scholarly journals Spatial Distribution of Green Mold Foci in 30 Commercial Mushroom Crops

Plant Disease ◽  
1999 ◽  
Vol 83 (1) ◽  
pp. 71-76 ◽  
Author(s):  
D. J. Royse ◽  
K. Boomer ◽  
Y. Du ◽  
M. Handcock ◽  
P. S. Coles ◽  
...  

Statistical analyses were performed on spatial distributions of mushroom green mold foci caused by Trichoderma spp. in 30 standard Pennsylvania doubles (743 m2 production surface) selected at random from over 900 total crops mapped. Mapped production houses were divided into four tiers of six beds each with 16 sections per bed (total = 384 sections per double). Each section contained approximately 2 m2. Green mold foci were mapped according to presence or absence in each section as they became visible during the course of the mushroom production. There was a trend toward higher disease incidence at the ends of the doubles, although this was not consistent from level to level. Spatial analysis revealed that green mold foci were more likely to occur in neighboring sections along the beds rather than above, below, or across from each other. Cultural practices that were associated with movement along the beds, i.e., nutrient supplementation, spawning, bed tamping, surface covering, etc., were considered the most likely factors influencing the incidence of green mold in spawned compost. Airborne contamination was considered a less likely source of inocula contributing to epidemic development. Sanitation practices that reduce spore loads along the beds are expected to provide the greatest degree of green mold control.

Plant Disease ◽  
1999 ◽  
Vol 83 (3) ◽  
pp. 223-228 ◽  
Author(s):  
D. H. Noriega-Cantú ◽  
D. Téliz ◽  
G. Mora-Aguilera ◽  
J. Rodríguez-Alcazar ◽  
E. Zavaleta-Mejía ◽  
...  

The temporal progress of malformation (MM) of mango (Mangifera indica) was studied from 1993 to 1995 with three management technologies applied to commercial plantations in North Guerrero, Mexico. Management influenced shoot production and thus determined the dynamics of epidemics. Environmental factors also affected disease incidence, particularly through an apparent effect on inoculum dispersal. In general, integrated management (IM), consisting of pruning, acaricide, and fungicide sprays, resulted in slower rates of epidemic development, lower levels of initial and final disease, and lesser areas under the disease progress curves. In the first cycle, IM increased yield per tree by 51% in relation to high technology (HT) and 74% in relation to lower traditional technology (LT), representing a benefit-cost rate of 2.8 and 3.3, respectively. Change of malformation incidence was correlated positively with the number of macroconidia of Fusarium sp. trapped in the canopy (r = 0.90, P = 0.0001) and wind speed (r = 0.83, P = 0.0001); both variables lagged over a 4-month period. The greatest change in malformation occurred during the main vegetative flush, which occurred 3 to 6 months after picking the fruit (May). The accumulated proportion of diseased shoots was correlated with the following variables measured over a 1-week period: average maximum daily temperature (r = -0.68, P = 0. 01), average temperature per hour (r = -0.59, P = 0.04), average number of hours with relative humidity ≥60% (r = -0.82, P = 0.001), and wind speed (r = 0.94, P = 0.0001). In general, the greatest spore density was found during the rainy season, with a morning periodicity showing the highest correlation with wind speed (r = 0.812, P = 0.0001). F. subglutinans was isolated consistently from diseased (86%) and asymptomatic (5%) vegetative and flowering shoots.


2018 ◽  
Vol 3 (2) ◽  
pp. 129
Author(s):  
Nor Shahila Mansor ◽  
Normaliza Abd Rahim ◽  
Roslina Mamat ◽  
Hazlina Abdul Halim

This paper investigates the choices of second person terms of address in the Malay culture. It examines the different patterns of address terms used in a range of communicative situations by interlocutors coming from diverse social backgrounds. The data for this study was obtained from two Malay dramas Ijab & Qabul (The solemnization of marriage) and Tiga Hari Menanti Mati (Three Days Until Death). These dramas were selected because they reflect in the usage of terms of address in an authentic social context of the Malay culture and represent various interpersonal relationships in a range of situations. This is a descriptive study with a qualitative approach. Forty-eight different second person terms of address were recorded and analysed in specific contexts based on the framework for classifying address terms established by Kroger, Wood and Kim (1984). The findings suggest that sociolinguistic elements such as interlocutors, contexts, determinants of interpersonal relationship, and intentions were determining factors influencing the choice of second person terms of address in the Malay culture. These findings have implications on the understanding of current trends in choosing the terms of address among Malay speakers.


Plant Disease ◽  
1998 ◽  
Vol 82 (12) ◽  
pp. 1404-1404 ◽  
Author(s):  
M. E. de la Fuente ◽  
D. M. Beyer ◽  
D. L. Rinker

Button mushrooms of Agaricus bisporus (Lange) Imbach are commercially cultivated under environmentally controlled conditions. In California they are the most economically important agricultural crop in Santa Clara and San Mateo counties, and also an important crop in 10 other counties. Trichoderma harzianum Rifai, biotype Th4, can reduce production by preventing formation of fruiting bodies. Biotype Th4 was previously detected and described in Canada (2), Pennsylvania, and Delaware. Unofficial reports suggest its presence in San Mateo County since 1995. Disease incidence and severity on the mushroom farms varied; some mushrooms became severely infected. Green epigeous mycelia and conidia were present on the casing layer resulting in empty patches. On some farms 30% of the production surface was infected during the peak of the epidemic. Initial identification of the species was made by isolating the fungus from the substrate and casing layer. Potato dextrose agar (PDA) cultures coincided with the cultural description of T. harzianum (1,3). Biotype assessments with standard procedures were conducted at Penn State, with polymerase chain reaction (PCR) amplification of total genomic DNA to screen the California isolates of T. harzianum. Random amplified polymorphic DNA (RAPD)-PCR analysis with 14 different primers indicated that they were the same RAPD haplotype as biotype Th4. The Horticultural Research Institute of Ontario relies on morphological observations from cultures grown on 2% MEA (malt extra agar) at 24°C under diffuse daylight to identify biotypes of T. harzianum (2), and microscopic characters of biotype Th4 were also positively confirmed on the California isolates. More than a parasite or pathogen, T. harzianum biotype Th4 is considered a weed mold of mushroom cultivation. The precise interaction is yet unknown. Modified Koch's postulates were confirmed with bags of commercial mushroom substrate (45 kg) inoculated by spraying 100 ml of a spore suspension (3.0 × 106 spores per ml) at filling, to give final concentrations of 103 to 108 spores per kg of compost. Treatments were T. harzianum biotype Th4, strain Th1, an unidentified isolate, control (distilled water only), and noninoculated. Eight replications per treatment were laid out in a randomized block design. Bags were subjected to standard mushroom cultivation practices. Biotype Th4 was reisolated from empty patches on the casing of all Th4 repetitions. Mean percent cover of the mold (therefore mushroom empty patches) was 30% for crops (flushes) 1 and 2, but individual bags varied from 15 to 90%. The mean percent cover in the other two treatments and in the controls was 0% for crops 1 to 4, therefore significantly different. Green mold was covering the total surface on all Th4 repetitions at third crop. No yields were recorded, but serious losses were obvious for the Th4 treatments. Green mold was not observed in the controls. References: (1) H. M. Grogan et al. Mushroom News 45:29, 1997. (2) D. L. Rinker et al. Mushroom World 8:71, 1997. (3) D. A. Seaby. Plant Pathol. 45:905, 1996.


Citrus canker is the most devastating bacterial disease. In Pakistan, where canker is endemic, cultural practices and chemical control is vital module of integrated management system. But due to non-prudent use of chemicals wicked impacts start to appear on human health and environment there was need of some alternative management which should be eco-friendly and has no adverse effect for human. Therefore, our present study was based on screening of different cultivars of citrus and allelopathic management of citrus canker. The results revealed that Cara cara navel and kinnow both performed as moderately susceptible response in field condition than all other cultivars of citrus in screening experiment. Consequently, disease incidence was observed increasing by increasing the lesion area and these cultivars can be suggested as a source of resistance against canker pathogen. In allelopathic management we observed that ethanolic extracts were more efficient than aqueous extracts and their efficacy was also increasing by increasing the concentration. Ethanolic extracts of jatropha (13.33cm) followed by amaltas (12.5cm), Arjun (11.13cm), Bougenvilla (7.21cm) have great potency against the pathogen. So these ethanolic extracts can be used as good and alternative management of citrus canker disease.


Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1577-1583 ◽  
Author(s):  
M. Muñoz ◽  
J. E. Faust ◽  
G. Schnabel

Botrytis cinerea Pers. infects cut flower roses (Rosa × hybrida L.) during greenhouse production and gray mold symptoms are often expressed in the postharvest environment, resulting in significant economic losses. Disease management is based on cultural practices and preventative chemical treatments; however, gray mold outbreaks continue to occur. Rose tissues from six commercial shipments from two greenhouses in Colombia were evaluated to determine the Botrytis species composition as well as identify other pathogens present, gray mold incidence and severity, and fungicide resistance profiles. Botrytis isolates (49 total) were grouped into six morphological phenotypes, and all were identified to be B. cinerea sensu stricto. Disease incidence was higher in the petals than in the stem, stamen, ovary, sepal, or leaf tissues. Other fungi were isolated infrequently and included Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, Penicillium citrinum, Aspergillus brasiliensis, and Diplodia sp. Fungicide resistance profiles were determined using previously established discriminatory doses. Isolates resistant to thiophanate-methyl, iprodione, boscalid, and cyprodinil were found frequently in all shipments and in both greenhouses. The frequency of resistance to penthiopyrad, fenhexamid, fluopyram, isofetamid, and fludioxonil varied between shipments and greenhouses. No resistance to pydiflumetofen was observed at the discriminatory doses tested. Isolates with resistance to multiple chemical classes were commonly found. These results indicate that fungicide resistance management practices may improve preharvest and postharvest gray mold control of cut flower roses.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Gosaye Eshetu ◽  
Yekedem Bimrew ◽  
Hassen Shifa

Field survey was conducted in south eastern Ethiopia to determine the disease intensity of chocolate spot and rust and to investigate the association of disease intensity (incidence and severity) with environmental factors and crop cultural practices. A total of 280 faba bean fields were surveyed in eight districts, and type of cropping system, weed management practices, crop growth stage, previous crop in the field, and sowing date were recorded. The associations of disease intensity with independent variables were evaluated using logistic regression model. Mean disease incidence of chocolate spot varied from 70.9 to 93.2% in most fields while percentage severity index (PSI) ranged from 10.5 to 47.1%. In a reduced multiple variable model, chocolate PSI ≤ 30% showed high probability of association with mixed cropping system, good weed management practices, late planting, and when faba bean was rotated with vegetables and cereals. The mean disease incidence of faba bean rust was varied from 23.6 to 78.2%, while the mean PSI of rust was varied from 4.8 to 37.9%. In Gasera, Dinsho, and Agarfa districts, poor weed management practices, fields planted in the month of July, and when previous crop was legume had a high probability of association to (>20) rust PSI in a multiple variable reduced model. In contrast, soil types, fertilizer applied, and fungicides sprayed were not associated with disease intensity. The present study has identified cropping system, planting date, previous crop, district, and weed management practices as important variables that influence faba bean chocolate spot and rust epidemics in diversified fields. Therefore, proper weeding management practices, late planting, crop rotation habit, and other related farm practices should be carried out to reduce chocolate spot and rust impact until resistant faba bean genotypes are developed and distributed to the area.


Plant Disease ◽  
2019 ◽  
Vol 103 (5) ◽  
pp. 938-943 ◽  
Author(s):  
A. S. Grode ◽  
E. Brisco-McCann ◽  
P. Wiriyajitsonboom ◽  
M. K. Hausbeck ◽  
Z. Szendrei

Onion thrips (Thrips tabaci) is a major insect pest of onion and it has been identified as a likely vector of Pantoea agglomerans (bacterial stalk and leaf necrosis), a relatively new pathogen to Michigan’s onion industry. Our objective was to develop an integrated insect and disease management program by examining the efficacy of bactericides and insecticides alone and in combination to limit bacterial stalk and leaf necrosis caused by P. agglomerans. We also examined the association of onion thrips and disease incidence in the field, because thrips are known to transmit this pathogen. In the pesticide trial, insecticides reduced both thrips abundance and bacterial stalk and leaf necrosis incidence whereas bactericides alone did not reduce disease severity. Positive correlations among thrips population density, numbers of thrips positive for P. agglomerans, and bacterial stalk and leaf necrosis incidence in onion fields were determined. This study suggests that onion thrips feeding can facilitate the development of bacterial stalk and leaf necrosis in Michigan’s commercial onion fields, and results from the pesticide trials indicate that thrips feeding damage is positively correlated with disease incidence. Therefore, in order to reduce bacterial stalk and leaf necrosis incidence in onion, management efforts should include reducing onion thrips populations through the use of insecticides and other cultural practices.


Mycobiology ◽  
2020 ◽  
Vol 48 (4) ◽  
pp. 313-320
Author(s):  
Song Hee Lee ◽  
Hwa Jin Jung ◽  
Seung-Beom Hong ◽  
Jong In Choi ◽  
Jae-San Ryu

2019 ◽  
Vol 46 (4) ◽  
pp. 608-627 ◽  
Author(s):  
Guangzhen Wu ◽  
David A. Makin

This study examines the individual, organizational, and ecological factors influencing police officers’ adherence to the code of silence, while accounting for their evaluation of the seriousness of each identified behavior. This study collected 353 responses from a sample of police officers receiving in-service training at a national police university in China. Results show salient influences for several individual and ecological factors contributing to the extent of the code of silence and those influences varied based on the type of behavior. In addition, this study lends further support to an emerging body of research suggesting Chinese police display a strong code of silence, although the existence and perpetuation of that code must take into consideration unique cultural practices within China.


2015 ◽  
Vol 26 (2) ◽  
pp. 103-108
Author(s):  
MM Anwar ◽  
A Parveen ◽  
MM Hossain ◽  
NU Mahamud ◽  
RK Roy

Potato cultivars grown in Bangladesh have low levels of general resistance to late blight. As such, most commercial potato farmers rely on fungicide applications for control of Phytophthora infestans, the causal agent of late blight. Management of late blight of potato requires an integrated approach that includes rotation with non-hosts, resistant cultivars, cultural practices, and fungicides. The study on efficacy of some new fungicides against late blight disease of potato was conducted at ARS, Alamnagar Rangpur during rabi season 2010-2011 to select suitable fungicides against late blight of potato. Thirteen different fungicides were tested and all the tested fungicides showed significantly better performance over control. Considering percentage disease incidence T4,T6 and T12 showed better performance than all other treatment. In case of T4,T6 and T12 treatment disease reduction was more than 80 % over control. Significantly the highest tuber yield 25.5 t ha-1was obtained from T3  which was statistically similar to the yield of T2,T5 , T6, T9, T10, T11and T12  treatment whereas the lowest tuber  yield 14.5 t ha-1 was obtained from control treatment. Field experiment was conducted from 2010 to 2011 to investigate the comparative efficacy of the fungicides. In the field, applications of fungicide that preceded the largest incremental increase in disease incidence provided the best control of disease or increased yield.Progressive Agriculture 26 (2): 103-108, 2015


Sign in / Sign up

Export Citation Format

Share Document