesecloth. Right: spore suspension adjusted to a concentration of 1 x 106 spores/ml. October 1990 |
| 1570827 |
Fruit(s) |
Decayed lemon after harvesting spores. June 1994 |
| 1570828 |
Fruit(s) |
Imazalil-sensitive Penicillium digitatum on imazalil-treated lemon. Note the sporulating area. This was isolated and found to be imazalil-resistant. Was this the result of a mutation or a contaminant? May 1994 |
| 1570829 |
Research |
Inoculated fruit decaying in sterile mason jar. June 1994 |
| 1570832 |
Research |
Rotted lemon in mason jar for spore harvest. July 1994 |
| 1570835 |
Research |
Rotted lemon in mason jar for spore harvest. July 1994 |
| 1570289 |
Research |
A colorless mutant of Penicillium digitatum (isolate J-56W) resistant to imazalil compared to the original colored isolate (isolate J-56 from which the colorless mutant originated) on imazalil-treated lemon. Results show that the mutation to colorless is stable and that growth and sporulation on potato dextrose agar is similar. September 1991 |
| 1570290 |
Research |
The effect of pH on growth of Penicillium digitatum (left column) and on the activity of imazalil (right column). Imazalil has a pKa of 6.53. October 1991 |
| 1570760 |
Fruit(s) |
Green mold of lemon showing soiling of adjacent fruit and what appears to be spread by contact (nesting). Note also the presence of whisker mold (Penicillium ulaiense) March 1994 |
| 1570761 |
Fruit(s) |
Green mold of lemon showing soiling of adjacent fruit and what appears to be spread by contact (nesting). Note also the presence of whisker mold (Penicillium ulaiense) March 1994 |
| 1570762 |
Fruit(s) |
Green mold of lemon showing soiling of adjacent fruit. March 1994 |
| 1570763 |
Fruit(s) |
Green mold of lemon showing soiling of adjacent fruit. March 1994 |
| 1570764 |
Fruit(s) |
Sharp edges of wooden crate create injuries which provide an infection court for Penicillium digitatum. March 1994 |
| 1570149 |
Culture |
Colony reverse. Imazalil-resistant Penicillium digitatum growing on imazalil-amended potato dextrose agar. Colony started from 10 mm agar plug. Colony becomes raised and striated on fungicide-amended agar. May 1990 |
| 1570150 |
Culture |
Normal growth of Penicillium digitatum on potato dextrose agar. |
| 1570146 |
Culture |
Imazalil-resistant Penicillium digitatum growing on imazalil-amended potato dextrose agar. Colony started from 10 mm agar plug. Colony becomes raised and striated on fungicide-amended agar. |
| 1570147 |
Culture |
Sectoring in Penicillium digitatum on imazalil-amended potato dextrose agar. Both Petri plates were infested with the same isolate of P. digitatum. Right plate: the fungus has produced a sector that is growing faster than the original colony. May 1990 |
| 1570151 |
Culture |
Three sectors of Penicillium digitatum emerging from original colony. Medium is potato dextrose agar. |
| 1570152 |
Culture |
A single sector has overgrown the original colony of Penicillium digitatum. Sectoring is a common phenomenon in P. digitatum. |
| 1570154 |
Culture |
Germinated spores of Penicillium digitatum embedded in solid potato dextrose agar. It takes approximately 18 hours at 25 oC for P. digitatum to reach this stage of growth. May 1990 |
| 1570155 |
Culture |
Germinated spore of Penicillium digitatum embedded in solid potato dextrose agar. It takes approximately 18 hours at 25 oC for P. digitatum to reach this stage of growth. May 1990 |
| 1570156 |
Culture |
Germinated spores of Penicillium digitatum embedded in solid potato dextrose agar amended with the fungicide imazalil. Compare to 1570155 for non-fungicide control. Hyphae are enlarged and distorted. It takes approximately 18 hours at 25 oC for P. digitatum to reach this stage of growth. May 1990 |
| 1570157 |
Culture |
Germinated spores of Penicillium digitatum embedded in solid potato dextrose agar amended with the fungicide imazalil. Compare to 1570155 for non-fungicide control. Hyphae are enlarged and distorted. It takes approximately 18 hours at 25 oC for P. digitatum to reach this stage of growth. May 1990 |
| 1570173 |
Culture |
Incubator set at 25 oC for growth of Penicillium digitatum on potato dextrose agar. October 1990 |
| 1570174 |
Culture |
A grid of Petri plates showing the reaction of seven biotypes of Penicillium digitatum (rows) to potato dextrose agar with and without fungicide. Column 1 (far left)= no fungicide; column 2 = 1 ppm methyl benzimidazole carbamate (MBC); column 3 = 0.1 ppm imazalil; column 4 = 0.2 ppm imazalil; column 5 = 0.3 ppm imazalil. All isolates that grew on MBC (rows 1, 4 and 6) grew very little on 0.3 ppm imazalil. Conversely, all isolates that do not grow on MBC (rows 2, 3, 5 and 7) are growing well on 0.3 ppm imazalil. This demonstrates the cost associated with double resistance. |
| 1570175 |
Culture |
In vitro bioassay for fungicide resistance in Penicillium digitatum. Agar plug containing 24-hour-old germlings of Penicillium digitatum, was transferred to the center of a Petri dish containing imazalil-amended potato dextrose agar. After 5 days incubation at 25oC, the imazalil-sensitive isolate has not grown beyond the initial inoculum plug. October 1990 |
| 1570176 |
Culture |
In vitro bioassay for fungicide resistance in Penicillium digitatum. Agar plug containing 24-hour-old germlings of Penicillium digitatum, are transferred to the center of a Petri dish containing imazalil-amended potato dextrose agar. After 5 days incubation at 25oC, colony diameter is measured. October 1990 |
| 1570177 |
Culture |
Measuring radial colony growth of Penicillium digitatum. In vitro bioassay for fungicide resistance in P. digitatum. Agar plug containing 24-hour-old germlings of Penicillium digitatum, are transferred to the center of a Petri dish containing imazalil-amended potato dextrose agar. After 5 days incubation at 25oC, colony diameter is measured and compared to growth on non-amended agar. October 1990 |
| 1570189 |
Fruit(s) |
In planta bioassay for fungicide resistance in Penicillium digitatum. Fruit were dipped for 30 seconds in solutions containing 4000, 6000 and 8000 ppm imazalil, injected with a spore suspension of P. digitatum and incubated at 25oC for 7 days. Results show that the imazalil-resistant isolate will decay and sporulate on treated fruit. October 1990 |
| 1570190 |
Fruit(s) |
In planta bioassay for fungicide resistance in Penicillium digitatum. Fruit were dipped for 30 seconds in solutions containing 4000, 6000 and 8000 ppm imazalil, injected with a spore suspension of P. digitatum and incubated at 25oC for 7 days. Results show that the imazalil-resistant isolate will decay and sporulate on treated fruit. October 1990 |
| 1570191 |
Fruit(s) |
In planta bioassay for fungicide resistance in Penicillium digitatum. Fruit were dipped for 30 seconds in a solution containing 1000 ppm imazalil, injected with a spore suspension of P. digitatum and incubated at 25oC for 7 days. Results show that the imazalil-resistant isolate will decay and sporulate on treated fruit (right) while the sensitive isolate will decay, but not sporulate on treated fruit (left). An excellent example of sporulation inhibition by a triazole fungicide. March 1991 |
| 1570193 |
Fruit(s) |
In planta bioassay for fungicide resistance in Penicillium digitatum. Lemon was dipped for 30 seconds in a solution containing 1000 ppm imazalil, injected with a spore suspension of P. digitatum and incubated at 25oC for 7 days. Results show that the imazalil-sensitive isolate will decay, but not sporulate on treated fruit. An excellent example of sporulation inhibition by a triazole fungicide. March 1991 |
| 1570197 |
Culture |
Isolates of Penicillium digitatum stored on silica gel. October 1990 |
| 1570199 |
Culture |
Isolates of Penicillium digitatum stored on silica gel. March 1991 |
| 1570200 |
Culture |
Preparation of inoculum plugs of Penicillium digitatum for fungicide resistance bioassay. April 1991 |
| 1570201 |
Culture |
The relationship of inoculum density to growth of Penicillium digitatum on fungicide-amended medium. A range of spore concentrations (0.4, 0.8, 1.6, 3.2 6.3 and 12.6 x 106spores/ml) were spread over the surface of potato dextrose agar amended with 0.3, 0.5 and 0.7 ppm imazalil. Results show that very large fluctuations in inoculum concentration are needed in order to have a measureable effect on growth. August 1991 |
| 1570414 |
Research |
Lemons were inoculated with imazalil-sensitive isolate of Penicillium digitatum 48 h prior to treatment with the fungicide imazalil. Shows curative action of imazalil. April 1992 |
| 1570415 |
Asexual Spore |
Phialides and conidia of Penicillium digitatum, causal agent of citrus green mold. April 1992 |
| 1570455 |
Research |
Lemons treated with imazalil and infected by Penicillium digitatum will decay, but not sporulate. This is an excellent example of the antisporulant effect of imazalil and other triazole fungicides. May 1992 |
| 1570169 |
Research |
In planta biological assay for fungicide resistance. Lemons (treated with a mixture of 4000 ppm imazalil + 5000 ppm thiabendazole and 2000 ppm imazalil and non-treated) inoculated with Penicillium digitatum (imazalil-sensitive isolate) show the typical reaction. Decay and sporulation on treated fruit is greatly reduced compared to non-treated fruit. August 1990 |
| 1570555 |
Asexual Spore |
|
| 1570556 |
Asexual Spore |
|
| 1570509 |
Research |
Agar seeded with 1 ml of 106 spores/ml of Penicillium digitatum after 48 h incubation at 25C. Fungus is just beginning to sporulate, so olive green color of sporulation, is not yet apparent. Jul 1992 |
| 1570510 |
Fruit(s) |
Valencia oranges showing sporulation control of Penicillium digitatum by the fungicide imazalil. July 1992 |
| 1570165 |
Fruit(s) |
Lemons (treated with 1000 and 2000 ppm imazalil and non-treated) inoculated with Penicillium digitatum (imazalil-sensitive isolate M6R) show the typical reaction. Treated fruit rot, but sporulation and the degree of decay is reduced by treatment with imazalil. August 1990 |
| 1570166 |
Fruit(s) |
Lemons (treated with 1000 and 2000 ppm imazalil and non-treated) inoculated with Penicillium digitatum (imazalil-resistant isolate) show the typical reaction. Decay and sporulation on imazalil-treated fruit is slightly less than on non-treated fruit. August 1990 |
| 1570167 |
Fruit(s) |
In planta biological assay for fungicide resistance. Lemons (treated with 1000 and 2000 ppm imazalil and non-treated) inoculated with Penicillium digitatum (imazalil-resistant isolate) show the typical reaction. Decay and sporulation on imazalil-treated fruit is identical to non-treated fruit. August 1990 |
| 1570168 |
Fruit(s) |
In planta biological assay for fungicide resistance. Lemons (treated with a mixture of 4000 ppm imazalil + 5000 ppm thiabendazole and 2000 ppm imazalil and non-treated) inoculated with Penicillium digitatum (imazalil-resistant isolate) show the typical reaction. Decay and sporulation on treated fruit is similar to non-treated fruit. August 1990 |
| 1570170 |
Fruit(s) |
In planta biological assay for fungicide resistance. Lemons (treated with a mixture of 4000 ppm imazalil + 5000 ppm thiabendazole and 2000 ppm imazalil and non-treated) inoculated with Penicillium digitatum (imazalil-sensitive isolate) show the typical reaction. Decay and sporulation on treated fruit is greatly reduced compared to non-treated fruit. August 1990 |
| 1570171 |
Fruit(s) |
In planta biological assay for fungicide resistance. Lemons (treated with a mixture of 4000 ppm imazalil + 5000 ppm thiabendazole and 2000 ppm imazalil and non-treated) inoculated with Penicillium digitatum (imazalil-sensitive isolate) show the typical reaction. Decay and sporulation on treated fruit is greatly reduced compared to non-treated fruit. August 1990 |
| 1570172 |
Fruit(s) |
In planta biological assay for fungicide resistance. Lemons (treated with a mixture of 4000 ppm imazalil + 5000 ppm thiabendazole and 2000 ppm imazalil and non-treated) inoculated with Penicillium digitatum (imazalil- and thiabendazole-resistant isolate) show the typical reaction. Decay and sporulation on treated fruit is virtually identical to that on non-treated fruit. October 1990 |
| 1570284 |
Research |
A colorless mutant of Penicillium digitatum (isolate J-56W) compared to the normal phenotype (isolate J-15) on imazalil-treated and untreated lemons. |
| 1570285 |
Research |
A colorless mutant of Penicillium digitatum (isolate J-56W) compared to the normal phenotype (isolate J-56) on lemon. Arrows indicate point of inoculation. Results show that the mutation to colorless is stable and that the growth rates of both isolates are similar in lemon. September 1991 |
| 1570286 |
Research |
A colorless mutant of Penicillium digitatum (isolate J-56W) compared to the normal phenotype (isolate J-56) on lemon. Left: isolates were inoculated into lemon from opposite sides. Right: a mixture of the same isolates was inoculated into lemon. Results show that the mutation to colorless is stable and that the growth rates of both isolates are similar in lemon. September 1991 |
| 1570287 |
Research |
A colorless mutant of Penicillium digitatum (isolate J-56W) resistant to imazalil compared to a wild type phenotype (isolate YUMA) on imazalil-treated lemon. Arrows indicate the point of inoculation. Results show that the mutation to colorless is stable and that growth and sporulation on imazalil-treated lemons is similar to the normal/colored phenotype. September 1991 |
| 1570288 |
Research |
A colorless mutant of Penicillium digitatum (isolate J-56W) resistant to imazalil compared to a wild type phenotype (isolate YUMA) on imazalil-treated lemon. Arrows indicate the point of inoculation. Results show that the mutation to colorless is stable and that growth and sporulation on imazalil-treated lemons is similar to the normal/colored phenotype. September 1991 |
| 1570395 |
Culture |
Culture of Penicillium digitatum showing a sector with a different growth pattern and texture. February 1992 |
| 1570396 |
Research |
Culture of a single isolate of Penicillium digitatum after seeding onto two replicate plates of imazalil-amended medium. The results should be identical, but they are quite opposite due to sectoring of the isolate. This result was highly unusual. February 1992 |
| 1570397 |
Research |
Culture of Penicillium digitatum showing a sector with a different growth pattern and texture. Transfers from the white sector onto plates with and without imazalil resumed sporulation. February 1992 |
| 1321062 |
Symptoms |
Grapefruit infected with green mold. |
