Greenhouse Crops Research Articles

Why are phytoseiid predatory mites not effectively controlling Echinothrips americanus?

The poinsettia thrips, Echinothrips americanus Morgan (Thysanoptera: Thripidae), is a key pest of various ornamental and vegetable greenhouse crops. As current biological control alternatives lack efficiency, applying chemicals remains the dominant control strategy, thereby heavily disturbing the biocontrol-based integrated management of other pests. For a range of other thrips pests, phytoseiid predatory mites have shown to be effective biocontrol agents, being able to overcome the thrips' physical and chemical defense armory. Here, we investigated potential underlying causes for the lack of phytoseiid efficacy in controlling E. americanus. First, we assessed the nutritional value of E. americanus for the predatory mite Amblydromalus limonicus (Garman and McGregor) (Acari: Phytoseiidae) when its physical or chemical defenses were eliminated by freezing the thrips. The phytoseiid could complete its immature development when frozen thrips instars were offered, but not when these were offered alive. Subsequently, we tested whether adult female A. limonicus had a higher predation rate on first instar E. americanus when they had been given experience with either live or frozen E. americanus during their immature development (i.e., conditioning). Conditioning significantly increased the predation capacity of the phytoseiid. Finally, we tested the control potential of conditioned A. limonicus versus naïve ones when exposed to E. americanus on sweet pepper plants. In contrast to the laboratory trials, at the plant level, conditioning did not yield better control. Possible factors explaining insufficient control of E. americanus by phytoseiids are discussed.

The influence of Ahy1 strain of Acremonium hansfodii on functional response of Neoseiulus barkeri to Tetranychus urticae

The two spotted spider mite (TSSM) Tetranychus urticae is one of the most economically key mite pests of fields and greenhouse crops over the world. In order to clarify the control efficacy of Neoseiulus barkeri on Tetranychus urticae in the presence of entomopathogenic fungus (EPF) Acremonium hansfodii. This study was conducted to evaluate the control of combining N. barkeri with A. hansfodii against T. urticae. The results showed that the functional response of N. barkeri treated with Ahy1 strain to T. urticae was Holling type II equation. Among these, the highest predation number and the shortest attack time were obtained for the predator feeding on eggs, then followed by feeding on nymphs, female adults ranked as the lowest. That of N. barkeri to T. urticae treated with Ahy1 strain was also Holling type II equation. The predation capacity of N. barkeri on nymphs and female adults of T. urticae treated by Ahy1 strain increased with the increase of the concentration of Ahy1 strain, but that when feeding eggs had no significant difference. Therefore, the combination of EPF with N. barkeri on control of TSSM had synergistic effects, which will provide the guidance to carry out combined utilization of entomogenous fungi with predatory mites.

Understanding bud rot development, caused by Botrytis cinerea, on cannabis (Cannabis sativa L.) plants grown under greenhouse conditions

Botrytis cinerea is a widespread necrotrophic plant pathogen that causes diseases on >1000 plant species, including vegetables and ornamental greenhouse crops. On cannabis ( Cannabis sativ a L.), the pathogen is responsible for causing “bud rot”, a major disease affecting the inflorescences (compound flowers), as well as seedling damping-off and leaf blight under certain conditions. During greenhouse cultivation, Botrytis cinerea can destroy cannabis inflorescences rapidly under optimal relative humidity conditions (>70%) and moderate temperatures (17–24 °C). Little is currently known about the host–pathogen interactions of Botrytis cinerea on cannabis. Information gleaned from other hosts can provide valuable insights for comparative purposes to understand disease development, epidemiology, and pathogenicity of Botrytis cinerea on cannabis crops. This review describes the pathogenesis and host responses to Botrytis infection and assesses potential mechanisms involved in disease resistance. The effects of microclimatic and other environmental conditions on disease development, strategies for early disease detection using prediction models, and the application of biological control agents that can prevent Botrytis cinerea development on cannabis are discussed. Other potential disease management approaches to reduce the impact of Botrytis bud rot are also reviewed. Numerous opportunities for conducting additional research to better understand the cannabis– Botrytis cinerea interaction are identified.

Effects of different cultivation media on root bacterial community characteristics of greenhouse tomatoes.

Tomato, as a typical greenhouse crop, is commonly first planted as seedlings in a variety of substrates before being transplanted into soil. However, there is rare research on the characteristics of the bacterial community in tomato roots under this planting mode. In this study, tomatoes were planted in pots containing three different cultivation media, including soil and two types of substrates in a greenhouse, followed by a transplanting treatment. After collecting tomato root samples, high-throughput sequencing and bioinformatic analysis were used to compare the differences in bacterial diversity and functions between tomato roots before and after transplanting in different cultivation media. In total, 702776 sequences were obtained, and the OTUs were belonging to 109 genera, 58 families, 41 orders, 14 classes, and 12 phyla. Among the three cultivation media, the β-diversity was significant, and there was a slight difference in bacterial species diversity along with a large difference in their abundance at the genus level. Soil and both substrates had 79 bacterial genera in common, these genera accounted for 68.70%, 76.70%, and 71.17% of the total genera found in the soil, substrate 1, and substrate 2, respectively. After being transplanted from the two substrates to the soil, the bacterial community structure and abundance exhibited similarities with those found in the soil. Furthermore, based on microbial function prediction, the microbial communities in the two-substrate environment demonstrated a greater potential for promoting growth, while the microbial communities in the soil exhibited a greater tendency to exert their antibacterial potential. Our findings offer theoretical support for the creation of artificially reconstructed microbial communities in greenhouse cultivation.

Reusing drainage water and substrate to improve the environmental and economic performance of Mediterranean greenhouse cropping

The objective of this study is to provide decision makers and policy makers with adequate information to support the diffusion of reuse strategies in Mediterranean greenhouses. Sixteen alternative scenarios are compared through eco-efficiency analysis, combining four technologies to manage drainage water (open-loop fertigation vs. wastewater treatment plant vs. cascade cropping vs. closed-loop fertigation) with two substrate materials and two substrate management options at end-of-life. System differences are modelled through detailed primary data, collected and validated via a multi-step process. Results show that cascade cropping and closed-loop fertigation have, respectively, the highest and second-highest eco-efficiency, with respect to their ability to reduce freshwater eutrophication (up to −6,63 kg P) and marine eutrophication (up to −47.1 kg P eq), while generating profits for the farmer. Selecting a biodegradable substrate and reusing it on farm can increase greenhouse profitability by 20%. This article is a new contribution to the literature by (i) supporting the improvement and harmonisation of eco-efficiency analysis in the agricultural sector; (ii) providing a comprehensive comparative assessment that is missing from the published literature; (iii) giving special emphasis to data and the data collection process, to provide input to further research; (iv) by generating lessons learnt of practical usefulness for reducing uncertainty in decision making and policy making; (v) by delivering policy recommendations to address key barriers to the diffusion of eco-efficient greenhouse cropping. The involvement of local and multidisciplinary stakeholders is required to improve the methodological approach and the acceptability of the proposed solution, especially in case of trade-offs among the different impact domains, and to identify and prioritise tailored interventions on the conditions and stakeholder needs.

If Only You Could Catch Me—Catch Me If You Can: Monitoring Aphids in Protected Cucumber Cultivations by Means of Sticky Traps

Aphids are important pests in many greenhouse and field crops. For plant protection, early detection of relevant species and reliable assessment of population development throughout the season is mandatory to address countermeasures in time. In practice, coloured sticky cards or pan traps are frequently used as monitoring tools, but as well as the flight activity of focal insects, many other factors influence reliable interpretation of trapping data. Since monitoring data have been more and more integrated into automated decision support systems, soundness of insect count data and interpretation of results needs to be reviewed in more detail. Therefore, we investigated the applicability of yellow sticky traps for monitoring of the cotton aphid, Aphis gossypii in greenhouse cucumber crop. In separate greenhouse chambers, we infested cucumber plants with Aphis gossypii and installed several yellow sticky traps. Insects were counted on the plants and sticky traps on a weekly basis and number of insects were correlated. Our results indicate mismatches between trap catches and aphid population density especially early in the season, which most likely is related to immigration of winged aphids into the greenhouse. The following population build-up of the cotton aphid Aphis gossypii on the cucumber plants correlated quite well with counts of alate cotton aphids on the sticky traps. In conclusion, trapping of winged aphids provides valuable information for integrated pest control in the greenhouse. Nevertheless, to avoid wrong interpretation the taxonomic identity of trapped aphids has to be confirmed at all times. Results are further discussed in the context of factors influencing aphid wing development and attraction to yellow sticky traps. Potential strategies to optimize aphid monitoring with coloured sticky traps are proposed.

System Design, Analysis, and Control of an Intelligent Vehicle for Transportation in Greenhouse

Smart agriculture represents a significant trend in agricultural development, given its potential to enhance operational efficiency and reduce labor intensity. Despite the adoption of modern greenhouse technologies, such as sensors and automation systems, crop transportation is still largely achieved through manual labor, largely due to the complex environment and narrow terrain of greenhouses. To address this challenge, this work proposes the design of an intelligent vehicle that is capable of transporting crops in a commercial greenhouse, with the aim of improving operational efficiency and reducing labor intensity. To enable the vehicle to navigate the horizontal and rail surfaces within the greenhouse, a novel chassis structure is designed that is capable of simultaneous driving on both ground and rail surfaces. Additionally, the two-dimensional codes is adopted for positioning and navigation, thereby avoiding the need to modify existing greenhouse road surfaces. Through the implementation of a comprehensive system-control strategy, the intelligent vehicle realized various functions, including ground driving, rail driving, moving up and down the rail, and automatic rail changing. Experimental results demonstrate that the designed intelligent vehicle successfully meets the basic requirements for crop transportation in a greenhouse, providing a solid foundation for future unmanned operations.

Optimizing Crop Yield and Reducing Energy Consumption in Greenhouse Control Using PSO-MPC Algorithm

In this study, we present a novel smart greenhouse control algorithm that optimizes crop yield while minimizing energy consumption costs. To achieve this, we relied on both a greenhouse climate model and a greenhouse crop yield model. Our approach involves applying the model predictive control (MPC) method, which utilizes the particle swarm optimization (PSO) algorithm to identify optimal controllable parameters such as heating, lighting, ventilation levels. The objective of the optimization is to maximize crop yield while minimizing energy consumption costs. We demonstrate the superiority of our proposed control algorithm in terms of performance and energy efficiency compared to the traditional control algorithm. The effectiveness of the PSO-based optimization strategy for finding optimal controllable parameters for MPC control is also demonstrated, outperforming the traditional genetic algorithm optimization. This study provides a promising approach to smart greenhouse control with the potential for increasing crop yield while minimizing energy costs.

An Optimal Control Method for Greenhouse Climate Management Considering Crop Growth’s Spatial Distribution and Energy Consumption

The environmental factors of greenhouses affect crop growth greatly and are mutually coupled and spatially distributed. Due to the complexity of greenhouse climate modeling, the current optimal control of greenhouse crop growth rarely considers the spatial distribution issues of environmental parameters. Proper Orthogonal Decomposition (POD) is a technique to reduce the order of a model by projecting it onto an orthogonal basis. In this paper, POD is used to extract environmental features from Computational Fluid Dynamics (CFD) simulations, and a low-dimensional feature subspace is obtained by energy truncation. With multi-dimensional interpolation, fast and low-dimensional reconstruction of the dynamic variation of greenhouse climates is achieved. On this basis, a rolling-horizon optimal control scheme is proposed. For each finite horizon, the external meteorological data are updated, and the response of the greenhouse environment is quickly calculated by the POD model. With the performance criterion J of maximizing crop production and energy efficiency, through the particle swarm optimization algorithm, the optimal settings for the greenhouse shading rate and the fan speed are derived. Such control computations are rolled forward during the whole planting season. Results of a case study show that the proposed method has low computation cost and high spacial resolution and can effectively improve the spatiotemporal accuracy of greenhouse climate management. In addition, different from traditional global optimal control methods, the proposed rolling-horizon scheme can correct various external disturbances in the procedure of crop growth, and thus it is more robust and has potential for engineering applications.

Study on optimization model control method of light and temperature coordination of greenhouse crops with benefit priority

Facility agriculture is the foundation of modern agriculture. In recent years, energy consumption has become a major bottleneck restricting the development of greenhouse. However, with the support of intelligent control methods, the greenhouse energy-saving market with cost reduction and efficiency has gained increasing attention. Therefore, there is a great potential to expand the research on coordinated energy conservation and optimal control of greenhouse environment, with the objective of improving greenhouse yield and reducing production costs. In this study, a phototemperature coupled net photosynthetic rate (Pn) model was established by using the rectangular hyperbolic correction model of temperature correction, and the model parameters were obtained by Nlinfit fitting. Based on the NSGA-II algorithm, the Pareto optimal frontier was obtained with the objective of minimizing energy consumption and maximizing predicted crop yield. The artificial fish swarm algorithm was used to find the maximum point for the three-dimensional interpolation network of the established crop model. Different evaluation strategies were used to evaluate the optimal solution. The results showed that the average power consumption before and after optimization was reduced by 4.31 %, when Pn remained basically unchanged. When the power consumption remained basically unchanged, the average increase in Pn was about 9.59 %.

Thermal Environment Analysis of Selected Polyethene Cladded Single-Span Greenhouse Shapes Models Towards Cooling Needs

Greenhouse energy management is one of the most significant factors of consideration in greenhouse agriculture. Besides implementing energy supply systems to the facility, energy-saving measures must also be taken into consideration. To address the issue of energy demand by greenhouses in a tropical environment, three greenhouse models were developed to simulate their thermal environments utilizing the Transient Systems Simulation Program (TRNSYS 18) as a building energy simulation (BES) platform. The proposed models were used to examine the impact of greenhouse design parameters; roof shape, orientation, covering (polyethene), and ventilation, on their temperature, relative humidity (RH), vapour pressure deficit (VPD), and cooling load. It was found that the most suitable roof design and orientation was the split-gable roof design with the ventilation switched on and 0o (E-W) orientation that had the lowest mean temperature of 24.12 oC and the least cooling demand of 454.59W. While the tunnel greenhouse had the highest cooling load of 21.30 kW. The split-gable greenhouse had. Also, the RH and VPD in the split-gable greenhouse with ventilation were within the acceptable ranges of 50-75% and 0.8 and 1.1 kPa, respectively, for successful greenhouse crop production. The developed models can aid greenhouse farmers in knowing the cost-benefit of a greenhouse before venturing into greenhouse agriculture in the tropical regions.

Occupational exposure to pesticides as a potential risk factor for epilepsy

Epilepsy is a chronic neurological disorder in which brain activity becomes abnormal, causing seizures. In a previous study we found that environmental exposure to pesticides was associated with a greater risk of epilepsy. The present study examined possible occupational risk factors that may contribute to the occurrence of epilepsy in farmers and pesticide applicators (sprayers). A case-referent study was conducted on 19,704 individuals over a 17-year study period (2000–2016). Epilepsy cases (n = 5091) were collected from Hospital records and referents (non-epilepsy cases, n = 14.613) from the Centre for Prevention of Occupational Risks, both from Almería (South-Eastern Spain). A significant increased risk of having epilepsy was found in farmers working in intensive agriculture (high-yield greenhouse crops) compared to extensive agriculture (open-air crops). The risk was greater for farmers residing in rural areas with high pesticide use (intensive farming crops in plastic greenhouses) and for those not wearing protective gloves. As for sprayers, the greatest risk of epilepsy was observed in those not wearing face mask, and in those living in areas with high pesticide use (greenhouse intensive agriculture). Overall, this study supports previous findings on the association between epilepsy and pesticide exposure in the general population, and extends the risk to farmers occupationally exposed to pesticides, mainly those engaged in intensive agriculture.

First Report of the Pepper Fruit Fly Atherigona orientalis (Schiner 1968) (Diptera: Muscidae) Infesting Commercial Pepper Crops in Greece.

The pepper fruit fly Atherigona orientalis (Schiner 1968) (Diptera: Muscidae) is a cosmopolitan tropical pest which has been recently recorded in several European countries. The biology of the pest has been primarily associated not only with decomposing fruits and vegetables, but even vertebrate and invertebrate carrion, dung and faeces. Relatively recently, A. orientalis has been reported as a primary pest of pepper fruits as well. In this short communication, we report, for the first time in Greece and, to the best of our knowledge, in Europe, cases of pepper fruit fly damage to pepper fruits in commercial greenhouse crops (in Crete in 2022). In this direction, possible implications and concerns regarding the occurrence of this pest in Crete are discussed.

Valorisation des eaux de retour des serres agricoles chauffée par l’eau géothermique dans le sud tunisien

Le secteur des cultures protégées sous serres chauffées dans le sud tunisien n’a cessé de se développer avec la disponibilité des ressources géothermiques. La mauvaise gestion de ces ressources entraîne leur dégradation en termes de quantité et qualité. Cette situation s’aggrave avec la demande en eau dans le secteur agricole. De ce fait, la valorisation de ces potentiels géothermiquess’avère nécessaire pour assurer leur durabilité. Le présent travail vise la caractérisation des eaux de retour et l’évaluation de leur impact sur les cultures sous serres et les systèmes oasiens. L’étude s’est basée sur des analyses physico-chimiques des eaux de retour prélevées auprès de neuf pôles géothermiques répartis sur les trois gouvernorats (Gabès, Kébili et Tozeur), des visites de terrain et des enquêtes menées auprès des agriculteurs exploitants. Ces analyses physico-chimiques indiquent une qualité d’eau médiocre à moyenne qui présente un risque salin très élevé et un risque alcalin moyen. En effet, la salinité des eaux varie de 2,6 à 11,9 g/l et le SAR de 5,1 à 8,8. Ajoutons que les techniques de gestion de la salinité adoptées par les agriculteurs restentencore limitées à cause de leur faible capacité financière.

Effectiveness of chemical insecticides and entomopathogenic fungi Lecanicillium muscarium against Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) infesting geothermal crops in southern Tunisia

The whitefly, Bemisia tabaci (Homoptera: Aleyrodidae), is one of the most serious pests of protected and geothermal crops. To improve control of B. tabaci, we studied the efficacy of a group of chemical insecticides and a biological product based on an entomopathogenic fungus, offering a diversity of modes of action and innovative activity pathways. The results showed that these treatments were effective in reducing the development stages of B. tabaci. L. muscarium caused a significant reduction of the different developmental stages of B. tabaci with a percentage varying between 57.87 and 79.69 %. Egg and larvae reduction percentages were above 60% for Imidacloprid, Pyriproxyfen, Pyrethrinoids, Sulfoxaflor, and Imidacloprid + lambda-cyhalothrin. These treatments can be used as part of an integrated control program against whiteflies associated with crops in geothermal greenhouses in southern Tunisia.

Development and Application of a Mathematical Simulation Model to Evaluate Environmental Performance of Greenhouses Using Physical and Climatic Indicators

This study was conducted to determine and apply a mathematical model to simulate the environmental and climatic parameters to evaluate the performance of different greenhouses in three areas within the Khartoum North – Sudan (Date Palm Technology Company., Abu Halima Center and Khartoum University). The assessment method depends on development of a computer simulation model to generate from house physical characteristics and climate data ten environmental performance evaluation indicators (Relative moisture efficiency; Cooling effectiveness, Moisture saturation efficiency; Water consumption rate; House overall efficiency; House ventilation rate, Optimum internal temperature and internal relative humidity).The result of application of the evaluation model for nine greenhouses in three different locations in Khartoum North reveals that there is no significant differences (P = 0.05) in evaluation indicators between the three studied areas. The study concluded that additional work is needed to upgrade the mode of running greenhouse crop cultivation system with regards to: using sustainable and energy efficient cooling and ventilation technologies, adopting new techniques to conserve water and its efficient utilization, introducing properly adapted materials for high temperatures and strong solar radiation, and accessibility of technologies such as automation systems. In the current system moisture use efficiency in particular found to be lower than expected and measures to improvement are critically needed. With respect to the system efficiency and utility of fan and pad greenhouse the effectiveness of cooling system is function of internal environmental parameter (temperature and relative humidity with negative relation). The evaluation model shows that cooling efficiency tends to go up in the areas with low relative humidity.

Diversity of Aphids Associated with Field and under Greenhouse Crops (Wheat, Barley and Chili Pepper) across the Dryland Climate in Algeria

Diversity of Aphids Associated with Field and under Greenhouse Crops (Wheat, Barley and Chili Pepper) across the Dryland Climate in Algeria

Abundance of Tuta absoluta (Meyrick, 1917) and its natural enemies on tomato crops in greenhouses of different production modes (Azores, Portugal) (Lepidoptera: Gelechiidae)

Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae) is a major pest of tomato (Solanum lycopersicum L.) crops produced in the Azorean greenhouses. Despite the major concerns, no systematic study is available to describe population dynamics of T. absoluta and its natural enemies. The objective of this study was to compare the abundance of the pest (eggs and larvae) and its native natural enemies, in greenhouses of tomato crops produced under different production modes (biological, traditional and intensive). A sampling program was carried out during 2020-2021 and two production seasons of spring-summer and fall-winter. The abundance of eggs and larvae of T. absoluta were higher in tomato crops in intensive production and lower in biological production mode. Infestations by eggs and larvae were higher in spring-summer seasons. The natural enemies recorded were Macrolophus pygmaeus (Rambur, 1839) (Hemiptera: Miridae), Dicyphus cerastii Wagner, 1951 (Hemiptera: Miridae) and Trichogramma achaeaeNagaraja & Nagarkatti, 1960 (Hymenoptera: Trichogrammatidae). The abundance of natural enemies were very low and, virtually, do not occur during the fall-winter seasons. We found no significant difference between the abundance of M. pygmaeus amongst tomato crops from different production mode but D. cerastii was more abundant on greenhouses of biological production mode. Parasitism rate by T. achaeae does not differ between production modes and crop seasons. Considering the major concerns of the growers by the infestation levels of their crops, together with low abundance of native natural enemies, we suggest the use of biological production mode or an inoculative or augmentative strategy to control the pest in intensive and traditional productions modes.

Effect of the Landscape on Insect Pests and Associated Natural Enemies in Greenhouses Crops: The Strawberry Study Case

Compared to open-field crops, the influence of the surrounding landscape on insect diversity in greenhouse crops has been poorly studied. Due to growing evidence of insect influx in greenhouses, identifying the landscape properties influencing the protected crop colonization by insect pests and their natural enemies would promote the improvement of both pest prevention and conservation biological control methods. Here, we present a field study on the effect of the surrounding landscape on the colonization of greenhouse crops by insect pests and associated natural enemies. By monitoring 32 greenhouse strawberry crops in the South West of France, we surveyed crop colonization by four insect pests and four natural enemy groups over two cultivation periods. Our results showed that the landscape structure and composition could have contrasting effects on insect colonization of greenhouse crops so there could be species-specific effects and not general ones. While the degree of openness of greenhouses and the pest management practices modulated insect diversity marginally, we also showed that seasonality represented a key factor in insect crop colonization. The various responses of insect pests and natural enemy groups to the landscape support the idea that pest management methods must involve the surrounding environment.

Technology and Materials for Passive Manipulation of the Solar Spectrum in Greenhouses

AbstractGreenhouse horticulture grows increasingly important due to its ability to provide a controlled microclimate which is optimizable for highly efficient crop growth and resource use, although it may come at a significant energy and investment cost. One of the most crucial inputs in any greenhouse is sunlight, giving free energy and light for greenhouse crop growth. However, it is enormously variable, both geographically and seasonally. This review discusses materials and technologies usable in greenhouse cover and screen materials which can passively manipulate the incident sunlight to transmit a light spectrum that is ideal for crop growth, thereby improving the yield, and for greenhouse microclimate management, thereby reducing the energy usage of greenhouses. The current status of spectrum‐manipulating technology in greenhouses, developments over the last few years, some potential innovations adaptable from diverse fields to greenhouse horticulture, and the associated challenges, are discussed.