scholarly journals Effect of Spray Application Technique on Spray Deposition and Losses in a Greenhouse Vegetable Nursery

2020 ◽  
Vol 12 (17) ◽  
pp. 7052
Author(s):  
Sabina Failla ◽  
Elio Romano

The cultivation of vegetables in greenhouses requires seedlings produced in nurseries with high levels of practice specialisation. The nurseries are dedicated to the early stages of growth, from sowing to the first leaves. There, the seeding density and the hydro-climatic conditions favour diseases. Plant protection treatments are carried out with the use of low-cost machines, whose efficiencies and safety conditions depend on the workers’ ability. The irrigation system with a mechanised horizontal spray boom could be an alternative solution to the hand-held spray gun. This research aimed to investigate the use of a horizontal boom sprayer for the distribution of pesticides in different pressure conditions and forward speeds compared with a spray gun, in relation to tomato growth stages. The tests were carried out on tomato seedlings grown in polystyrene seeding boxes and arranged on hanging benches. Deposits on the seedlings (µL cm−2) and losses in the soil (µL cm−2) were assessed by means of standard colorimetric analysis. In order to reduce the environmental pollution and increase the sustainability of the treatments, the pressure at the horizontal spray boom should be reduced and the arrangement of the outermost nozzles may also be better set on the boom.

HortScience ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Dieter Foqué ◽  
Jan G. Pieters ◽  
David Nuyttens

Flemish greenhouse growers predominantly use handheld spray guns and lances for their crop protection purposes despite the heavy workload and high risk for operator exposure associated with these techniques. These spray application techniques have also shown to be less effective than spray boom equipment under many conditions. Handheld spraying techniques are less expensive, however, and they are more flexible in practical use. Many growers also erroneously believe that high spray volumes and pressures are needed to assure good plant protection. The aim of this work was to evaluate the spray deposition, penetration, and uniformity between a manually pulled horizontal spray boom as compared with a spray gun under controlled laboratory conditions. In this study, we evaluated six spray application techniques, i.e., three spray boom and three spray gun techniques. In general, the deposition results were comparable between the spray boom and the spray gun applications. The spray boom applications, however, resulted in a more uniform spray distribution. At the plant level, the spray distribution was not uniform for any of the techniques used; the highest deposits were observed on the upper (or adaxial) side of the top leaves. Using spray guns at a higher spray pressure did not improve spray penetration in the canopy or deposition on the bottom (or abaxial) side of the leaves. Of the different nozzle types tested on the spray boom, the extended range flat fan XR 8003 gave the best results. Crop density clearly affected crop penetration and deposition on the bottom side of the leaves.


2021 ◽  
Vol 64 (6) ◽  
pp. 1735-1745
Author(s):  
Rajeev Sinha ◽  
Lav Khot ◽  
Gwen Hoheisel ◽  
Matthew Grieshop

HighlightsVariants of a solid set canopy delivery system were evaluated in a high-density apple orchard.A pair of hollow-cone nozzles installed in three tiers had optimum spray performance for studied crop growth stages.A shower-down arrangement of emitters was the simplest design but had lesser deposition on abaxial leaf surfaces.Abstract. Optimally configured solid set canopy delivery system (SSCDS) based spraying has potential to improve tree-fruit crop pest and disease management by reducing application time and eliminating dependence on ground conditions. In such an effort, this study attempted to optimize SSCDS variants. Four different emitter types (E1 to E4) installed in different mounting configurations (C1 to C4) were evaluated for spray deposition and coverage in a high-density apple orchard trained in tall spindle architecture. Emitters E1, E2, and E4 had full circle spray patterns, and E3 had a hollow-cone pattern. Configuration C1 had a pair of E1 emitters spraying in a vertical plane and installed between two trees at 1.5 m above ground level (AGL). Another E1 emitter spraying in a horizontal plane was mounted atop each tree at 3.3 m AGL. Configurations C2 and C4 had emitters (E2 and E4, respectively) mounted atop each tree at 3.3 m AGL, and C3 had a pair of E3 emitters installed in a three-tier arrangement between two trees in the crop row. During field trials, a tree canopy about 3.0 m tall was divided into three zones (0 to 1.4 m, >1.4 to 2.2 m, and >2.2 to 3.0 m AGL) as bottom, middle, and top canopy zones, respectively. Mylar cards were used to quantify spray deposition using fluorometry, and water-sensitive papers (WSPs) were used to quantify coverage using image processing. Configuration C3 with 80° hollow-cone nozzles in a twin-emitter, three-tier arrangement had the highest overall spray deposition (581.1 ±77.8 ng cm-2, mean ± standard error) and coverage (18.4% ±4.1%). Moreover, C3 also had a significantly higher coverage on the abaxial surfaces of leaves compared to the other configurations. Configurations C1 was non-optimal because it lacked abaxial surface coverage as the canopy grew in the middle and late growth stages. Moreover, significant spray runoff from leaf surfaces was observed visually in the middle zone for C1 during the middle and late stages. This may be attributed to canopy growth around the emitters. Configurations C2 and C4, with emitters in a shower-down arrangement, had the highest deposition and coverage in the top canopy zone compared to the middle and bottom zones. Configurations C2 and C4 also had significantly higher spray coverage on the adaxial surfaces of leaves compared to the abaxial surfaces. Overall, despite the complex design of configuration C3 with six emitters per tree, it may be the most ideal arrangement for agrochemical application in an apple orchard trained in tall spindle architecture. For commercial feasibility, we recommend exploring this three-tier SSCDS configuration with low-cost emitter alternatives. Pertinent continuing efforts have been published by our group in which we successfully modified low-cost irrigation emitters, and the resulting three-tier SSCDS configurations had improved spray performance over expensive hollow-cone nozzles. Keywords: Fixed spray system, High-density apple orchard, Solid set canopy delivery system, Spray coverage, Spray deposition, SSCDS.


The proper usage of water is essential in irrigation because of the shortage of water. The shortage of water is due to lack of rain and continuous supply of water for irrigation as a result lot of water got wasted. It is very much essential to manage the use of water efficiently. The main objective in this project is to watering crops automatically by monitoring soil moisture for supply water based on the requirement and to maintain the water level in the overhead tank. This system suits for all climatic conditions. This project proposed on the usage of automatic irrigation system based on Arduino board, soil moisture sensor, float switch and solar panel. This automatic irrigation system senses the moisture content of the soil and automatically switches the solenoid valve and the overhead water level is monitor by float switch sensor and the power the required for the entire system is generated by using the solar panel. It will automatically control the water level in the tank also. The Global system for mobile communication (GSM) module sends the message, whenever the valve is turn ON and OFF. This project is fully automatic to support farmers, provides water as required, deploys renewable energy, minimize man power, less space, low cost and user friendly.


2021 ◽  
Vol 13 (5) ◽  
pp. 2836
Author(s):  
Khawar Shahzad ◽  
Muhammad Sultan ◽  
Muhammad Bilal ◽  
Hadeed Ashraf ◽  
Muhammad Farooq ◽  
...  

Poultry are one of the most vulnerable species of its kind once the temperature-humidity nexus is explored. This is so because the broilers lack sweat glands as compared to humans and undergo panting process to mitigate their latent heat (moisture produced in the body) in the air. As a result, moisture production inside poultry house needs to be maintained to avoid any serious health and welfare complications. Several strategies such as compressor-based air-conditioning systems have been implemented worldwide to attenuate the heat stress in poultry, but these are not economical. Therefore, this study focuses on the development of low-cost and environmentally friendly improved evaporative cooling systems (DEC, IEC, MEC) from the viewpoint of heat stress in poultry houses. Thermodynamic analysis of these systems was carried out for the climatic conditions of Multan, Pakistan. The results appreciably controlled the environmental conditions which showed that for the months of April, May, and June, the decrease in temperature by direct evaporative cooling (DEC), indirect evaporative cooling (IEC), and Maisotsenko-Cycle evaporative cooling (MEC) systems is 7–10 °C, 5–6.5 °C, and 9.5–12 °C, respectively. In case of July, August, and September, the decrease in temperature by DEC, IEC, and MEC systems is 5.5–7 °C, 3.5–4.5 °C, and 7–7.5 °C, respectively. In addition, drop in temperature-humidity index (THI) values by DEC, IEC, and MEC is 3.5–9 °C, 3–7 °C, and 5.5–10 °C, respectively for all months. Optimum temperature and relative humidity conditions are determined for poultry birds and thereby, systems’ performance is thermodynamically evaluated for poultry farms from the viewpoint of THI, temperature-humidity-velocity index (THVI), and thermal exposure time (ET). From the analysis, it is concluded that MEC system performed relatively better than others due to its ability of dew-point cooling and achieved THI threshold limit with reasonable temperature and humidity indexes.


2019 ◽  
Author(s):  
Johannes Brändle ◽  
Norbert Kunert

Abstract Tree autotrophic respiratory processes, especially stem respiration or stem CO2 efflux (Estem), are important components of the forest carbon budget. Despite the efforts to investigate the controlling processes of Estem in the last years a considerable lack in our knowledge remains on the abiotic and biotic drivers affecting Estem dynamics. It has been strongly advocated that long-term measurements would shed light into those processes. The expensive scientific instruments needed to measure gas exchange has prevented from applying Estem measurements on a larger temporal and spatial scale. Here, we present an automated closed dynamic chamber system based on inexpensive and industrially broadly applied CO2 sensors reducing the costs for the sensing system to a minimum. The CO2 sensor was cross-calibrated with a commonly used gas exchange system in the laboratory and in the field, and we found very good accordance of these sensors. We tested the system under harsh tropical climatic conditions, characterized by heavy tropical rainfall events, extreme humidity, and temperatures, in a moist lowland forest in Malaysia. We recorded Estem of three Dyera costulata trees with our prototype over various days. The variation of Estem was large among the three tree individuals and varied by 7.5-fold. However, clear diurnal changes in Estem were present in all three tree individuals. One tree showed high diurnal variation in Estem and the relationship between Estem and temperature was characterized by a strong hysteresis. The large variations found within one single tree species highlights the importance of continuous measurement to quantify ecosystem carbon fluxes.


2020 ◽  
Vol 13 (1) ◽  
pp. 144
Author(s):  
Dianxi Zhang ◽  
Muhammad Safdar Sial ◽  
Naveed Ahmad ◽  
António José Filipe ◽  
Phung Anh Thu ◽  
...  

Water scarcity is rising as a global issue, because the planet earth is facing a global water crisis, which is considered something that can destroy environmental sustainability of our planet. The fact is that humanity’s demand is depleting natural resources faster than nature can replenish itself; if human habits and unsustainable use of water resources do not change, water scarcity will inevitably intensify and become a major cause of conflict among different nations of the world. The water scarcity issue is a crucial issue but unfortunately it has not received due attention in past. Pakistan, which once was a water abundant country, now facing a situation of water scarcity. Pakistan has a poor irrigation system which results 60% loss of its water; Pakistan uses more water for crop production than other countries. Likewise, the country harvests water from rainfall, rivers, snow, and glaciers. The country is facing a serious water crisis that is caused by different factors, such as changing climatic conditions, rising population, poor irrigation system, poor political will, and rapid urbanization. The water crisis of Pakistan is expected to worsen in coming years. This is a drastic situation which calls for emergency measures. With this background, the present study provides a detailed view of the water situation in the country with challenges to water management. The study also suggests some recommendations for policymakers to improve the water crisis situation in the future.


2021 ◽  
Author(s):  
◽  
Matt Cryer

<p>Colloidal semiconductor nanocrystals (NCs) with bandgaps less than 1 eV allow the development of mid wave infrared (MIR) sensitive detectors that exploit the benefits of colloidal materials, primarily bandgap selection and solution deposition. Additionally, the electrical behaviour of these films can be examined for characteristics that can increase the functionality of NC based detectors.  The production of devices that are designed to be competitive as ultra-low-cost, room temperature MIR detectors, operating with photonic, rather than thermal detection is detailed. The evolution of the colloidal synthesis, spray deposition methods, substrate materials and post deposition treatments used here lead to highly robust and high performing devices. These devices demonstrate a “colour” sensitivity down to 300 nm in the MIR (≈10 % of scale), with superior responsivities for this class of device, up to 0.9 AW⁻¹, and competitive specific detectivity up to 8 × 10⁹ Jones at 200 Hz and 300 K. Furthermore, these devices utilise a cheap and robust substrate material that allows operation after deformation up to 45 ° without degradation over many cycles. These devices offer a template for ultra-low-cost MIR detectors with performance that rivals microbolometers but with better measurement speed and spectral sensitivity. As such these devices showcase the key advantages of using colloidal NCs in MIR applications.  Planar and fully air processed thin film devices that demonstrate photo-induced memristive behaviour and can be used as a transistors, photode-tectors or memory devices are investigated. Following long term (60 h) air exposure, unpackaged NC films develop reliable memristive characteristics in tandem with temperature, gate and photoresponse. On/off ratios of more than 50 are achieved and the devices show long term stability, producing repeatable metrics over days of measurement. The on/off behaviour is shown to be dependent on previous charge flow and carrier density, implying memristive rather than switching behaviour. These observations are described within a long term trap filling model. This work represents an advance in the integration of NC films into electronic devices, which may lead to the development of multi-functional electronic components.  Building on the previous work the steps taken to move from a planar device, that works well in controlled conditions, to a multi-pixel sensor that can demonstrate MIR video imaging at room temperature in a noisy environment are shown. This is achieved with a 15 pixel detector that consists only of a polymer substrate and solution patterned NC pixels. This device can detect a 373 K object with the device at 298 K in a noisy environment. This performance is enabled by photogain at 5 V bias that reaches a maximum External Quantum Efficiency (EQE) of 1940 ± 290 % for a pixel with a 3.3 µm bandgap. Through the use of four separate bandgaps it is shown that “multicolour” thermal imaging systems can deliver another layer of information, on top of intensity, to the user. The behaviour of the system is examined under use and it is shown that the photoconductive device behaves as expected with regards to bias, and that trap enabled gain is sensitive to total incident flux, more than the spectral energy distribution of the target. Finally, it is shown that solution patterned QD fabrication methods can deliver electrical reproducibility between pixels that is sufficient to allow an imaging plane of multiple pixels.  The somewhat neglected tin chalcogenide semiconductor nanocrystals are investigated and inverse MIR detection at room temperature is demonstrated with planar, solution and airprocessed PbSnTe and SnTe QD devices. The detection mechanism is shown to be mediated by an interaction between MIR radiation and the vibrational stretches of adsorbed hydroxyl species at the oxdised NC surface. Devices are shown to possess mAW⁻¹ responsivity via a reduction in film conductance due to MIR radiation and, unlike classic MIR photoconductors, are unaffected by visible wavelengths. As such these devices offer the possibility of MIR thermal imaging that has an intrinsic solution to the blinding caused by higher energy light sources.  In summary, it is shown that semiconductor NCs with an all ambient fully solution processed deposition and ligand exchange procedure can be used to create simple, robust and cheap devices that are beginning to demonstrate metrics on par with current commercial thermal detector systems. It is also shown that these devices can under certain circumstances demonstrate novel behaviours that offer the prospects of enhanced or novel functionality.</p>


2021 ◽  
pp. 15-23
Author(s):  
V. F. Pivovarov ◽  
A. V. Soldatenko ◽  
O. N. Pyshnaya ◽  
L. K. Gurkina

The article reflects the issues of the current state of scientific research at the FSBSI FSVC, shows the directions and prospects for the development of selection and seed production of vegetable crops. The main mission of the selection and seed-growing work of the FSVC is the creation and reproduction of varieties and hybrids of vegetable and melon crops of a new generation, characterized by resistance to abiotic and biotic stressors, high productivity and product quality. One of the main ways to increase the efficiency of the breeding process is the use of modern methods of biotechnology and molecular genetics, which make it possible to obtain new genotypes and reduce the time of breeding. Success has been achieved in the creation of homozygous lines of cabbage, squash, cucumber, carrots. For the first time, it was possible to complete a full cycle of obtaining doubled radish haploids in microspore culture in vitro. The institution pays special attention to immunological research on the resistance of crops and new varieties to diseases, as well as protecting plants from pests and diseases. Phytosanitary monitoring, assessment and selection of resistant genotypes are carried every years. One of the important theoretical and practical problems solved at the institution is the development of environmentally friendly products based on preparations obtained from plants with a high content of biologically active compounds with adaptogenic properties. In the center, a new direction of research in traditional breeding has received significant development - the creation of varieties of vegetable plants with an increased content of biologically active substances and antioxidants, on the basis of which functional products are created. The persistence of modern varieties and hybrids of table carrots, depending on the biochemical composition, has been studied. Methods for enriching vegetable plants with micronutrients are being developed. A large amount of scientific research is being carried out on the development of technologies for the cultivation of new varieties and hybrids, as well as technologies for their seed production. At the branches located in different soil and climatic conditions, hospitals were established to study the interaction of factors controlling soil fertility and the productivity of vegetable crops in agrocenoses (crop rotation, soil treatment systems, fertilizers and plant protection). In general, at the FSBSI FSVC, all research is aimed at developing and improving methods in breeding and seed production of vegetable crops, creating new breeding achievements and developing varietal technologies for their cultivation.


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