scholarly journals Bioecology of the fungus Sphaeropsis sapinea dyko & Sutton - agents of pinus species decline

2002 ◽  
pp. 7-29 ◽  
Author(s):  
Tanja Milijasevic

Sphaeropsis sapinea is a cosmopolitan fungus, identified in more than 50 countries of the world, on all continents, but it is primarily the species of warm lands. It is also a polyphagous fungus recorded from 11 coniferous genera. The most endangered and the most frequent host plants are Pinus species - it occurs on 48 pine species, among which the most susceptible are Pinus Radiata, P. nigra, P. sylvestris, P. ponderosa, P. resinosa, P. mugo, P. pinaster and P. elliotti. The greatest damage is caused on the introduced Pinus species and on those cultivated in artificial plantations, shelterbelts and in urban environments. In Yugoslavia S. sapinea is widely distributed both in the continental and in the Mediterranean parts. It was identified from ten pine species and six hosts from other coniferous genera. By the study in our country, the new hosts of this fungus were detected - Pinus jeffrey, P. peuce and P. heldreichii. The most endangered species in our country is Austrian pine, both in urban environments, and in plantations The symptoms of the disease are bud wilt, curling, stunting and necrosis of current year shoots and needles, dieback of top shoots, parts of crown or tree tops, branch and stem bark canker, root collar rot on the young plants in nurseries and their dying. This fungus also prevents seed germination of Pinus species and causes blue sap stain of the freshly cut wood, although sap stain was also observed on standing trees. More rarely it causes root rot and crown wilt of Pinus species. The main symptoms of infection, both of young plants and older trees, are the dieback of current year shoots S. sapinea can penetrate through buds, bark of young shoots and needles. The critical time of infection is the period from mid April to mid May. Then infection mainly penetrates through the bark of young shoots, which results in their dying. Infection through the needles occurs mainly at the time of their sudden growth or during summer months. The first visible symptoms of infection of the young shoots are in the form of brown necroses, resin bleeding and several short pairs of needles at the place. S. sapinea can infect male and female flowers, current year and second-year cones. The pycnidia with mature conidia can form on the shoots, needles, first-year and second-year cones during the year of infection. The first mature fructifications are mostly formed in the bark of young shoots, in the zone of infection, and they were recorded in late June at the earliest. They were recorded on the cones at the beginning of the third decade of July. Pycnidia are formed in the bark, on the needles and on the second-year and older cones, on male and female flowers, as well as on the cones in the first year of development. The size of S. sapinea conidia on different Pinus species is very variable throughout the world and ranges widely from 16.8-55.0?7.0-21.0 ?m. Our study shows that the size of pycnospores in our country is also variable and it ranges 14.8-51.4?9.7-20.2 ?m The optimal temperature for spore germination and germ tube growth is 27?C, and the optimal temperature for mycelial growth on the media PDA and MEA is 28?C. The formation of fruiting bodies in the culture is affected by light and the presence of sterilised needles on the mycelium The correct and timely control measures can contribute to reduce the consequences of this serious disease, by the combined application of silvicultural and chemical measures. Chemical control is recommended in the nurseries, severely infected plantations and in urban environments. The fungicides which showed the greatest efficiency are the preparations based on copper and Benomil.

2003 ◽  
pp. 141-156 ◽  
Author(s):  
Tanja Milijasevic

The study of the parasitic fungus Sphaeropsis sapinea life cycle shows that the conidia disseminate most massively during the period April-May, i. e. during the critical time of infection, but also during the period June-August. Infection can occur through the buds in the spring, before their flushing, but also in the summer of the year of their development. Infection occurs most frequently through the bark of the young shoots, because of which they die while needle infections mostly lead to the so-called localized infections. Both male and female flowers can be infected, as well as the current-year and second-year cones. In some cases this fungus can behave as a latent parasite, i. e. endophyte.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Evgeniya Vorontsova

Due to the growing interest in the phenomenon of self-efficacy, the psychological science examines the directions of studying self-efficacy in domestic and foreign exploratory development. The attention is focused on studies that reveal the interrelation of the self-efficacy phenomenon with other psychological phenomena, such as motivation to succeed and avoidance of failure, as well as studies devoted to the features of self-efficacy ideas in male and female students. There are publications on the data of the empiric investigation of interrelation of self-efficacy and success motivation in young people at various university training stages with presentations of analysis of differences in correlation features in male and female students. A conclusion is made that there are differences existing between the investigated indicators of self-efficacy in substantive work, self-efficacy in interpersonal communication and success motivation in the first-year and the second-year students, as well as the differences existing in the outlined indicators in the young people taking university psychological and legal courses.


2018 ◽  
Vol 10 (12) ◽  
pp. 336
Author(s):  
Maryzélia F. de Farias ◽  
Roberto L. V. Boas ◽  
Khalil de M. Rodrigues ◽  
Francisca G. de S. Garreto ◽  
Marileia B. Furtado ◽  
...  

Soybeans stand out among the main oilseeds in the world, with potassium (K+) as the second most required nutrient and exported by the plant. The objective of this study was to evaluate the effect of potassium fertilization on soybean crop and its correlation with the electrical conductivity in a Yellow Dystrophic Latosol in the Cerrado of Maranhão. The experiments were conducted in the years of 2015 and 2016. The design was a randomized block design, with five treatments and five replications. Treatments consisted of the following K2O doses: 0, 50, 100, 200 and 300 kg ha-1 in the sowing groove. The data collected were submitted to analysis of variance and regression. The response of soybean to potassium fertilization occurred for the mass of 100 grains. The highest grain yield was evidenced in the first year of soybean cultivation. The increase in the adjustment parameters of the regression models in the electrical conductivity of 20-40 cm in the second year of cultivation occurred as a function of the increase of the potassium fertilization.


2020 ◽  
Vol 5 (1) ◽  
pp. 74-89
Author(s):  
Hugh Crago

In a seminal 1973 paper, Robert Clark described the very different “cultures” of the first and second year students in a four year clinical psychology PhD programme. The author applies Clark’s template to his own experiences as trainee or trainer in five different counsellor education programmes, one in the US and four in Australia. Each of the programmes, to varying degrees, demonstrates key features of the pattern identified by Clark, where the first year is “therapeutic” and other-oriented, the second is “professional” and self-focused. The author concludes that all the surveyed programmes exhibited some level of “second year crisis”, in which a significant number of students felt abandoned, dissatisfied, or rebellious. The author extends and refines Clark’s developmental analogy (first year = childhood; second year = adolescence) to reflect recent neurological research, in particular, the shift from a right hemisphere-dominant first year of life, prioritising affiliative needs, to a left hemisphere-dominant second year, prioritising autonomy and control. This shift is paralleled later by a more gradual move from a protective, supportive childhood to necessary, but sometimes conflictual, individuation in adolescence. The first two years of a counsellor training programme broadly echo this process, a process exacerbated by the second year internship/placement, in which students must “leave home” and adjust to unfamiliar, potentially less nurturing, authority figures. Finally, the author suggests introducing more rigorous “academic holding” into the first year, and greater attention to “therapeutic holding” of dissident students in the second, hopefully decreasing student dropout, and achieving a better balanced training experience.


2014 ◽  
Vol 2 (2) ◽  
pp. 67-71 ◽  
Author(s):  
Abdoul Amir Rahnama ◽  
Esmaeil Rahkhodaei

Date palm is unisexual, being either male or female. Male and female flowers grow on buds called Spathe, which opens naturally when fully mature. It is easy to identify the male and female flowers. Under the method of manual pollination, pollen from a male flower is smeared over female flowers. The pollen variety and pollination time have important effects on date palm fruit set, yield and quality. This experiment was carried out to study the effect of date pollinizer variety and pollination time on fruit set, growth and development of Medjhol date palm variety, in date palm garden of date palm and tropical fruit research institute of Iran during three years from 2009 to 2011. The trail was randomized complete block design in factorial manner with three pollen variety as Ghaname, Vardy, and Samesmave, two pollination time as 1-3 days before or after spathe opening and four replication. The results showed that the Vardy pollen had significant effects and increased the fertility percent and fruit yield, rather than two other pollen varieties. The pollen variety had no significant effects on fruit quality as total sugar, acidity, and bricx. The pollination time before spathe opening significantly increased fertility percent, decreased fruit weight and date palm yield. Finally the pollen variety and pollination time interaction effects showed that, application of Vardy pollen from 1-3 days after spathe opening with the most production date palm yield, equal 19.9 kilogram per any date palm trees, so this treatment is the best and are recommended.


Author(s):  
Umar Iqbal ◽  
Deena Salem ◽  
David Strong

The objective of this paper is to document the experience of developing and implementing a second-year course in an engineering professional spine that was developed in a first-tier research university and relies on project-based core courses. The main objective of this spine is to develop the students’ cognitive and employability skills that will allow them to stand out from the crowd of other engineering graduates.The spine was developed and delivered for the first time in the academic year 2010-2011 for first-year general engineering students. In the year 2011-2012, those students joined different programs, and accordingly the second-year course was tailored to align with the different programs’ learning outcomes. This paper discusses the development and implementation of the course in the Electrical and Computer Engineering (ECE) department.


2020 ◽  
Author(s):  
Jennifer McDonald ◽  
Rebecca Merkley ◽  
Jacqueline Mickle ◽  
Lisa Collimore ◽  
Daniel Ansari

Research in cognitive development has highlighted that early numeracy skills are associated with later math achievement, suggesting that these skills should be targeted in early math education. Here we tested whether tools used by researchers to assess mathematical thinking could be useful in the classroom. This paper describes a collaborative project between cognitive scientists and school board researchers/educators implementing numeracy screeners with kindergarten students over the course of three school years. The Give-A-Number task (Wynn, 1990) was used with first-year kindergarten students and the Numeracy Screener [BLINDED] with second-year kindergarten students. Results indicated that educators (N = 59) found the tools feasible to implement and helpful for exploring their students’ thinking and targeting instruction. The Educators’ feedback also helped inform improvements to the implementation of the tools and future directions for both the schools and the researchers. This work emphasizes the importance of transdisciplinary collaboration to address the research-practice gap.


2019 ◽  
pp. 81-88
Author(s):  
Ozoem Martha ◽  
Chibuike Victoria C. ◽  
Ugwunwoti Emeka P.

This study was carried out to determine the modern office technology competencies expected of office technology and management (OTM) graduate workers by supervisors in Delta State. The study was guided by two research questions and two hypotheses tested at 0.05 level of significance. The respondents consisted of 142 supervisors, made up of 74 heads of department and directors of government establishments, and 68 managers and directors of private establishments in the study area. Descriptive survey research design was used to conduct the study and 28 – items questionnaire were used to collect data from respondents. The instrument was validated by three experts and had a Cronbach Alpha reliability coefficient of 0.77. Means with standard deviations were used to answer the research questions, while t-test was used to test the null hypotheses. The extent of supervisor‟s expectations of information processing competencies did not differ significantly based on the mean ratings of male and female supervisors of OTM graduates in government and private establishments. The findings also revealed that supervisors expect much information processing and communication competencies from the OTM graduate workers. Based on the findings and the implications, it was recommended among others that, curriculum planners, business and OTM education lecturers should ensure that the competencies required for modern office technologies are entrenched and taught in the institutions to prepare the OTM graduates for the world of work.


2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Chinweike Eseonu ◽  
Martin A Cortes

There is a culture of disengagement from social consideration in engineering disciplines. This means that first year engineering students, who arrive planning to change the world through engineering, lose this passion as they progress through the engineering curriculum. The community driven technology innovation and investment program described in this paper is an attempt to reverse this trend by fusing community engagement with the normal engineering design process. This approach differs from existing project or trip based approaches – outreach – because the focus is on local communities with which the university team forms a long-term partnership through weekly in-person meetings and community driven problem statements – engagement.


2016 ◽  
Vol 3 (3) ◽  
Author(s):  
ARVIND KUMAR ◽  
POOJA KHULBE

Influence of abiotic factors and hosts on population dynamics of green lacewing, Chrysoper lacarnea (Stephens) was studied in sunflower, Helianthus annus (Linn.).The maximum number of C. carnea population was found during mid March –mid April in the first year and mid April – mid May in the second year in sunflower crop. The maximum number of host population viz. egg and larva of Helicoverpa armigera and Myzuspe rsicae population were found during mid March –mid April in both the year and correlation studies revealed the positive and significant correlation between larval population of H. armigera, M. persicae and predator C. carnea. While there was no significant relationship found between eggs of H. armigera and C. carnea. The C. carnea population on H. annus during both the year was positively correlated with maximum temperature and found significant,while negatively correlated with relative humidity.However, no significant correlation of C. carnea was found with minimum temperature in both the year.


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