Currently, the use of alternative tools for chemical control has become one of the most sustainable and eco-friendly options for crop protection against phytopathogens. Thus, the present study aimed to assess the effect of essential oils (EOs) on the control of tomato early blight (EB), a highly destructive disease of this crop. The antifungal activity and ability to induce resistance induction of the EOs of thyme (Thymus vulgaris), lemongrass (Cymbopogon citratus) and tea tree (Melaleuca alternifolia) were tested for control of A. linariae in tomato plants. In vitro, mycelial growth and conidial germination were strongly inhibited when thyme EO (TEO; 2000 ppm) and lemongrass (LGEO; 2000 ppm) were applied. The infected leaf area and final disease index were decreased by 47.78% and 39.00%, respectively, compared to the water treatment. Foliar spraying with TEO increased the activity of the defense-related enzymes peroxidase, polyphenol oxidase and β-1,3-glucanase. Furthermore, callose deposition and phenolic compound accumulation in tissues infected by A. linariae improved after TEO application. In conclusion, TEO stimulated the defense system of tomato plants infected by A. linariae, which was associated with a reduced severity of EB. These results indicate that TEO is a potential tool in tomato EB disease management.

Wheat blast, caused by Pyricularia oryzae Triticum lineage (PoTl), is one of the most destructive and significant fungal diseases affecting wheat crops. The stability of the G143A mutation in the cytB gene, which confers resistance to Quinone outside inhibitor fungicides (QoIs) in PoTl isolates, has not been extensively studied. This study was conducted to evaluate the stability of fungicide resistance, fitness, and competitive ability of the QoI-resistant (R) PoTl isolates group over nine and five consecutive transfer cycles in vitro and in vivo, respectively, without fungicide exposure. No changes in azoxystrobin sensitivity were observed in either the QoI-resistant or sensitive (S) PoTl isolate groups after the successive transfer cycles in vitro and in vivo. The mycelial growth of the QoI-R PoTl isolate group remained stable, while the conidial germination capacity increased over time. For the QoI-resistant isolates, leaf and head disease, conidial production, and the latent period on wheat leaves did not change between the first and fifth infection cycles. In each transfer cycle, the highest levels of leaf and head disease, as well as the largest quantities of conidia collected from wheat leaves, were observed in isolate mixtures. Also, the G143A mutation responsible for QoI resistance remained stable after five transfer cycles of the QoI-resistant (0S:100R) isolate on wheat leaves. Our findings indicate that the G143A mutation remains stable, and there are adaptive benefits in QoI-R PoTl isolates. We discuss the ecological implications of the wheat blast population’s adaptation and PoTl QoIs resistance stability in wheat-cropping areas in Brazil.

New alternatives for white mold management need to be discovered by the researchers. Phosphites, a reduced form of phosphate (PO₄^3-), are composed of a phosphorous acid salt that is systemically mobile in the plant and has been shown to control diseases in several economically crops (^{Smillie et al. 1989}; ^{Brackmann et al. 2004}; ^{Peruch and Bruna 2008}; ^{Dianese et al. 2009}; ^{Nojosa et al. 2009}; ^{Araújo et al. 2010}, ²⁰¹⁵; ^{Fagundes-Nacarath et al. 2018}). Fungal mycelial growth and sporulation of pathogens can be both directly affected by phosphites or the host defense responses (e.g., production of phenolics, phytoalexins, and lignin as well as high activities of chitinase, β-1,3-glucanase, peroxidase, polyphenoloxidase, and phenylalanine ammonia-lyase) activity can be activated by them (^{Panicker and Gangadharan 1999}; ^{Daniel and Guest 2005}; ^{Dalio et al. 2014}; ^{Novaes et al. 2019}; ^{Fagundes-Nacarath et al. 2018}).

Although plant breeding and chemical approaches contribute to disease control, they are not able to completely contain it, due to the ability of the pathogen to resist against the fungicides and may overcome the resistance offered by plants of certain genotypes. Endophytic Penicillium citrinum strains GP1 and GP3, inoculated on seeds before sowing or sprayed on leaves, reduced the severity of rice blast while improving the growth of rice plants from cultivar BRSMG Caçula. Rice seed treatment with conidia of P. citrinum GP3, prior to seeding, led to a 58% reduction of blast severity. An association of GP1 and GP3 applied via seed treatment or foliar spray decreased blast severity by 33 and 37%, respectively. The area under the disease progress curve of the treatment of seeds (T5) with GP3 was lower than other treatments. For plant growth promotion, the association of GP1 and GP3 significantly enhanced the number of tillers per plant with 11 as compared to control, 10. Microscopic analysis revealed the endophytic colonization of rice root tissues by Penicillium GP1 and GP3. The P. citrinum reduced blast in rice plants while improving their fitness.