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This study evaluated a β-D-1,6-glucan derived from the regional oomycete Lasiodiplodia theobromae, comparing its effectiveness with the traditional elicitor ASM in inducing post-harvest resistance in grapes and promoting sustainable practices. Commercial grape varieties (Bordô and Niágara Rosada) were sourced locally and treated with water (Control), β-D-1,6-glucan (200 mg L⁻¹), or ASM (Bion® 500 WG, 100 mg L⁻¹). Grapes treated with β-D-1,6-glucan consistently showed a tendency for lower AUDPC (Area Under the Disease Progress Curve) values across both varieties and injury conditions. In wounded Niágara grapes, ASM initially showed a tendency to reduce AUDPC until the 8th day, but β-D-1,6-glucan had the lowest value by day 10. β-D-1,6-glucan-treated fruits also had the highest Total Phenol Content (TPC) and pulp firmness compared to those treated with ASM or water. This study underscores β-D-1,6-glucan’s potential as a natural alternative to synthetic fungicides, enhancing grape resistance to Glomerela cingulata, extending shelf life, and reducing environmental and health impacts.

Despite the positive results of using elicitors to induce resistance against plant diseases, some factors have inhibited the popularization of their use in agriculture. There is an energetic cost related to the elicitors' induced response which can cause undesired effects on growth under low-pressure disease conditions. Elicitors can create phytotoxicity and show high variation in their efficiency between different genotypes within the same crop; in addition, the positive results related to the induced resistance may not repeat in field treatments, adding to the possibility that they are not economically viable. Thus, we carried out two experiments to investigate the technical and economic efficiency of acibenzolar-S-methyl (ASM) and its association with fungicides in the control of leaf diseases of susceptible and resistant wheat varieties, and as how it reflects on the photosynthetic and production performance of wheat. This study showed the limitations of incorporating ASM into foliar fungal disease control in economic terms. However, it was evident that ASM effectively induced plant resistance against Leaf Rust and Powdery Mildew in the field and can be considered a sustainable option for wheat cultivation. Even though its association with chemical control was not the best economic strategy the use of ASM is a tool that can be incorporated into wheat cultivation to minimize the emergence of fungicide-resistant pathogens due to the diversification of modes of action employed and reduce the toxic residue deposition to the environment and human health.

Despite recognizing the importance of genetic improvement in the production of barley grains, little information is available on the contribution of phenological development to the genetic improvement of Brazilian barley. Field experiments were carried out between 2011 to 2013, in the absence of biotic and abiotic stresses and with preventive lodging control. Five two-rowed spring barley cultivars, released between 1968 and 2008, were evaluated. Although there was no significant association in the cycle length (Emergence - Anthesis) of the cultivars with the year of release, the genetic improvement increased the proportion of the Doble ridge - Maximum number of spikelet primordia/Maximum number of spikelet primordia - anthesis period to the total time to anthesis. The period between DR-MNP was increased in modern cultivars, to the detriment of the Doble ridge - Maximum number of spikelet primordia period. However, the duration of the period between emergences to the double ridge (vegetative phase) was not altered in the analyzed period. Barley breeding in Brazil did not change the total number of leaves on the main stem but caused an increase in the number of leaves earlier in the development, favoring the high level of tillering. The leaf architecture of modern barley was altered towards a more vertical inclination (erectophilic canopy), allowing the penetration of photosynthetically active radiation into the crop canopy.