Tomato is the most economically important vegetable crop worldwide and the second most important for Mexico. However, viral diseases are among the main limiting factors that affect the productivity of this crop, causing total losses in some cases. This review provides key information and findings on the symptoms, distribution, transmission, detection, and management of diseases caused by viruses of major importance in tomato crops in Mexico. Currently, about 25 viruses belonging to nine different families have been reported infecting tomato in Mexico, but not all of them cause economically significant diseases. Viruses of economic importance include tomato brown rugose fruit virus (ToBRFV), tomato spotted wilt virus (TSWV), tomato yellow leaf curl virus (TYLCV), pepino mosaic virus (PepMV), and tomato marchitez virus (ToMarV). The topics discussed here will provide updated information about the status of these plant viruses in Mexico as well as diverse management strategies that can be implemented according to the specific circumstances of each viral pathosystem. Additionally, a list of tomato-affecting viruses not present in Mexico that are continuous threats to the crop health is included.

Tomato brown rugose fruit virus (ToBRFV) is an emerging pathogen affecting tomato-production systems in several countries, including Mexico. This situation involves challenges due to the negative impact on yield and the lack of disease-management measures. This work analyzes the spatiotemporal distribution of ToBRFV in commercial tomato greenhouses. The presence or absence of diseased plants was evaluated weekly, assigning a location in space (x, y). Temporal analysis consisted of fitting the incidence to the monomolecular, logistic, log-logistic, Gompertz, exponential, Weibull, and Richard models, evaluated using the Akaike information criterion, significance, correlation, coefficient of determination, and root mean square error. Spatial analysis consisted of determining spatial aggregation using the Moran, Fisher, and Lloyd indices. In addition, spatial distribution was assessed by sequence observations, point patterns using the inverse distance index, and analysis by SADIE distance indicators. Results indicated that the logistic models (log-logistic and logistic) best described the temporal progress of ToBRFV. This disease also had slightly aggregated patterns in the initial phase, highly aggregated in the exponential phase, and uniform in the deceleration and stationary phases. This study demonstrates that the spatial and temporal dynamics of ToBRFV have important implications for the monitoring, diagnosis, management, and risk prediction of this disease.

Eggplant (Solanum melongena L.) is an important solanaceous crop that is produced mainly in tropical and subtropical regions and is widely consumed worldwide. In 2018, eggplant production in Mexico...

Papaya (Carica papaya L.) is grown on approximately 16,000 ha in Mexico. In August 2014, a fruit rot was observed on papaya fruit grown in Colima Mexico. Disease symptoms included an initial soft rot and then, the production of profuse mycelial growth with light-brown to dark sporangia on the infected fruit. Fungal colonies on potato dextrose agar (PDA) grew rapidly at 1.4 cm/day at 25°C. Morphological characteristics include coenocytic mycelia, spherical sporangia 86.31μm (69.23 to 146.20 μm) with a persistent wall covered with crystalline spines. Sporangia split longitudinally into two halves to release the spores, were columellae obvoid 58.84 (31.24-88.57) x 49.71 (32.15-71.65) μm, sporangiospores were smooth mainly ellipsoid, hyaline, unicellular, 8.37 (5.54-10.99) x 6.52 (4.43-9.06) μm (n=100) with hyaline filiform appendages arising from the ends of the spores. The cardinal temperatures were 10, 25 and 40°C. Based on these morphological characteristics the fungus was identified as Gilbertella persic...

Papaya (Carica papaya L.) is an economically important crop in Mexico, which is the fifth largest producer worldwide. Anthracnose disease is the main limitation of papaya production. In October 2014, nine fruits with small lesions with sunken and irregular edges and white to grey sporulation at the center were collected in two orchards in Oaxaca State (16°08’12’’N, 97°45’11’’W). The obtained fungal culture from lesion edges showed white aerial mycelia with black perithecia on potato dextrose agar (PDA) medium after seven days. Conidia were single celled and hyaline, cylindrical, with rounded ends and 4.2 (3.4-5.5) x 13.9 (10.8-17.6) µm. Ascospores, which measured 4.04 (2.9-4.8) x 15.05 (10.3-23.4) µm (n= 100), were cylindrical, curved and tapered towards the ends. This description is similar to species belonging to the Colletotrichum gloeosporioides species complex (Weir et al. 2012). The internal transcribed spacer (ITS), calmodulin (CAL), β-tubulin 2 (TUB2) and glyceraldehyde 3-phosphate dehydrogenase (...