Banca de DEFESA: DOUGLAS GRACIEL DOS SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : DOUGLAS GRACIEL DOS SANTOS
DATE: 03/02/2023
TIME: 08:30
LOCAL: Sala virtual através do link https:
TITLE:

EFFECT OF SILICON ON THE RESISTANCE OF SORGHUM GENOTYPES AND ON THE BIOLOGY OF THE SORGHUM APHID (Melanaphis sorghi)

 

KEY WORDS:

Sorghum bicolor, Sorghum aphid, varietal resistance, induced resistance.

PAGES: 66
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitotecnia
SPECIALTY: Fisiologia de Plantas Cultivadas
SUMMARY:

Sorghum is a plant belonging to the Poaceae family, C4, with several agronomic uses, also showing itself as a great alternative ingredient, especially to corn. Melanaphis sorghi is the main phytosanitary problem of this crop in Brazil. Its main damage is the suction of sap, causing losses in production, debilitating or causing the death of the plant. Among the control methods used in countries that have lived with the plague for longer is the use of resistant cultivars. Another method used to control arthropods is to increase the tolerance of the plants by applying silicon. The silicon (Si) has a mechanical effect with the silification of the epidermis and, according to the literature, a chemical effect with the production of phenolics and antioxidants. This study aims to characterize the effects of fertilization of different doses of Si combined to different sorghum genotypes, to evaluate plant tolerance and biological aspects of M. sorghi. Five genotypes (AG1090, BRS373, BRS658, Ponta Negra and BRS716) were evaluated in four different doses of precipitated silicic acid (0, 2, 4 and 6 t ha ^-1). Si was applied to the soil in 20 l pots, in two doses, with half applied at planting and the second half applied in the top dressing. To evaluate the aphid population dynamics, the pre-reproductive period, reproductive period, fecundity, number of nymph days, longevity and mortality and biological aspects of the life table were evaluated in the laboratory in a controlled environment from first instar nymphs to death. For tolerance evaluation, plants of each treatment were evaluated for: (i) injury level (percentage of the plant attacked) and infestation (percentage of colonies infesting the plants) every seven days, starting from the V2 stage; after 50 days it was done (ii) green and dry weight of the aerial part, height and number of leaves; (iii) activity of antioxidant enzymes of the leaves; (iv) analysis of plant composition (lignin and fiber contents) and (v) quantification of silicon and macro and micronutrients. For the biology of M. sorghi, the silicon doses had different effects in each genotype. The genotypes with graniferous aptitude, had better performance with the dosage of 6 t ha^-1; while the genotypes with forage aptitude had better performance with the dosage of 4 t ha ^-1; and the biomass genotype with the dosage 0, with the reduction of M. sorghi fertility.

 

BANKING MEMBERS:
Externo à Instituição - BRUNO HENRIQUE SARDINHA DE SOUZA
Presidente - 1973686 - LEONARDO LUCAS CARNEVALLI DIAS
Interno - 1725637 - MARCOS ANTONIO MATIELLO FADINI