Study of the effects of a liquid foam technology injected between the double layer of polyrthylene of the greenhouse on light transmission and spectral quality, microclimate, physiology of tomato and sweet pepper crops, and energy saving

L'introduction d'une mousse liquide entre les deux films de polyethylene d'une serre est une technologie innovatrice pour l'augmentation de l'isolation en hiver et l'amélioration du microclimat en été. L'objectif principal de ce projet de doctorat était d'étudier les performances de cette technologie sur le climat de la serre, la physiologie d'une culture de tomate (Lycopersicon esculentum Mill.) et de poivron (Capsicum annuum L.) et l'économie d'énergie. Lorsque la mousse a été déployée durant la nuit pour des fins d'isolation et que les lampes étaient en fonction pour assurer un éclairage photosynthétique, la lumière a été en partie réfléchie à l'intérieur de la serre par la mousse isolante. Une augmentation de 5% dans le PAR et de 18% dans le NIR a été mesurée. De plus, durant des journées chaudes et ensoleillées d'été, une réduction de la température de l'air de 2 à 6 °C a été obtenue (sous 40% à 65% d'ombrage). La mousse ombrageante a permis aussi d'augmenter l'humidité relative de la serre durant la journée (10% à 15%). De plus, l'ombrage a réduit le niveau du stress physiologique. Une diminution du rapport Fv/Fm ainsi qu'une augmentation du ratio centres réactionnels/flux de photons absorbés par les antennes de la chlorophylle (RC/ABS) et de l'indice de performance (PI) ont été mesurées en ombrageant les cultures. Toutefois, la culture de la tomate était plus sensible à la hausse de température et de radiation que la culture de poivron. Ceci se traduit par sa faible conductance stomatique. Les résultats ont montré aussi une réduction de la consommation énergétique de la serre durant la nuit allant de 33% à 64%. Les moins bonnes performances ont été notées lors des conditions de froid extrême

Conocimientos sobre el uso pesticidas y el consumo de frutas y legumbres en agricultores y consumidores en la provincia de Nador, Marruecos. Resultados de una encuesta.

Introduction: Pesticides are increasingly used in agriculture to protect crops against diseases, insect pests, weeds, etc. Pesticides leave residues and chemical active material, which can affect the health of consumers. Several epidemiological studies have demonstrated a link between pesticide residues in fruits and vegetables and disease infestations in humans and problems related to sterility, allergies, and even carcinogenic diseases. Consumer awareness and the application of strict legislation about the application of pesticides in agriculture remain as a good alternative to face this issue. Methods: This survey was carried out in the region of Nador, North-East of Morocco. It is a quantitative study of a representative sample made up of 100 consumers and 50 farmers in relation to fruit and vegetables and the use of pesticides. Results: Most consumers are not aware of the danger of pesticides and residues in fruits and vegetables. In addition, the survey revealed that potato, tomato, apples, and bananas are the most consumed. These foods are usually characterized by a high rate of application of pesticides and with a higher rate of pesticides residues. In addition, surveys carried out in farmers, revealed that they consider the economic and agronomic interest of the application of these pesticides without considering the residual effects on health. Moreover, a high rate of sterility was observed among these surveyed farmers (31%). Conclusions: The consumers are less aware of the danger of pesticides. The choices of farmers are only accentuated on the aspect of economic use of these products and not on the health and environment.Introducción: Los pesticidas se usan cada vez más en la agricultura para proteger los cultivos contra enfermedades, plagas de insectos, malezas, etc. Varios estudios epidemiológicos han demostrado una relación directa entre los residuos de plaguicidas en frutas y verduras y la contracción de enfermedades en humanos, siendo las más frecuentes las asociadas con problemas relacionados con la esterilidad, las alergias e incluso las enfermedades carcinogénicas. La concientización del consumidor y la aplicación de una legislación estricta sobre la aplicación de pesticidas en la agricultura siguen siendo una buena alternativa para enfrentar este problema. Metodología: Esta encuesta se llevó a cabo en la región de Nador, al noreste de Marruecos. Se trata de un estudio cuantitativo de una muestra representativa formada por 100 consumidores y 50 agricultores, en relación con las frutas y hortalizas y el uso de plaguicidas. Resultados: La mayoría de los consumidores no son conscientes del peligro de los pesticidas y residuos en frutas y verduras. Además, la encuesta reveló que la papa, el tomate, la manzana y el plátano son los más consumidos. Estos alimentos suelen caracterizarse por una alta tasa de aplicación de plaguicidas y con una mayor tasa de residuos. Además, las encuestas realizadas a los agricultores revelaron que estos últimos tienen en cuenta el interés económico y agronómico de la aplicación de estos plaguicidas, pero no sus efectos residuales sobre la salud. Asimismo, se observó un alto nivel de esterilidad entre estos agricultores encuestados (31%). Conclusiones: Los consumidores son menos concienciados respecto al peligro de estos plaguicidas. Las opciones de los agricultores sólo se acentúan en el aspecto del uso económico de estos productos y no en la salud y el medio ambiente

Removal of organic matter and polyphenols in the olive oil mill wastewater by coagulation-flocculation using aluminum sulfate and lime.

This work aims to treat the liquid discharges from the olive oil crushing units to protect the receiving environments by the coagulation-flocculation process using lime and aluminum sulfate as chemical coagulants. We proceed by studying the effectiveness of the coagulation-flocculation technique in eliminating organic matter and polyphenols that characterize our samples and the possibility of reusing the treated wastewater in irrigation.Analysis shows that adding 1.7 g/l aluminum sulfate can eliminate 58% of COD, 23% of TSS, and 24% of polyphenols, producing 21g/l of sludge, and eliminating 52% of COD, 48% of TSS, and 72% Of polyphenols requires the addition of 20 g/l of lime, but 25 g/l of sludge is produced. Combining two coagulants (1.7 g/l of aluminum sulfate and 20 g/l of lime) reduces 64 % of COD, 72 % of TSS, and 62 % of polyphenols, with the sludge is 29g/l. The germination test by cucumber seeds showed the validity of the use of treated olive oil wastewater in agricultural irrigation

Effect of Using Basal Fertilizer 15-15-15 on Leaf Chlorophyll a Fluorescence, Plant Growth and Fruit Yield of Table Grapes Grown under the Mediterranean Climate Conditions of the Northeast of Morocco

Plant nutrition presents one of the main concerns of table growers in Morocco. Since the increase of the prices of fertilizers, the optimization of the amount of nutrients elements is important. Crop deficiency in terms of Nitrogen (N), Phosphorus (P) and Potassium (K) was demonstrated to decrease growth and productivity of plants. The objective of this research was to investigate the effect of adding Basal N-P-K Fertilizer (15-15-15) to soil on some physiological parameters of table grapes, such as chlorophyll fluorescence, plant growth and fruit yield. Trials were conducted northeast of Morocco and under Mediterranean climate conditions on a production of 8-year-old table grapes (v. Regal). The planting density was 2000 plants/ha. In a field of 10 ha of commercial production, a plot of twenty-four trees were selected for each treatment (control (C) and treated (Tr) plants with basal fertilizer). A basal fertilizer (15-15-15) was applied in the beginning of the vegetative growth stage, at 5 cm above to the root system. An amount of 150 g/tree was applied. A conventional fertilization program was used by the grower in both control and treated plots, except for the prototype treatment plots where the basal fertilizer was only applied. No significant effect of the treatment on plant growth and fruit yield was noted. Moreover, no significant difference was recorded on leaves relative water content (RWC), chlorophyll content (LCC), and chlorophyll fluorescence parameters such as: F0, Fm, Fv/Fm, Vi Vj, ABS/RC, DI0/RC, TR0/RC, ET0/RC and RE0/RC

Yeast Warriors: Exploring the Potential of Yeasts for Sustainable Citrus Post-Harvest Disease Management

Citrus fruits stand as pivotal and extensively cultivated fruit crops on a global scale, boasting substantial economic and nutritional significance. Despite their paramount importance, citrus growers and the industry face a formidable obstacle in the form of post-harvest losses caused by plant pathogens. Effectively addressing this challenge has become imperative. The predominant approach to tackle these pathogens has traditionally involved the use of chemical fungicides. However, the escalating environmental concerns associated with chemical interventions, coupled with a growing consumer preference for pesticide-free produce, have catalyzed an earnest quest for alternative methods of disease control in the citrus industry. The antagonistic yeasts hold great promise as biocontrol agents for mitigating post-harvest fungal diseases in citrus. In this regard, this review summarizes the current state of knowledge regarding the study of yeast strains with biocontrol potential. Thus, the various modes of action employed by these yeasts and their effectiveness against prominent citrus pathogens such as Penicillium digitatum, Penicillium italicum and Geotrichum citri were discussed. Additionally, the review delved into the challenges associated with the practical implementation of yeast-based biocontrol strategies in citrus post-harvest management and investigated the potential of yeast-based approaches to enhance the safety and quality of citrus produce, while reducing the reliance on chemical fungicides and contributing to the sustainable and environmentally responsible future of the citrus industry

Modes of Action of Biocontrol Agents and Elicitors for sustainable Protection against Bacterial Canker of Tomato

Tomato is one of the world’s most commonly grown and consumed vegetables. However, it can be attacked by the Gram-positive bacterium Clavibacter michiganensis subsp. michiganensis (Cmm), which causes bacterial canker on tomato plants, resulting in significant financial losses in field production and greenhouses worldwide. The current management strategies rely principally on the application of various chemical pesticides and antibiotics, which represent a real danger to the environment and human safety. Plant growth-promoting rhizobacteria (PGPR) have emerged as an attractive alternative to agrochemical crop protection methods. PGPR act through several mechanisms to support plant growth and performance, while also preventing pathogen infection. This review highlights the importance of bacterial canker disease and the pathogenicity of Cmm. We emphasize the application of PGPR as an ecological and cost-effective approach to the biocontrol of Cmm, specifying the complex modes of biocontrol agents (BCAs), and presenting their direct/indirect mechanisms of action that enable them to effectively protect tomato crops. Pseudomonas and Bacillus are considered to be the most interesting PGPR species for the biological control of Cmm worldwide. Improving plants’ innate defense mechanisms is one of the main biocontrol mechanisms of PGPR to manage bacterial canker and to limit its occurrence and gravity. Herein, we further discuss elicitors as a new management strategy to control Cmm, which are found to be highly effective in stimulating the plant immune system, decreasing disease severity, and minimizing pesticide use

Assessing <i>Panonychus ulmi</i> (Acari: Tetranychidae) Infestations and Their Key Predators on <i>Malus domestica</i> Borkh in Varied Ecological Settings

This study investigates the infestation dynamics of Panonychus ulmi McGregor 1916 and its associated predators in Malus domestica borkh orchards across three towns in Morocco: Midelt, Ait Sebaa, and Imouzzer-Kender, situated in the Fez-Meknes and Draa-Tafilalt regions. Ait Sebaa (Fez-Meknes region), characterized by high temperatures and a lower altitude, exhibited a substantial increase in P. ulmi and its predators. In contrast, Midelt (Draa-Tafilalt region), with the highest altitude, demonstrated lower mite counts. Imouzzer-Kender (Fez-Meknes region), at an intermediate altitude, showed moderate mite levels. Detailed findings reveal a positive correlation between P. ulmi and temperature, as well as with phytoseiid mites. Conversely, a negative correlation exists between P. ulmi and altitude. Additionally, a positive correlation between phytoseiid mites and temperature is identified. Overall, this study provides valuable information on the ecological interactions between mites, temperature, altitude and humidity in distinct Moroccan regions, highlighting the need to take regional specificities into account in pest management strategies