Banca de DEFESA: TATIANNE RAIANNE COSTA ALVES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : TATIANNE RAIANNE COSTA ALVES
DATA : 22/07/2025
HORA: 13:00
LOCAL: Sala 21 PROPPG
TÍTULO:

MONOCULTURE OF MELON CROPS CAUSES CHANGES IN SOIL COMPOSITION AND IN THE ACTIVITIES OF MICROORGANISMS AND THE POTENTIAL OF COMBINED USE OF BACTERIA AND METABOLITES IN REDUCING ROOT ROT OF MELON AND INCREASING ENZYMATIC ACTIVITY OF THE SOIL

PALAVRAS-CHAVES:

Keywords: Soil health; Soil-borne pathogens; Microorganisms; Cucurbitaceae.

PÁGINAS: 68
RESUMO:

The increasing demand for food from limited resources by the human population remains a constant global concern. Brazil is one of the world's largest food producers and excels in the international trade of certain fruits, such as melons, where it is the second-largest exporter. To meet this demand, melons are cultivated over large areas, often through monoculture practices. This approach can cause significant damage to soil microbiota, decreasing both the quantity and diversity of microorganisms and reducing soil carbon storage. Additionally, monoculture favors the proliferation of phytopathogens that cause serious damage to melons, such as Fusarium sp., Macrophomina sp., and others. Controlling these pathogens is challenging due to their broad host range and resistance structures, which enable them to survive in the soil for extended periods. Environmental concerns have led to bans on chemical pesticides by importing markets, creating a need for sustainable alternatives to manage these phytopathogens. Therefore, the present study aimed to evaluate microbial activity in clayey and sandy soils subjected to different periods of melon monoculture and to evaluate the effect of alternative products and their combinations on the management of root diseases in melon crops. The first part of the work consisted of two experiments in each soil texture (sandy and clayey) and was carried out at Fazenda Agrícola Famosa. Part of the analyses were conducted at the Federal Rural University of the Semi-Arid (UFERSA) in Mossoró, Brazil, and the other part of the analyses was carried out at the Connecticut Agricultural Experiment Station (CAES) in New Haven, United States. The experimental design of the first trial was completely randomized, with four treatments (1 = native area, 2 = 8 years of monoculture, 3 = 15 years of monoculture, and 4 = 20 years of melon monoculture), with six replicates. Soil health indicator enzymes (β-glucosidase, arylsulfatase, and acid phosphatase), microbial biomass carbon, total organic carbon, labile carbohydrate, quantification of total bacteria, sporulating bacteria, and total fungi, and the soil microbiome were evaluated. When the data followed a normal distribution, analysis of variance was performed, and Tukey's test was used at a 5% probability level to compare treatment means. When they did not follow a normal distribution, the Kruskal-Wallis test was used, and means were compared using the Bonferroni test. Although melon monoculture is a common practice in melon-producing areas in Brazil and generates high employment, it reduces the activity of microorganisms that are so important for soil health, hindering the sustainability of this system. The study showed that if producers maintain monoculture for long periods, they need to adopt practices that further promote the activity of these microorganisms, such as increasing soil organic matter, increasing the use and diversity of microorganisms adapted to semiarid conditions, implementing green manure, and reducing practices that disturb the soil. The second part of the study also consisted of two field experiments in areas with a history of diseases caused by soil-dwelling pathogens, using a randomized block experimental design with six treatments and seven replicates. The treatments were previously chosen in a greenhouse experiment, using a completely randomized design with 30 treatments and four replicates. The treatments consisted of beneficial bacteria and fungi, and microbial metabolites. In the field experiments, the treatments were T1 = (Bacillus subtilis and B. licheniformis + Metabolites 1), T2 = (B. subtilis, Lactobacillus plantarum, and Enterococcus faecium + Metabolites 2), T3 = (Metabolites 1 + Metabolites 2), T4 = (B. subtilis, B. licheniformis + L. plantarum and E. faecium + Metabolites 1 + Metabolites 2), T5 = standard management of the farm (T. asperelum, B. subtilis, Metabolites 1 and Metabolites 2), and T6 = Control. The parameters evaluated were: plant stem diameter, shoot dry mass, disease severity, number of fruits per plant, fruit weight, and ºbrix, and soil enzymes. Analysis of variance was performed, and means were compared using Tukey's test at 5% probability. Regarding disease severity, none of the treatments stood out, however, T4 showed promising signs, such as increased soil enzyme activity, a greater number of fruits per plant, and was one of those that provided the greatest reduction in disease severity caused by soilborne pathogens in melons.

MEMBROS DA BANCA:
Interna - ***.979.544-** - ANDREIA MITSA PAIVA NEGREIROS - UFERSA
Externa ao Programa - 1780797 - EULENE FRANCISCO DA SILVA - nullExterno à Instituição - FRANCISCO ROMÁRIO ANDRADE FIGUEIREDO - PESQUISADOR
Externo à Instituição - HAILSON ALVES FERREIRA PRESTON - UFRN
Presidente - 1544411 - MARCIA MICHELLE DE QUEIROZ AMBROSIO
Interno - ***.076.546-** - WASHINGTON LUÍS DA SILVA - CAES