Effect of air temperature, rain and drought on hot water weed control

This is a monitoring research, the purpose of which is to point out the danger of scalding with water from loose garden hoses. All the stated data are the result of this research, which occurred during the month of August. To adequately compare the maximum temperature that the water reaches in garden hoses exposed to sunlight, 2 different surfaces were chosen, namely grass and concrete. It has been found that water in garden hoses, which lie in a place exposed to sunlight, is able to reach temperatures at which, in case of contact with human skin, there is a risk of scalding. The results confirmed the assumption that the temperature in the grass will be lower in the hoses than in the concrete surface. At an air temperature of 35°C, the water in the hoses on the grass reached a temperature of up to 47.3°C. On a concrete surface at an air temperature of 28.5°C, the water in the hoses reached 49.8°C. There is a risk of scalding from such hot water contact with the skin, and especially with sensitive baby skin. The aim of this research is to provide valid data on the risk of spilling hyperthermic water in free-lying garden hoses exposed to sunlight. The threat of scalding can occur unknowingly or through negligence, the risk of scalding with such water increases during tropical days significantly.

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FLUAZIFOP-P-BUTYL EFFICACY AS A FUNCTION OF APPLICATION TIME AND HERBICIDE DOSE

Planta Daninha ◽

10.1590/s0100-83582017350100011 ◽

2017 ◽

Vol 35 (0) ◽

Cited By ~ 1

Author(s):

L.F. CIESLIK ◽

R.A. VIDAL ◽

A.B. MACHADO ◽

M.M. TREZZI

Keyword(s):

Relative Humidity ◽

Common Bean ◽

Weed Control ◽

Air Temperature ◽

Field Experiments ◽

Time Of Day ◽

Leaf Angle ◽

Herbicide Application ◽

The Common ◽

Bean Crop

ABSTRACT Grass weeds are common in summer crops and strongly decreases the grain yield of the common bean crop. The time of herbicide application influences the variability of environmental conditions and affects the product performance. The objectives of this work were to identify the time of fluazifop-p-butyl (fluazifop) application which gives best grass weed control in the common bean crop and to elucidate the environmental variables most important for the efficacy of this herbicide. Field experiments were conducted involving five application times (2 a.m., 6 a.m., 11 a.m., 4 p.m. and 9 p.m.) and five doses of fluazifop (80, 110, 140, 170 and 200 g ha-1), with additional no-herbicide control. At the time of the herbicide application it was determined the air temperature, relative humidity, the photosynthetically active radiation (PAR) and the leaf angle, whereas the weed control and the dry mass of the weed Urochloa plantaginea was assessed at 20 days after treatment (DAT). Efficacy on grass control with fluazifop was dependent on the herbicide dose and on the time of day that the product was applied. Spray at early morning hours (6 a.m.) showed better efficacy on weed control in relation to periods during warmer conditions of the day (11 a.m. and 4 p.m.). Nocturnal fluazifop application had better weed control when compared to herbicide sprayed in the afternoon. The air temperature, relative humidity and PAR were correlated to weed leaf angle, which correlated the most with fluazifop performance.

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Effect of Pre-Treatment on the Drying Characteristics and Kinetics of Okra (Abelmoschus esculetus (L.) Moench) Slices

International Journal of Food Engineering ◽

10.2202/1556-3758.1191 ◽

2009 ◽

Vol 5 (2) ◽

Cited By ~ 13

Author(s):

Olajide Sobukola

Keyword(s):

Air Temperature ◽

Sample Thickness ◽

Hot Water ◽

Drying Rate ◽

Diffusivity Coefficient ◽

Drying Characteristics ◽

Rate Period ◽

Pretreatment Conditions ◽

Air Dryer ◽

Kinetics Of

The effects of air temperature (50, 60 and 70°C), sample thickness (2, 4 and 6mm) and pretreatment conditions (hot water blanching, 1 and 3% sodium metabisulphite solutions) on the drying characteristics and kinetics of okra were investigated using a convective hot air dryer at a flow rate of 1.5m/s. It was observed that pretreatment conditions, sample thickness and drying air temperature significantly (P<0.05) affected drying rate. Drying rate increases as temperature of drying air increases from 50 to 70°C. The drying curve for all experiments occurred in the falling rate period with no constant rate period. Three thin layer drying models (Page, modified Page I and Wang and Singh) were evaluated using coefficient of determination (R2), root mean square error (RMSE) and the reduced chi square (?2). The three models can appropriately describe the drying kinetics of okra slices considering the different experimental conditions. The effective diffusivity was determined using the Ficks model and was observed to vary between 1.125x10-8 9.93x10-9m2/s and 1.165x10-8 7.131x10-9 m2/s for treated and untreated samples. The Arrhenius-type relationship describes the temperature dependence of diffusivity coefficient and was determined to be 16.749kJ/mol and 22.437kJ/mol for treated and untreated samples respectively.

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Researches on ecological weed control in vegetable crops

E3S Web of Conferences ◽

10.1051/e3sconf/201911203008 ◽

2019 ◽

Vol 112 ◽

pp. 03008

Author(s):

Adriana Muscalu ◽

Cristian Sorică ◽

Cătălin Persu ◽

Ana-Maria Andrei ◽

Angela Dorogan ◽

...

Keyword(s):

Weed Control ◽

Integrated Control ◽

Hot Water ◽

Thermal Method ◽

Vegetable Crops ◽

Organic Farms ◽

Increased Sensitivity ◽

Bioactive Ingredients ◽

Real Challenge ◽

Methods Of Control

In recent years, intense concerns about the increasing resistance of weed populations to herbicide treatments, the low availability of bioactive ingredients for vegetable crops, as well as the expansion of organic farms for these niche crops have stimulated the development of new non-chemical methods of control or new approaches to those already used. In general, vegetable crops exhibit increased sensitivity to weeds compared to other crops. Therefore, weed control in organic vegetable crops is a real challenge for farmers, mainly using the so-called physical combat methods. Therefore, weed destruction is accomplished by using manual, mechanical, thermal or mulching means. The paper presents the preliminary experimental results obtained under laboratory conditions, referring to an innovative model of equipment for the ecological weed control in vegetable crops. It will achieve the destruction of weeds, combining the thermal method based on using hot water with the mechanical one, by equipping the machine with environmentally friendly active parts. The results obtained constitute an important premise for developing efficient equipment for the ecological weed control that can be used within integrated control systems, specific for organic onion, bean and bell pepper crops.

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Impact of wetting agents, time of day and periodic energy dosing strategy on the efficacy of hot water for weed control

Weed Research ◽

10.1111/wre.12212 ◽

2016 ◽

Vol 56 (4) ◽

pp. 323-334 ◽

Cited By ~ 1

Author(s):

B De Cauwer ◽

A De Keyser ◽

N Biesemans ◽

S Claerhout ◽

D Reheul

Keyword(s):

Weed Control ◽

Time Of Day ◽

Hot Water ◽

Wetting Agents ◽

Dosing Strategy

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Time of Day Impacts Postemergence Weed Control in Corn

Weed Technology ◽

10.1614/wt-08-150.1 ◽

2009 ◽

Vol 23 (3) ◽

pp. 346-355 ◽

Cited By ~ 20

Author(s):

Christie L. Stewart ◽

Robert E. Nurse ◽

Peter H. Sikkema

Keyword(s):

Light Intensity ◽

Weed Control ◽

Air Temperature ◽

Ambient Air ◽

Field Trials ◽

Time Of Day ◽

Weed Species ◽

Application Timing ◽

Reducing Costs ◽

Species Specific

Field trials were conducted from 2005 to 2007 at two locations in southwestern Ontario to investigate how weed control in corn was affected by the time of day that herbicides were applied. Weed control following the application of six POST herbicides (atrazine, bromoxynil, dicamba/diflufenzopyr, glyphosate, glufosinate, and nicosulfuron) at 06:00, 09:00, 12:00, 15:00, 18:00, 21:00, and 24:00 h was assessed. For many weed species herbicide efficacy was reduced when applications were made at 06:00, 21:00, and 24:00 h. Velvetleaf was the most sensitive to the time of day effect, followed by common ragweed, common lambsquarters, and redroot pigweed. Annual grasses were not as sensitive to application timing; however, control of barnyardgrass and green foxtail was reduced in some environments at 06:00 h and after 21:00 h. Only in the most severe cases was the grain yield of corn reduced due to decreased weed control. Daily changes in air temperature, relative humidity, and light intensity that cause species-specific physiological changes may account for the variation in weed control throughout the day. The results of this research suggest that there is a strong species-specific influence of ambient air temperature, light intensity, and leaf orientation on the efficacy of POST herbicides. These results should aid growers in applying herbicides when they are most efficacious, thus reducing costs associated with reduced efficacy.

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