The objective of this work was to estimate the genetic parameters of cassava (Manihot esculenta) genotypes cultivated in the field, as well as the genetic divergence between them, in order to identify which ones show a greater resistance to anthracnose and bacteriosis. Three independent experiments were carried out, evaluating 133 accessions and nine commercial cultivars of cassava distributed in five blocks, with five plants per plot in each experiment. In the first experiment, the plants were subjected to inoculation with Xanthomonas phaseoli pv. manihotis (bacteriosis). In the second, the plants were subjected to inoculation with Colletotrichum gloeosporioides f. sp. manihotis (anthracnose). In the third, carried out in an augmented block design and under naturally occurring diseases, visual evaluations of the plants were performed using a rating scale. Heritability was used as a genetic parameter, and the unweighted pair group method with arithmetic mean was applied to determine genetic divergence and clustering. In the third experiment, genetic variability was detected among accessions, which were evaluated for the area under the disease progress curve (AUDPC) for anthracnose and bacteriosis. In the first and third experiments of bacteriosis, the chances of success in the selection of resistant accessions are higher due to the high heritability values obtained. The BGM-1170 and BGM-1134 accessions show the lowest mean for AUDPC and are considered resistant to anthracnose and bacteriosis.

Aluminum is an element present in Brazilian soils, mainly in the Cerrado biome and its presence is responsible for the formation of reactive oxygen species, which results in damage to the plasma membrane. Hydrogen peroxide has been studied as an acclimatization inducer and it is possible to obtain a plant with greater tolerance to the adverse environment. This work aimed to subject Crotalaria ochroleuca seeds previously treated with hydrogen peroxide to the stress caused by aluminum. The physiological quality of the seeds was evaluated by means of germination and vigor test determined by first count, germination speed index, shoot and root length test, and shoot and root dry mass. Crotalaria ochroleuca seeds are sensitive to aluminum and high concentrations of hydrogen peroxide impaired seedling development.

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