STUDIES OF THE AGING OF CONIDIA OF MONILINIA FRUCTICOLA (WINT.) HONEY: I.GERMINATION RATES AND LONGEVITY

1957 ◽  
Vol 35 (5) ◽  
pp. 635-645 ◽  
Author(s):  
S. H. Z. Naqvi ◽  
H. M. Good
Keyword(s):  
Relative Humidity ◽  
Storage Temperature ◽  
Potato Dextrose Agar ◽  
Monilinia Fructicola ◽  
High Humidity ◽  
Percentage Germination ◽  
Low Humidity ◽  
Nutrient Solutions

Conidia of Monilinia fructicola (Wint.) Honey were stored 1–10 months at temperatures of 5°, 25°, and 35 °C. and at constant relative humidities approximating 0, 15, 45, 75, and 90%. The germination of these spores was tested on potato dextrose agar containing 6% glucose, and curves of the percentage germination against time are given for representative samples.A pronounced delay in germination developed under all conditions of storage. The rate at which this delay developed was virtually independent of the storage temperature. All spore samples gave 100% germination after 3 months but only those at 5 °C. gave; any germination after 10 months. Storage in a relative humidity of 75% gave the best preservation of spore vigor, there being evidence in other conditions of either high humidity or low humidity injury. Of the nutrient solutions tested, glucose was the only one which gave substantially better germination than water, the effect being most marked on spores stored for some months at high humidity. With glucose, such spores sometimes germinated faster than those stored at intermediate humidities.

Some Effects of Humidity on the Translocation of 2,4,5-T in Bean Plants

Weed Science ◽  
1970 ◽  
Vol 18 (3) ◽  
pp. 396-398 ◽  
Author(s):  
Eddie Basler ◽  
Fred W. Slife ◽  
John W. Long
Keyword(s):  
Acetic Acid ◽  
Relative Humidity ◽  
Nutrient Solution ◽  
Leaf Tissue ◽  
Phloem Transport ◽  
High Humidity ◽  
Plant Parts ◽  
Bean Plants ◽  
Low Humidity ◽  
Nutrient Solutions

The effect of humidity on the rate and direction of translocation of stem-injected (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T) in bean (Phaseolus vulgaris L., var. Stringless Green-pod) seedlings was determined. A total of 0.75 μg of 14C-labeled 2,4,5-T was injected into the stem with a 1-μl syringe pipette. Translocation was determined by assaying the nutrient solution and plant parts for 14C. High relative humidities enhanced downward translocation to roots and nutrient solutions. About 41% of the applied 2,4,5-T was found in the nutrient solution after 2 days' treatment at about 95% relative humidity while only 23% was found when treatment was conducted at 20% relative humidity. Low humidity during treatment caused much more 2,4,5-T to be translocated upward to the primary leaves and young shoots of the seedlings and this effect was more pronounced in plants which were grown in low humidity prior to treatment. The results confirm the conclusions of others and show that the increased basipetal phloem transport of herbicides in plants under high humidity is not due to an effect on penetration of herbicides in leaf tissue.

scholarly journals High Relative Humidity after Ethylene Gassing is Important to Banana Fruit Quality

1995 ◽  
Vol 5 (2) ◽  
pp. 150-151 ◽  
Author(s):  
Sylvia M. Blankenship ◽  
Robert W. Herdeman
Keyword(s):  
Relative Humidity ◽  
Fruit Quality ◽  
High Relative Humidity ◽  
High Humidity ◽  
Banana Fruit ◽  
Fruit Firmness ◽  
Compression Injury ◽  
Peel Color ◽  
Before And After ◽  
Low Humidity

Bananas were held at 18C in all possible combinations of 65%, 75%, or 95% relative humidity (RH) before and after gassing with ethylene. Peel color, fruit firmness, starch loss, compression injury to peel and pulp, and overall peel scarring were measured. Peels were greener and the fruit were slightly firmer when fruit were held in the higher humidity combinations, particularly when the humidity was high after gassing with ethylene. Starch loss was not different among humidity treatments. Overall peel scarring was about twice as severe with 65% RH compared to 95% RH during the ripening phase. Low humidity before ethylene gassing had little effect on overall scarring. There were some instances where humidity had a significant effect on compression injury; high humidity caused less injury, but the effect was inconsistent.

scholarly journals Maintaining Impatiens Seed Quality

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 867F-867
Author(s):  
David Cross ◽  
Roger Styer
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Seed Quality ◽  
Storage Temperature ◽  
Seed Storage ◽  
Storage Conditions ◽  
High Humidity ◽  
Quality Changes ◽  
Salt Solutions ◽  
Temperature And Humidity

Impatiens (Impatiens wallerana Hook.f.) flower seeds are believed to be sensitive to storage temperature and humidity conditions. A study was conducted to evaluate seed quality changes occurring during a 1-year period of storage under various temperature and humidity combinations. Four seed lots of `Super Elfin Red' and `Super Elfin White' impatiens were studied. Constant humidity treatments were obtained using saturated salt solutions; 15% relative humidity (RH) with LiCI, 25% RH with KAc, 33% RH with MgCl2, and 43% RH with K2CO3. Constant temperature treatments were 5, 15, and 22C. At 3-month intervals, replicate samples were sown in plug flats in the greenhouse. Seed quality was evaluated as the percentage of usable seedlings 21 days from sowing. Rapid deterioration of seed quality was seen under high temperature and high humidity storage conditions. Seeds became less sensitive to humidity at 5C. Conditions of 20% to 25% RH and 5C are recommended for impatiens seed storage.

scholarly journals Colonization of Tomatoes by Salmonella Montevideo Is Affected by Relative Humidity and Storage Temperature†

2007 ◽  
Vol 70 (1) ◽  
pp. 30-34 ◽  
Author(s):  
MONTSERRAT H. ITURRIAGA ◽  
MARK L. TAMPLIN ◽  
EDUARDO F. ESCARTÍN
Keyword(s):  
Relative Humidity ◽  
Lycopersicon Esculentum ◽  
Pathogenic Bacteria ◽  
Storage Temperature ◽  
High Humidity ◽  
Scanning Electron Micrographs ◽  
Peptone Water ◽  
Growth Promoting ◽  
And Storage ◽  
Scanning Electron

The influences of the relative humidity (RH) and storage temperature on the colonization of tomato surfaces by Salmonella Montevideo were studied. Red, ripe tomatoes (Lycopersicon esculentum) were spot inoculated in three separate trials with 100 μl (approximately 106 CFU) of Salmonella Montevideo and stored for 90 min at 22°C under 97% RH to facilitate attachment of cells to the blossom end of tomato surfaces. Following this attachment step, tomatoes were washed to remove loosely adhered cells and then stored at 22 or 30°C for up to 10 days under RH of 60, 75, 85, or 97%. At 0, 0.4, 1, 4, 7, and 10 days of storage, three tomatoes were individually hand massaged in 50 ml of 0.1% peptone water and the washes were separately analyzed to enumerate populations of Salmonella Montevideo. The number of Salmonella Montevideo cells attached after 90 min at 22°C was 3.8 log CFU per tomato; this level was determined to be the initial colonizing population. After 10 days of storage at 30°C, the Salmonella Montevideo population increased to 0.7, 1.0, 1.2, and 2.2 log CFU per tomato at 60, 75, 85, and 97% RH, respectively. A similar trend was observed at 22°C, although populations were lower than at 30°C. Scanning electron micrographs of tomato cuticles after storage revealed a well-defined biofilm containing bacteria. These findings reinforce the importance of maintaining stored tomatoes at temperatures that do not support growth of pathogenic bacteria and demonstrate the growth-promoting effects of high humidity.

scholarly journals Influence of temperature, humidity, and diluent type on survival of Salmonella spp. on the surface of raw tomatoes

10.5219/1121 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 325-330
Author(s):  
Oleksandr Tokarskyy ◽  
Keith Schneider
Keyword(s):  
Relative Humidity ◽  
Storage Period ◽  
High Humidity ◽  
Salmonella Spp ◽  
Influence Of Temperature ◽  
Pathogen Elimination ◽  
Peptone Water ◽  
Low Humidity ◽  
Fresh Tomato ◽  
The U.S

Tomatoes are an important commodity, placing fourth among most popular vegetables in the U.S. However, fresh tomatoes lack a final pathogen elimination step and have been implicated in Salmonella-related outbreaks. The purpose of the study was to evaluate survival of Salmonella post-drying in three diluents on the surface of green mature tomatoes at 12 °C or 25 °C. Additionally, low and high air relative humidity influence was evaluated at 25 °C on pathogen survival. A five Salmonella rifampin-resistant strain cocktail was double-washed in buffered peptone water (BPW) and resuspended in 0.1% peptone, BPW, or fresh tomato serum. Inoculum (0.1 mL) was allowed to dry on the surface of tomatoes. For study I, tomatoes were placed in 12 °C and 25 °C incubators with no humidity control and sampled on days 0, 1, 3, and 5. For study II, tomatoes were sampled on days 0, 1 (biosafety hood storage) and on day 5 after storage in two 25 oC incubators (low and high relative humidity). Salmonella was recovered from tomatoes (20 mL BPW) and plated (TSA-rif80, 37 °C, 48 hours). Post-drying Salmonella counts (ca. 4.5 – 5.0 log10 CFU.mL-1) remained at 4.03 and 4.40 log10 CFU.mL-1 in serum after 5 days of storage at 12 °C and 25 °C, respectively. Conversely, corresponding counts in BPW and peptone were lower at ca. 1.4 to 1.8 and 2.2 to 2.8 log units at 12 °C and 25 °C, respectively. At low humidity, post-drying Salmonella counts showed highest decline for peptone (final 1.98 log10 CFU.mL-1) compared to BPW (3.79 log10 CFU.mL-1) and tomato serum (4.75 log10 CFU.mL-1) on day 5. Counts declined rapidly to 0.03, 0.56, and 0.44 log10 CFU.mL-1 for peptone, BPW, and tomato serum, respectively, at high humidity on day 5. To summarize, it was shown that increased solutes have protective effect on Salmonella in desiccated conditions, while high humidity storage causes accelerated death of stationary culture within five days storage period.

scholarly journals High Temperatures Decrease the Flight Capacity of Diaphorina citri Kuwayama (Hemiptera: Liviidae)

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 394
Author(s):  
Carlos A. Antolinez ◽  
Tobias Moyneur ◽  
Xavier Martini ◽  
Monique J. Rivera
Keyword(s):  
Relative Humidity ◽  
High Temperatures ◽  
Insect Pest ◽  
The United States ◽  
Diaphorina Citri ◽  
Long Distance ◽  
Flight Duration ◽  
Custom Made ◽  
Flight Capacity ◽  
Low Humidity

Diaphorina citri Kuwayama (Hemiptera: Liviidae), commonly known as Asian citrus psyllid (ACP), is an invasive insect pest and the vector of the bacterium causing Huanglongbing (HLB), a lethal disease of citrus. In the United States, ACP has been established in all citrus-producing zones, all of which have different environmental conditions. The spread of ACP and, more importantly, HLB, has progressed differently depending on the state, with more rapid spread in Florida and Texas than in California. Climatic variations between the regions are likely a strong factor in the difference in the rate of spread. Despite this, it is unknown how the flight capacity of D. citri is influenced by high temperatures (>30 °C) and subsequently, low humidity experienced in California but not in Texas or Florida. In this study, by using a custom-made, temperature-controlled flight mill arena, we assessed the effect of high temperatures on the flight capacity and flight propensity of D. citri under low (20–40%) and high (76–90%) relative humidity conditions. We found that temperature and humidity influence the propensity to engage in short or long-distance flight events. Psyllids exposed to temperatures above 43 °C only performed short flights (˂60 s), and a high relative humidity significantly decrease the proportion of long flights (≥60 s) at 26 and 40 °C. The flight capacity for insects who engaged in short and long flights was significantly affected by temperature but not by humidity. For long flyers, temperature (in the 26–43 °C range) was negatively correlated with distance flown and flight duration. The most favorable temperature for long dispersion was 26 °C, with suboptimal temperatures in the range of 32–37 °C and the least favorable temperatures at 40 and 43 °C. In conclusion, D. citri is able to fly in a broad range of temperatures and efficiently fly in high and low humidity. However, temperatures above 40 °C, similar to those experienced in semi-arid environments like Southern California or Arizona, are detrimental for its flight capacity.

The effect of post-harvest storage on the weight of Golden Delicious apples

2021 ◽  
Vol 13 (2) ◽  
pp. 7-11
Author(s):  
Salma Kassebi ◽  
Péter Korzenszky
Keyword(s):  
Relative Humidity ◽  
Storage Temperature ◽  
Extended Period ◽  
Food Products ◽  
Significant Loss ◽  
Loss Of Weight ◽  
Ambient Storage ◽  
Golden Delicious ◽  
Different Levels ◽  
Careful Management

Apples, like other fruits, are exposed to stress during their growth and development in the field, also during harvest and the postharvest environment (processing, storage, and transportation). The refrigeration system allows for bulk handling of food products from harvest to market, ensuring that food products are maintained in their freshness and integrity for an extended period through careful management of storage temperature and humidity. This study investigated the effects of storage on the weight loss of apples (Golden Delicious fruits harvested at maturity), under refrigerated conditions at a temperature of 5±0.5°C and relative humidity of 82% and under ambient storage at a temperature of 25 ±0.5 °C and relative humidity of 60 %, over 3 months. The findings revealed that the two groups of apples experienced weight reduction at different levels. Apples placed at cold storage presented a loss of weight between 3.31g and 4.49g; however, apples stored at ambient temperature showed a significant loss of weight between 21.9g and 31.76g.

High Humidity, Low Humidity, and Mist Therapy for Croup

JAMA ◽  
2006 ◽  
Vol 296 (4) ◽  
pp. 393
Author(s):  
Richard Gabor
Keyword(s):  
High Humidity ◽  
Low Humidity

scholarly journals Nutritional Changes and Early Warning of Moldy Rice under Different Relative Humidity and Storage Temperature

Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 185
Author(s):  
Jing Du ◽  
Yingxue Lin ◽  
Yuan Gao ◽  
Yanyan Tian ◽  
Jixiang Zhang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Relative Humidity ◽  
Early Warning ◽  
Storage Temperature ◽  
Starch Content ◽  
Protein Secondary Structure ◽  
Principal Component ◽  
Storage Conditions ◽  
Factors Affecting ◽  
Total Starch

Processed unhusked rice is prone to mildew during storage. In this study, the storage conditions were simulated at temperatures of 20, 30, and 35 °C and a relative humidity of 40%, 60% and 80%, respectively. The water, fatty acid, and total starch content and the peak viscosity, mold colony number, protein secondary structure, and spatial structure of rice were monitored in order to propose the critical point of mildew during storage. In the process of rice from lively to moldy, the water content, fatty acid contents and the peak viscosity were increased. The total starch content decreased and then showed a slow increasing trend, while the microstructure of the powder particles changed from smooth and complete to loosen and hollow. With the increase in storage time, the vibration of the amide Ⅰ band of the rice samples decreased slightly, indicating that the total contents of β-fold, β-turn, α-helix, and random curl of the rice protein also changed. PCA (Principal Component Analysis) analysis showed that rice mildew index was closely related to temperature and humidity during storage. In our investigation, the best and most suitable temperature and relative humidity for rice storge is 20 °C and 40%, respectively. These results suggested that temperature and environmental humidity are vital factors affecting the physicochemical properties and nutrient changes, which provides a theoretical basis for the early warning of rice mildew during storage.

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

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