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The root-knot nematode, Meloidogyne javanica is a devastating pest affecting tomato production worldwide. Entomopathogenic nematodes (EPNs) are considered very promising biocontrol agents that could be used to effectively manage plant-parasitic nematode. The antagonistic activity of five EPN strains isolated from different fields in Morocco was evaluated against juvenile (J2s) antagonism in soil, the number of egg masses, and the galling index of M. javanica and J2s reproduction in the root. In greenhouse experiments, Steinernema feltiae strains (EL45 and SF-MOR9), Steinernema sp. (EL30), and those of Heterorhabditis bacteriophora (HB-MOR7 and EL27) were applied to the soil alongside RKN J2s. There was a significant reduction in M. javanica densities in the soil and roots by EPNs treatments when compared to the positive control. The EPNs decreased both egg masses formation and galling index by 80% compared to the positive control. The application of EPNs at a rate of 50 and 75 infective juveniles (IJs) cm−2 gave significant control of all studied nematological parameters compared to the positive control, which confirmed the importance of the doses applied. The applied dose was significantly correlated with M. javanica parameters according to polynomial regression models. The results also showed that S. feltiae strain (EL45) significantly increased plant height and root length, while H. bacteriophora strain (HB-MOR7) only enhanced root fresh weight. Therefore, both indigenous EPN strains; EL45 and SF-MOR9 have eco-friendly biological potential against M. javanica in vegetable crops. [ABSTRACT FROM AUTHOR]

In a grove in north-eastern Morocco in 2020, severe root rot and crown rot symptoms were noticed on olive trees (Olea europaea). Pythium schmitthenneri was identified as the pathogen based on conidia morphology and cytochrome oxidase subunit II (COXII) gene sequence analysis. Koch's postulates were verified by re-isolation of the fungus P. schmitthenneri from artificially inoculated olive seedlings after a pathogenicity test. This is the first time P. schmitthenneri has been identified as the cause of olive tree root and crown rot in Morocco. [ABSTRACT FROM AUTHOR]

This study aimed at evaluating the antibacterial activity of Cinnamomum cassia and Syzygium aromaticum essential oils and their nanoparticles (EOs-NPS) against Erwinia amylovora, the causal agent of fire blight disease. First, EOs of C. cassia and S. aromaticum were obtained by hydrodistillation and analysed using a GC–MS/FID. Results showed that the main components of C. cassia EOs are E-Cinnamaldehyde (73.23%), alpha-Copaene (6.44%), and Eugenol (4.23%) while the EOs of S. aromaticum showed the presence of Eugenol (58.64%), β-Caryophyllene (32.91%), and Humulene (3.25%). C. cassia EOs was the most effective with an inhibition zone of 37.7 mm and a minimum bactericidal concentration (MBC) of 1.04%. However, EOs-NPS of C. cassia had greater effects than S. aromaticum with an MBC of 0.75%, rather than the effect of EOs alone. Significant reduction of the disease incidence (86%) was observed in the in vivo pre-treatment using EOs-NPS of C. cassia. Therefore, C. cassia EOs-NPS is recommended against E. amylovora. [ABSTRACT FROM AUTHOR]

This paper documents pest management practices adopted by citrus farmers in two of the citrus-growing regions in Morocco. The survey data propose possible recommendations to ensure sustainable pest management strategies. By variety, the surface area occupied by the Navel and Maroc-late represented 25% and 23%, respectively. 54% of the citrus farmers used certified sour orange rootstocks. 79% of farmers adopted soil plowing using a plow called Cover-Crop. Drip irrigation was widely practiced in the two regions studied. Citrus growers perceived mealybug, medfly, and mites as the most common insects, and Phytophthora rot and dry root rot as the most devastating fungal diseases infecting citrus production. 54% of the respondents used a pre-established treatment schedule. A total of 21 active ingredients of insecticides belonging to 15 different chemical groups were inventoried during the survey. Organophosphates were the most widely used insecticides (28%), followed by pyrethroids (17.9%), and neonicotinoids (16%). For disease control, copper compounds were used by all respondents. The manual–mechanical weed control method was widely practiced. 29% of respondents admitted to having little knowledge about the impact of climate change, 43% reported about a shift in dates of production practices, and 35% experienced pest outbreaks in their orchards. Due to the unregulated management practices, our findings emphasize the necessity of extension services to citrus farmers on the adoption of integrated citrus production. This system will help achieve sustainable citrus production, protect the environment, and optimize citrus yield. [ABSTRACT FROM AUTHOR]

Citrus have been grown as a commercial fruit crop in Morocco for a decade. The area dedicated to growing and producing citrus has increased from 2006 to 2018 throughout the country. The rapid decline of citrus trees has been observed in many locations. Therefore, this study aimed to identify and characterize fungal pathogens associated with dry root rot (DRR) disease of citrus from diseased trees and soil collected from different citrus-growing plantations. Isolation and morphological identification of pathogens were performed using PDA-SC medium. Thirty-four Fusarium isolates were recovered from symptomatic plants. These isolates were identified based on morphological traits and the sequence of the internal transcribed spacer (ITS) region. Four Fusarium species were identified. Fusarium solani (Martius) was most frequently identified (70.60%), followed by F. oxysporum (17.65%), F. equiseti (8.82%) and F. brachygibbosum (2.94%). The two latter species have recently been associated with DRR in Morocco. Two separate pathogenicity trials were conducted to test the effect of the pathogens on young citrus seedlings. Results indicated that, with the exception of F. equiesti, Fusarium isolates were aggressive pathogens of citrange-Troyer and sour orange seedlings 2 months postinoculation. Citrus trees displayed key symptoms of DRR such as root rot, discolored and necrotic roots, purple wood discoloration, plant yellowing and general weakness. Further, all four species were able to induce lesions when they were used to inoculate citrus branches. This is the first detailed report of Fusarium species associated with DRR in Morocco. [ABSTRACT FROM AUTHOR]

Zucchini (Cucurbita pepo) and watermelon (Citrulus lanatus) rank among the most cultivated cucurbits in Morocco. These crops are prone to infection with a wide range of viral diseases responsible for tremendous losses. Field surveys carried out in 2016 and 2017 in four major cucurbit-growing areas revealed the presence of many virus-like symptoms on these crops, including severe yellowing and chlorosis. Therefore, symptomatic samples were collected and analysed serologically with DAS-ELISA for ZYMV, WMV, PRSV, CABYV and CMV and by The PCR and RT-PCR for ToLCNDV, and CVYV and MNSV, respectively. Results indicated that out of 136 samples, 79% of zucchini and 60% of watermelon samples were serologically positive for ZYMV, CMV, WMV, PRSV and CABYV. CVYV and MNSV were negatively amplified by RT-PCR using specific primer pairs. Interestingly, the PCR test revealed the occurrence of natural infection with ToLCNDV in Morocco. [ABSTRACT FROM AUTHOR]

Mediterranean cereal cyst nematode (CCN) Heterodera latipons is considered as one of the main CCN that causes significant economic losses in the production of intolerant cereal crops in Turkey. Accordingly, this study aimed at evaluating the effect of different storing temperatures and durations on the emergence of second-stage juveniles (J2s) of the nematode populations obtained from the eastern Mediterranean (Adana and Hatay) and south-eastern (Gaziantep and Kilis) regions of Turkey. The obtained results revealed a variation in the J2s hatching profiles of the regional nematode populations. The eastern-Mediterranean and the south-eastern populations hatched at between 5 and 20 °C; however, considerable divergences in the J2 hatching were noticed. The highest emergence of J2s for the populations occurred at 10 °C, whereas the lowest level was observed at 5 °C. To simulate the preplanting soil temperatures in Turkey, the cysts were stored at 5 °C and 20 °C, before incubation at 10 and 15 °C, to stimulate hatching of the J2s. The highest cumulative hatching was obtained at a constant temperature of 10 °C, while the lowest cumulative hatching occurred at 5 °C. Moreover, storing cysts at 5 °C, before incubation at 10 and 15 °C, significantly stimulated hatching of the populations of H. latipons when compared to the control. However, storing the cysts at 20 °C, before incubation at 10 °C, substantially stimulated the emergence of J2s relative to the control. The obtained results about the hatching behaviour of H. latipons may help in the development of effective control strategies for this nematode in Turkey. [ABSTRACT FROM AUTHOR]

Main conclusion: ATR-FTIR spectroscopy in combination with uni- and multivariate analysis was used to quantify the spectral-chemical composition of the leaf cuticle of pea, investigating the effects of variety and heat stress.Field pea (Pisum sativum L.) is sensitive to heat stress and our goal was to improve canopy cooling and flower retention by investigating the protective role of lipid-related compounds in leaf cuticle, and to use results in the future to identify heat resistant genotypes. The objective was to use Attenuated Total Reflection (ATR)-Fourier Transform Infrared (FTIR) spectroscopy, a non-invasive technique, to investigate and quantify changes in adaxial cuticles of fresh leaves of pea varieties that were subjected to heat stress. Eleven varieties were grown under control (24/18 °C day/night) and heat stress conditions (35/18 °C day/night, for 5 days at the early flowering stage). These 11 had significant spectral differences in the integrated area of the main lipid region, CH2 region, CH3 peak, asymmetric and symmetric CH2 peaks, ester carbonyl peak, and the peak area ratio of CH2 to CH3 and ester carbonyl to CH2 asymmetric peak, indicating that cuticles had spectral-chemical diversity of waxes, cutin, and polysaccharides. Results indicated considerable diversity in spectral-chemical makeup of leaf cuticles within commercially available field pea varieties and they responded differently to high growth temperature, revealing their diverse potential to resist heat stress. The ATR-FTIR spectral technique can, therefore, be further used as a medium-throughput approach for rapid screening of superior cultivars for heat tolerance. [ABSTRACT FROM AUTHOR]

Fifty-five soil samples were collected from sugarbeet fields with rhizomania occurrence in the region of Tadla. BNYVV was ascertained by RT-PCR in 40 out of 55 fields surveyed and the positive samples were subsequently examined for the presence of the different pathotype of BNYVV. Using the same technique, a survey was simultaneously undertaken to identify the occurrence of other soil-borne viruses, which might frequently associate with BNYVV such as beet soilborne virus (BSBV), beet soilborne mosaic virus (BSBMV) and beet virus Q (BVQ). Results indicated that most samples were infected with A-type BNYVV, but only 9% of the samples were positive for B-type BNYVV. BNYVV (72.7%) was the most frequently detected, followed respectively by BSBV (36.36%) and BVQ (30.9%). However, P-type BNYVV was not detected at all. Our results also indicated the likely absence of BSBMV in the Tadla region. Surprisingly, among the 40 BNYVV-infected samples, 17 were also infected with BVQ and 20 with BSBV. In conclusion, BSBV occurred in triple infections with BNYVV and BVQ. In addition, there was only one sample revealed positive for both viruses BNYVV-B and BVQ and four samples for BSBV infection. Therefore, this study is the first investigation of BSBV and BVQ in fields-grown sugarbeet of Morocco. [ABSTRACT FROM AUTHOR]

Field pea (Pisum sativum), a major grain legume crop, is autogamous and adapted to temperate climates. The objectives of this study were to investigate effects of high temperature stress on stamen chemical composition, anther dehiscence, pollen viability, pollen interactions with pistil and ovules, and ovule growth and viability. Two cultivars ("CDC Golden" and "CDC Sage") were exposed to 24/18°C (day/night) continually or to 35/18°C for 4 or 7 days. Heat stress altered stamen chemical composition, with lipid composition of "CDC Sage" being more stable compared with "CDC Golden." Heat stress reduced pollen viability and the proportion of ovules that received a pollen tube. After 4 days at 35°C, pollen viability in flower buds decreased in "CDC Golden," but not in "CDC Sage." After 7 days, partial to full failure of anthers to dehisce resulted in subnormal pollen loads on stigmas. Although growth (ovule size) of fertilized ovules was stimulated by 35°C, heat stress tended to decrease ovule viability. Pollen appears susceptible to stress, but not many grains are needed for successful fertilization. Ovule fertilization and embryos are less susceptible to heat, but further research is warranted to link the exact degree of resilience to stress intensity. Heat stress induced anther indehiscence and reduced pollen viability and the proportion of ovules that received a pollen tube in field pea. Heat stress also altered stamen chemical composition, with the lipid composition of "CDC Sage" being more stable than "CDC Golden," which may explain the greater robustness of pollen viability in "CDC Sage" to heat. Ovule viability is less susceptible to heat stress. [ABSTRACT FROM AUTHOR]

• A new alternative control strategy for managing grapevine trunk diseases (GTDs) was investigated. • Bacterial isolates are found to be potent inhibitors. • Bacterial isolates showed the ability to produce volatile antifungal compounds (VOCs) and promote plant growth. • Bacterial isolates can be adopted simultaneously and developed for managing GTDs. Rhizospheric bacteria isolated from the root system of Vitis vinifera plants in Morocco were evaluated for their activities against fungi associated with grapevine trunk diseases namely Diplodia mutila , Neoscytalidium dimidiatum , Trichothecium roseum , and Neopestalotiopsis vitis. Those pathogens cause grapevine decline and impede growth and are known as the greatest threat to production worldwide. Among a collection of 196 rhizobacteria, twenty-four isolates exhibited potential antifungal activity against all the tested fungal pathogens. Based on the partial 16S rDNA genes, different genera were identified namely Bacillus, Pseudomonas, Achromobacter, Ensifer, and Brucella. In particular, Bacillus halotolerans (JFM-64 and JMS-14), Pseudomonas koreensis (JRSK-45), and Ensifer adhaerens (JRSK-84) were found to be the most effective strains. Furthermore, the potential of bacterial isolates to promote plant growth was assessed. The funding revealed that of twenty-four antagonist rhizobacteria, seventeen displayed protease and chitinase production, while fifteen, thirteen, and twelve bacteria demonstrated the production of amylase, cellulase, and pectinase respectively. Furthermore, thirteen bacterial isolates produced hydrocyanic acid (HCN), sixteen isolates harbor the ability to solubilize tricalcium phosphate and seventeen were able to produce siderophores and indole acetic acid (IAA). The results of the current study showed that the most effective bacterial isolates could exhibit traits other than Plant Growth-Promoting Rhizobacteria (PGPR). Our results showed that the bacterization of B. napus seedlings with the selected bacteria improved plant growth when compared to untreated controls. Autoclaved grape wood assays were used to further confirm the in vitro results. The growth of Diplodia mutila, Neopestalotiopsis vitis, Neoscytalidium dimidiatum, and Trichothecium roseum was effectively reduced by rhizobacterial isolate Pseudomonas koreensis (JRSK-45) by 97.31, 97.14, 94.17, and 91.91%, respectively. This study highlights the potential of specific rhizobacteria as a promising approach to controlling fungal trunk pathogens associated with grapevine decline. [ABSTRACT FROM AUTHOR]

This article, published in the Journal of Plant Pathology, reports on the first occurrence of Fusarium tricinctum causing root rot on sugar beet plants in Morocco. The study describes the symptoms of the disease, the characteristics of the fungal isolate, and the molecular identification of the pathogen. The researchers conducted inoculation experiments to confirm the pathogenicity of the isolate and re-isolated the pathogen from infected plants. This finding contributes to the understanding of sugar beet diseases in Morocco and provides valuable information for farmers and researchers in the field of plant pathology. [Extracted from the article]

The growth and development of citrus trees and the quality of their fruits are significantly influenced by the essential role of mineral plant nutrition. This study aimed to improve the productivity of the citrus (Citrus clementina Hort. Ex Tanaka) orchards by optimizing mineral nutrition through well-monitored fertilization and fertigation aspects using lysimetry. The first phase consisted of studying the behavior of the nutrients in the soil solution at the high root concentration level, analysis of the nutritional status of five varieties of clementines (Sidi Aissa, Cadoux, Orogrande, Nules, and Nour), and the variation of leaf composition in major elements (Nitrogen, phosphorus, potassium, magnesium, and calcium) for the five varieties along phenological stages, through the exploitation of the results of analyses carried out for the management of mineral nutrition in 47 plots of citrus fruit in the Souss-Massa region with the use of lysimetry. The results obtained in this first part revealed an important variation of the nut rients in the soil solution (55.24%) in terms of water inputs, fertilizers, and edaphic conditions, as well as a large variation of foliar compositions (62.98%). The second phase, consisting of regular monitoring of the mineral nutrition dynamics targeting the "Nules" variety grafted on "Citrus macrophylla" affirmed the importance of the citrus fertilization approach for determining the availability, distribution, nutrient interactions in soil solution and plant response by regular leaf diagnostics. Thus, mobile lysimetry offered a powerful tool for achieving both productivity and sustainability in citrus fertilization programs. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is the largest cereal crop grown in Western Canada where drought during late vegetative and seed filling stages affects plant development and yield. To identify new physiochemical markers associated with drought tolerance, epidermal characteristics of the flag leaf of two wheat cultivars with contrasting drought tolerance were investigated. The drought resistant ‘Stettler’ had a lower drought susceptibility index, greater harvest index and water‐use efficiency than the susceptible ‘Superb’. Furthermore, flag leaf width, relative water content and leaf roll were significantly greater in Stettler than in Superb at moderate drought stress (MdS). Visible differences in epicuticular wax density on the adaxial flag leaf surfaces and larger bulliform cells were identified in Stettler as opposed to Superb. Mid‐infrared attenuated total internal reflectance spectra revealed that Stettler flag leaves had increased asymmetric and symmetric CH2 but reduced carbonyl esters on its adaxial leaf surface compared to Superb under MdS. X‐ray fluorescence spectra revealed a significant increase in total flag leaf Zn concentrations in Stettler in response to MdS. Such information on the microstructural and chemical features of flag leaf may have potential as markers for drought tolerance and thereby accelerate the selection and release of more drought‐resistant cultivars. [ABSTRACT FROM AUTHOR]

Whereas long days (LDs) sustain shoot elongation, short days (SDs) induce growth cessation and formation of dormant buds in young individuals of a wide range of temperate and boreal tree species. In specific conifers, including Norway spruce, photoperiodic control of bud development is associated with the formation of a plate of thick-walled cells, denoted as the crown, at the base of the bud. Information about cellular characteristics of this crown region is limited. We aimed to test whether the crown region is an important SD-induced barrier ensuring dehydration of the developing winter bud by preventing water influx. Using microscopy and synchrotron techniques, we show here that under LD, cell walls in growing shoot tips had highly methyl-esterified homogalacturonan pectin. During SD-induced bud development, the homogalacturonan in the crown region was de-methyl-esterified, enabling Ca2+ binding and crosslinking, a process known to decrease cell wall water permeability by reducing pectin pore size. In addition, there was abundant callose deposition at plasmodesmata in the crown region, and xylem connections between the bud and the subtending shoot were blocked. Consistent with reduced water transport across the crown region into the bud, uptake of fluorescein in shoot tips was blocked at the base of the bud under SD. Upon transfer from SD to bud-break-inducing LD, these processes were reversed, and aquaporin transcript levels significantly increased in young stem tissue after 4 weeks under LD. These findings indicate that terminal bud development is associated with reduced water transport through decreased cell wall permeability and blocking of plasmodesmata and xylem connections in the crown structure. This provides further understanding of the regulatory mechanism for growth-dormancy cycling in coniferous tree species such as Norway spruce. [ABSTRACT FROM AUTHOR]