scholarly journals Episodic Growth and Shoot Differentiation in Apple (Malus ×domestica Borkh.)

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 603b-603
Author(s):  
Jacques J. Crabbe

The flushing behavior of shoot growth and its consequences on shoot differentiation are important features in fruit tree development, with regard to flowering ability. In this respect, two different approaches were applied to young `M26' apple trees. First, poorly branched 2-year-old trees were headed back, either in the second-year or in the first-year wood, at different times from right before to 6 weeks after budbreak. Early pruning resulted in rapid and prolonged regrowth, with a final very similar shaping of the tree to that of the intact controls. Late pruning, in contrast, leads to a two-step reaction (late spring and summer flushes), sometimes stronger on 2-year-old than on 1-year-old wood. In a second experiment, buds and young shoots were sampled on pruned trees in locations where they could be supposed to remain short shoots or grow long, with one or two flushes. They were weighed, their leaves and internodes measured, and the plastochron evaluated. During budbreak and the first month afterwards, shoot differentiation appears achieved. The primary difference between long and short shoot types does not consist in faster internode elongation but, rather, in faster production (reduced plastochron) of larger leaves.

Author(s):  
C. Booth

Abstract A description is provided for Cryptodiaporthe populea. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Poplar, willow. A wide range of poplar species are more or less susceptible, with members of the tacamahacca and algeros groups principally affected. Populus alba var. pyramidalis is very susceptible in Britain and P. alba and P. tremula are tolerant; complete resistance is unknown in the genus: The fungus has been recorded on cricket bat willow in Belgium. DISEASE: Dothichiza canker, Dorhichiza dieback, poplar canker. The conidial state is the form of this fungus most commonly found associated with the dieback or canker of poplar. The fungus is a wound parasite unable to invade sound bark tissues, although very small wounds, such as scars left by bud scales, may permit infection (38, 341). Infection usually occurs in the winter, when bark moisture and turgor are lowest (36, 673; 37, 684). First signs are a discoloration of the cortex under the bark, which develops to a sunken, dead patch of bark, often at the base of twigs or at the junction of first-year and second-year wood. The lesion may have an unpleasant odour and later develops black, globular, pycnidia on the surface. The lesion may heal over in a single season but it can spread to cause severe damage or death of the host. Injury is believed to be due to toxin formation as well as physical girdling by the canker (35, 797; 38, 103). The crowns of old trees or young plants in nurseries and plantations are mainly affected. The disease may be distinguished from that caused by Valsa sordida Nits. by its larger conidia and larger and less frequent stromata in infected tissues. GEOGRAPHICAL DISTRIBUTION: Europe (all western Europe excluding Portugal, Norway, Yugoslavia, Rumania, Bulgaria, Poland, Estonia, Ukraine and south-east Russia). Near East (Turkey, Cyprus). North America (east Canada, north-east USA). South America (Argentina) (CMI Map 344, ed. 2, 1968). TRANSMISSION: Mainly by airborne splash-dispersed conidia.


2012 ◽  
Vol 60 (2) ◽  
pp. 39-44
Author(s):  
Alina Trejgell ◽  
Andrzej Tretyn

Regenerated plants of <i>Carlina acaulis</i> subsp. <i>simplex</i> induced on shoot tips and fragments of hypocotyls, cotyledons and roots were used as an experimental material. Explants were isolated from 10-day-old, sterile seedlings and were put on growth media supplemented with BA (3 mg×dm<sup>-3</sup>), and NAA (0,1 mg×dm<sup>-3</sup>). Plantlets were acclimatized to <i>ex vitro</i> conditions and planted to the field. Analysis of flowering ability, inflorescence stem morphology, and survival level was the objective of the study. The plants regenerated from shoot tips and cotyledons were able to flower in the first year after acclimatization, however no vital seeds were found, while in the case of hypocotyl- and root- regenerated plants flowering appeared in the second year after acclimatization. Number of flowering-able plants grew in time, reaching 100% level. Few percent of inflorescence stems displayed branches ending with additional capitula. The number of this type of plants decreased in successive years, while the average length of inflorescence stem increased. In the case of intensively flowering plants, the survival rate decreased in 3 consecutive years.


1979 ◽  
Vol 57 (14) ◽  
pp. 1557-1572 ◽  
Author(s):  
John N. Owens ◽  
Marje Molder

The time and method of cone-bud differentiation and the phenology of cone-bud development were studied in 10- to 20-year-old trees growing outside their natural range and three 50-year-old trees growing within their natural range.Both pollen-cone and seed-cone buds of western larch (Larix occidentalis Nutt.) normally differentiated on short shoots that were at least 1 year old. Pollen-cone buds were commonly on proximal nonvigorous, often pendant vegetative long shoots in lower regions of the crown, whereas seed-cone buds were usually found on distal short shoots on vigorous but less pendant vegetative long shoots in upper regions of the crown.All potential cone buds were indistinguishable from potential vegetative short shoot buds during bud-scale initiation. In early June, when vegetative short shoots had begun to initiate leaves, cone-bud apices entered a period of differentiation during which time the mitotic frequency of the apices greatly increased followed by a marked increase in apical size. During differentiation, pollen-cone apices did not initiate any basal foliar organs and a short stalk resulted at the base of the cone, whereas seed-cone apices initiated a few basal foliar primordia before bract initiation began. Microsporophyll initiation began during the last half of June and initiation occurred rapidly until the end of July. Micros porangial development occurred from August to late October when fully developed pollen-cone buds became dormant. Pollen mother cells began meiosis before dormancy and overwintered at the diffuse stage. Bract initiation began about the end of June, was rapid until mid-August, then continued more slowly until seed-cone buds became dormant in late October. Ovuliferous scales were initiated acropetally from mid-August until dormancy. Cone-bud differentiation occurred at about the end of the period of vegetative lateral long shoot elongation at all locations.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 125
Author(s):  
Magdalena Kapłan ◽  
Agnieszka Lenart ◽  
Kamila Klimek ◽  
Andrzej Borowy ◽  
Dariusz Wrona ◽  
...  

The research was carried out in a commercial apple orchard in southeastern Poland. The aim of the research was to evaluate the effect of fertilizer with biostimulation and humic acids with algae extracts and agrogel on the reception and growth of newly planted maiden apple trees of the ‘Gala Must’ variety. One-year-old budwoods were planted annually on the site where fruit trees had grown for 20 years. For the purpose of the experiment, old trees were grubbed up every year in autumn. The experiment assessed the growth and quality of apple trees in the fall of the first year after planting them permanently using a biostimulator in the form of fertilizer and agrogel. On the basis of 3-year studies, it was shown that the application of the assessed preparations had a positive effect on the quality parameters of the trees. The experiment showed the positive effect of the preparation with biostimulation on the best growth and quality parameters every year, which was confirmed by the multidimensional cluster analysis. The fact that the use of agrogel significantly modified the height of the evaluated apple trees in the second year of the study, when lower amounts of rainfall were recorded, is particularly noteworthy.


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.


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.


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.


1955 ◽  
Vol 47 (5) ◽  
pp. 224-228 ◽  
Author(s):  
James H. Torrie ◽  
Earle W. Hanson
Keyword(s):  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Gerhard Müller ◽  
Manuela Bombana ◽  
Monika Heinzel-Gutenbrenner ◽  
Nikolaus Kleindienst ◽  
Martin Bohus ◽  
...  

Abstract Background Mental disorders are related to high individual suffering and significant socio-economic burdens. However, it remains unclear to what extent self-reported mental distress is related to individuals’ days of incapacity to work and their medical costs. This study aims to investigate the impact of self-reported mental distress for specific and non-specific days of incapacity to work and specific and non-specific medical costs over a two-year span. Method Within a longitudinal research design, 2287 study participants’ mental distress was assessed using the Hospital Anxiety and Depression Scale (HADS). HADS scores were included as predictors in generalized linear models with a Tweedie distribution with log link function to predict participants’ days of incapacity to work and medical costs retrieved from their health insurance routine data during the following two-year period. Results Current mental distress was found to be significantly related to the number of specific days absent from work and medical costs. Compared to participants classified as no cases by the HADS (2.6 days), severe case participants showed 27.3-times as many specific days of incapacity to work in the first year (72 days) and 10.3-times as many days in the second year (44 days), and resulted in 11.4-times more medical costs in the first year (2272 EUR) and 6.2-times more in the second year (1319 EUR). The relationship of mental distress to non-specific days of incapacity to work and non-specific medical costs was also significant, but mainly driven from specific absent days and specific medical costs. Our results also indicate that the prevalence of presenteeism is considerably high: 42% of individuals continued to go to work despite severe mental distress. Conclusions Our results show that self-reported mental distress, assessed by the HADS, is highly related to the days of incapacity to work and medical costs in the two-year period. Reducing mental distress by improving preventive structures for at-risk populations and increasing access to evidence-based treatments for individuals with mental disorders might, therefore, pay for itself and could help to reduce public costs.


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