Huanglongbing (HLB) is the most destructive disease of citrus worldwide. Monitoring of health and detection of diseases in trees is critical for sustainable agriculture. HLB symptoms are virtually the same wherever the disease occurs. The disease is caused by Candidatus Liberibacter spp., vectored by the psyllids Diaphorina citri Kuwayama and Trioza erytreae. Electron microscopy was the first technique used for HLB detection. Nowadays, scientists are working on the development of new techniques for a rapid HLB detection, as there is no sensor commercially accessible for real-time assessment of health conditions in trees. Currently, the most widely used mechanism for monitoring HLB is exploration, which is an expensive, labor-intensive, and time-consuming process. Molecular techniques such as polymerase chain reaction are used for the identification of HLB disease, which requires detailed sampling and processing procedures. Furthermore, investigations are ongoing in spectroscopic and imaging techniques, profiling of plant volatile organic compounds, and isothermal amplification. This study recognizes the need for developing a rapid, cost-effective, and reliable health-monitoring sensor that would facilitate advancements in HLB disease detection. This paper compares the benefits and limitations of these potential methods for HLB detection.

Diaphorina citri Kuwayama (Hemiptera: Liviidae) is a vector of Liberibacter asiaticus Jagoueix et al. and Liberibacter americanus Teixeira et al., causal agents of the critical yellow dragon disease or Huanglongbing (HLB), which affects citrus production worldwide. Recently, green synthetic nanoparticles have emerged as a potential alternative to control of agricultural insect pests. The insecticide effect of silver nanoparticles (AgNPs) on 2nd instar nymphs of D. citri under laboratory and greenhouse conditions was evaluated. Mortality was recorded 24, 48, and 72 h after application on D. citri nymphs under both laboratory and greenhouse conditions. The laboratory results showed that AgNPs caused 97.84 and 100% mortality at 32 and 64 ppm, respectively, 72 h after treatment. In the greenhouse, AgNPs caused 78.69 and 80.14% mortality using 64 and 128 ppm 72 h after application. This research is the first to evaluate the green synthesis AgNPs on D. citri and are a promising strategy to control the pest.

Garlic in Mexico is one of the most profitable vegetable crops, grown in almost 5,451ha; out of which more than 83% are located in Zacatecas, Guanajuato, Sonora, Puebla, Baja California and Aguascalientes. Blossom-end rot caused by Fusarium spp is widely distributed worldwide and has been a limiting factor in onion and garlic production regions, not only in Mexico but also in other countries. The presence of Fusarium oxysporum has been reported in Guanajuato and Aguascalientes. Fusarium culmorum has been reported in onion cultivars of Morelos; and Fusarium proliferatum, Fusarium verticillioides, Fusarium solani and Fusarium acuminatum have been previously reported in Aguascalientes. The goal of this work was identifying the Fusarium species found in Zacatecas, Guanajuato and Aguascalientes, to assess their pathogenicity. Plants with disease symptoms were collected from hereinabove mentioned States. The samples resulted in the identification of: F. oxysporum, F. proliferatum, F. verticillioides, F. solani and F. acuminatum species; out of which Aguascalientes AGS1A (F. oxysporum), AGS1B (F. oxysporum) and AGSY-10 (F. acuminatum) strains showed higher severity under greenhouse conditions.

Garlic (Allium sativum) is an important crop worldwide and it is widely grown and used in different industries to manufacture food, pharmaceutical, and insecticidal products. (Shang et al., 2019, V...

Tomato brown rugose fruit virus (ToBRFV) is considered an emerging disease and a viral pandemic for tomato consumers. The objectives of this research were to analyze the biological and physicochemical characteristics of ToBRFV in tomato and tobacco plants, as well as to evaluate its natural host range. Inoculant seeds were recovered from ToBRFV-infected tomato samples in Coahuila, Mexico, and confirmed by RT-PCR. In the first greenhouse experiment, tomato plants of the F1 hybrid variety 172–300 (Yüksel), infected with ToBRFV, were used to evaluate viral inclusions (VI), dilution endpoint (DEP), the incubation period (IP), and latency period (LP). In a greenhouse experiment, Nicotiana longiflora plants were inoculated with ToBRFV to determine the in vitro longevity (IVL) and thermal inactivation (TI) of the virus in sap. Finally, the inoculation of tomato plants grown in open fields was carried out to evaluate transmission to natural hosts. The plants tested for possible ToBRFV reservoirs near the inoculum source were inspected and confirmed by a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). The results indicate that the VIs on tomato leaves manifested as X-bodies and rounded, stacked plaques within epidermal cells. The DEP required to induce the infection in plants was from a ToBRFV concentration of 1 × 10^−5.5, the IP of ToBRFV occurred 9 to 12 days post-inoculation, and LP could be detected one day after inoculation. The TI of ToBRFV in N. longiflora plants occurred at 85 °C for 30 min. Ipomoea purpurea, Mirabilis jalapa, Clematis drummondii, and Solanum tuberosum were newly identified hosts of ToBRFV. The results found contribute to a better understanding of the impact of ToBRFV, managing and preventing the spread of ToBRFV in diverse environments.

Meloidogyne incognita is one of the main biological agents that affects tomato production, alternatives to chemical pesticides are currently being evaluated, looking for compounds for nematode control. The objective of the study was to evaluate the nematicidal activity of limonene, allyl isothiocyanate, eucalyptol (2000, 1000, 500, 250, 100 and 0 ppm), β-citronellol (200, 100, 50, 25, 10, 0 ppm) and azadirachtin (12000, 10000, 8000, 6000, 4000, 0 ppm), on J2 of M. incognita. Samples were carried out in greenhouses in the State of Morelos, where soil and root samples were taken, to obtain the nematodes. The bioassays were carried out following the Cristóbal - Alejo methodology, in a controlled environment, the biological activity of five compounds was evaluated, under six treatments with five repetitions each; and as an experimental unit a Petri dish with 30 juveniles (J2) of M. incognita was used and 3 mL of each concentration was added to see the mortality response, the evaluations were carried out at 24 hours considering dead individuals they responded to the stimulation of the entomological pin, the correction of mortality was made by Abbott's formula and the mean lethal concentration was obtained using SAS 9.0. The mortality results were between 12 and 87.9%, however; β-citronellol was the one that presented the highest mortality rates and lowest LC50, so it can be considered as an alternative for nematode control.