Approach for Assessing the Prevalence of Psychosocial Risks of Workers in the Greenhouse Construction Industry in South-Eastern Spain.

This paper shows the prevalence of psychosocial risks for workers in the greenhouse construction industry in south-eastern Spain. Method: The assessment of the workers' psychosocial risks was carried out through simple random sampling, which uses a questionnaire containing 13 variables characterizing the companies, 14 variables characterizing the workers, and 15 questions proposed by the Mini Psychosocial Factors (MPFs) risk assessment method. A descriptive analysis and multiple correspondence analysis were performed on the sample data. Results: Greenhouse construction businesses in south-eastern Spain can generally be classified as small companies with an average annual turnover below EUR 2.0 million (69.3%), an average of 22.8 workers with an average age of 39.84 years old, most of whom are married, with an average of 1.76 children. The prevalence of workers at high risk was 2.9%, while 45.1% were at medium-high risk. Of the 12 psychosocial factors assessed using the MPF method, 7 of them presented a high level of worker risk: Mobbing (3.2%), Relationships (1.6%), Recognition (1.6%), Autonomy (12.9%), Emotional (8.0%), Control (4.8%), and Demands (3.2%). Lastly, the variables were grouped into four clusters, showing that larger companies are correlated with a medium (workers over 40 years of age or less than 25 years of age) to high (workers under 25 years of age) risk level in several of the psychosocial factors assessed for workers who are Spanish nationals, while in smaller companies, the workers are usually middle aged (between 25 and 40 years old) and from Eastern Europe or Africa, presenting either a low or high level of risk depending on the psychosocial factors and tasks performed. Impact of the results: The study reveals a lack of prevention management regarding psychosocial risks. Therefore, it is necessary to carry out new prevention programmes that optimise the psychosocial conditions of the workers, involving the workers, employers, and other social agents.

Spray performance assessment of a remote-controlled vehicle prototype for pesticide application in greenhouse tomato crops.

Intensive horticultural production is a sector seeking to provide high-quality foods by means of safe and sustainable procedures in compliance with regulations. This requires improvements in the spraying technologies since currently plant protection products are applied by means of hand-held equipment due to its lower cost and easy maintenance. In order to fulfil these requirements, a remote-controlled vehicle prototype (ROBOT SPRAY) was used. After optimizing the spray profile and the air assistance system of the "ROBOT SPRAY" sprayer in laboratory, its performance using two different nozzle sets (full cone and hollow cone) with and without air assistance was compared with those of a spray gun in a greenhouse tomato crop. The spray deposition on canopy, spray coverage and losses to soil were assessed. The "ROBOT SPRAY" provided better penetration and coverage on the underside of the leaves while no improvement was shown with the use of air assistance. Overall, a higher spray deposition was observed for the full cone nozzles when compared to hollow cone nozzles.

Potential dermal exposure to operators applying pesticide on greenhouse crops using low-cost equipment.

During pesticide application, operators are exposed to chemical products. Dermal exposure has been reported as the principal means of exposure for growers. In the present work, potential dermal exposure (PDE) has been assessed when using new low-cost equipment (a knapsack with a vertical spray boom) and compared to a hand-held spray lance, which is the equipment most widely used by growers in greenhouses. Two sprayers were used, a hand-held spray lance with four twin flat-fan nozzles and a knapsack fitted out with a vertical spray boom containing 3 pairs of twin flat-fan nozzles. Three applications were carried out and compared, one with the spray lance walking backwards (the reference application), and two with the spray boom - the first stopping at the turns and the second with no stopping. The patch method (19 position on the body) and tartrazine (the tracer) were used to assess de PDE. Each application tested was replicated three times. The results show that the knapsack with the vertical boom should not be used walking continuously along the greenhouse rows because the total PDE (1637.12mL 1000L-1) is greater than in the rest of the configurations tested. If the operator stops at the turns for a few seconds, allowing the previously sprayed droplet cloud to dissipate, the level of exposure decreases significantly (324.63mL 1000L-1), providing similar results to the reference application with the spray lance walking backwards (292.25mL 1000L-1).

Mechatronic description of a laser autoguided vehicle for greenhouse operations.

This paper presents a novel approach for guiding mobile robots inside greenhouses demonstrated by promising preliminary physical experiments. It represents a comprehensive attempt to use the successful principles of AGVs (auto-guided vehicles) inside greenhouses, but avoiding the necessity of modifying the crop layout, and avoiding having to bury metallic pipes in the greenhouse floor. The designed vehicle can operate different tools, e.g., a spray system for applying plant-protection product, a lifting platform to reach the top part of the plants to perform pruning and harvesting tasks, and a trailer to transport fruits, plants, and crop waste. Regarding autonomous navigation, it follows the idea of AGVs, but now laser emitters are used to mark the desired route. The vehicle development is analyzed from a mechatronic standpoint (mechanics, electronics, and autonomous control).

Field evaluation of a self-propelled sprayer and effects of the application rate on spray deposition and losses to the ground in greenhouse tomato crops.

BACKGROUND: In the greenhouses of south-eastern Spain, plant protection products are applied using mainly sprayers at high pressures and high volumes. This results in major losses on the ground and less than uniform spray deposition on the canopy. Recently, self-propelled vehicles equipped with vertical spray booms have appeared on the market. In this study, deposition on the canopy and the losses to the ground at different spray volumes have been compared, using a self-propelled vehicle with vertical spray booms versus a gun sprayer. Three different spray volumes have been tested with a boom sprayer, and two with a spray gun. RESULTS: The vehicle with the vertical spray boom gave similar depositions to those made with the gun, but at lower application volumes. Also, the distribution of the vertical spray boom was more uniform, with lower losses to the ground. CONCLUSIONS: The vertical spray booms used in tomato crops improve the application of plant protection products with respect to the spray gun, reducing the application volumes and the environmental risks of soil pollution.