scholarly journals Infection Courts and Timing of Infection of Apple Fruit by Phacidiopycnis washingtonensis in the Orchard in Relation to Speck Rot During Storage

Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1467-1475 ◽  
Author(s):  
P. Sikdar ◽  
M. Mazzola ◽  
C. L. Xiao
Keyword(s):  
Control Strategies ◽  
Growing Season ◽  
Apple Fruit ◽  
Fruit Rot ◽  
Effective Control ◽  
Micro Cracks ◽  
Fuji Apple ◽  
Phacidiopycnis Washingtonensis ◽  
Inoculation Time ◽  
Rot Disease

Phacidiopycnis washingtonensis is the cause of speck rot, a recently reported postharvest fruit rot disease of apple. The pathogen is believed to incite infections in the field, and disease symptoms become evident only during storage. To determine the timing of apple fruit infection in relation to development of speck rot in storage, ‘Red Delicious’ and ‘Fuji’ apple fruit were inoculated in the orchard with P. washingtonensis at different times during the growing season, harvested, and monitored for decay development during storage at 0°C. Fruit inoculated in both field and laboratory also were used to identify the infection courts and mode of apple fruit penetration by P. washingtonensis. In all 3 years, stem-end speck rot and calyx-end speck rot developed during cold storage on fruit inoculated during the growing season, regardless of inoculation time; and the incidence of total speck rot in storage increased as the fruit inoculation time approached harvest. On fruit floral parts, the pathogen colonized sepals at higher rates than stamens. Availability of naturally occurring necrotic tissues favored the colonization of the fungus on sepals. Histological studies indicated that infection occurred through micro-cracks on the surfaces of pedicels and sepals of the fruit, and invasion of these tissues was restricted between the cuticle and epidermis. Findings of this study will assist in the development of effective control strategies for speck rot.

scholarly journals Control of Sphaeropsis Rot in Stored Apple Fruit Caused by Sphaeropsis pyriputrescens with Postharvest Fungicides

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1075-1079 ◽  
Author(s):  
C. L. Xiao ◽  
Y. K. Kim ◽  
R. J. Boal
Keyword(s):  
Mycelial Growth ◽  
Disease Incidence ◽  
Apple Fruit ◽  
Conidial Germination ◽  
Fruit Rot ◽  
Mitigation Measures ◽  
The Mean ◽  
Rot Disease ◽  
Sphaeropsis Rot

Sphaeropsis rot caused by Sphaeropsis pyriputrescens is a recently reported postharvest fruit rot disease of apple grown in Washington State. The objective of this study was to develop chemical-based mitigation measures for Sphaeropsis rot in stored apple fruit. To determine in vitro sensitivity of S. pyriputrescens to the three registered postharvest fungicides thiabendazole, fludioxonil, and pyrimethanil, 30 isolates of S. pyriputrescens obtained from various sources were tested for mycelial growth and conidial germination on fungicide-amended media. Golden Delicious apple fruit were inoculated with the pathogen in the orchard at 2 or 5 weeks before harvest. After harvest, fruit were either nontreated or dipped in thiabendazole, fludioxonil, or pyrimethanil solutions, stored at 0°C, and monitored for decay development for up to 9 months after harvest. The mean effective concentration of a fungicide that inhibits mycelial growth or spore germination by 50% relative to the nonamended control (EC50) values of thiabendazole, fludioxonil, and pyrimethanil on mycelial growth were 0.791, 0.0005, and 2.829 μg/ml, respectively. Fludioxonil and pyrimethanil also were effective in inhibiting conidial germination of the fungus with EC50 values of 0.02 μg/ml for fludioxonil and 5.626 μg/ml for pyrimethanil. All three postharvest fungicides applied at label rates immediately after harvest were equally effective in controlling Sphaeropsis rot in stored apple fruit, reducing disease incidence by 92 to 100% compared with the nontreated control. The results indicated that Sphaeropsis rot may be effectively controlled by the currently registered postharvest fungicides thiabendazole, fludioxonil, and pyrimethanil.

Emergence Pattern and Periodicity of Palmer Amaranth (Amaranthus palmeri) Populations from Southcentral Great Plains

2021 ◽  
pp. 1-21
Author(s):  
Rui Liu ◽  
Vipan Kumar ◽  
Prashant Jha ◽  
Phillip W. Stahlman
Keyword(s):  
Great Plains ◽  
Prediction Models ◽  
Agricultural Research ◽  
Control Strategies ◽  
Growing Season ◽  
Palmer Amaranth ◽  
Effective Control ◽  
Emergence Period ◽  
Emergence Pattern ◽  
Growing Seasons

Evolution of multiple herbicide-resistant Palmer amaranth warrants the development of integrated strategies for its control in the Southcentral Great Plains (SGP). In order to develop effective control strategies, an improved understanding of the emergence biology of Palmer amaranth populations from the SGP region is needed. A common garden study was conducted in a no-till (NT) fallow field at Kansas State University Agricultural Research Center near Hays, KS, during 2018 and 2019 growing seasons, to determine the emergence pattern and periodicity of Palmer amaranth populations collected from the SGP region. Nine Palmer amaranth populations collected from five states in the SGP region: Colorado (CO1, CO2), Oklahoma (OK), Kansas (KS1, KS2), Texas (TX), and Nebraska (NE1, NE2, NE3) were included. During the 2018 growing season, the CO1 and KS1 populations displayed more rapid emergence rates, with greater parameter b values (−5.4, and −5.3, respectively), whereas the TX and NE3 populations had the highest emergence rates (b = −12.2) in the 2019 growing season. The cumulative growing degree days (cGDD) required to achieve 10%, 50%, and 90% cumulative emergence ranged from 125 to 144, 190 to 254, and 285 to 445 in 2018 and 54 to 74, 88 to 160, and 105 to 420 in the 2019 growing season across all tested populations, respectively. The OK population exhibited the longest emergence duration (301 and 359 cGDD) in both growing seasons. All tested Palmer amaranth populations had peak emergence period between May 11 and June 8 in 2018, and April 30 and June 1 in the 2019 growing season. Altogether, these results indicate the existence of differential emergence pattern and peak emergence periods of geographically-distant Palmer amaranth populations from the SGP region. This information will help in developing prediction models for decision-making tools to manage Palmer amaranth in the region.

scholarly journals Effects of Calcium Salts on the Cranberry Fruit Rot Disease Complex

Plant Disease ◽  
2002 ◽  
Vol 86 (7) ◽  
pp. 747-752 ◽  
Author(s):  
A. B. Blodgett ◽  
R. W. Caldwell ◽  
P. S. McManus
Keyword(s):  
Calcium Chloride ◽  
Calcium Nitrate ◽  
Calcium Content ◽  
Growing Season ◽  
Fruit Rot ◽  
Calcium Salts ◽  
Calcium Propionate ◽  
Rot Disease ◽  
Time Of Harvest

Calcium salts were applied during the growing season to fresh-fruit cranberry beds to test their effects on cranberry fruit rot incidence and the incidence of specific fungi isolated from rotten and sound cranberry fruit at the time of harvest and after storage. Calcium salts did not affect fruit rot incidence, nor did they affect the recovery of specific fungi from berries. The field treatments did not result in higher calcium content in mature berries, nor did they affect the force required to penetrate the berry epidermis. Calcium propionate inhibited growth in vitro of Allantophomopsis cytisporea, A. lycopodina, Coleophoma empetri, Fusicoccum putrefaciens, and Physalospora vaccinii. Calcium chloride and calcium nitrate inhibited growth of Coleophoma empetri and Fusicoccum putrefaciens, but these salts enhanced growth of Physalospora vaccinii. P. vaccinii was the fungus most frequently isolated from rotten berries at the time of harvest. The fungi most frequently isolated from rotten berries after several weeks in storage varied among sites. P. vaccinii, which was common in sound fruit at harvest, persisted in sound fruit in storage but was also isolated frequently from rotten berries after storage. A. lycopodina and F. putrefaciens, which were isolated infrequently from sound berries at the time of harvest, were isolated frequently from rotten berries after storage. In two of four trials, no fungi were isolated from a large proportion of fruit that decayed in storage.

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

Plant Disease ◽  
2009 ◽  
Vol 93 (10) ◽  
pp. 1059-1064 ◽  
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.

Preharvest Applications of Fungicides for Control of Sphaeropsis Rot in Stored Apples

2013 ◽  
Vol 14 (1) ◽  
pp. 9
Author(s):  
Y. K. Kim ◽  
C. L. Xiao
Keyword(s):  
Mycelial Growth ◽  
Apple Fruit ◽  
Fruit Rot ◽  
Economic Losses ◽  
In Vitro Tests ◽  
Conidial Suspension ◽  
Growth Assay ◽  
Rot Disease ◽  
Sphaeropsis Rot

Sphaeropsis rot caused by Sphaeropsis pyriputrescens is a recently reported postharvest fruit rot disease of apple in Washington State and causes significant economic losses. Infection of apple fruit by the fungus occurs in the orchard, but decay symptoms develop during storage or in the market. The objective of this study was to evaluate preharvest fungicide applications to control Sphaeropsis rot. Thirty isolates of the fungus collected from various sources were tested for sensitivity to the registered fungicides Pristine, Topsin M, and Ziram using an in vitro mycelial growth assay. In the orchard, ‘Golden Delicious' apple fruit were inoculated with the conidial suspension of the fungus at 2 or 5 weeks before harvest, sprayed with fungicides within 2 weeks before harvest, and harvested and stored at 0°C for disease evaluation. All three fungicides effectively inhibited mycelial growth of the fungus in the in vitro tests. On apple fruit in four seasons, Pristine applied 1 week and Ziram applied 2 weeks before harvest significantly reduced incidence of Sphaeropsis rot compared to the nontreated control by 43 to 80% and 42 to 83%, respectively. In 4 years of testing, the performance of Topsin M was less consistent than that of Pristine and Ziram. Accepted for publication 18 July 2013. Published 19 September 2013.

scholarly journals Sources and Availability of Inoculum and Seasonal Survival of Sphaeropsis pyriputrescens in Apple Orchards

Plant Disease ◽  
2014 ◽  
Vol 98 (8) ◽  
pp. 1043-1049 ◽  
Author(s):  
C. L. Xiao ◽  
Y. K. Kim ◽  
R. J. Boal
Keyword(s):  
Apple Fruit ◽  
Fruit Rot ◽  
Limiting Factor ◽  
North Central ◽  
Canker Disease ◽  
Growing Seasons ◽  
Apple Production ◽  
Rot Disease ◽  
Sampling Times ◽  
Sphaeropsis Rot

Sphaeropsis pyriputrescens is the cause of Sphaeropsis rot, a recently reported postharvest fruit rot disease of apple. Infection of apple fruit by the fungus is believed to occur in the orchard, and symptoms develop during storage or in the market. S. pyriputrescens also is the cause of a twig dieback and canker disease of apple and crabapple trees. To determine sources of pathogen inoculum in the orchard, twigs with dieback and canker symptoms, dead fruit spurs, dead bark, and fruit mummies on the trees were collected and examined for the presence of pycnidia of S. pyriputrescens. To monitor inoculum availability during the growing season from early May to early November, dead fruit spurs or twigs from Fuji trees, and twigs with dieback from crabapple trees (as a source of pollen for apple production) in a Fuji orchard as well as dead fruit spurs and dead bark from Red Delicious trees in a Red Delicious orchard were sampled periodically and examined for the presence and viability of pycnidia of S. pyriputrescens. To determine seasonal survival and production of pycnidia of the fungus on twigs, apple twigs were inoculated in early December, sampled periodically for up to 12 months after inoculation, examined for the presence of pycnidia, and subjected to isolation of the fungus from diseased tissues to determine its survival. Pycnidia of S. pyriputrescens were observed on diseased twigs, dead fruit spurs and bark, and mummified fruit on both apple and crabapple trees, suggesting that these tissues were the sources of inoculum for fruit infection in the orchard. With the combined observations from two orchards during three growing seasons, viable pycnidia of the fungus were present throughout the year and observed in 50 to 100% of the Fuji trees, >90% of crabapple trees, and 0 to 50% of the Red Delicious trees. S. pyriputrescens was recovered from diseased tissues of inoculated twigs at all sampling times up to 12 months after inoculation. The results suggest that S. pyriputrescens can survive as mycelium in diseased twigs in north-central Washington State and that availability of viable S. pyriputrescens pycnidia is unlikely a limiting factor for infection of apple fruit in the orchard leading to Sphaeropsis rot during storage.

Effects of Bacillus velezensis on Fusarium avenaceum, a causal agent of post-harvest apple fruit rot

2020 ◽  
Author(s):  
Mladen Petres ◽  
Marta Loc ◽  
Mila Grahovac ◽  
Vera Stojsin ◽  
Dragana Budakov ◽  
...  
Keyword(s):  
Apple Fruit ◽  
Causal Agent ◽  
Fruit Rot ◽  
Fusarium Avenaceum ◽  
Bacillus Velezensis ◽  
Post Harvest

scholarly journals Marine Organisms for the Sustainable Management of Plant Parasitic Nematodes

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 369
Author(s):  
Pasqua Veronico ◽  
Maria Teresa Melillo
Keyword(s):  
Crop Production ◽  
Control Strategies ◽  
Marine Organisms ◽  
New Drugs ◽  
Effective Control ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Wide Range ◽  
Plant Growth Stimulants ◽  
Plant Parasitic

Plant parasitic nematodes are annually responsible for the loss of 10%–25% of worldwide crop production, most of which is attributable to root-knot nematodes (RKNs) that infest a wide range of agricultural crops throughout the world. Current nematode control tools are not enough to ensure the effective management of these parasites, mainly due to the severe restrictions imposed on the use of chemical pesticides. Therefore, it is important to discover new potential nematicidal sources that are suitable for the development of additional safe and effective control strategies. In the last few decades, there has been an explosion of information about the use of seaweeds as plant growth stimulants and potential nematicides. Novel bioactive compounds have been isolated from marine cyanobacteria and sponges in an effort to find their application outside marine ecosystems and in the discovery of new drugs. Their potential as antihelmintics could also be exploited to find applicability against plant parasitic nematodes. The present review focuses on the activity of marine organisms on RKNs and their potential application as safe nematicidal agents.

scholarly journals Label-Free Comparative Proteomics of Differentially Expressed Mycobacterium tuberculosis Protein in Rifampicin-Related Drug-Resistant Strains

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 607
Author(s):  
Nadeem Ullah ◽  
Ling Hao ◽  
Jo-Lewis Banga Ndzouboukou ◽  
Shiyun Chen ◽  
Yaqi Wu ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Targets ◽  
Control Strategies ◽  
Multidrug Resistant ◽  
Differentially Expressed ◽  
Effective Control ◽  
Drug Resistant ◽  
Differentially Expressed Proteins ◽  
Label Free ◽  
Candidate Target

Rifampicin (RIF) is one of the most important first-line anti-tuberculosis (TB) drugs, and more than 90% of RIF-resistant (RR) Mycobacterium tuberculosis clinical isolates belong to multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB. In order to identify specific candidate target proteins as diagnostic markers or drug targets, differential protein expression between drug-sensitive (DS) and drug-resistant (DR) strains remains to be investigated. In the present study, a label-free, quantitative proteomics technique was performed to compare the proteome of DS, RR, MDR, and XDR clinical strains. We found iniC, Rv2141c, folB, and Rv2561 were up-regulated in both RR and MDR strains, while fadE9, espB, espL, esxK, and Rv3175 were down-regulated in the three DR strains when compared to the DS strain. In addition, lprF, mce2R, mce2B, and Rv2627c were specifically expressed in the three DR strains, and 41 proteins were not detected in the DS strain. Functional category showed that these differentially expressed proteins were mainly involved in the cell wall and cell processes. When compared to the RR strain, Rv2272, smtB, lpqB, icd1, and folK were up-regulated, while esxK, PPE19, Rv1534, rpmI, ureA, tpx, mpt64, frr, Rv3678c, esxB, esxA, and espL were down-regulated in both MDR and XDR strains. Additionally, nrp, PPE3, mntH, Rv1188, Rv1473, nadB, PPE36, and sseA were specifically expressed in both MDR and XDR strains, whereas 292 proteins were not identified when compared to the RR strain. When compared between MDR and XDR strains, 52 proteins were up-regulated, while 45 proteins were down-regulated in the XDR strain. 316 proteins were especially expressed in the XDR strain, while 92 proteins were especially detected in the MDR strain. Protein interaction networks further revealed the mechanism of their involvement in virulence and drug resistance. Therefore, these differentially expressed proteins are of great significance for exploring effective control strategies of DR-TB.

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