Spray Frequency Research Articles

Faktor yang Berhubungan dengan Perilaku Petani Padi dalam Penggunaan Pestisida di Desa Muara, Cilamaya Wetan Kabupaten Karawang

Unwise use of pesticides can cause residues that are harmful to human health and have a negative impact on the environment. Factors related to farmers' behavior can be one of the key determinants of how far they understand and implement safe, sustainable pesticide use practices. The study aims to analyze the factors associated with the behavior of peasants in Muara village, Cilamaya Wetan district, Karawang district. Behavior includes knowledge, attitudes, and actions consisting of aspects of pesticide type, dosage, time, spray frequency, self-protection, pesticides application techniques, and compliance with instructions for use. The research was conducted from September to October 2023. Sampling proportionate stratified random sampling obtained 85 respondents. Data collection techniques include observations, tests, questionnaires, and interviews. The study used a survey method using Spearman Rank analysis. Data were analyzed using validity tests, reliability tests, quantitative descriptive analysis, and Spearman Rank correlation tests. The results of the research showed that the factors associated with the behavior of wildfish farmers in the use of pesticides were land area (X3) with a correlation of 0.239, farming experience (X4) with the correlations of 0.258, and perception of pests and plant diseases (X7) with a correlation of 0,233. Whereas education (X1), income (X2), social involvement (X5), as well as the role of the farmer (X6) had no significant correlation with farmers' behaviour in pesticide use.

Evaluating the Efficacy of Insecticide on the Management of Onion Thrips (Thrips tabaci, Lindemann) in Northwestern Zone of Tigray

Ethiopia has enormous potential to produce the onions throughout the year both for domestic use and export market. It is also the most cultivated and high market value of vegetable crops in Tigray Northern Ethiopia. However, the productivity of onion is highly constrained such as insect pests, diseases, lack of improved verities, lack of improved management practices etc. The major insect pest of onion is Onion thrips and important pests especially in areas where onions are grown under irrigation. The purpose of this study was to test the insecticide chemicals application and application frequency on the Onion production technologies. Therefore, field experiment was conducted to evaluate the insecticide chemical applications with frequency application in 2017 and 2018 under irrigation conditions. Thirteen treatments were used three different insecticide types namely Karatae 5% EC, Dimethote 40%EC, Profit72%EC with four different spraying frequency and untreated (control) laid out in Randomized Complete Block Design (RCBD) with three replications. The current findings showed that the profitable yield was obtained Karatae 5% EC (1st spray) (14.25 t ha-1) followed by Profit72%EC (4th spray) that is (20.25 t ha-1) and the obtained profit was 128053 &181788 birr per ha with the maximum Marginal Rate of Return of 3025 & 2417% respectively in Tselemti woreda. In Medebaayzana woreda also, the profitable yield was obtained Karatae 5% EC (1st spray) (25.79 t ha-1) followed by Karatae 5% EC (4st spray) at (27.75 t ha-1) & Dimethote 40% EC (3rd spray) at (25.78 t ha-1) and 231976, 249463 & 231544 birr per ha obtained profit with the maximum Marginal Rate of Return of 2634, 2395 & 2311 % respectively. Therefore, Karatae 5% EC (1st spray) in Tselemti & Medebayzana woreda & Profit72%EC (4th spray) in Tselemti woreda and Dimethote 40% EC (3rd spray) in Medebayzana woreda was profitable preventive Onion Thrips for Onion production in the studies area.

Coconut Growers: Challenges Faced and Solutions Proposed

Aim: To analyse the challenges faced by the coconut growers and suggestion to overcome. Research Design: Ex-post facto research design. Sample: Coconut growers of Coimbatore district, Simple random sampling. Methodology: A structured interview schedule was developed to collect the data from 200 respondents. An Ex-post facto research was employed and Simple random sampling technique was used to select the 200 coconut growers. Results: Ninety-eight percent of respondents voiced concerns about their insufficient understanding of various plant protection aspects, including chemicals, spray frequency, symptoms, and application methods. Ninety-two and a half percent of respondents are worried about the toxicity of plan protection to both cattle and humans. Additionally, the lack of nearby repair facilities (89%) and the belief that traditional methods are more effective (87%) add to the difficulties encountered by farmers. Ensuring Fair Market Prices for Produce" ranked highest (88%), showing that farmers prioritize stable prices to secure their income and reduce risks. "Technical Guidance on Coconut Farming" (76%) and "Timely Availability of Quality Inputs at Subsidized Rates" (75%) were also important, indicating the need for ongoing support and reliable inputs from the government.

A comparative study between the efficacy of fertigation and spraying procedures in terms of the content of Cadmium (Cd) and Arsenic (As) in greenhouse cucumber.

A comparative study between fertigation and spraying procedures in terms of the status of Cadmium (Cd) and Arsenic (As) in greenhouse cucumber was conducted as a two-factor split plot based on a randomized complete block design with three replications at the Soil and Water Research Institute, Karaj, Iran in 2023. The main and sub-factors were respectively fertigation and spraying that were used in two levels [the maximum permissible concentration of Cd and As in granular triple super phosphate fertilizer (25ppm Cd and 50ppm As) and the minimum permissible concentration of these metals in granular triple super phosphate fertilizer (5ppm Cd and 5ppm As)]. Spraying was done in three modes (spraying of leaves, leaves and fruit, and fruit). On average, the results showed that the order of the concentration of Cd in plant tissues (DW) was as leaf (0.284mg/kg) > fruit peel (0.102mg/kg) > fruit peel + flesh (0.054mg/kg) > fruit flesh (0.044mg/kg). This order for As was as leaf (0.608mg/kg) > fruit flesh (0.127mg/kg) > fruit peel + flesh (0.109mg/kg) > fruit peel (0.072mg/kg). Based on the measurements, the spraying procedure accumulated more amounts of Cd and As in the fruit (i.e., peel + flesh) than the fertigation procedure. In general, it is concluded that under soilless culture, the status of heavy metals in plant tissues of greenhouse cucumber is related to the nature of the metal, the organ exposed to the metal, and the fertilization procedure. Because there is the risk of contamination of vegetables grown in the areas fertigated and sprayed with poor-quality nutrient solutions in terms of the content of heavy metals, the frequency of fertigation and spraying needs to be monitored continuously for the quality of the vegetables cultivated in greenhouses.

Determinan Pajanan Pestisida Terhadap Kadar Haemoglobin Wanita Usia Subur (WUS) di Kecamatan Dempo Selatan Pagar Alam

Women of childbearing age are a group that plays an important role in the agricultural sector not only in Indonesia but also in other agricultural countries around the world. The types of agricultural activities undertaken by WUS are sometimes the same as those of men, even those that allow contact with pesticides. Women of childbearing age in Pagaralam are at risk of experiencing health effects such as anemia, due to their exposure to Organophosphates. It is necessary to conduct research aimed at analyzing the determinants of pesticide exposure to the haemoglobin level in WUS as a basis for recommendations for efforts to prevent and overcome the effects of pesticide exposure. The design of this study was observational with a cross sectional study approach. The study population was women of childbearing age who were exposed to pesticides in the South Dempo District of Pagaralam, with a sample size of 120 WUS. Sampling using cluster sampling technique. Data collection was carried out through interviews using a questionnaire, observation using a checklist, measurement of body weight using a weight scale, height using a microtoise, and Hb levels using the Easy Touch GCHB tool. Data analysis of the results of the study was carried out univariately, and bivariate using the Chi- Square.The results of bivariate analysis of variables show that were significant with the haemoglobin level in women of childbearing age in South Dempo District were tenure, long time laundry spraying and length of time preparing pesticide. While variables that are not associated with haemoglobin levels are length of spraying, length of time mixed, frequency of spraying, and use of PPE. It is recommended that women of childbearing age reduce the length of time washing clothes spraying and the length of time preparing pesticides through good time management. Keywords : Haemoglobin level, pesticide exposure, woman of childbearing age

Determination of the rate and frequency of Natura 250 EW fungicide for the management of cedar rust from Gesho (Rhamnus prinoides) in the north west Amhara Region, Ethiopia

Rhamnus prinoides (Gesho) is grown in the homesteads of farmers in western Amhara. The leaves, twigs, and stems of Gesho are indispensable ingredients in traditional beverages. Its production has recently suffered from cedar rust caused by the fungus Gymnosporangium. To manage this disease, different fungicides have been recommended. Therefore, this research was designed to determine the rate and frequency of the use of the Natura 250 EW system for managing this disease in Gesho during 2020. Five application rates of Natura 250 EW and three spray frequencies were used as treatments to manage the disease in infected Gesho plants via the Randomized Complete Block Design (RCBD). Statistically significant differences (P ≤ 0.05) were found between treatments for most parameters. Among these 0.75 litter ha-1 treatments, two spray applications resulted in the lowest severity and greatest relative efficacy, followed by three spray applications of 0.50 litter ha−1 at Bahir Dar Zuria district. However, at Yilmana Densa district, the lowest severity and greatest relative efficacy were found for the 0.75 litter ha−1 spray, followed by the 0.50 litter ha−1 spray, compared with the other treatments. Even though 0.75 litter ha−1 had greater relative efficacy and lower disease severity than the other treatments, there was no statistically significant difference between the three sprays of 0.50 litter ha−1 at both locations. Therefore, three sprays of Natura 250 EW at 0.50 litter ha−1 in 15-day intervals should be recommended and demonstrated for the management of cedar rust disease on Gesho.

Optimizing Insecticide Application: Evaluating Frequency and Timing for Effective Management of Pink Bollworm Infestation

The pink bollworm (Pectinophora gossypiella), a significant pest affecting cotton crops, necessitates an optimized approach to insecticide application. This study investigates the critical factors of frequency and timing in insecticide application to enhance the efficacy of pest control measures. An experiment conducted at the Main Agricultural Research Station (MARS), University of Agricultural Sciences Raichur, focused on managing pink bollworm in Bt cotton using newer insecticides registered for cotton. Various spray frequencies and intervals were tested as part of an ETL (Economic Threshold Level) and prophylactic spray regimen. The results indicated that the treatment T1, which involved four sprays of profenofos 50 EC, chlorantraniliprole 18.50 SC, emamectin benzoate 5 SG, and bifenthrin 10 EC at 65, 80, 95, and 110 days after sowing (DAS), respectively, showed the lowest incidence of pink bollworm larvae, green boll damage, bad boll opening, locule damage, and the highest rate of good boll opening. This performance was comparable to treatment T5, which followed the same spraying schedule but with spinetoram 11.70 SC and fenpropathrin 10.00 EC instead of emamectin benzoate and bifenthrin, and treatment T9, which employed an ETL-based spray schedule using chlorantraniliprole 9.3 + lambda-cyhalothrin 4.6 ZC. Similarly, the highest yield of seed cotton was obtained from treatment T1 (18.10 q/ha), which was statistically equivalent to treatments T5 (18.12 q/ha) and T9 (18.10 q/ha). Additionally, the cost-benefit analysis revealed the highest benefit-cost ratio in treatment T1 (1.55), followed by treatments T9 (1.46) and T5 (1.44).

Mild Cognitive Impairment Associated with Pesticides use Among Vegetable Farmers and Their Wives in Sukorambi Village Jember Regency

Introduction: Mild Cognitive Impairment (MCI), according to several studies, has been discovered to be related to exposure to pesticides. Sukorambi Village is the largest vegetable producer village in Jember Regency and pesticides are used in the vegetable cultivation process. This study aimed to analyze the relationship between the age of vegetable farmers and the frequency of pesticide spraying with the incidence of MCI and to analyze differences in the incidence of MCI in farmers and their wives. Methods: This research is an analytical research with a cross-sectional design which was carried out in Sukorambi Village, from June to December 2022. The samples of this research are 142 people, obtained from a proportional stratified random sampling technique and represented groups of farmers in each hamlet. In this case, the research variables include age, frequency of pesticide spraying, as well as the incidence of MCI in vegetable farmers and their wives. Data were further collected through direct interviews, which were then analyzed through bivariate analysis using Spearman and paired t tests. Results: The results showed that the majority of vegetable farmers were above 55 years old and most of them sprayed pesticides for 3-4 and 5-6 times a month. Most farmers and their wives experience MCI. Conclusion: The farmer's age and the frequency of spraying pesticides are related to the incidence of MCI in farmers. There is a significant difference between the incidence of MCI in vegetable farmers and their wives, where MCI is more experienced by vegetable farmer wives.

A Preliminary Study of The Javan Leopard Behaviour in Meru Betiri National Park

Meru Betiri National Park (MBNP, 526km2), is one of only three protected areas in east Java that can support a viable Javan leopard population. The Javan leopard has become a priority for management following the extinction of the Javan tiger. Therefore, it is important to know how the Javan Leopard behaves to improve species management. We conducted a field study using camera traps to determine the daily behavior of the Javan leopard in MBNP. A monitoring site was established with 73 stations, with a density of one station per 0.5 x 0.5 km grid cell, providing different but comparable densities and spatial coverage. The results indicate that the Javan leopard displays 9 daily behaviors including walking, observing, standing, cheek rubbing, scraping, urine spraying, claw marking, parenting, vocalizing, and others. Each behavior was observed with a relative frequency of walking (63.25%), observing (14.53%), standing (7.69%), cheek rubbing (5.98%), scraping (4.27%), urine spraying (1.71%), claw marking (0.85%), parenting (0.85%) and vocalizing (0.85%). An analysis of the time spent on each behavior revealed their proportion as follows: walking (382 s, 49.29%), watching (208 s, 26.84%), standing (66 s, 8.52%), cheek rubbing (27 s, 3.48%), scraping (57 s, 7.35%), urine spraying (17 s, 2.19%), vocalizing (9 s, 1.16%), claw marking (4 s, 0.52%) and parenting (5 s, 0.65%).

Spatial and temporal analysis on the impact of ultra-low volume indoor insecticide spraying on Aedes aegypti household density

BackgroundAedes aegypti is the primary mosquito vector for several arboviruses, such as dengue, chikungunya and Zika viruses, which cause frequent outbreaks of human disease in tropical and subtropical regions. Control of these outbreaks relies on vector control, commonly in the form of insecticide sprays that target adult female mosquitoes. However, the spatial coverage and frequency of sprays needed to optimize effectiveness are unclear. In this study, we characterize the effect of ultra-low-volume (ULV) indoor spraying of pyrethroid insecticides on Ae. aegypti abundance within households. We also evaluate the effects of spray events during recent time periods or in neighboring households. Improved understanding of the duration and distance of the impact of a spray intervention on Ae. aegypti populations can inform vector control interventions, in addition to modeling efforts that contrast vector control strategies.MethodsThis project analyzes data from two large-scale experiments that involved six cycles of indoor pyrethroid spray applications in 2 years in the Amazonian city of Iquitos, Peru. We developed spatial multi-level models to disentangle the reduction in Ae. aegypti abundance that resulted from (i) recent ULV treatment within households and (ii) ULV treatment of adjacent or nearby households. We compared fits of models across a range of candidate weighting schemes for the spray effect, based on different temporal and spatial decay functions to understand lagged ULV effects.ResultsOur results suggested that the reduction of Ae. aegypti in a household was mainly due to spray events occurring within the same household, with no additional effect of sprays that occurred in neighboring households. Effectiveness of a spray intervention should be measured based on time since the most recent spray event, as we found no cumulative effect of sequential sprays. Based on our model, we estimated the spray effect is reduced by 50% approximately 28 days after the spray event.ConclusionsThe reduction of Ae. aegypti in a household was mainly determined by the number of days since the last spray intervention in that same household, highlighting the importance of spray coverage in high-risk areas with a spray frequency determined by local viral transmission dynamics.Graphical abstract

Anggapan Pestisida Sebagai Obat Bagi Petani Bawang Merah Di Kabupaten Solok Dan Konsekwensinya Pada Lingkungan

Increasing shallot production in Lembah Gumanti District, Solok Regency, is very dependent on the use of pesticides. Farmers seem to view pesticides as plant healing medicines rather than dangerous poisons. This research aims to determine farmers' perceptions about pesticides, and farmers' behavior in using pesticides and their influence on public health risks. The research was conducted in Nagari Sungai Nanam, Lembah Gumanti District, Solok Regency. The research uses descriptive qualitative research methods combined with a quantitative approach. Data collection techniques using questionnaires and interviews with a sample of 98 shallot farmers were selected using simple random sampling. The research results show that the majority of farmers have a positive perception of pesticides, viewing them as poisons that are dangerous but beneficial if used according to the rules. Most farmers have positive behavior in terms of knowledge, attitudes and actions, such as choosing the type of pesticide, spraying time, paying attention to the weather, using personal protective equipment and disposing of pesticide packaging. Negative behaviors such as excessive dosage and high spraying frequency are still found. Farmers' positive behavior has a good impact on the environment, especially reducing the risk of poisoning. The impacts of pesticide use such as dizziness/nausea/skin irritation were never felt by respondents who used complete PPE (52%), and some always experienced these impacts (4%). The use of pesticides according to regulations has never had an impact on respondents (53%). The use of pesticides has quite an impact on health risks and the sustainability of environmentally friendly agriculture

Assessing the Impact of Integrated Dogwood Disease Management Practices on Labor Needs and Production Costs in Tennessee Nurseries

Early and accurate detection of diseases, and implementation of efficient disease management practices are crucial to reducing the economic impact associated with plant disease outbreaks. Based on survey responses from dogwood nursery growers in Tennessee, USA, scouting was identified as an important disease management practice adopted by a majority of growers for disease management in field-grown, container-grown, and pot-in-pot production systems. Our results show a significant positive correlation between disease severity and scouting frequency for dogwood plants grown in container and pot-in-pot production systems. Our efficiency measure is a self-rated efficacy scale perceived by the nursery growers about their existing disease management system in nursery plants. A significant positive correlation was found between the efficacy of disease management and the number of workers involved in scouting and a negative association between the worker hours spent in scouting and the grower's experience/exposure to other disease detection methods. The majority of nursery growers followed a set spray schedule between May and October, with applications scheduled every other week. In addition, our results showed significant positive correlations between efficacy and spray-related factors, such as disease severity and worker hours spent in spraying; efficacy of disease management and spraying frequency in field-grown dogwoods; and foliar spray costs and efficacy of disease management. We estimated ≈$379/acre per year average costs for dogwood disease management, which the growers find to be one of the major components of the dogwood production budget. Moving to automated systems of disease scouting and management has the potential to reduce the cost of these labor-intensive disease management practices of dogwood production.

Comparison of Insecticide Sprays in Alternate Rows and in All Rows on Asian Citrus Psyllid Control and Huanglongbing Progress in Sweet Orange Orchards.

One strategy to reduce huanglongbing (HLB) is controlling its insect vector, the Asian citrus psyllid (ACP) Diaphorina citri, by preventive insecticide sprays. The recommendation is to spray insecticide in all rows (conventional spray [CONV]), but some growers empirically spray in alternate rows (ALT) to increase the spray frequency without increasing the operating cost. Therefore, this work compared the effect of ALT with CONV on the ACP population and HLB incidence. The spray deposition (amount of metallic copper per leaf area), coverage (percentage of water-sensitive paper area covered by spray), and efficacy (ACP mortality) of each treatment were also evaluated on both sides of the trees. Two field trials were performed: Trial #1 compared ALT every 7 days (ALT7) with CONV every 14 days (CONV14), and trial #2 compared different spray frequencies of ALT with CONV every 7 days (CONV7). In trial #1, no differences were observed in the ACP population or HLB progress between ALT7 and CONV14 after 5 years. In trial #2, ALT7 presented the highest percentage of ACP and cumulative HLB incidence than CONV7 and ALT every 3 to 4 days, after 2 years. Hence, when the frequency of ALT was half the frequency of CONV, similar results were observed. Spray deposition, coverage, and efficacy were similar between tree sides in CONV, but they were uneven in ALT, resulting in higher values on the tree side that directly received the spray. Insecticide spray should be performed with the frequency enough to keep new shoots protected during their growth.

Experimental investigation of the intermittent spray heat transfer characteristics of nanofluids in single- and two-phase states

Traditional air-cooled cooling systems used in engineering vehicles consume significant energy and do not align well with future development trends. To address this problem, a single- and two-phase intermittent spray cooling technique for nanofluids was proposed in this study. The effects of the duty cycle and spray frequency on the heat transfer performance and surface temperature uniformity of intermittent spray were determined by experiments, and the thermal behaviour of intermittent spray with different mass fractions of Al2O3 nanofluids was compared in detail. The results revealed that when the spray frequency is constant, the heat transfer coefficient increases with an increase in duty cycle, but the cooling efficiency decreases. The spray frequency mainly affects the average heat transfer surface temperature and its uniformity. At 2.0 Hz, nanofluids with a mass fraction of 0.7 % exhibited the best intermittent spray performance, with an average heat transfer coefficient of 431.8 W/(m2·K). However, a continuous increase in the mass fraction of the nanofluids inhibited the heat transfer performance. The impact of droplets on the heat transfer surface, the liquid film heat transfer process, and the heat transfer characteristics of the nanofluid intermittent spray in the single- and two-phase states were further studied. The results revealed that the heat transfer of intermittent spray mainly depends on the properties and flow rate of the coolant in a single-phase state. Although the heat transfer performance of intermittent spray is evidently enhanced in the two-phase state, it still does not exceed that of continuous spray. These findings highlight the flexibility of nanofluid intermittent spray cooling in enhancing heat transfer control and can inform the development of energy-saving and intelligent cooling systems for engineering vehicles.

Impact of Commercial Beauveria bassiana Application on Cucumber (Cucumis Sativus L.) Insect Pests, Pollinator Densities and Some Growth and Fruit Parameters

A field trial was conducted in 2021 and 2022 at the Experimental Farm, Federal University of Agriculture, Abeokuta to establish the bio-efficacy of Beauveria bassiana on the abundance of pests, beneficial insects, agronomic characteristics, storability and fruit quality of cucumber. The experiment was designed using a 4 x 3 factorial arrangement in a Randomized Complete Block Design and replicated three times. The treatment comprised four Beauveria bassiana (FIXITGA ™) concentrations (8.00, 6.00, 4.00 and 2.00 kg/ha) applied at three different spray frequencies (spray once a-week, once in two-weeks and once in three-weeks) along with the untreated control. The results indicated that the densities of Aulacophora hilaris, Epilachna chrysomelina, and Bactrocera cucurbitae were significantly reduced in B. bassiana-sprayed plots compared to unsprayed ones in both seasons. Higher densities (6.33 and 5.33) of Apis mellifera were observed in plots sprayed at 8.00 kg/ha once a week than the unsprayed plots (2.00 and 0.33). The agronomic traits significantly increased when B. bassiana was sprayed once a- week at a concentration of 8.00 kg/ha compared to other treatments. At 8.00, 6.00, and 4.00 kg/ha of B. bassiana applied once a week, cucumber fruits showed an extended shelf life, lasting between 13 to 15 days before deterioration. In contrast, cucumber fruits sprayed at 2.00 kg/ha and untreated plots deteriorated faster, within 1 to 3 days. Furthermore, the nutritional composition of fruits from the untreated plots was comparable to that of fruits from the treated plots.

Performance Development of Fluidic Oscillator Nozzle for Cleaning Autonomous-Driving Sensors

Contaminated autonomous-driving sensors frequently malfunction, resulting in accidents; these sensors need regular cleaning. The autonomous-driving sensor-cleaning nozzle currently used is the windshield-washer nozzle; few studies have focused on the sensor-cleaning nozzle. We investigated the flow characteristics of the nozzle to improve its performance in cleaning the autonomous-driving sensor. The nozzle concept was based on the fluidic oscillator nozzle. Various performance parameters of the fluidic oscillator nozzle were selected and investigated. Transient fluid flow was simulated to determine the effect of the design parameters to maximize the oscillation flow phenomenon. Additionally, the spray angle and frequency were calculated. Analysis results showed that the change in flow speed affects the frequency, and the change in feedback-channel-inlet flow rate affects the angle change. To verify the simulation result, the three best models (R4+RC10, R6+RC11, R8+RC10) and the base model were manufactured and tested. The test results were consistent with the simulation results within a 6% error.

FAKTOR-FAKTOR YANG BERHUBUNGAN DENGAN KEJADIAN HIPERTENSI PADA PETANI PADI DI DESA PRAJEGAN KECAMATAN SUKOREJO KABUPATEN PONOROGO

The application of pesticides in agriculture can have an impact in environmental quality and cause health problems for farmers. Prajegan Village is one of the villages that uses a large amount of pesticides and the highest cases of hypertension in Sukorejo District. The aimed of this study was to find out the factors related to the incidence of hypertension among paddy farmers in Prajegan Village, Sukorejo District, Ponorogo Regency. This type of study was analytic observational with a cross-sectional design. The total population in the research was 718 paddy farmers. The sample in this study was 97 paddy farmers who was taken by purposive sampling. The data were collected using a questionnaire and sphygmomanometer. The results showed that as many 58 farmers (59.8%) had hypertension, low education level was found in 67 farmers (69.1%), working period >5 years was found in 81 farmers (83.5%), inappropriate pesticide doses were found in 57 farmers (58.8%), risky spraying time was found in 13 farmers (13.4%), the average spraying frequency of 1x/week was found in 66 farmers (68%), and the use of PPE <5 was found in 57 farmers (58.8%). Chi-square test results showed that there is correlation between education level (p= 0.047), working period (p= 0.023), pesticide doses (p = 0.002), the use of PPE (p= 0.023), and there is no correlation between spraying time (p= 0.439) and spraying frequency (p= 1.000). From this study, it can be concluded that the factors related to the incidence of hypertension are education level, working period, pesticide doses, and the use of PPE.

Development of an energy-saving PWM driving method for precision pesticide application using adjustable frequency and characterization of spray

Precise pesticide application is mainly to control the solenoid valve by pulse width modulation (PWM). However, as the number of solenoid valves increases, power consumption and heat generation become significant challenges that impact values the efficiency and lifetime. In this study, an automated pressure monitoring system was constructed and an energy-saving PWM driving method was developed that uses different frequency drive signals during different stages of the solenoid valve operation. The parameters such as power consumption, coil surface temperature rise, opening and closing delays, rise and fall times, activation time, and spray flow characteristics were tested and evaluated. The results showed that this method can significantly reduce the holding current of the solenoid valves, resulting in energy savings of up to 92% and effectively reducing the surface temperature rise. Furthermore, the pattern between flowrate and opening/closing delays was established, with an RMSE of 1.96% in flowrate prediction based on activation time. The developed energy-saving driving method enhances the application potential while the established flowrate model provides valuable insights for precise pesticide application based on PWM technology.

Experimental study on 18650 lithium-ion battery-pack cooling system composed of heat pipe and reciprocating air flow with water mist

Lithium-ion batteries (LIBs) are critical power sources for portable devices, electric vehicles, power grids, and energy-storage systems. Effective thermal management is mandatory for achieving optimal battery performance. Although the air-cooling method has been investigated extensively owing to its simple structure, convenient maintenance, and low cost, it is insufficient for cooling large-scale battery packs because of its limited air-cooling capacity and unsatisfactory temperature uniformity. Thus, a reciprocating spray cooling system comprising a reciprocating air flow channel, heat pipe array, and spray nozzle is proposed herein for the efficient cooling of 18,650 LIB packs. The effects of the inlet air speed, spray frequency, and spray duty cycle on the cooling performance of the reciprocating mist cooling system and the corresponding optimal operating parameter range are analyzed. Additionally, the competitive mechanism between forced air convection and evaporative cooling is discussed. The results indicate that, compared with the case of natural convection cooling, the temperature increment of the battery pack decreases by 32.1 % under reciprocating mist cooling. Meanwhile, the maximum temperature difference reduces to approximately 3.41 °C with 3C of discharge. The spray frequency minimally affects the overall heat dissipation but induces surface temperature fluctuations in individual batteries. Increasing the spray duration per 10 s in a single spray duty cycle can reduce the average temperature of the battery pack by approximately 2 °C. Additionally, the power-allocation scheme affects the heat dissipation of the system. Decreasing the flow rate of spray cooling water and increasing the inlet air speed promote the evaporation of water mist inside the system, thus further improving heat dissipation. This study provides new insights into the design of air-cooled thermal management systems for battery packs.

Biophysical factors and agronomic practices associated with Fusarium ear rot and fumonisin contamination of maize in multiple agroecosystems in Ethiopia

AbstractIn Ethiopia, Fusarium ear rot (FER) reduces yield, quality, and safety of maize and negatively impacts the economics of maize growers. However, there is almost no published information on geographic distribution, severity, or causal agents of FER in Ethiopia or levels of preharvest fumonisin contamination, biophysical factors, and agronomic practices associated with FER. Therefore, we surveyed 480 agricultural fields located in 10 Ethiopian zones to assess the incidence and severity of FER as well as agricultural practices and biophysical factors associated with each field. We also determined the concentration of fumonisin in samples taken from the fields. Results revealed that FER was prevalent with varied disease intensity and yield loss levels among the assessed zones. The highest percent severity index (PSI) was recorded in Mirab Wellega (33.2%), with a correspondingly maximum estimated mean grain yield loss of 13.6%, while the minimum disease severity 11.3% and yield loss 5.4% were recorded from the Ilubabor zone. Fumonisins (FB1, FB2, FB3, and FB4) were detected in 98% of the samples, and the levels ranged from 5 to 7517 μg kg−1 (mean, 540 μg kg−1 and median 82.4 μg kg−1). The mean fumonisin contamination of 1524.4, 1316.8, 744.5, and 742.6 μg kg−1 was recorded for Mirab Welega, Misraq Wellega, Assosa, and Hawassa zones, respectively. In total, about 11.3% of the maize samples exceeded the maximum tolerable total fumonisin limit set by the European Union in maize flour (>1000 μg kg−1) and are not suitable for human consumption. Disease severity highly significantly (p < 0.0001) correlated with biophysical factors such as insect infestation (r = 0.60, p < 0.0001) and weed infestation (r = 0.64, p < 0.0001) and agronomic practices such as nitrogen phosphorus sulfur fertilizer application rate (r = −0.39, p < 0.0001) and insecticide spray frequency (r = −0.55, p < 0.0001). Other agronomic practices such as earlier or later sowing date and inter‐cropping systems significantly reduced (p < 0.001) FER incidence, PSI, and the associated grain yield loss. There was significant (p < 0.0001) variation among maize cultivars currently under production in reaction against FER disease intensity. Moreover, the result of the present study attests a strong positive association (p < 0.001) between disease intensity and maize fumonisin concentrations. Generally, the study revealed a wider distribution of FER and fumonisin contamination of maize in the southwest major maize‐growing belts of Ethiopia. Thus, appropriate integrated pre‐harvest ear rot management strategies including the use of resistant cultivars and suitable agronomic practices are recommended for the management of FER and the associated mycotoxins in Ethiopia.