scholarly journals Light-Intercepting Characteristics and Growth of Tomatoes Cultivated in a Greenhouse Using a Movable Bench System

Horticulturae ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 60
Author(s):  
Yuta Ohashi ◽  
Misato Murai ◽  
Yasuhiro Ishigami ◽  
Eiji Goto

The objective of this study was to investigate the growth and light-intercepting characteristics of tomatoes when movable benches are used in their cultivation. We cultivated tomatoes in a greenhouse (168 m2) during summer (9 July–9 September 2018) under different furrow distances (F1.0 = 1.0 m and F1.6 = 1.6 m) and movable benches (M indicates that the furrow distance = 0.4–0.8 m). Compared to the other treatments, when the movable bench was used to the change furrow distance depending on the plant growth stage (M treatment), the percentage of canopy light interception increased to ~90% at the early stage of plant growth (~20 days after transplanting). The percentage of canopy light interception for different treatments increased in the order of M > F1.0 > F1.6, and it increased towards the end of cultivation. In addition, the yield per unit area exhibited the same trend. Therefore, the solar radiation inside a greenhouse can be efficiently intercepted by plants when movable benches are used. This indicated that it was possible to increase plant yield per unit area using movable benches in plant cultivation.

2009 ◽  
Vol 99 (7) ◽  
pp. 879-886 ◽  
Author(s):  
Kaveh Ghanbarnia ◽  
W. G. Dilantha Fernando ◽  
Gary Crow

Blackleg, also known as Phoma stem canker, caused by Leptosphaeria maculans (Phoma lingam), is one of the most serious diseases of canola worldwide. In this study, the mean disease severity (Ds) and incidence (Di) of canola cv. Westar plants infected at the cotyledon, three-leaf, and six-leaf stages by pycnidiospores of L. maculans were monitored in the greenhouse after infection of the plants under field conditions in two successive years and associated with meteorological data during infection time. Pearson's correlation coefficient showed that total rainfall per week (R) was significantly correlated to Ds on plants infected at the cotyledon, three-leaf, and six-leaf stages, and average maximum temperature per week (Tmax) only showed significant correlation with plants infected at the cotyledon and six-leaf stages. These results also indicated that there is correlation between Di and R for plants infected at all three growth stages. A nonlinear model was developed to evaluate the combined effects of R and Tmax on Ds. The best model comprised monomolecular function and β probability density function for plants infected at the above three growth stages. Parameters, including maximum potential for Ds at a given rainfall (dmax), rate of changes with respect to rainfall (k), constant of integration (B), maximum potential for Ds with respect to Tmax (e), rate of increase with increasing Tmax to optimum (n), and rate of decrease as Tmax increased and passed the optimum Tmax (p), were estimated for plants infected at the above three growth stages. The effect of plant growth stage was characterized by differences in the upper limit parameter a. This parameter was greater for the plants infected at the cotyledon stage than for plants infected at the other two stages. The estimate of parameter k was the same for the plants infected at the cotyledon and three-leaf stages. This parameter was much lower for the plants infected at the six-leaf stage compared with two other stages. The logistic model could describe the disease incidence with respect to R slightly better than the other two models in the plants infected at all three growth stages. Based on the model, upper-limit estimate (dmax) was ≈100, 94.4, and 88.8% in the plants infected at cotyledon, three-leaf, and six-leaf stages, respectively. Di increased until rainfall reached ≈18, 10, and 13 mm/week and became constant in the plants at cotyledon, three-leaf, and six-leaf stages, respectively. Effects of plant growth stage on the rate of change with respect to R (parameter k) were lower in the plants infected at cotyledon than at the other two stages. The accuracy of the nonlinear models suggests that they could be used to develop a comprehensive model to evaluate epidemics of blackleg based on pycnidiospores as sources of inoculum. However, additional years of data collection should improve model fit and evaluation of introduced models and contribute to the development of a more robust predictive model.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 877C-877
Author(s):  
Susan Parent

The most appropriate time for VAM inoculation has been assumed to be the early stages of plant growth, and this study aimed to investigate the impact of VAM inoculation at the seedling and at the 10-week geranium plant stage. Seeds were planted in propagation plug trays (200) filled with four different seed-germinating substrates: half were inoculated with Glomus intraradices while the other half were noninoculated controls. Two types of media received inoculum or not (control); they consisted of sphagnum peat with perlite in one case and vermiculite in the other. After 10 weeks growth, the root systems were checked for colonization, and height, weight, and leaf number were registered. The subsequent growth was carried out in 4-inch azalea pots with the appropriate medium. The pre-in-oculated plants were transferred in Mycori-Mix, and the controls were transferred in Pro-Mix. All plants received mild liquid fertilization at each irrigation time (20N–2P–20K). The number of cuttings and flowers were monitored 6 weeks after beginning of pot growth. The pots were displayed in a complete factorial block with six replicates per treatment, and 10 plants were used for each experimental unit. Significant differences did occur between plants initiated in the different germinating substrates; when pre-inoculated, 12.5 cuttings and 7 flowers were recorded in comparison to 9.8 and 3.9, respectively, for controls. These results reflect the importance of introducing VAM at the earliest growth stage.


2013 ◽  
Vol 655-657 ◽  
pp. 2006-2009
Author(s):  
Heng Hua Shi ◽  
Yu Jie Wang ◽  
Cheng Kui Guo ◽  
Yan Zhang ◽  
Jia Xin Wu

Plant light interceptions directly impact on plant photosynthesis, and thus have an impact on plant growth. According to the characteristics of plant photosynthesis and growth and development, we abstract plant growth form as the geometry. Based on solar elevation angle, solar azimuth angle and spacing of plant cultivation, we get the relationship model of plant light interception and planting cultivation form under assumptions. In the simulation environment, we set spindle trees as an example and analyze the best cultivation form of plants under the conditions of the specific latitude.


Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1685
Author(s):  
Maria Concetta Di Bella ◽  
Stefania Toscano ◽  
Donata Arena ◽  
Diego A. Moreno ◽  
Daniela Romano ◽  
...  

Some new foods (sprouts, microgreens and baby leaf) of the brassica genus are appreciated for their nutritional and nutraceutical values. The aim of this experimental trial was to improve the nutraceutical traits of these foods by evaluating the effects of the climatic condition, genotype, and plant growth stage on the development of greater quality in relation to these new foods. The morphometric and glucosinolates (GLSs) traits of three traditional Italian cultivars of Brassica oleracea crops, such as broccoli (B. oleracea var. italica), namely the traditional Sicilian landrace ‘Broccolo Nero’ (BN) and the commercial ‘Cavolo Broccolo Ramoso Calabrese’ (CR), as well as the commercial kale cultivar ‘Cavolo Laciniato Nero di Toscana’ (CL) (B. oleracea var. acephala DC.), were evaluated in an unheated greenhouse in Catania during the end of 2019 and the beginning of 2020. Plant growth was studied at different phenological stages—from seeds to sprouts, microgreens, and baby leaves—over two growing cycles, one in autumn–winter and the other in spring–summer. ‘Broccolo Nero’ (BN) broccoli showed more rapid growth and biomass production than the other two cultivars evaluated (i.e., weight, hypocotyl length, and leaf width). The GLS profile varied significantly (p < 0.05), in relation both to plant’s growth stage and to genotype. The highest amount of glucoraphanin was detected for BN microgreens and baby leaves, about 8 µmol g−1 d.w., whereas glucobrassicin and its related derivatives were about 14 µmol g−1 d.w. in microgreens and baby leaves of CL and about 15 µmol g−1 d.w. and 10 µmol g−1 d.w. for glucoraphanin in CR, respectively. These new foods can also be produced at home with simple and cheap equipment


Author(s):  
Carmen García-Alba

This study is part of a larger research study (doctoral dissertation), in which a comparative study with adolescent samples is done: 50 anorexic restricting patients (ANP), 50 patients diagnosed with depression (DP) and 50 non patients (NP). The proposed objective is two-fold: 1) To try to clarify the existing relationship between Anorexia (AN) and Depression (D), investigated from diverse disciplines but without conclusive results. 2) To detect in the ANP personality different traits from those of other groups, which should, if possible, allow to detect them at an early stage for an adequate prognosis. The current article presents the Rorschach findings in relation to the cognitive functioning of the ANP. In them, the following has been detected: (1) An information processing similar to that of the other groups, even with a more complete (L ≤ .99), more complex (DQ+↑) and better discriminated (Zd↑) grasp of the stimulus; (2) Mediating processes very similar to those of the other groups, sharing with them the perceptive maladjustments (X–%↑) and an excessive individualism (Xu%↑); (3) A clearly differentiating ideation disorder. Definitely, the ANP use predominantly ideation (M↑), but their thought, usually well-adjusted (MQo↑), presents eventual operations of delusional type (MQnone↑). Above that, their thinking is marked by a great passivity (Mp↑), which makes them more vulnerable to accept ideas without criticizing them and it results in a very inefficient thinking, which spins around these concepts without finding solutions, entering into a sort of ruminating which is completely unproductive. The differences toward the obsessive pathology are established. The discriminant analysis conducted with all the Rorschach variables that resulted as significant throughout the research, provides quite a consistent function which discriminates the ANP: MQnone↑, Mp↑, FD↓, Ma↑, MQo↑, AdjD↑, Sum H↑, (H)↑. Based on this we can understand that these adolescents, being in a developmental period of big changes and disorientations in relation with their own image, confronted with life events, and possibly starting off with some biologic vulnerability: (1) Due to the alterations of their ideation, accept without criticism (Mp) irrational ideas dominating in our culture, in which slimness appears as the only model, synthesis of intelligence, beauty and success; remaining captured in this type of mental activity (MQnone), which they cannot escape nor criticize (Mp), despite they reason adequately on other topics (MQo); (2) Their alterations of self-perception [(H)] make them hide themselves in a fantasized image, which is the axis of their interests and the only thing that really matters to them; (3) The resources they have to decide on behaviors and to finish these deliberately (AdjD), and their scarce tendency to the introspection (FD) lead to their decision of not eating, based on distorted and passively accepted thinking, which has great power and thus, so difficult to modify. Finally, based on the Rorschach data obtained, the hypothesis of a personality disorder as underlying pathology is pointed out.


Author(s):  
Menghan TAO ◽  
Ning XIAO ◽  
Xingfu ZHAO ◽  
Wenbin LIU

New energy vehicles(NEV) as a new thing for sustainable development, in China, on the one hand has faced the rapid expansion of the market; the other hand, for the new NEV users, the current NEVs cannot keep up with the degree of innovation. This paper demonstrates the reasons for the existence of this systematic challenge, and puts forward the method of UX research which is different from the traditional petrol vehicles research in the early stage of development, which studies from the user's essence level, to form the innovative product programs which meet the needs of users and being real attractive.


1988 ◽  
Vol 80 (4) ◽  
pp. 586-591 ◽  
Author(s):  
W. B. Hallmark ◽  
C. J. DeMooy ◽  
H. F. Mooris ◽  
John Pesek ◽  
K. P. Shao ◽  
...  

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 752
Author(s):  
Chung-Guei Huang ◽  
Avijit Dutta ◽  
Ching-Tai Huang ◽  
Pi-Yueh Chang ◽  
Mei-Jen Hsiao ◽  
...  

A total of 15 RT-PCR confirmed COVID-19 patients were admitted to our hospital during the in-itial outbreak in Taiwan. The average time of virus clearance was delayed in seven patients, 24.14 ± 4.33 days compared to 10.25 ± 0.56 days post-symptom onset (PSO) in the other eight pa-tients. There was strong antibody response in patients with viral persistence at the pharynx, with peak values of serum antibody 677.2 ± 217.8 vs. 76.70 ± 32.11 in patients with delayed versus rapid virus clearance. The patients with delayed viral clearance had excessive antibodies of compromised quality in an early stage with the delay in peak virus neutralization efficacy, 34.14 ± 7.15 versus 12.50 ± 2.35 days PSO in patients with rapid virus clearance. Weak antibody re-sponse of patients with rapid viral clearance was also effective, with substantial and comparable neutralization efficacy, 35.70 ± 8.78 versus 41.37 ± 11.49 of patients with delayed virus clearance. Human Cytokine 48-Plex Screening of the serial sera samples revealed elevated concentrations of proinflammatory cytokines and chemokines in a deceased patient with delayed virus clear-ance and severe disease. The levels were comparatively less in the other two patients who suf-fered from severe disease but eventually survived.


2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 26-27
Author(s):  
Caroline Chappell ◽  
Landon Marks ◽  
Katie Mason ◽  
Mary K Mullenix ◽  
Sandra L Dillard ◽  
...  

Abstract A 2-yr study was conducted at Black Belt Research and Extension Center in Marion Junction, AL, to evaluate the effect of nitrogen (N) fertilizer application rate on forage production characteristics, nutritive value, and animal performance of beef heifers grazing a mixture of native warm-season grasses (NWSG) including big bluestem, little bluestem, and indiangrass. Six, two-hectare plots were randomly assigned to one of two treatments (0 or 67 kg N ha-1 applied in early April; n = 3 replications per treatment). Paddocks were continuously stocked with four weaned Angus × Simmental beef heifers (initial BW 288 ± 7 kg) from late May/early June through mid-to-late August during 2018 (73 grazing d) and 2019 (70 grazing d), respectively. Put-and-take cattle were used to manage forage to a target of 38 cm. Forage mass and canopy heights were collected every two weeks during the trial. Visual ground cover ratings, canopy light interception, and botanical composition were measured at the beginning and end of the trial in each year. Hand-plucked samples were collected every two weeks during the grazing trial to determine forage nutritional value. Data were analyzed using the PROC MIXED procedure in SAS 9.4, and differences were declared significant when P ≤ 0.05. Nitrogen fertilized NWSG had greater crude protein (P &lt; 0.0001), sward heights (P = 0.0003), and canopy light interception at the beginning of the season (P = 0.0049) compared to non-fertilized paddocks. However, there were no differences (P ≥ 0.05) among N-fertility treatments for mean forage mass, heifer ADG, or BCS across the 2-yr study. Botanical composition data indicated that indiangrass decreased from 64% to 61% (P = 0.0022) and weed pressure increased from 11% to 15% (P = 0.0064) across the summer grazing season. Canopy light interception decreased by 51% from early June to August in fertilized NWSG and 26% in unfertilized paddocks, respectively. These data illustrate that NWSG systems may provide a viable grazing system in the summer months under reduced N inputs.


Sign in / Sign up

Export Citation Format

Share Document