Breaking seed coat dormancy in Macrotyloma daltonii

2006 ◽  
Vol 28 (2) ◽  
pp. 179 ◽  
Author(s):  
N. Chikumba ◽  
C. Mapiye ◽  
X. Poshiwa
Keyword(s):  
Acid Treatment ◽  
Climatic Conditions ◽  
Rangeland Management ◽  
Hot Water ◽  
Management Options ◽  
Hard Seed ◽  
Positive Effects ◽  
Dry Heat ◽  
Dry Heating ◽  
Sowing Seed

Methods for breaking hard seed to allow germination of 2 seedlots of Macrotyloma daltonii (Webb) Verdc., were investigated. Treatments included soaking, application of dry heat, hot water, acid scarification, sand paper scarification, pre-chilling, alone and in combination with acid and dry heat. The treated seeds were tested for germination over 21 days in an incubator with 12 h of light and 12 h of darkness and temperatures of 25 and 18°C during the light and dark phases, respectively. A 20-min exposure to 98% concentrated sulphuric acid was most effective in increasing germination from 10 to 80% in seedlot 1. The 10-min acid treatment increased germination from 21 to 38% in seedlot 2, but 20 min reduced germination and increased the number of dead seeds. Seedlot 1 had greater levels of hard seed (88%) than seedlot 2 (61%). Soaking, hot water, dry heating, pre-chilling, or sandpaper scarification were not effective in breaking hard seed in either seedlot 1 or 2. Combining pre-chilling with 10 min of acid treatment damaged seed and impaired germination across the 2 seedlots. The range of pre-sowing seed treatments that indicated positive effects on germination, particularly acid treatments need to be further investigated in the field under different pedo-climatic conditions to allow appropriate rangeland management options to be developed.

scholarly journals SEED DORMANCY BREAKING TREATMENTS FORAFRICAN PURSLANE (Zaleya pentandra)

2015 ◽  
Vol 33 (4) ◽  
pp. 623-629 ◽  
Author(s):  
S. MUNAWAR ◽  
M. NAEEM ◽  
H.H. ALI ◽  
M. JAMIL ◽  
M. IQBAL ◽  
...  
Keyword(s):  
Seed Dormancy ◽  
Arid Zone ◽  
Hot Water ◽  
Plant Management ◽  
Dormancy Breaking ◽  
Invasive Weed ◽  
Hard Seed ◽  
Dry Heat ◽  
Breaking Dormancy ◽  
Seed Scarification

ABSTRACT Understanding the mechanisms involved in releasing seed dormancy is crucial for effective plant management and renewal of species in the arid zone. Zaleya pentandra is an emerging invasive weed of the arid areas of Pakistan. We investigated the effects of different dormancy breaking treatments on the germination of Z. pentandra seeds. Seeds were treated with hot water (by placing them in boiling water for 5, 15, 30, 60, 90, 120, and 150 min), dry heat (by placing them in a preheated oven at 70 oC for 1, 2, and 4 hours; at 70 oC for 1, 2, 3, and 4 days, and at 200 oC for 5, 10, 15, 30, and 45 min) and stratification (by placing them at 2-5 ºC in a refrigerator for 5, 10, 30, and 60 min; for 3, 6, and 12 hours, and for 1, 2, 4, 8, 15, and 30 days). Seeds also were soaked in thiourea ([(NH2)2CS] (0, 2,500, 5,000, 7,500, and 10,000 mg L-1 for 24 h at 30 oC) and in KNO3 (0, 10,000, 20,000, 30,000, 40,000, 50,000, and 60,000 mg L-1 for 24 h at 30 oC). Additionally, seeds were scarified with HCl (for 3, 6, 9, 12, 15, 18, and 21 h), HNO3 (for 3, 6, 9, 12, 15, 18, and 21 h), and H2SO4 (for 20, 40, 60, 80, 100, and 120 min at 30 oC) and also mechanically scarified with sandpaper. Zaleya pentandra seeds showed typical signs of hard seed coat dormancy. Mechanical scarification and acid treatments promoted seed germination to a varying degree. Seed scarification with HNO3 for 12 to 18 h as well as with HCl for 12 h and 15 h was efficient in breaking dormancy of Z. pentandra seeds, providing germination up to 92.5%. Seed scarification with H2SO4 from 20 to 120 min showed little effect, whereas hot water, dry heat, stratification and various concentrations of thiourea and KNO3 were ineffective in breaking Z. pentandra seed dormancy.

scholarly journals Germination and emergence of four rattan Calamus species of Western ghats in response to different pre-sowing seed treatments

2016 ◽  
Vol 8 (2) ◽  
pp. 760-768
Author(s):  
K. Vidyasagaran ◽  
E. D. Jisha ◽  
Vikas Kumar
Keyword(s):  
Water Treatment ◽  
Sulphuric Acid ◽  
Acid Treatment ◽  
Complete Removal ◽  
Germination Percentage ◽  
Hot Water ◽  
Hot Water Treatment ◽  
Calamus Thwaitesii ◽  
Sowing Seed ◽  
Germination Value

The present investigation was carried out to study the effect of ten pre-sowing treatments on germination parameter of the four Calamus species in the nursery of College of Forestry, Vellanikkara. Most of the pre-sowing treatments of Calamus spp. gave better performance compared to the control. Complete removal of outer pericarp and sarcotesta of each seed manually (T2), Sulphuric acid treatment for 3-5 minutes after removing sarcotesta (T6) and Hot water treatment (500C) after removing sarcotesta for two minutes followed by soaking in water for 12 hours (T7) were found promising in all the species. The higher germination percentage (83.82, 89.96), mean daily germination (0.020, 3.39), peak value of germination (0.026, 3.45) and germination value (0.00041, 11.56) and was recorded for Calamus thwaitesii and C. metzianus in treatment with GA3 (T9) respectively. The maximum germination percentage (27.74), MDG (0.41), PVG (0.46) and GV (0.20) for C. hookerianus in T7 (Hot water treatment (500C) after removing sarcotesta for two minutes followed by soaking in water for 12 hours), and highest MDG (0.078), PVG (0.91) and GV (0.0065) for C. travancoricus in T5 (Sulphuric acid treatment for 3-5 minutes without removing sarcotesta). The present study reiterated that the pre-sowing treatments hold major scope in the propagation of rattan seedlings which usually could not germinate well under ordinary conditions due to dormancy.

scholarly journals New Deterministic Mathematical Model for Estimating the Useful Energy Output of a Medium-Sized Solar Domestic Hot Water System

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2753
Author(s):  
Miroslaw Zukowski ◽  
Walery Jezierski
Keyword(s):  
Thermal Power ◽  
Optimization Procedure ◽  
Climatic Conditions ◽  
Point Of View ◽  
Hot Water ◽  
Energy Output ◽  
Daily Consumption ◽  
Software Environment ◽  
Optical Efficiency ◽  
Domestic Hot Water

According to the authors of this paper, the mathematical point of view allows us to see what sometimes cannot be seen from the designer’s point of view. The aim of this study was to estimate the influence of the most important parameters (volume of heat storage tanks, daily consumption of domestic hot water, optical efficiency, heat loss coefficient, and total area of a solar collector) on the thermal power output of solar domestic hot water (SDHW) system in European climatic conditions. Three deterministic mathematical models of these relationships for Madrid, Budapest, and Helsinki were created. The database for the development of these models was carried out using computer simulations made in the TRNSYS software environment. The SDHW system located at the Bialystok University of Technology (Poland) was the source of the measurement results used to validate the simulation model. The mathematical optimization procedure showed that the maximum annual useful energy output that can be obtained from 1 m2 of gross collector area is 1303 kWh in the case of Madrid, 918.5 kWh for Budapest, and 768 kWh for Helsinki weather conditions.

RENEWABLE ENERGY INTEGRATION FOR HOT WATER SUPPLY AND HEATING OF BUILDINGS

2021 ◽  
pp. 3-12
Author(s):  
Yu. Selikhov ◽  
K. Gorbunov ◽  
V. Stasov
Keyword(s):  
Solar Energy ◽  
Heat Production ◽  
Heat Supply ◽  
Alternative Energy ◽  
Fossil Fuel ◽  
Heat Pumps ◽  
Climatic Conditions ◽  
Economic Feasibility ◽  
Hot Water ◽  
The Cost

Solar energy is widely used in solar systems, where economy and ecology are combined. Namely, this represents an important moment in the era of depletion of energy resources. The use of solar energy is a promising economical item for all countries of the world, meeting their interests also in terms of energy independence, thanks to which it is confidently gaining a stable position in the global energy sector. The cost of heat obtained through the use of solar installations largely depends on the radiation and climatic conditions of the area where the solar installation is used. The climatic conditions of our country, especially the south, make it possible to use the energy of the Sun to cover a significant part of the need for heat. A decrease in the reserves of fossil fuel and its rise in price have led to the development of optimal technical solutions, efficiency and economic feasibility of using solar installations. And today this is no longer an idle curiosity, but a conscious desire of homeowners to save not only their financial budget, but also health, which is possible only with the use of alternative energy sources, such as: double-circuit solar installations, geothermal heat pumps (HP), wind power generators. The problem is especially acute in the heat supply of housing and communal services (HCS), where the cost of fuel for heat production is several times higher than the cost of electricity. The main disadvantages of centralized heat supply sources are low energy, economic and environmental efficiency. And high transport tariffs for the delivery of energy carriers and frequent accidents on heating mains exacerbate the negative factors inherent in traditional district heating. One of the most effective energy-saving methods that make it possible to save fossil fuel, reduce environmental pollution, and meet the needs of consumers in process heat is the use of heat pump technologies for heat production.

Hot water seed treatment for Leucaena glauca (L.) Benth

1962 ◽  
Vol 2 (6) ◽  
pp. 178 ◽  
Author(s):  
SG Gray
Keyword(s):  
Water Treatment ◽  
Effective Treatment ◽  
Sulphuric Acid ◽  
Seed Treatment ◽  
Hot Water ◽  
Sowing Seed

Seed of Leucaena glauca (L.) Benth. germinates slowly, and irregularly unless treated before sowing to render the testa permeable to water. Treatment with sulphuric acid is effective but inconvenient to use. Experiments with hot water over a range of temperature and time are described. An effective treatment was to immerse the seed in water at 80�Cfor two minutes. After this treatment seed can be dried rapidly and stored before sowing. Seed treated in this way has retained full viability for 15 months.

scholarly journals Effect of pre-sowing treatments and growing media on seed germination and seedling growth of Albizia lebbeck (L.) Benth

2018 ◽  
Vol 10 (3) ◽  
pp. 860-863
Author(s):  
Naresh Kumar ◽  
A. K. Handa ◽  
Inder Dev ◽  
Asha Ram ◽  
A. R. Uthappa ◽  
...  
Keyword(s):  
Seedling Growth ◽  
Room Temperature ◽  
Cold Water ◽  
Hot Water ◽  
Albizia Lebbeck ◽  
Physical Dormancy ◽  
Growing Media ◽  
Hard Seed ◽  
Collar Diameter ◽  
Hard Seed Coat

The seeds of Albizia lebbeck have been observed to exhibit physical dormancy due to presence of hard seed-coat. To overcome this problem, the seeds were subjected to seven pre-sowing treatments viz., T1-immersion of seeds in cold water for 12 h; T2-immersion of seeds in cold water for 24 h; T3-immersion of seeds in hot water (100 °C) and subsequent cooling at room temperature for 12 h; T4-immersion of seeds in hot water (100 °C) and subsequent cooling at room temperature for 24 h; T5-immersion of seeds in cold water for 12 h followed by immersion in hot water (100 °C) and allowed to cool for 1 h; T6-immersion of seeds in cold water for 24 h followed by immersion in hot water (100 °C) and allowed to cool for 1 h. Untreated seeds served as control (T0). Treatment T3 gave highest germination (96%) which was comparable with T5 (95 %), T4 (94 %) and T6 (93%). Nine growing media viz., T1: soil,  T2: soil+sand (2:1), T3: soil+perlite (2:1), T4: soil+Farm Yard Manure (FYM) (2:1), T5: soil+vermicompost (2:1), T6: soil+sand+FYM (1:1:1), T7: soil+sand+vermicompost (1:1:1), T8: soil+perlite+FYM (1:1:1) and T9: soil+perlite+ vermicompost (1:1:1) were, also, studied for their effect on seedling growth of A. lebbeck. Among these media, maximum values of shoot length (23.82 cm), root length (21.14 cm), collar diameter (3.59 mm) and seedling quality index (0.350) were observed in T7.

scholarly journals Evaluating the Tourist Climate Comfortable Period of China in a Changing Climate

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Dan-Dan Yu ◽  
Shan Li ◽  
Zhong-Yang Guo
Keyword(s):  
Climate Change ◽  
Global Climate ◽  
Scientific Evidence ◽  
Climatic Conditions ◽  
Climate Index ◽  
Climate Indices ◽  
Climate Data ◽  
Climate Conditions ◽  
Positive Effects ◽  
Changing Climate

The evaluation of climate comfort for tourism can provide information for tourists selecting destinations and tourism operators. Understanding how climate conditions for tourism evolve is increasingly important for strategic tourism planning, particularly in rapidly developing tourism markets like China in a changing climate. Multidimensional climate indices are needed to evaluate climate for tourism, and previous studies in China have used the much criticized “climate index” with low resolution climate data. This study uses the Holiday Climate Index (HCI) and daily data from 775 weather stations to examine interregional differences in the tourist climate comfortable period (TCCP) across China and summarizes the spatiotemporal evolution of TCCP from 1981 to 2010 in a changing climate. Overall, most areas in China have an “excellent” climate for tourism, such that tourists may visit anytime with many choices available. The TCCP in most regions shows an increasing trend, and China benefits more from positive effects of climate change in climatic conditions for tourism, especially in spring and autumn. These results can provide some scientific evidence for understanding human settlement environmental constructions and further contribute in improving local or regional resilience responding to global climate change.

scholarly journals Pre-Treatment Methods for Regeneration of Spent Activated Carbon

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4561
Author(s):  
Sang Youp Hwang ◽  
Gi Bbum Lee ◽  
Ji Hyun Kim ◽  
Bum Ui Hong ◽  
Jung Eun Park
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Acid Treatment ◽  
Chemical Activation ◽  
Fixed Carbon ◽  
Treatment Methods ◽  
Positive Effects ◽  
Area Increase ◽  
Pre Treatment ◽  
Surface Area Increase

Spent activated carbon (SAC) usually exhibits a low specific surface area due to its high ash contents. In this study, pre-treatments, such as heat and acid treatments, were optimized to improve this feature. The heat pre-treatment did not reduce the ash content, nor did it increase the surface area. Because metallic ions adsorbed in SACs turn into ash upon the heat treatment. In the acid pre-treatment, the volatiles and fixed carbon were increased with decreasing ash contents. In this study, it was found that the surface area increase was correlated with the ratio between fixed carbon and ash. Among the pre-treatment methods, the combined heat and acid pre-treatment method highly increased the ratio, and therefore led to the surface area increase. Additionally, the acid pre-treatment was carried out using different types of acid (organic and inorganic acids) solutions to further improve the surface areas. The organic acid treatment caused a significant structural collapse compared to the inorganic acid treatment, decreasing the surface area. In particular, H3PO4 effectively removed ashes adsorbed on the activated carbon surface and regenerated the exhausted activated carbon. Both the heat and acid pre-treatments before chemical activation resulted in the positive effects such as strong desorption of pollutants and ashes within the internal structure of the activated carbon. Therefore, the regeneration introduced in this study is methodically the best method to regenerate SAC and maintain a stable structure.

scholarly journals Benefits and Limitations of Decision Support Systems (DSS) with a Special Emphasis on Weeds

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 548 ◽  
Author(s):  
Panagiotis Kanatas ◽  
Ilias S. Travlos ◽  
Ioannis Gazoulis ◽  
Alexandros Tataridas ◽  
Anastasia Tsekoura ◽  
...  
Keyword(s):  
Decision Support ◽  
Decision Support Systems ◽  
Weed Management ◽  
Crop Production ◽  
Support Systems ◽  
Management Strategies ◽  
Farming Systems ◽  
Climatic Conditions ◽  
Management Options ◽  
The Right

Decision support systems (DSS) have the potential to support farmers to make the right decisions in weed management. DSSs can select the appropriate herbicides for a given field and suggest the minimum dose rates for an herbicide application that can result in optimum weed control. Given that the adoption of DSSs may lead to decreased herbicide inputs in crop production, their potential for creating eco-friendly and profitable weed management strategies is obvious and desirable for the re-designing of farming systems on a more sustainable basis. Nevertheless, it is difficult to stimulate farmers to use DSSs as it has been noticed that farmers have different expectations of decision-making tools depending on their farming styles and usual practices. The function of DSSs requires accurate assessments of weeds within a field as input data; however, capturing the data can be problematic. The development of future DSSs should target to enhance weed management tactics which are less reliant on herbicides. DSSs should also provide information regarding weed seedbank dynamics in the soil in order to suggest management options not only within a single period but also in a rotational view. More aspects ought to be taken into account and further research is needed in order to optimize the practical use of DSSs for supporting farmers regarding weed management issues in various crops and under various soil and climatic conditions.

scholarly journals Energy-efficient solar power plants for autonomous heat supply in Russia

2018 ◽  
Vol 251 ◽  
pp. 03012 ◽  
Author(s):  
Pavel Khavanov ◽  
Anatoly Chulenyov
Keyword(s):  
Power Plants ◽  
Renewable Energy Sources ◽  
Water System ◽  
Climatic Conditions ◽  
Hot Water ◽  
Partial Replacement ◽  
Water Heating ◽  
Technical Requirements ◽  
Solar Power Plants ◽  
Technical Operation

In the complex of measures for energy saving, partial replacement and reduction of consumption of fossil energy and electricity, water heating solar installations for heating systems have long been in practice for small energy facilities. Solar energy is one of the most dynamically developing directions of use of renewable energy sources, especially the introduction of which are associated with climatic conditions and technical requirements of their application. The territory of Russia is located mainly in the cold climatic zone and in regions with a sharply continental climate in which the operation of water heating solar plants is justified and most rational in seasonal use, in this case, their technical operation is carried out mainly during the non-heating period of the year. In such installations, in a number of cases, it is possible to avoid the need to use “non-freezing” heat carriers, and therefore the thermal schemes of the plants are simpler in design and cheaper, since heat exchangers or bivalent storage tanks can be excluded to transfer heat from the antifreeze to the water of the heating circuit or hot water system.

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