Ajuste de modelos para estimativa do índice de área foliar e acúmulo de biomassa do pimentão em função de graus-dias

Abstract

This study was carried out at SIPA (Integrated Agroecological Production System), in Seropédica, RJ, Brazil, with the objective of generating models for characterizing variation and evolution of leaf area index (LAI) and total dry mass of Bell pepper as a function of degree days. Experimental design was of plots split in time, with three replications. The matematical models obtained by regression analysis on the basis of the significance of the coefficients, the F value in the variance analysis of regression, and higher determination coefficient (R 2 ). Based on adjusted curves for LAI and dry mass and in their respective maximum values degree days is a viable methodology for determination of crop phenological stages. The values of LAI and biomass accumulated by the plants were not significantly different between tillage systems. Bell pepper needed a total of 1533 degree days for completing its productive cycle, with maximum dry mass accumulation occurring at 1059 and 1148 degree days for conventional and no till cropping, respectively.

Morphological analysis and chlorophyll index of bell pepper cultivars under protected cultivation

“…(Araquam, 2013) The largest leaf area (35.96 cm²) was found for the cultivar Amarelo Satrapo (Table 3). According to (Carvalho, 2011), leaf area is connected to the photosynthetic capacity of plants to intercept solar radiation and assimilate carbon dioxide; this results in a greater amount of energy available for the plant to perform its metabolic activities, such as growth and fruit production (Reis et al, 2013). This result corroborates the higher results found for fruit weight, yield, and transversal diameter found Amarelo Satrapo in the present study.…”

Agronomic Performance and Water Use Efficiency of Irrigated Cactus Pear Cultivars

“…According to Ramírez-Tobias, Aguirre-Rivera and Pinos-Rodriguez (2010), cactus pear plants present three growth stages, with approximately 40 days for the Lag stage; 200 days for the exponential growth stage, with increases in the root system and high CO 2 absorption; and then, the stabilization stage. This was confirmed for the cultivars evaluated in the present study, allowing the evaluation of cultural practices and analysis of plant production of the species as a result of their photosynthetic capacity and radiation interception and their effects on the final crop production (ADAMI et al, 2008;CARVALHO;PEREIRA, 2011;CEPEDA et al, 2013;ZEGBE;PÉREZ;COVARRUBIAS, 2014). However, CAI varies depending on the genus, clone, and crop conditions, making it an information that allows the evaluation of plant development without the need of knowing the accumulated biomass of the crop (OLIVEIRA JÚNIOR et al, 2009).…”

Gas exchange, leaf and root dry mass in Bell Pepper under fertigation with nitrogen and potassium

“…According to Andrade Júnior et al (2011), the measurement of gas exchange contributes to the study of physiological changes in plants submitted to adverse conditions. According to Carvalho et al (2011), there is a growing need to estimate the productive capacity of crops in view of the possible effects caused by the changes in cultivation techniques. In this sense, it is important to determine the effect of nutritional factors on plant physiology in order to ensure greater accumulation of biomass and production.…”