Occurrence of Foliar Pathogens of Watermelon on Commercial Farms in South Carolina Estimated with Stratified Cluster Sampling

A survey of foliar pathogens of watermelon based on two-stage cluster sampling was conducted on commercial farms in South Carolina in spring 2015, spring and fall 2016, and fall 2017. In total, 60 fields from 27 different growers in seven counties representing the main watermelon-producing areas in the state were sampled, using a stratified two-stage cluster sampling approach. In the sampling design, counties corresponded to strata, growers to first-stage clusters, and fields to second-stage clusters. In each field, 100 symptomatic leaves were collected at five equidistant sampling points along four transects encompassing a square shape of 2,500 m2. After collection, pathogens were identified based on reproductive structures formed on leaves during >12 h incubation. Estimates were obtained for the statewide probability of pathogen occurrence and associations between pathogen pairs. Six fungal pathogens, Stagonosporopsis spp., Podosphaera xanthii, Cercospora citrullina, Colletotrichum orbiculare, Myrothecium sensu lato (s.l.), and Corynespora cassiicola; the oomycete Pseudoperonospora cubensis; and three viral pathogens were identified on the examined leaves. With the exception of fall 2017, Stagonosporopsis spp. was the most prevalent pathogen in every season, followed by P. xanthii. The highest occurrence of P. cubensis was in spring 2015; it did not occur in 2016. The highest occurrence of C. orbiculare was in spring 2016; it did not occur in spring 2015. Myrothecium s.l. was the most common pathogen in fall 2017 and the second most common pathogen occurring by itself in fall 2016. The third most common pathogen in fall 2017, Corynespora cassiicola, was not observed in any other season. Eight of the 80 isolates of Stagonosporopsis spp. collected were identified as S. caricae, the rest as S. citrulli. All isolates of S. caricae were found in spring 2015 and originated from two fields in different counties. A total of three positive and five negative associations were found between pathogen pairs co-occurring on the same leaf. A positive association between Stagonosporopsis spp. and C. citrullina was the only significant association between pathogens found in two seasons, spring 2015 and spring 2016. Based on estimates of probability of pathogen occurrence across seasons, Stagonosporopsis spp. and P. xanthii are the most common pathogens on watermelons in South Carolina. This is the first report of C. cassiicola, S. caricae, and Myrothecium s.l. on watermelon in South Carolina.

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Factors Influencing the Occurrence of Foliar Pathogens in Commercial Watermelon Fields in South Carolina Based on Stratified Cluster Sampling

Plant Disease ◽

10.1094/pdis-07-18-1188-re ◽

2019 ◽

Vol 103 (3) ◽

pp. 484-494 ◽

Cited By ~ 1

Author(s):

Gabriel Rennberger ◽

Patrick Gerard ◽

Anthony P. Keinath

Keyword(s):

South Carolina ◽

Fungal Pathogens ◽

Sampling Design ◽

Field Size ◽

Lower Probability ◽

Cluster Sampling ◽

Probability Of Occurrence ◽

Commercial Farms ◽

Pathogen Occurrence ◽

Foliar Pathogens

The influence of environmental and management factors on the occurrence of foliar pathogens of watermelon was analyzed using survey-sampling data collected from commercial farms in South Carolina in spring 2015 and spring and fall 2016. A stratified two-stage cluster sampling design was used to sample symptomatic watermelon leaves from 56 fields of 27 growers in seven counties representing the main watermelon-producing areas in the state. In the sampling design, counties corresponded to strata, growers to first-stage clusters, and fields to second-stage clusters. Pathogens were identified on 100 leaves collected per field based on reproductive structures that formed on the leaves. Information about previous crops, fruit type, field size, transplanting date, first harvest date, and fungicides applied within 7 days and within 7 to 14 days prior to sampling was obtained from growers. Field alignment was determined with a compass. Survey-specific logistic regression procedures were used to analyze the effect of these factors on the probabilities of pathogen occurrence. Five fungal pathogens, Stagonosporopsis spp., Podosphaera xanthii, Cercospora citrullina, Colletotrichum orbiculare, and Myrothecium sensu lato (s.l.), and the oomycete Pseudoperonospora cubensis were included in the analyses. Among the factors we analyzed, there was a consistent increased probability of occurrence of Stagonosporopsis spp. in fields with a previous cucurbit crop, increasing probabilities of pathogen occurrence with increasing plant age, a lower probability of occurrence of some pathogens on triploid cultivars compared with diploid cultivars, and a decrease in probability of pathogen occurrence in fields aligned toward southwest or west. Application of fungicides significantly reduced the probability of observing C. citrullina, P. cubensis, and Stagonosporopsis spp. in 2015 and P. xanthii in spring 2016. This study emphasizes the importance of crop rotation and fungicide applications to manage foliar diseases of watermelon, particularly gummy stem blight, powdery mildew, and downy mildew. Crop age, cultivar type, and field alignment also were found to significantly influence the probability of pathogen occurrence. To the best of our knowledge, this is the first study examining the influence of various factors on foliar pathogens of watermelon with data collected from commercial fields.

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Two-stage mental health survey of first-line medical staff after ending COVID-19 epidemic assistance and isolation

European Archives of Psychiatry and Clinical Neuroscience ◽

10.1007/s00406-021-01239-x ◽

2021 ◽

Author(s):

Li Xu ◽

Dingyun You ◽

Chengyu Li ◽

Xiyu Zhang ◽

Runxu Yang ◽

...

Keyword(s):

Mental Health ◽

Sleep Quality ◽

Medical Staff ◽

Psychological Intervention ◽

Psychological Status ◽

Vulnerable Groups ◽

Cluster Sampling ◽

Cross Sectional Survey ◽

Two Stage ◽

Cross Sectional

AbstractFacing with COVID-19 epidemic such a catastrophic health emergency, the mental health status of medical staff deserves attention. We conducted a two-stage of psychological status monitoring after the end of the assistance and 14 days of isolation, further targeted the vulnerable groups in need of intervention. The study is a cross-sectional survey on 1156 Yunnan medical staff aid to Hubei. Used Cluster sampling method to collect data at 2 time points (at the end of returning from Wuhan and the 14th day of isolation), from March 18, 2020 to April 6, 2020. Female and nurse had higher rates of depressive symptoms than male and doctors and other occupations. The proportion of female with mild and above moderate anxiety levels (22.91%, 2.61%) was higher than male (17.35%, 1.03%) (p < 0.05). Female had a better impaired sleep quality (45.06%, 17.49%) more than male (28.57%, 7.94%). Medical staff supported in Wuhan and with junior professional titles reported a higher proportion of sleep quality impairment. At the 14th isolation day stage, the proportion of nurses changed from depression to health (9.15%) and from health to depression (6.1%) better than doctors. The front-line medical staffs had suffered greater psychological pressure in the treatment process of major public health emergency. Researches on the dynamic monitor for the change of psychological status after aiding epidemic areas were still in relatively blank stage. Targeting the vulnerable characteristics of aiding medical staff is significant for effective psychological intervention and sustainable operation of health system.

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PERAN EFIKASI DIRI DAN MOTIVASI INTRINSIK TERHADAP RESILIENSI ORANGTUA DENGAN ANAK BERKEBUTUHAN KHUSUS PADA SEKOLAH LUAR BIASA (SLB) DI BALI

Jurnal Psikologi Udayana ◽

10.24843/jpu.2017.v04.i02.p10 ◽

2018 ◽

Vol 4 (02) ◽

pp. 347

Author(s):

Ni Nyoman Tri Marheni Wulandari ◽

Drs. Supriyadi

Keyword(s):

Cluster Sampling ◽

Two Stage ◽

Probability Sampling

Resiliensi adalah kemampuan seseorang untuk menilai, mengatasi, dan meningkatkan diri ataupun mengubah dirinya dari keterpurukan atau kesengsaraan dalam hidup yang membuat seseorang berhasil menyesuaikan diri dalam berhadapan dengan kondisi yang tidak menyenangkan. Kemampuan resiliensi dipengaruhi oleh keyakinan individu terhadap kemampuan yang dimiliki dalam menjalani suatu tugas. Di samping itu dorongan dari dalam diri individu untuk menjalani suatu tugas juga dapat mengembangkan kemampuan untuk beradaptasi dari keterpurukan. Penelitian ini bertujuan untuk melihat peran efikasi diri dan motivasi intrinsik terhadap resiliensi orangtua dengan anak berkebutuhan khusus pada Sekolah Luar Biasa (SLB) di Bali. Subjek penelitian ini adalah 78 orangtua dengan anak berkebutuhan khusus pada SLB di Bali. Teknik pengambilan sampel yang digunakan adalah two stage cluster sampling dalam probability sampling. Instrumen penelitian ini adalah skala resiliensi, skala efikasi diri dan skala motivasi intrinsik. Hasil yang diperoleh dari analisis regresi ganda menunjukkan nilai R=0,686 (p<0,05) dan koefisien determinasi sebesar 0,471, dengan demikian dapat disebutkan bahwa efikasi diri dan motivasi intrinsik secara bersama-sama berperan sebesar 47,1% dalam menjelaskan varian resiliensi orangtua dengan anak berkebutuhan khusus. Koefisien beta efikasi diri sebesar 0,340 dan siginifikansi 0,008 (p<0,05) menunjukkan efikasi diri ,berperan terhadap resliensi. Koefisien beta motivasi intrinsik sebesar 0,473 dan signifikansi 0,000(p<0,05) menunjukkan motivasi intrinsik berperan dalam menjelaskan varian resiliensi. Hal ini menunjukkan setiap kenaikan 0,340 pada efikasi diri dan 0,473 pada motivasi intrinsik, terjadi peningkatan 1 poin pada resiliensi orangtua dengan anak berkebutuhan khusus pada SLB di Bali. Kata Kunci: resiliensi, efikasi diri, motivasi intrinsik, orangtua dengan anak berkebutuhan khusus

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Investigation of Fungi Causing Twig Blight Diseases on Peach Trees in South Carolina

Plant Disease ◽

10.1094/pdis-06-18-1052-re ◽

2019 ◽

Vol 103 (4) ◽

pp. 705-710 ◽

Cited By ~ 1

Author(s):

Martha H. Froelich ◽

Guido Schnabel

Keyword(s):

South Carolina ◽

Fungal Pathogens ◽

Management Strategies ◽

Brown Rot ◽

Cambium Layer ◽

Twig Blight ◽

Botryosphaeria Obtusa ◽

Peach Trees ◽

Moderately Resistant ◽

Prevalent Species

A survey of fungal pathogens causing twig blight on commercial peach trees was conducted in South Carolina in the fall of 2016. Shoots with cankers, pycnidia, and dieback were collected from six locations around the state. Isolates obtained from these samples were identified as Botryosphaeria obtusa, Phomopsis amygdali, Leucostoma persoonii, and Cytospora sp., based on colony morphology, conidia size and shape, and ribosomal DNA sequence analysis. L. persoonii was the most prevalent species and was isolated in five of the six locations, followed by P. amygdali and B. obtusa. The sensitivity of representative isolates of B. obtusa, P. amygdali, and L. persoonii to fungicides of different FRAC codes was evaluated. All species tested were sensitive to thiophanate-methyl (FRAC 1) and pyraclostrobin and azoxystrobin (both FRAC 11), whereas all species were resistant to boscalid and fluopyram (both FRAC 7). P. amygdali and B. obtusa were sensitive to difenoconazole and propiconazole (both FRAC 3), whereas L. persoonii was moderately resistant. L. persoonii was the most virulent species based on expansion of mycelium in the cambium layer of 2-year-old, detached twig pieces. Bacterial spot (BS)-sensitive cultivar ‘O’Henry’ was most susceptible to B. obtusa compared with BS-sensitive ‘Summerprince’, brown rot (BR)-resistant ‘Contender’, and BR-sensitive ‘Coronet’ but was least susceptible to L. persoonii. Coronet was most susceptible to L. persoonii. There were no significant differences between susceptibility of the cultivars to P. amygdali. This study established that L. persoonii is currently the most frequent twig blight pathogen in South Carolina, perhaps owing to its superior fitness. Some fungicides were effective in controlling all twig blight pathogens and may therefore be useful for chemical management strategies. Our study also provides the first evidence that the genetic basis of resistance to BS and BR in peach trees is not necessarily linked to tolerance to wood pathogens.

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Pengaruh Informasi Kesetaraan Gender pada Suplemen "Geulis" Harian Umum Pikiran Rakyat terhadap Persepsi Pembaca tentang Kesetaraan Gender

Jurnal Penelitian Komunikasi ◽

10.20422/jpk.v15i2.713 ◽

2012 ◽

Vol 15 (2) ◽

pp. 171-182

Author(s):

Nila Nurlimah

Keyword(s):

Cluster Sampling ◽

Two Stage

Maraknya perilaku yang melecehkan kaum perempuan banyak terjadi akhir-akhir ini. Kondisi ini menuntut upaya pemberdayaan terhadap kaum perempuan untuk lebih dioptimalkan lagi. Persepsi positif mengenai kesetaraan gender pada gilirannya akan mewujudkan kesadaran terhadap motif perempuan dalam memberdayakan dirinya. Tujuan dari penelitian ini adalah untuk menentukan pengaruh informasi tentang kesetaraan gender dalam suplemen “Geulis” dalam Harian Umum Pikiran Rakyat terhadap persepsi pembaca tentang kesetaraan gender di Kota Bandung. Populasinya adalah pembaca Harian Umum Pikiran Rakyat di Kota Bandung, teknik penarikan sampel dilakukan secara two stage cluster sampling. Penelitian ini menyimpulkan bahwa persepsi pembaca tentang kesetaraan gender dipengaruhi oleh informasi tentang kesetaraan gender pada suplemen “Geulis” HU Pikiran Rakyat.

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