Biological and Chemical Control of Fruit Rot in Greenhouse Sweet Peppers (Capsicum 
annum L.) Caused by Fusarium subglutinans

Fruit rot is the primary threat to cranberry (Vaccinium macrocarpon) production in the northeastern United States, and increasingly in other growing regions. Efficacy of chemical control is variable because the disease is caused by a complex of pathogenic fungi. In addition, cranberries are often grown in environmentally sensitive areas, placing restrictions on chemical control measures. Thus, a major focus of the cranberry breeding program is to develop cultivars with improved fruit rot resistance (FRR). Several genetically diverse sources of FRR have been identified in our germplasm collection. However, the most resistant accessions lack one or more attributes; e.g., productivity, required for commercial acceptance. These resistant accessions were used in crosses with elite high-yielding selections and in 2009, 1624 progeny from 50 crosses were planted in 2.3-m2 field plots. During 2011–13, under field conditions with very limited fungicide management, disease pressure was severe, allowing evaluation for FRR. Plots were rated on a 1–5 scale for incidence of fruit rot (where 1 = 0% to 20% rot and 5 = 81% to 100% rotted fruit), and rotted fruit counts were made from selected plots to validate the ratings. There was a good correlation in the ratings between years (2011 vs. 2012: r = 0.59, P < 0.0001; 2011 vs. 2013: r = 0.50, P < 0.0001; 2012 vs. 2013: r = 0.62, P < 0.0001), and between rot ratings and percent rotted fruit (r = 0.90, P < 0.0001). Significant differences were found between and within families for FRR. High heritability estimates (h2 = 0.81) were obtained with midparent-offspring regression of mean fruit rot ratings, indicating additive genetic variance for FRR. Introgression of FRR into higher yielding genetic backgrounds was also accomplished, as some progeny exhibiting high FRR also had commercially viable yield (>300 g/0.09 m2), as well as good berry size and color. Selections are being further evaluated for potential cultivar release.

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Infection of ‘d'Anjou’ Pear Fruit by Potebniamyces pyri in the Orchard in Relation to Phacidiopycnis Rot during Storage

Plant Disease ◽

10.1094/pdis-93-10-1059 ◽

2009 ◽

Vol 93 (10) ◽

pp. 1059-1064 ◽

Cited By ~ 6

Author(s):

Q. Liu ◽

C. L. Xiao

Keyword(s):

Chemical Control ◽

Growing Season ◽

The United States ◽

Fruit Rot ◽

Pear Fruit ◽

Growing Seasons ◽

Naturally Occurring ◽

Fruit Growing ◽

Rot Disease ◽

Decay Development

Phacidiopycnis rot, caused by Potebniamyces pyri, is a recently recognized postharvest fruit rot disease of ‘d'Anjou’ pear (Pyrus communis) in the United States. To determine the timing of fruit infection in the orchard in relation to incidence of Phacidiopycnis rot during storage, fruit were inoculated in the orchard at different times during the growing season, harvested, and monitored for decay development during storage at 0°C. Fruit inoculated in the field and laboratory were also used to determine the infection courts and the importance of necrotic tissues to infection of sepals that may lead to calyx-end Phacidiopycnis rot. Phacidiopycnis rot was observed during cold storage on the fruit inoculated any time after bloom till near harvest but not on the fruit inoculated during bloom. Phacidiopycnis rot symptoms only developed at the stem and calyx end of the fruit during storage. Relatively more calyx-end rot was observed than stem-end rot on the fruit inoculated before August. Incidence of stem-end rot increased significantly on the fruit inoculated near harvest. Incidence of total Phacidiopycnis rot increased as the timing of fruit infection in the orchard approached harvest. Potebniamyces pyri was recovered more frequently from sepals than from styles and stamens of the fruit. Most infections on sepals were associated with the necrotic tissues. Naturally occurring necrotic tissues occurred on more than 85% and all sepals in the early fruit-growing and late growing seasons, respectively. Such necrotic tissues on sepals could serve as potential infection sites for P. pyri. The results may suggest that chemical control of Phacidiopycnis rot should focus on protecting the pedicel (stem) and floral parts of fruit and that fungicides applied near harvest are likely most important in controlling latent infections of pear fruit by P. pyri leading to Phacidiopycnis rot during storage.

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CULTURAL AND CHEMICAL CONTROL OF BOTRYTIS FRUIT ROT OF STRAWBERRY IN ANNUAL WINTER PRODUCTION SYSTEMS

Acta Horticulturae ◽

10.17660/actahortic.2002.567.141 ◽

2002 ◽

pp. 651-654 ◽

Cited By ~ 2

Author(s):

D.E. Legard ◽

J.C. Mertely ◽

C.L. Xiao ◽

C.K. Chandler ◽

J.R. Duval ◽

...

Keyword(s):

Chemical Control ◽

Production Systems ◽

Fruit Rot

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Chemical control of fruit rot and leaf blight of bell pepper in India

Agriculture Ecosystems & Environment ◽

10.1016/0167-8809(85)90092-1 ◽

1985 ◽

Vol 14 (1-2) ◽

pp. 151-153

Author(s):

Shakti S. Bhardwaj ◽

S.L. Sharma

Keyword(s):

Chemical Control ◽

Leaf Blight ◽

Bell Pepper ◽

Fruit Rot

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Fusarium Fruit Rot of Greenhouse Sweet Peppers in Canada

Plant Disease ◽

10.1094/pdis.2003.87.1.100c ◽

2003 ◽

Vol 87 (1) ◽

pp. 100-100 ◽

Cited By ~ 9

Author(s):

R. Utkhede ◽

S. Mathur

Keyword(s):

Fusarium Species ◽

Sweet Pepper ◽

Spore Suspension ◽

Fruit Rot ◽

Research Centre ◽

Vegetable Crops ◽

Harvest Time ◽

Single Spore ◽

Fusarium Subglutinans ◽

Stem And Fruit Rot

In the summer of 2001, a fruit rot of orange sweet peppers (Capsicum annum L. cv. Sympathy MZ) was observed in commercial greenhouses in British Columbia, Canada. According to the grower's estimate, approximately 40% of fruits in the commercial greenhouse were severely affected in the year 2001 and approximately 10% in 2002. The disease appeared on mature fruits at harvest time, and affected fruits are considered as culls. The disease appeared as discolored soft patches or necrotic spots predominantly at the calyx end and occasionally, anywhere on the mature fruit at harvest time. Seeds and the surrounding area inside the fruits were covered with fungal growth and orange-pink spore masses. Five fungal isolations were made from the lesions. Infected tissues from the edge of lesions were surface sterilized in 1% sodium hypochlorite for 2 min, blotted dry on sterile filter paper, and cultured on potato dextrose agar (PDA). Plates were incubated at 22°C for 7 days. Single spore fungal colonies isolated from the tissues yielded Fusarium sp. Only one fungal species was consistently isolated from affected pepper fruits. Morphology of the fungus was consistent with Fusarium subglutinans (Wollenweber & Reinking) Nelson et al. according to Keith Seifert of Eastern Cereal and Oilseed Research Centre, Ottawa, Canada. Molecular tests are being developed to confirm the identification of the fungus. To confirm pathogenicity, 10 flowers and developing fruits of sweet pepper cv. Sympathy MZ grown in a greenhouse were inoculated with the pathogen. For inoculation, 20 μl of spore suspension of the fungus (concentration 106 spores/ml) was drop-inoculated on the wounded and unwounded surfaces of fruits. To inoculate flowers, a spore suspension was drop-inoculated in the middle of flowers without any wounding. Controls were treated with 20 μl of sterile water. The experiment was repeated once. Approximately 80% of inoculated fruits and flowers developed symptoms on fruits similar to naturally infected fruits at maturity. Fruits from control plants did not develop any disease. On PDA, a Fusarium species identical to the original one was recovered from all inoculated infected fruits. A preliminary study showed that this pathogen does not infect other greenhouse crops such as tomato, cucumber, or lettuce. Sweet pepper stem and fruit rot caused by Fusarium solan has been reported previously (1) but there is no report of fruit rot caused by a Fusarium subglutinans-like species on greenhouse sweet peppers. Reference: (1) J. G. Menzies and W. R. Jarvis. Fusarium stem and fruit rot. Pages 333–334 in: Diseases and Pests of Vegetable Crops in Canada. R. J. Howard et al. eds. The Canadian Phytopathological Society and Entomological Society of Canada, 1994.

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