scholarly journals Preharvest Application of a Boscalid and Pyraclostrobin Mixture to Control Postharvest Gray Mold and Blue Mold in Apples

Plant Disease ◽  
2009 ◽  
Vol 93 (2) ◽  
pp. 185-189 ◽  
Author(s):  
C. L. Xiao ◽  
R. J. Boal

After harvest, apples (Malus × domestica) may be kept in cold storage for up to 12 months prior to packing. Gray mold caused by Botrytis cinerea and blue mold caused by Penicillium expansum are common postharvest fruit rot diseases affecting apples and are controlled commonly by applications of fungicides after harvest. To search for an alternative strategy, Pristine (a premixed formulation of boscalid and pyraclostrobin) as a preharvest treatment was evaluated for control of postharvest gray mold and blue mold in cultivars Fuji and Red Delicious apples during 2004 to 2006. Pristine (0.36 g per liter of water) was applied 1, 7, or 14 days before harvest. For comparison, thiram (2.04 g per liter of water) was applied 7 days before harvest and ziram (2.4 g per liter of water) was applied 14 days before harvest, to Fuji and Red Delicious, respectively. Fruit were harvested at commercial maturity, wounded with a finishing nail head, inoculated with conidial suspensions of either B. cinerea or P. expansum, stored in air at 0°C, and evaluated for decay after 8 or 12 weeks. In 2004 and 2005, Pristine was equally effective when applied to Fuji 1 or 7 days before harvest, reducing gray mold incidence by 93 to 99% and blue mold incidence by 78 to 94% compared with the nontreated control. Thiram reduced gray mold incidence by 38 to 85%. Thiram reduced blue mold incidence by 22% in 2004 but not in 2005. On Red Delicious, Pristine was equally effective when applied 7 or 14 days before harvest and reduced gray mold incidence by 69 to 85% and blue mold incidence by 41 to 70%. Ziram applied 2 weeks before harvest reduced gray mold incidence by 97 and 94% in 2005 and 2006, respectively, but it did not reduce blue mold incidence. The results indicate that Pristine applied within 2 weeks before harvest may be an effective alternative to postharvest fungicides for control of postharvest gray mold and blue mold in Fuji and Red Delicious apples.

Plant Disease ◽  
2001 ◽  
Vol 85 (7) ◽  
pp. 755-759 ◽  
Author(s):  
Robert A. Spotts ◽  
Louis A. Cervantes

The objective of this research was to determine quantitative relationships between incidence of pear fruit decay and inoculum dose of Botrytis cinerea and Penicillium expansum using dry conidia applied to wet or dry pears in a settling tower. On wet fruit, incidence of gray mold fruit rot increased from 0.1 to 83.1% as the airborne concentration of B. cinerea conidia increased from 0 to 8.6 spores per liter of air. Significantly less decay occurred in fruit inoculated dry compared to wet, particularly in fruit wounded after inoculation. Incidence of blue mold increased from 1 to 100% as the airborne concentration of P. expansum conidia increased from 0.1 to 803.5 spores per liter of air. Blue mold incidence was not affected by fruit wetness or time of wounding relative to inoculation. All regressions of decay incidence versus airborne and surface conidial concentrations were highly significant (P = 0.01).


2002 ◽  
Vol 92 (3) ◽  
pp. 281-287 ◽  
Author(s):  
Carla Nunes ◽  
Josep Usall ◽  
Neus Teixidó ◽  
Maribel Abadias ◽  
Immaculada Viñas

The potential enhancement of Candida sake (CPA-1) by ammonium molybdate to control blue and gray mold caused by Penicillium expansum and Botrytis cinerea, respectively, on Blanquilla pears was investigated. In laboratory trials, improved control of blue and gray molds was obtained with the application of ammonium molybdate (1, 5, 10, and 15 mM) alone or in combination with C. sake at 2 × 106 or 2 × 107 CFU ml-1 on Blanquilla pears stored at 20°C. In semicommercial trials at 1°C for 5 months, the efficacy of C. sake at 2 × 106 CFU ml-1 on reducing P. expansum and B. cinerea decay was enhanced more than 88% with the addition of ammonium molybdate 5 mM in the 1999-2000 season. In two seasons, the performance C. sake at 2 × 106 CFU ml-1 plus ammonium molybdate was similar to or greater than that of C. sake at 2 × 107 CFU ml-1. Similar control of blue mold was obtained on pears stored under low oxygen conditions. The preharvest application of ammonium molybdate did not reduce postharvest blue mold decay. The population of C. sake on pear wounds significantly decreased in the presence of ammonium molybdate 1 and 5 mM at 20 and 1°C.


Plant Disease ◽  
2011 ◽  
Vol 95 (6) ◽  
pp. 666-672 ◽  
Author(s):  
S. Konstantinou ◽  
G. S. Karaoglanidis ◽  
G. A. Bardas ◽  
I. S. Minas ◽  
E. Doukas ◽  
...  

The incidence of pathogens associated with postharvest fruit rots on the four most extensively cultivated apple cultivars (Red Delicious, Golden Delicious, Granny Smith, and Fuji) in Greece was surveyed during two consecutive storage periods (2008–09 and 2009–10) in five packinghouses located in northern Greece. The fungi isolated were identified based on their morphological characteristics and internal transcribed spacer gene sequencing. In the four cultivars sampled, Penicillium expansum and Botrytis cinerea were the predominant pathogens, accounting for averages of 44.2 and 23.6%, respectively, of the pathogens isolated from the sampled fruit. Two other important rot pathogens were Alternaria tenuissima and Mucor pyriformis, accounting for 16.1 and 6.6%, respectively, of the diseased apple fruit. Other pathogens such as Monilinia laxa, M. fructigena, Botryosphaeria obtusa, Geotrichum candidum, Fusarium avenaceum, and F. proliferatum were isolated at low frequencies and are considered of minor importance. Measurements of the resistance level of the four apple cultivars to fruit rot caused by P. expansum and Botrytis cinerea revealed that Golden Delicious was the most susceptible to blue mold while Fuji was the most susceptible to gray mold infections. Susceptibility to gray mold was negatively correlated with flavonoid and phenol concentration as well to fruit antioxidant activity, while susceptibility to blue mold was negatively correlated with fruit firmness and phenol concentration. Patulin production was significantly higher in Red Delicious and Golden Delicious fruit than in Granny Smith and Fuji fruit and was negatively correlated with the acidity of the fruit. The high incidence of P. expansum and A. tenuissima along with the presence of F. avenaceum and F. proliferatum, all of which are potentially mycotoxin producers, emphasize the risk for mycotoxin contamination of apple fruit juices and by-products. Furthermore, information on the distribution of the pathogens on the main cultivars may be useful for the implementation of strategies to control the diseases and minimize the threat of mycotoxin contamination on each cultivar.


2002 ◽  
Vol 65 (1) ◽  
pp. 178-184 ◽  
Author(s):  
CARLA NUNES ◽  
JOSEP USALL ◽  
NEUS TEIXIDÓ ◽  
ROSARIO TORRES ◽  
IMMACULADA VIÑAS

The effectiveness of Candida sake (CPA-1) in combination with Pantoea agglomerans (CPA-2) for controlling Penicillium expansum and Botrytis cinerea on pears and apples was determined. The concentrations tested were 2 × 106 and 2 × 107 CFU/ml for C. sake and 2 × 107 and 8 × 107 CFU/ml for P. agglomerans. At room temperature, the two antagonists were combined in proportions of 0 to 100% in 25% increments. At the proportion of 50:50, no rot development was observed in pears, and the greatest control of blue mold in apples was observed at this proportion for all the tested concentrations. Under cold temperature on pears, the highest effectiveness of the mixture was observed when C. sake at 2 × 107 CFU/ml was combined with P. agglomerans at 2 × 107 or at 8 × 107 CFU/ml at the proportion 50:50. Under these conditions, no rot development of blue mold was reported, and gray mold lesion size was reduced by more than 95%. On apples, the mixture of C. sake at 2 × 107 CFU/ml and P. agglomerans at 8 × 107 CFU/ml at the proportion 50:50 reduced blue and gray mold incidence by 90%. Populations of the two antagonists had the same growth pattern at 20°C when they were applied individually or in combination, but the population level was always higher when they grew alone. In contrast, at 1°C, the population of both antagonists in combination formed a stable community with the same levels as individual application during the first 30 days; after that, C. sake dominated, and P. agglomerans decreased on apples and pears. At both temperatures, the maximum population level of C. sake was observed in apples, and the maximum population level of P. agglomerans was observed in pears.


HortScience ◽  
1990 ◽  
Vol 25 (3) ◽  
pp. 320-322 ◽  
Author(s):  
F. Takeda ◽  
W.J. Janisiewicz ◽  
J. Roitman ◽  
N. Mahoney ◽  
F.B. Abeles

Postharvest treatment with pyrrolnitrin (250 mg·liter-1) and low storage temperatures delay postharvest rot development in fall-harvested `Tribute' strawberries (Fragaria × ananassa Duch.). Untreated fruit stored at 18C developed gray mold fruit rot (Botrytis cinerea) and rhizopus rot (leak) by the second day. Fruit that did not develop gray mold or leak eventually developed blue mold rot (Penicillium spp.). No rot was observed at 1C, but gray mold and rhizopus rots developed after berries were transferred to 18C. Pyrrolnitrin delayed the appearance of the various rots by 2 to 4 days, but did not reduce the rate of rot development. Chemical name used: 3-chloro-4-(2'-nitro-3'-chlorophenyl)pyrrole (pyrrolnitrin).


Plant Disease ◽  
2008 ◽  
Vol 92 (3) ◽  
pp. 451-455 ◽  
Author(s):  
Robert A. Spotts ◽  
Kelly M. Wallis ◽  
Maryna Serdani ◽  
Daniel T. O'Gorman ◽  
Peter L. Sholberg

The objective of this research was to determine quantitative relationships between incidence of stem end decay of pear fruit and inoculum concentration of Botrytis cinerea and Penicillium expansum using dry conidia applied to pear fruit in a settling tower. Five concentrations of conidia were applied to pear fruit, fruit were stored at –1°C for 8 months, and stem end decay was evaluated. In addition, conidia were washed from the surface of inoculated fruit, and DNA was extracted and quantified with real-time polymerase chain reaction (PCR). The linear regression relationships between percent stem end gray mold and B. cinerea conidia per liter of air or per square centimeter of fruit surface were significant (P = 0.01). At the highest inoculum dose introduced into the settling tower, conidia per liter of air, conidia per square centimeter, and percent stem end gray mold at 8 months after inoculation were 12, 31, and 39, respectively for 2000 and 6, 33, and 67, respectively for 2001. Similarly, the linear regression relationships between percent stem end blue mold and P. expansum conidia per liter of air or per square centimeter of fruit surface were significant (P = 0.01 and 0.05, respectively). At the highest inoculum dose introduced into the settling tower, conidia per square centimeter and percent stem end blue mold at 8 months after inoculation were 39 and 26, respectively for 2000 and 66 and 23, respectively for 2003. Real-time PCR provided a rapid, quantitative measure of B. cinerea and P. expansum DNA on pear fruit surfaces. Because of possible year-to-year shifts in susceptibility of fruit to decay, disease incidence:inoculum dose relationships may be of most value compared within years rather than across years. This would facilitate comparison of decay risk among orchards in order to determine which fruit is most suitable for long-term storage.


2008 ◽  
Vol 9 (1) ◽  
pp. 7 ◽  
Author(s):  
M. A. Ellis ◽  
L. V. Madden ◽  
S. R. Wright ◽  
L. L. Wilson

Applications of the fungicides Elevate 50WG and Switch 62.5WG to red raspberry prior to harvest were evaluated for post-harvest control of fruit rot, caused by Botrytis cinerea. Fungicides were applied three times during bloom only, three times pre-harvest (post-bloom) only, or six times full season (bloom through harvest), and symptomless fruit (at harvest) were incubated for 8 days in either cold storage (4°C) or at room temperature (23°C). Without fungicide, between 6 and 29% of the fruit had rot symptoms after 2 days of storage at room temperature over the 2 years of testing; after 8 days, 74 and 85% of the fruit had symptoms at room temperature. Zero and 12% of fruit had symptoms with 2 days of cold storage when plants were not treated with fungicide, and rot incidence increased to 9 and 60% at 8 days of cold storage over the 2 years. All fungicide treatments significantly reduced post-harvest fruit rot compared to the control (six water sprays). Applications of fungicide only at bloom generally had higher fruit rot incidence than found for the pre-harvest and full season fungicide programs. Results indicate that pre-harvest (post-bloom) fungicide sprays are beneficial for control of post-harvest Botrytis fruit rot, especially when coupled with cold-temperature storage. Accepted for publication 8 August 2008. Published 15 October 2008.


1968 ◽  
Vol 48 (3) ◽  
pp. 267-272
Author(s):  
C. O. Gourley

Captan, dichlofluanid at a high and a low rate, thiram, and a mixture of captan and thiram were tested in a field trial to control gray mold fruit rot caused by Botrytis cinerea Pers. on the strawberry varieties Gorella, Midway, Redcoat and Sparkle. The mean marketable yield of the varieties was increased by dichlofluanid (low) and thiram but not by the other treatments over that of non-sprayed plots. Dichlofluanid (high) gave better control of pre-harvest fruit rot than captan. Dichlofluanid (high) significantly reduced mean fruit size. Redcoat yields were higher with the low rate than the high rate of dichlofluanid, but pre-harvest fruit rot control and fruit size did not differ with the two rates. Gorella yields and fruit size were smaller with captan + thiram than with captan or thiram. Thiram reduced fruit size on Midway. The varietal reaction to fungicides suggests that marketable yield is the most important variable in selecting a fungicide for the control of gray mold fruit rot of strawberries.


HortScience ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 611-616 ◽  
Author(s):  
Peter L. Sholberg ◽  
Paul Randall

Stored apples and pears are subject to blue and gray mold decay incited by Penicillium expansum and Botrytis cinerea respectively. Hexanal, a C6 carbon aldehyde, used as a vapor provided effective control of both blue and gray molds in laboratory experiments on apple slices. A preliminary trial with ‘Anjou’ pears in bins showed that hexanal was not corrosive and could reduce gray mold in pears stored for 7 months. However details on the correct procedure for fumigating pome fruit were lacking, and further studies were needed to develop a reliable fumigation strategy. In trials with inoculated fruit, hexanal inactivated conidia of B. cinerea contaminating the pear surface when used at a rate of 2 mg·L−1 for 24 hours or 4 mg·L−1 for 18 hours. It was less effective on ‘Gala’ apples inoculated with conidia of P. expansum, but reduced blue mold decay to low levels at 15 ºC. On the other hand, hexanal increased gray and blue molds when used after wounds were made in inoculated fruit. The use of a preharvest treatment with cyprodinil (0.62 g·L−1) reduced both blue and gray molds in wounds with or without hexanal fumigation. Thus a strategy for controlling postharvest decay was developed by which fruit were treated 2 weeks before harvest with cyprodinil, followed by fumigation with hexanal immediately after harvest. The use of this strategy on ‘Anjou’ pears produced the highest number of mold-free fruit in 2003 and the least amount of gray and blue mold decay in 2003 and 2004 on pears stored for 4 months. Wounded apples only developed 1% rot compared with 10% in the control, indicating that hexanal fumigation of stored apples reduced contamination. Monitoring hexanal during fumigation showed that hexanal concentration declined slowly over a 24-hour period and could accurately be described by a third-order polynomial equation. Hexanal fumigation at low rates (2–3 mg·L−1) was not phytotoxic and improved aroma in ‘Anjou’ pears and ‘Gala’ apples with no harmful effects on apple or pear firmness, pH, titratable acidity, or soluble solids.


2012 ◽  
Vol 58 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Hanna Bryk ◽  
Dorota Kruczyńska

The occurrence of storage diseases on fruit of seven scab resistant apple cultivars (Freedom, Rajka, Topaz, Rubinola, Enterprise, Goldstar, GoldRush) grafted on M.9 was investigated in 2001-2005. The trees were planted in 1995. It was found that after storage (4 and 6 months at 2<sup>°</sup>C, 85-90% RH) the most severe appeared to be bull's eye rot (<i>Pezicula</i> spp.). The most sensitive cultivars to this disease were: Topaz, Freedom, Goldstar, the least sensitive were Rubinola, Enterprise, Rajka. Other postharvest diseases like gray mold (<i>Botrytis cinerea</i>), blue mold (<i>Penicillium expansum</i>) and brown rot (<i>Monilinia fructigena</i>) were not common. 'Rajka' and 'Goldstar' were susceptible to bitter pit, and 'Freedom' to superficial scald.


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