scholarly journals Root Restriction Affects Shoot Development of Peach in a High-density Orchard

1992 ◽  
Vol 117 (3) ◽  
pp. 362-367 ◽  
Author(s):  
J.G. Williamson ◽  
D.C. Coston ◽  
J.A. Cornell

Planting treatments were evaluated for their influence on shoot development and root distribution of own-rooted `Redhaven' peach [Prunus persica (L.) Batsch] trees planted to high density (5000 trees/ha). Planting in fabric-lined trenches (FLT) or narrow herbicide strips (NHS) reduced the diameter and length of primary shoots, the number and combined length of second-order shoots, and the total length of shoots. Flower density, the number of flowers per node, and the percentage of nodes containing one or more flowers were increased for FLT trees but not for NHS trees when compared with controls. The length of primary shoots increased quadratically for all treatments with increasing limb cross-sectional area (LCA). The total length of shoots increased more with increasing LCA for controls than for FLT trees. The number of flowers per shoot increased linearly for all treatments with increasing LCA values. Root concentration decreased with increasing soil depth and distance from tree rows for all treatments. Reduced widths of weed-free herbicide strips had little effect on root distribution. Roots of FLT trees were reduced in number and restricted vertically and laterally when compared with other planting treatments. The FLT treatment modified shoot development by reducing the length of total shoots and length of primary shoots across LCA values measured when compared with NHS and control-treatments.

HortScience ◽  
1996 ◽  
Vol 31 (3) ◽  
pp. 370-375 ◽  
Author(s):  
Richard E.C. Layne ◽  
Chin S. Tan ◽  
David M. Hunter ◽  
Robert A. Cline

Seven treatment combinations of irrigation and fertilizer were compared in a high-density (606 trees/ha) management system for peach [Prunus persica (L.) Batsch cv. Harrow Beauty/Bailey] on Fox sand in southwestern Ontario. Each treatment combination had an irrigation component (N = nonirrigated, D = drip irrigated, or M = microsprinkler irrigated) and a fertilizer placement component (B = banded fertilizer, L = low fertigation, or H = high fertigation). NB and DB are commonly used systems in Ontario, while the other five treatment combinations were experimental. Total soil water in the top 110 cm of soil was lowest under NB but was never at the permanent wilting point. Trunk cross-sectional area was largest under DH and DB, smallest under ML and NB, and intermediate for the other three treatment combinations. No symptoms of N or K deficiency or toxicity were noted for any of the fertilizer treatments. Leaf analyses in July and September indicated that most major and minor elements were in the adequate to slightly excess range. However, there were no significant treatment effects on leaf nutrient concentrations in July or September when averaged over the five years, except for Mg in July. There were large and significant year effects on leaf nutrient concentrations but no significant treatment × year interactions. During the first four cropping years, there were no significant treatment effects, averaged over years, for total yield, marketable yield, or cumulative yield efficiency; however, there were large year effects but no treatment × year interactions for these factors. There was no detectable yield advantage for D vs. M irrigation. B application of N and K promoted no higher yields than fertigation equivalent to the B rate or 50% of this rate. Fertigation of N and K during the first 4 years of this experiment did not provide a detectable yield advantage to warrant the added cost and labor associated with this system compared with the B applications of N and K.


HortScience ◽  
2000 ◽  
Vol 35 (5) ◽  
pp. 837-842 ◽  
Author(s):  
Richard P. Marini ◽  
Donald S. Sowers

`Norman' peach [Prunus persica (L.) Batsch] trees were trained to the central-leader or open-vase form and were planted at high (740 trees/ha), or low (370 trees/ha) density. A third density treatment was a HIGH → LOW density, where alternate trees in high-density plots were removed after 6 years to produce a low-density treatment. From 3 to 5 years after planting, trunk cross-sectional areas (TCA) increased most for low-density trees. After 9 years, TCA was greatest for low-density and least for high-density trees. Because of differences in tree training, central-leader trees were taller than open-vase trees and tree spread was greater for low-density than for high-density trees. Annual yield per hectare was 15% to 40% greater for high-density treatments than for low-density treatments, but tree form had little influence on yield. Average fruit weight tended to be greater for low-density than for high-density treatments, but cumulative marketable yield was greatest for high-density and lowest for HIGH → LOW treatments. Income minus costs for 9 years was nearly $4200/ha higher, and net present value was about $2200/ha higher, for open-vase than for central-leader trees (P = 0.08). Cumulative net present value for the 9 years was about $2660/ha higher for high-than for low-density trees (P = 0.36).


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 792E-792
Author(s):  
Richard E.C. Layne ◽  
Chin S. Tan ◽  
David M. Hunter ◽  
Robert A. Cline

Seven high-density (606 trees/ha) management systems for peach [Prunus persica (L.) Batsch cv. Harrow Beauty/Bailey] were compared on Fox sand in southwestern Ontario. Each system had an irrigation component (N = none D = drip, M = microsprinkler) and a fertilizer placement component (B = banded, L= low-rate fertigation, H = high rate fertigation). NB (nonirrigated, banded fertilizer) and DB (drip-irrigated) are commonly used systems in Ontario, while the other five treatment combinations were experimental. Trunk cross-sectional area (TCA) was generally greatest for DH and DB systems, smallest for ML and NB systems, and intermediate for the other three. No symptoms of N or K deficiency or excess were noted for any of the fertilizer treatments. The seven management systems each had similar cumulative yield efficiencies for the first 4 cropping years However, total marketable yields for the 4 years were highest for MB (58.7 t·ha–1), followed in descending order by DB (56.8 t·ha–1), DH (56.6 t·ha–1), MH (53.9 t·ha–1), DL (50.6 t·ha–1), ML (49.8 t·ha–1), and NB (47.5 t·ha–1). Each of the irrigated treatments outyielded the nonirrigated check (NB) and ranged from 4.8% to 23.6%. Only one of the irrigated treatments (MB) outyielded the irrigated check (DB), and by only 3.3%. There was no clear advantage for either the drip or microsprinkler system of irrigation. Banded application of N and K appeared to promote higher yields than by fertigation equivalent to the banded rate, while yields at the low rate of fertigation were lower than for either the high rate of fertigation or the banded application. It appeared that banded fertilizer combined with either microsprinkler (MB) or drip irrigation DB provided the most-effective of the management systems in the first 4 cropping years.


Author(s):  
Henry I. Smith ◽  
D.C. Flanders

Scanning electron beam lithography has been used for a number of years to write submicrometer linewidth patterns in radiation sensitive films (resist films) on substrates. On semi-infinite substrates, electron backscattering severely limits the exposure latitude and control of cross-sectional profile for patterns having fundamental spatial frequencies below about 4000 Å(l),Recently, STEM'S have been used to write patterns with linewidths below 100 Å. To avoid the detrimental effects of electron backscattering however, the substrates had to be carbon foils about 100 Å thick (2,3). X-ray lithography using the very soft radiation in the range 10 - 50 Å avoids the problem of backscattering and thus permits one to replicate on semi-infinite substrates patterns with linewidths of the order of 1000 Å and less, and in addition provides means for controlling cross-sectional profiles. X-radiation in the range 4-10 Å on the other hand is appropriate for replicating patterns in the linewidth range above about 3000 Å, and thus is most appropriate for microelectronic applications (4 - 6).


Author(s):  
Melvin K Mathews ◽  
Abubaker Siddiq ◽  
Bharathi D R

Background: Chronic obstructive pulmonary disease (COPD) is preventable and treatable disease state characterized by air flow limitation that is not fully reversible. Severity of the symptoms is increased during exacerbations. Objectives: The purpose of the study is to assess and improve the knowledge regarding COPD among study subjects. Materials and Methods: A Cross-sectional interventional study was carried out among the peoples in selected areas of the Chitradurga city for a period of six months. Result: A total 207 subjects enrolled in the study in that 155 male and 52 females. In our study mean score of post test was more (5.87±1.68) when compare to pre-test (2.63±1.46) which show significant increase in their knowledge after educating them (p=0.000). A total of 207 subjects were enrolled into the study. SPSS Software was used to calculate the statistical estimation. Paired t-test was used to detect the association status of different variables. Conclusion: The relatively good level of COPD awareness needs to be maintained to facilitate future prevention and control of the disease. This study had identified that negative illness perceptions should be targeted, so that they will not avoid patients from seeking for COPD treatment and adhere to it. Key words: Cross sectional study, Knowledge, practice, COPD.


2019 ◽  
pp. 68-73
Author(s):  
Trong Nghia Nguyen ◽  
Thi Nhan Nguyen ◽  
Thi Dua Dao

Background: The metabolic syndrome is a constellation of cardiometabolic risk factors that tend to cluster together in affected individuals more often than predicted by chance. The presence of the metabolic syndrome substantially increases the risk of developing type 2 diabetes and cardiovascular disease, and is associated with a range of adverse clinical outcomes, many of which are closely associated with aging. Current estimates suggest that approximately 20 - 25% of the world’s population is affected by the metabolic syndrome. The prevalence of the metabolic syndrome rises with age and more than 45% of people aged over 60 years have the metabolic syndrome. Recent studies show that low vitamin D status is very common in the world and this is a risk factor of metabolic syndrome. Objective: (1) Plasma 25-hydroxyvitamin D concentration in subjects with metabolic syndrome. (2) Cut off value of plasma 25-hydroxyvitamin D concentration for predicting metabolic syndrome. Material and method: A cross-sectional study with control group on 318 adult subjects for health examinations at International Medical Center at Hue Central Hospital, including 139 subjects with metabolic syndrome and control group of 179 healthy subjects. Metabolic syndrome was defined according to the IDF, NHLBI, AHA, WHF, IAS, IASO (2009). Plasma hydroxyvitamin D concentration was measured using chemiluminescent microparticle immunoassay. Reciever operating characteristic (ROC) curve were generated to assess sensitivity and specificity for different cut off value of 25-hydroxyvitamin D concentration for predicting metabolic syndrome. Results: Plasma 25-hydroxyvitamin D concentration in subjects with metabolic syndrome was 26.4 ng/ml, incidence of plasma 25-hydroxyvitamin D deficiency (59.7%) was significantly higher than in control group (23.5%) (p < 0.001). The optimal cut off point for 25-OH-D concentration for predictor of metabolic syndrome as 26.4 ng/ml (AUC=0.657, sensitivity=53.4%, specificity=71.6%). Conclusion: In 139 subjects with metabolic syndrome, the plasma 25-hydroxyvitamin D concentration was 26.4 ng/ml and the incidence of 25-hydroxyvitamin D deficiency in the metabolic syndrome group was 59.7%. The optimal cut off point for plasma 25-hydroxyvitamin D concentration for predictor of metabolic syndrome as 26.4 ng/ml. Key words: Metabolic syndrome, 25-hydroxyvitamin D


1997 ◽  
Vol 35 (11-12) ◽  
pp. 35-40 ◽  
Author(s):  
B. Genthe ◽  
N. Strauss ◽  
J. Seager ◽  
C. Vundule ◽  
F. Maforah ◽  
...  

Efforts to provide water to developing communities in South Africa have resulted in various types of water supplies being used. This study examined the relationship between the type of water supply and the quality of water used. Source (communal taps, private outdoor and indoor taps) and point-of-use water samples were examined for heterotrophic plate counts (HPC), total and faecal coliforms, E. coli, and coliphages. Ten percent of samples were also analysed for enteric viruses, Giardia and Cryptosporidium. Approximately 320 households were included in a case-control study. In addition, a cross-sectional study was conducted. Both studies examined the relationship between different types of water facilities and diarrhoea among pre-school children. The source water was of good microbial quality, but water quality was found to have deteriorated significantly after handling and storage in both case and control households, exceeding drinking water quality guideline values by 1-6 orders of magnitude. Coliphage counts were low for all water samples tested. Enteric viruses and Cryptosporidium oocysts were not detected. Giardia cysts were detected on one occasion in case and control in-house samples. Comparisons of whether in-house water, after handling and storage, complied with water quality guideline values demonstrated households using communal taps to have significantly poorer quality than households using private outdoor or indoor taps for HPC and E. coli (χ2 = 14.9, P = 0.001; χ2 = 6.6, P = 0.04 respectively). A similar trend (although not statistically significant) was observed for the other microbial indicators. The cross-sectional study demonstrated an apparent decrease in health risk associated with private outdoor taps in comparison to communal taps. This study suggests that a private outdoor tap is the minimum level of water supply in order to ensure the supply of safe water to developing communities.


2020 ◽  
Author(s):  
Yushi Mo ◽  
Yan Luo ◽  
Hong Li ◽  
Dewei Xiao ◽  
Shuqing Liu ◽  
...  

BACKGROUND In face of the sudden epidemic of COVID-19, strict prevention and control measures had been urgently carried out all over China. Because of the long-term home quarantine, all kinds of people were affected by it. OBJECTIVE In order to understand the mental health of children during the pandemic of COVID-19, this study investigated the prevalence and characteristics of emotional and behavioral problems of children aged 1-11 in Guizhou. METHODS Based on the online survey platform, the survey link was pushed through Wechat in April 2020. Electronic questionnaires were used to investigate children's demographic characteristics, emotional or behavioral problems. RESULTS A total of 3505 valid questionnaires were received from 9 prefectures and cities in Guizhou Province. 39.67% of the children in the 1-2-year-old group had emotional problems. 17.63% of the children agd 3-5 years had behavioral or emotional problems. And 23.57% of the children agd 6-11 years havd behavioral problems. CONCLUSIONS During the home quarantine period of prevention and control of COVID-19, even young children were adversely affected. The prevalence of emotional and behavioral problems in children was high, which was mainly manifested as anxiety, difficulty in concentration and sleep problems.


2021 ◽  
pp. 175717742110127
Author(s):  
Salma Abbas ◽  
Faisal Sultan

Background: Patient and staff safety at healthcare facilities during outbreaks hinges on a prompt infection prevention and control response. Physicians leading these programmes have encountered numerous obstacles during the pandemic. Aim/objective: The aim of this study was to evaluate infection prevention and control practices and explore the challenges in Pakistan during the coronavirus disease 2019 pandemic. Methods: We conducted a cross-sectional study and administered a survey to physicians leading infection prevention and control programmes at 18 hospitals in Pakistan. Results: All participants implemented universal masking, limited the intake of patients and designated separate triage areas, wards and intensive care units for coronavirus disease 2019 patients at their hospitals. Eleven (61%) physicians reported personal protective equipment shortages. Staff at three (17%) hospitals worked without the appropriate personal protective equipment due to limited supplies. All participants felt overworked and 17 (94%) reported stress. Physicians identified the lack of negative pressure rooms, fear and anxiety among hospital staff, rapidly evolving guidelines, personal protective equipment shortages and opposition from hospital staff regarding the choice of recommended personal protective equipment as major challenges during the pandemic. Discussion: The results of this study highlight the challenges faced by physicians leading infection prevention and control programmes in Pakistan. It is essential to support infection prevention and control personnel and bridge the identified gaps to ensure patient and staff safety at healthcare facilities.


Children ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 77
Author(s):  
Katerina Sdravou ◽  
Elpida Emmanouilidou-Fotoulaki ◽  
Athanasia Printza ◽  
Elias Andreoulakis ◽  
Athanasios Evangeliou ◽  
...  

Parental feeding practices and mealtime routine significantly influence a child’s eating behavior. The aim of this study was to investigate the mealtime environment in healthy children and children with gastrointestinal diseases. We conducted a cross-sectional case–control study among 787 healthy, typically developing children and 141 children with gastrointestinal diseases, aged two to seven years. Parents were asked to provide data on demographics and describe their mealtime environment by answering to 24 closed-ended questions. It was found that the majority of the children had the same number of meals every day and at the same hour. Parents of both groups exerted considerable control on the child’s food intake by deciding both when and what their child eats. Almost one third of the parents also decided how much their child eats. The two groups differed significantly in nine of the 24 questions. The study showed that both groups provided structured and consistent mealtime environments. However, a significant proportion of children did not control how much they eat which might impede their ability to self-regulate eating. The presence of a gastrointestinal disease was found to be associated with reduced child autonomy, hampered hunger cues and frequent use of distractions during meals.


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