Banca de QUALIFICAÇÃO: JULIANNA CATONIO DA SILVA
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.STUDENT : JULIANNA CATONIO DA SILVA
DATE: 01/12/2022
TIME: 09:00
LOCAL: virtual
TITLE:
PHYSIOLOGY AND PRODUCTIVITY OF SESAME AS A FUNCTION OF WATER AVAILABILITY
KEY WORDS:
Sesamum indicum L., Evapotranspiration, Drainage lysimetry, Climatic conditions
PAGES: 34
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Agrometeorologia
SUMMARY:
Irrigation management is an essential practice when it is desired to increase the productivity of a crop. Therefore, two field experiments were conducted to determine the water requirement (WUE), as well as to evaluate the physiology and productivity of sesame as a function of soil water availability, in the Rio Largo region, AL. The research was conducted from February 12 to June 14, 2021 (rainy season) and October 08, 2021 to January 24, 2022 (dry season). The determination of the ETC was obtained through a battery of drainage lysimeters, by the soil water balance. The reference evapotranspiration (ET0) was calculated by the Penman-Monteith-FAO method. Through the ETC/ET0 ratio the crop coefficient (KC) values were obtained for each phenological phase of sesame. An experiment was set up adopting randomized block design (BCT), with five treatments and four blocks. The treatments were: 50, 75, 100, 125 and 150% of ETC with daily applications via drip irrigation. Fortnightly evaluations were made to determine the following growth parameters: plant height, stem diameter, leaf area, leaf area index and total dry phytomass. The following physiological parameters were evaluated: relative leaf water content, pre-dawn leaf water potential, midday leaf water potential, SPAD index, net photosynthetic rate, internal CO2 concentration, stomatal conductance, transpiration rate, instantaneous water use efficiency, PSII quantum efficiency, maximum photosystem II photochemical efficiency, and leaf temperature. At the end of each cycle the production components were analyzed: yield, water use efficiency, weight of 1000 grains, number of pods per plant, number of grains per pod and dry mass of grains. The total accumulated rainfall (rain), the total ETC obtained by drainage lysimeters and the total ET0 were equal to 870.1 and 212.9 mm, 555.86 and 545.18 mm and 519.90 and 534.55 mm for the rainy and dry periods, respectively. The average KC values for each phenological phase were equal to 0.44; 0.88; 1.36 and 0.71 for the rainy period and 0.48; 1.00; 1.44 and 0.44 for the dry period. The total evapotranspiration (rainfall + irrigation) obtained for each blade of irrigation were: 889.96; 911.32; 932.03; 958.53 and 979.29 mm for the rainy season and 416.44; 506.51; 595.37; 690.11 and 775.80 mm for the dry season, in L1, L2, L3, L4 and L5, respectively. The highest values obtained were: 249.0 cm; 18.74 mm; 6506.99 cm2; 10.84 and 16629.83 kg ha-1, for the variables plant height, stem diameter, leaf area, leaf area index and total dry phytomass, respectively. The TRA ranged from 63.8 to 75.7% in the rainy period and 60.2 to 79.3% in the dry period. The leaf ΨW at dawn ranged from -1.74 and -0.98 Mpa for blades L1 and L5, respectively. At 12h it varied between -3.675 and -1.12 and -3.90 and -1.03 Mpa, for the rainy and dry periods, respectively. The maximum SPAD index (34.06 and 34.42) was obtained with the irrigation blade of 911.36 and 642.50 mm for the rainy and dry periods, respectively. The maximum "A" rates (36.09 and 33.73 μmol of CO2 -m-2-s-1) were obtained with the application of 923.45 and 648.88 mm. The highest Ci (233.75 and 238.25 μmol of CO2 -m-2-s-1) were observed at the blade of 150% of ETC. Gs obtained the highest values (0.33 and 0.45 μmol of H2O -m-2-s-1) with the application of 955.41 and 799.3 mm. The highest values for "E" are equal to 4.05 and 3.69 μmol of H2O -m-2-s-1 for the cycles conducted in the rainy and dry periods, respectively, found at the irrigation blade of 150% of ETC. The highest and lowest values for ΦPSII are 0.57 and 0.43, respectively, while for the Fv/Fm ratio these values are equal to 0.78 and 0.66. The leaf temperature at 50% of the ETC was 32.8°C, decreasing this value (29.9°C) until the highest irrigation. The maximum yield (2577.25 kg ha-1) was obtained with the application of 650 mm of water (105% of the ETC). In this context, it is possible to infer that the use of irrigation in dry periods allows satisfactory yields of sesame.
BANKING MEMBERS:
Presidente - 1996545 - ALEXSANDRO CLAUDIO DOS SANTOS ALMEIDA
Interno(a) - 1206894 - IEDO TEODORO
Interno(a) - 1347702 - LAURICIO ENDRES
Externo(a) à Instituição - RAFAEL BATTISTI - UFG
Externo(a) à Instituição - DANILTON LUIZ FLUMIGAN - EMBRAPA
Externo(a) à Instituição - THIERES GEORGE FREIRE DA SILVA