Method and phenological characterization of the stadiums and phases of the development of castor bean plants

Abstract

With increasing global energy demands, the production of biofuels has been gaining economic importance, with the castor oil plant being one option for the production of biofuel. This study was performed on irrigated cultivation of the castor oil plant, variety IAC 2028, from March to October 2011, in Lavras, Minas Gerais, Brazil, with the following aims: a) to characterise and estimate the sub stages and stages of the crop in days after sowing (DAS) and in growing degree days (GDD) and; b) determine a phenological model of development that describes the vegetative and reproductive behavior of the crop cycle. The experiment was conducted under optimal conditions of irrigation and fertilisation. To determine the phenological model, 15 sub stages and 4 stages of the crop were defined and estimated according to the periodic quantification of variables such as the number of leaves, leaf area, soil cover, and periods of floral initiation, anthesis, bean formation, and maturation by raceme order. We concluded that: a) the sub stages were well characterised and estimated, in particular Vo, A2, M2, and M3, which closed stages I, II, III, and IV with nearly 42, 65, 87, and 100% of the thermal power required by the crop during the lifecycle, respectively; b) the phenological model of the sub stages was determined satisfactorily in GDD; and c) the plant and reproductive sub stages were not completely distinguishable, and the maximum soil cover in M1 indicated that greater productivity could occur with a population increase.

Effects of Nitrogen Fertilization and Soil Water Content on Seed and Oil Yield in Perennial Castor in a Mediterranean Environment

“…Daily meteorological data and potential evapotranspiration (ET 0 ) were continuously measured through a weather station connected to a data logger (Delta-T, WS-GP1 Compact) and a class A evaporation pan (mm d −1 ). In the first year (2021), during the growing season, the date of occurrence of the main phenological stages of the crop [24], seedling emergence (Ve), anthesis (A), and physiological maturation (M) were recorded, and physiological plant gas exchange (photosynthesis and transpiration), using a portable system (LCi-SD, ADC BioScientific, Great Amwell, Hertfordshire, UK), was measured at 7-10-day intervals for a total of 9 measurements. Harvest was carried out starting from the primary racemes as follows: 7 September, 25 September, 20 October, and 20 November 2021 for I100, I60, I30, and I0, respectively.…”

Effects of Sowing Dates and Genotypes of Castor (Ricinus communis L.) on Seed Yield and Oil Content in the South Mediterranean Basin

“…Dates of phenological phases for each genotype were measured twice a week during the growing period. The scoring has been performed as described by Gervasio et al, (2016) [21] Hence, the phases recorded during the trial were emergence = E; main inflorescence appearance = F1; main flowering on the raceme = A1; beginning of fruit set on the main raceme = G1/1; conclusion of the main raceme fruit set = G1/2; maturation of the main raceme considered at the browning of all the present capsules = M.…”