Bean common bacterial blight reduces crop productivity and is difficult to control. However, biological control by yeast can be an efficient complementary measure in management. The objective was to evaluate the ability of Rhodotorula glutinis and Sporidiobolus johnsonii to reduce the severity of bean common bacterial blight. The cultivar used was IAPAR Tuiuiú. The first experiment was sown in March and repeated in October, in a 4 × 3 factorial scheme (zero, one, two and three applications and three treatments R. glutinis, S. johnsonii and Acibenzolar-S-Methyl (ASM)). For this purpose were evaluated the area under the disease progress curve (AACPD), number of pods per plant (NVP), number of grains per pod (NGV), thousand grain mass (MMG) and productivity. For the results of the March cultivation, due to the low temperature, the maximum severity of bean common bacterial blight was 8% and the applications of yeasts were not significant for AACPD. The isolate R. glutinis showed the highest average of productivity with two applications, being 1006.44 kg ha-1. For October cultivation, R. glutinis and S. johnsonii isolates reduced AACPD by 66.84 and 58.42%, respectively with three applications. For productivity, R. glutinis and S. johnsonii showed no difference between the number of applications. The ASM showed a productivity of 4418.56 kg ha-1 with three applications. The results indicate that the yeasts R. glutinis and S. johnsonii reduce the severity of bean common bacterial blight and the most appropriate number of applications are two for both isolates.

Wheat productivity is compromised by the number of diseases that affect it. The diseases control is basically effected by the use of fungicides, however, biological control has become important due especially to the demand for foods free of chemical compounds. The objective of this work was to evaluate the efficiency of yeasts in reducing diseases through the treatment of wheat seeds and the spraying of plants in the field. The tests were carried out in the field and laboratory, with the yeasts Candida albicans, Cryptococcus laurentii, Pichia guilliermondii, Rhodotorula glutinis, Zygoascus hellenicus and Saccharomyces cerevisiae compared with fungicide (carbendazim) and control with water. In the laboratory, seed health, germination, germination speed index, cold test and accelerated aging were analyzed. In the field, seed treatment and aerial application were carried out when the flag leaf was emitted and the occurrence of diseases, chlorophyll content, production components, productivity and production quality was evaluated. For the variables of production and quality of the wheat in field, the yeast Z. hellenicus was efficient for productivity resembling the fungicide. For the severity of diseases in field, parameters related to germination and seed health, yeasts were not efficient.

With intensive cultivation and the lack of crop rotation, the no-tillage system has been showing compacted areas. For its reduction, mechanical scarification and crop rotation has been recommended. Thus, the present study aimed to evaluate in a no-tillage system the effect of mechanical scarification and crop rotation systems on soil porosity and density after 18 months. The experimental design used was randomized blocks in a split-plot scheme, with four replications. The main plots consisted of maintaining the no-tillage system and minimal soil preparation with a chisel, carried out before the cultivation of cover plants. The subplots were composed of different plant species grown in winter: wheat, consortium of forage pea + black oat and consortium of black oat + forage turnip. Both were succeeded by cultivation of soy and lupin. Macroporosity, microporosity, total porosity and bulk density were evaluated. After 18 months, the scarified soil showed a higher bulk density (0.10-0.15 m layer) when compared to the no-tillage system, demonstrating that this isolated decompression alternative does not improve the physical properties of the soil. The area in succession to oat + turnip/soybean/lupin showed lower bulk density.

This work aimed to evaluate the effect of the yeasts Candida albicans, Pichia guilliermondii, Rhodotorula glutinis, Saccharomyces cerevisiae and Zygoascus hellenicus in the control of anthracnose in cucumbers. The influence of volatile and non-volatile compounds on mycelial growth and the effect of cell suspension and culture filtrate on conidial germination were evaluated. In a greenhouse, yeasts were tested on cucumber cotyledons, one cotyledon being treated and the other not; afterwards both cotyledons were challenged with C. orbiculare. The severity of the disease in both cotyledons was assessed by determining biological control and resistance induction. The production of volatile compounds from the yeasts R. glutinis and C. albicans reduced the pathogen growth by 90.7 and 90.0%, respectively. The production of non-volatile compounds stimulated the pathogen development. Conidia germination was affected when exposed to cell suspension of all tested isolates, ranging from 43 to 75%. For the culture filtrate from Z. hellenicus, it reduced the conidia germination by 11.4%. In the in vivo test, on the treated cotyledon, the yeasts Z. hellenicus, R. glutinis and S. cerevisiae reduced the anthracnose severity by 52.5, 50.0 and 42.5%, respectively.

One of the factors that cause the greatest loss of fruit in post-harvest are diseases, especially rotting such as anthracnose. Therefore, this work aimed to test the potential of the yeasts Candida albicans, Pichia guilliermondii, Rhodotorula glutinis, Saccharomyces cerevisiae, Cryptococcus laurentii and Zygoascus hellenicus in the control of Colletotrichum musae in bananas in post-harvest period. To test the potential of these yeasts, the effect of volatile and non-volatile compounds, culture pairing and spore germination of the fungus C. musae in vitro was evaluated. In post-harvest fruits, the area below the mycelial growth curve (AACCM) and the area below the disease progress curve (AACPD) were evaluated. The yeasts C. albicans, R. glutinis, S. cerevisiae and P. guilliermondii produced volatile compounds with antifungal action, reducing the development of the fungus in vitro. The yeast R. glutinis was shown to be more efficient in reducing mycelial growth in vitro of the fungus through the production of non-volatile compounds. The yeasts C. albicans and P. guilliermondii showed the presence of an inhibition halo. All yeasts induced the germination of C. musae conidia and were not efficient in controlling anthracnose in vivo.