scholarly journals Effects of Sequential Calcium Chloride, Ziram, and Yeast Orchard Sprays on Postharvest Decay of Pear

Plant Disease ◽  
2003 ◽  
Vol 87 (10) ◽  
pp. 1260-1262 ◽  
Author(s):  
D. Sugar ◽  
J. M. Benbow ◽  
K. A. Powers ◽  
S. R. Basile

The most effective nutritional, fungicidal, and biological control treatments previously evaluated for control of postharvest decay in pear were evaluated for 3 years as factorial treatments to determine the best combinations for an integrated program. Calcium chloride sprays during the growing season reduced incidence of side rot in each year and of blue mold in 1 year, while ziram was effective against side rot in 1 year and blue mold in 2 years. Ziram, but not calcium chloride, provided control of gray mold and bull's-eye rot. Application of the yeast Cryptococcus infirmominiatus to pear fruit 1 week before harvest at a concentration of 1.0 to 1.5 × 108 CFU/ml resulted in establishment of large populations of yeast on fruit surfaces, but did not reduce postharvest fungal decay incidence in 3 years of testing. In 1 year, ziram sprays applied 2 weeks before harvest significantly reduced yeast populations on fruit subsequently treated with C. infirmo-miniatus. Sequential treatments with calcium chloride and ziram are indicated in an integrated program to take advantage of their differential effectiveness to broaden the range of control of pear postharvest decay pathogens.

Plant Disease ◽  
2004 ◽  
Vol 88 (5) ◽  
pp. 474-478 ◽  
Author(s):  
Cheryl L. Lennox ◽  
Robert A. Spotts ◽  
Mardé Booyse

Postharvest decay causes losses to commercial pear industries. The incidence of decay in air and controlled-atmosphere (CA)-stored ‘d'Anjou’ pear fruit was investigated, and the effect of a prestorage thiabendazole drench on decay in CA-stored fruit was determined. In air storage, bull's-eye rot (31.37%) was most prevalent in 1996, whereas incidence of gray and blue mold (1996 and 1997) and bull's-eye rot (1997) were similar. Mucor, Alternaria, and Coprinus rot levels were low. Incidence of stem-end gray mold (2.58%) was significantly higher than calyx-end (0.73%) and puncture gray mold (0.61%). Incidence of gray mold (2.26%) was higher than all other decay in nondrenched CA-storage, and incidence of other decay types were similar. Incidence of puncture gray mold (1.13%) was higher than stem-end gray mold (0.84%), which in turn was higher than calyx-end gray mold (0.36%) in nondrenched CA-storage. Incidence of gray mold (1.04%) in CA-stored fruit was reduced by a prestorage thiabendazole drench. Drenching reduced stem-end (0.34%) and puncture gray mold (0.40%) but had no effect on all other decay or the total decay incidence. These results support the current recommendations of a single postharvest application of thiabendazole to control gray mold in ‘d'Anjou’ pear fruit.


Plant Disease ◽  
2003 ◽  
Vol 87 (6) ◽  
pp. 639-644 ◽  
Author(s):  
Cheryl L. Lennox ◽  
Robert A. Spotts ◽  
Louis A. Cervantes

The aims of this study were to examine the sources and population sizes of Botrytis cinerea and Penicillium spp. in ‘d'Anjou’ pear orchards, packinghouses, and storage, and to determine the relationship between population sizes and postharvest decay. Densities of B. cinerea ranged from nondetectable to 4.0 CFU/cm2 on fruit, nondetectable to 3.1 CFU/liter in orchard air, and nondetectable to 1,167 CFU/g in orchard litter. The majority of packinghouse air and orchard soil samples collected yielded no B. cinerea inoculum. Densities of Penicillium spp. ranged from nondetectable to 2.7 CFU/cm2 on pear fruit, nondetectable to 3.13 CFU/liter in orchard air, nondetectable to 11.8 CFU/liter in packingline air, nondetectable to 3.9 CFU/liter in cold-storage air, 38 to 431 CFU/g in orchard soil, and 131 to 1,128 CFU/g in orchard litter. The mean incidence of gray mold in stored d'Anjou pear fruit ranged from 0.7 to 10.7%. Incidence of blue mold ranged from 0 to 16.5%. Significant positive correlations were observed between decay and fruit surface populations of B. cinerea and Penicillium spp. In conclusion, inoculum levels of these important postharvest pathogens in orchard and packinghouse air, and orchard soil and litter, cannot be used as indicators of postharvest decay; whereas the inoculum level on fruit surfaces may be a useful predictor of decay.


Plant Disease ◽  
2004 ◽  
Vol 88 (5) ◽  
pp. 468-473 ◽  
Author(s):  
C. L. Lennox ◽  
R. A. Spotts

Botrytis cinerea causes significant levels of postharvest decay in the winter pear cultivar d'Anjou. The objectives of this study were to determine the timing of B. cinerea infection of pear stems and calyxes in the orchard during the growing season, to investigate the development of gray mold in storage, and to determine whether preharvest levels of B. cinerea in pear stems and calyxes can be used as predictors of gray mold levels observed in storage. Very low levels of B. cinerea were isolated from stem tissue prior to harvest. In a single year repeat experiment, stems sampled at harvest had higher levels of infection than those sampled earlier in the season. Little or no stem end gray mold was detected in fruit after 3 months in air-storage; however, incidence increased between 6 and 8 months. Calyx end gray mold was detected at low levels in fruit stored for up to 8 months. The mean incidence of stem end gray mold was 3.6 and 2.0%, and incidence of calyx end gray mold was 1.2 and 0.2%, in 1996 and 1997, respectively. Calyxes were susceptible to infection soon after full bloom; however, inoculation of calyxes in April or May did not result in higher levels of calyx end gray mold in storage. Therefore, preharvest level of calyx infection is a poor predictor of calyx end gray mold in storage. In addition, application of benomyl in the orchard reduced the level of B. cinerea in blossoms but had no effect on levels of calyx end gray mold of fruit in storage. Packing and shipping fruit within 3 to 6 months of harvest may mitigate economic losses due to gray mold.


Plant Disease ◽  
2004 ◽  
Vol 88 (4) ◽  
pp. 413-418 ◽  
Author(s):  
C. L. Xiao ◽  
R. J. Boal

Phacidiopycnis rot, caused by Phacidiopycnis piri, is a newly recognized postharvest disease in pear fruit (Pyrus communis cv. d'Anjou) in the United States. To determine the prevalence and incidence of this disease, decayed fruit were sampled during packing and repacking operations from four packinghouses in 2001 and 2002. During March to May (repacking) in 2001, Phacidiopycnis rot was found in packed fruit that were stored in cardboard boxes from 22 of 26 grower lots (orchards), and accounted for 5 to 71% of the total decay. Phacidiopycnis rot, gray mold caused by Botrytis cinerea, and blue mold caused by Penicillium spp. accounted for an average of 34.1, 10.3, and 33.6% of decayed fruit from conventional orchards, respectively; and 22.8, 35.7, and 23.5% of decayed fruit from organic orchards, respectively. During November 2001 to January 2002 (packing), Phacidiopycnis rot was observed in fruit that were stored in field bins before packing from 30 of 33 grower lots, accounting for 18.4% of decayed fruit sampled. During March to May in 2002, Phacidiopycnis rot was responsible for 2 to 68% of decayed fruit sampled from 36 of 39 grower lots. Phacidiopycnis rot, gray mold, and blue mold accounted for an average of 19.6, 26.8, and 37.4% of decayed fruit from conventional orchards, respectively; and 42.2, 25.7, and 8.2% of decayed fruit from organic orchards, respectively. Most Phacidiopycnis rot that occurred in field bins before packing appeared to originate from wound infections; whereas after packing, approximately 60 and 30% of Phacidiopycnis rot originated from stem and calyx infections, respectively. This study indicates that Phacidiopycnis rot should be considered one of the targets for control of postharvest diseases in d'Anjou pears in the region.


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.


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 ◽  
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).


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.


Plant Disease ◽  
2008 ◽  
Vol 92 (6) ◽  
pp. 940-946 ◽  
Author(s):  
Y. K. Kim ◽  
C. L. Xiao

Sphaeropsis rot, caused by Sphaeropsis pyriputrescens, is a recently recognized postharvest disease of apple in Washington State. To determine the distribution and incidence of this disease as well as other postharvest diseases, decayed fruit were sampled during packing or pre-sizing operations in commercial fruit packinghouses from 26, 72, and 81 grower lots in 2003, 2004, and 2005, respectively. Fungi associated with decayed fruit were isolated and identified. The most common postharvest diseases of apple in the region were blue mold caused by Penicillium spp., primarily P. expansum, gray mold caused by Botrytis cinerea, and Sphaeropsis rot, accounting for 32, 28, and 17% of the decayed fruit, respectively. Percentages of these diseases in the total decayed fruit varied from lot to lot. Bull's eye rot caused by Neofabraea spp. was responsible for 13.4% of the total decay and was most prevalent on Golden Delicious. Other minor diseases included speck rot caused by Phacidiopycnis washingtonensis, Alternaria rot caused by Alternaria spp., Mucor rot caused by Mucor piriformis, and core rot caused by a group of fungi, primarily Alternaria spp. Sphaeropsis stem-end rot was more common than calyx-end rot on Golden Delicious, whereas Sphaeropsis calyx-end rot was more common than stem-end rot on Fuji. On Red Delicious, both stem-end rot and calyx-end rot were common. Sphaeropsis rot resulting from infections through the fruit peel was more commonly seen on Golden Delicious and Fuji than on Red Delicious. The percentage of gray mold was higher on nondrenched fruit than on fruit drenched with thiabendazole (TBZ), whereas blue mold was more prevalent on TBZ-drenched fruit. Our results indicate that Sphaeropsis rot is an important component of storage rots of apples in Washington State.


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