Banca de DEFESA: LAURA CARINE CANDIDO DINIZ CRUZ

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LAURA CARINE CANDIDO DINIZ CRUZ
DATE: 14/03/2023
TIME: 10:00
LOCAL: On-line
TITLE:

Use of Organic Compost in Brassicaceae Fertilization and Effects on Clubroot Control.

KEY WORDS:

Brassica oleracea var. italica. Plasmodiophora brassicae. Poultry litter.

PAGES: 66
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Fitopatologia
SUMMARY:

The Brassicaceae family includes several species of vegetables of economic and social importance. In the mountainous region of Rio de Janeiro (Brazil), a major producer of brassica, broccoli is produced year-round in small areas owned by family farmers and with massive use of poultry litter as fertilizer. One of the main obstacles to the regular cultivation of broccoli and other brassicas is clubroot, caused by Plasmodiophora brassicae, whose losses are associated with failures in soil and crop management. As the losses caused by the disease can be aggravated by the chemical and physical characteristics of the soil and little is known about the effect of organic compounds on its development, the present work was carried out with the objectives of: a) adjusting the methodology for studying the effect of poultry litter on broccoli and on clubroot in a controlled environment, adjusting the ideal dose of compost and the density of resistant spores of the pathogen; b) to evaluate the effect of the time of application of poultry litter on disease intensity and broccoli growth and production. Initially, in a test under greenhouse conditions, the effect of applying six doses of composted poultry litter, equivalent to 0, 30, 60, 90, 120, 150 kg of N ha^-1, in inoculated plots was evaluated or not with resistant spores of P. brassicae (4.17 x 10⁶ spores per g of soil), in a 6x2 factorial scheme and 4 blocks. Then, a test was carried out in order to adjust inoculum densities of P. brassicae to be used in subsequent tests, evaluating five different densities (1.39 x 10², 1.39 x 10³, 1.39 x 10⁴, 1 .39 x 10⁵ and 1.39 x 10⁶ spores per g of soil). Subsequently, two tests were carried out in two greenhouses and in two different soils to evaluate the effect of the date of application of the poultry litter, on the day of transplanting the seedlings and at 7 and 14 days prior to transplanting, compared to mineral fertilization - in plots inoculated or not with resistant spores of the pathogen. A pre-adjusted spore density (10⁶ spores of P. brassicae per mL, equivalent to 6.25 x 10³ spores per g of soil) was used, a dose of 90 kg of N per ha and a control with an equivalent dose of NPK. A randomized block design in a 4x2 factorial scheme was adopted. In the first test, a high incidence and severity of the disease was observed in all compound doses tested due to the high concentration of inoculum used. In the non-inoculated plots, increases in plant growth and biomass accumulation were observed as a function of the dose, with optimal doses close to 90 kg of N ha^-1. In the inoculum density adjustment assay, the density of 10⁶ P. brassicae spores per mL was selected, as it provided high incidence and medium severity of the disease. In the study of times of application of poultry litter, it was found that this compound, regardless of the time of application, can favor the development of the disease when compared to fertilization only with mineral sources. In non-inoculated plots, significant gains in plant biomass were observed with the application of poultry litter, compared to mineral fertilization, with better results when the application was carried out seven days before transplanting. It is concluded that fertilization with poultry litter, regardless of the time of application in pre-planting, favors the development and production of broccoli, but that this benefit is annulled in soils contaminated with resistant spores of the pathogen by favoring the development of clubroot.

COMMITTEE MEMBERS:
Presidente - 1213072 - MARGARIDA GORETE FERREIRA DO CARMO
Interno - ***.960.133-** - EDNALDO DA SILVA ARAÚJO - EMBRAPA
Externo à Instituição - MARUZANETE PEREIRA DE MELO - UFPI