Artigos Publicados

2020 - Base Cut Quality and Productivity of Mechanically Harvested Sugarcane

Marcelo de Almeida Silva, Lucas Almeida de Holanda, Maria Márcia Pereira Sartori1, Gabriel Henrique Germino, Alexandrius de Moraes Barbosa e Leandro Bianchi
Sugar Tech - v.22, n.2, p.284-290.

This experiment aimed to assess the damage caused in the sugarcane ratoon by the wear of the base cutter blades over 5 h of effective harvester work and the influence of the damage on the growth and productivity of the next harvest. The experiment was carried out in Lenc¸o´is Paulista, Sa˜o Paulo state, Brazil, in a commercial area. The crop was in the cane plant cycle, and the damage caused by the base cutting to the clump was evaluated during the harvest. The tillering and the percentage of sprouting failures were evaluated during the growth of the plants in the second cycle to verify the damage in the crop. Evaluations were made in each hour of work of the harvester, according to a completely randomized design. The variables evaluated included wear of base cutter blades, number of stumps and stalks, tillering, percentage of sprouting failures, cut quality and productivity. A statistical analysis was performed using the Friedman test. The action of the base cutter lifted the stumps, but there was no increase due to wear of the blades. There was a reduction in cut quality and crop yield in the following harvest due to an increase in the wear of the base cutter blades from the third hour of work.

2018 - Water stress effects on chlorophyll fluorescence and chlorophyll content in sugarcane cultivars with contrasting tolerance

Marcelo de Almeida Silva, Renata Passos Pincelli e Alexandrius de Moraes Barbosa
Bioscience Journal - v.34, n1, p. 75-87.

One way to minimize the impacts caused by water deficit (WD) in agriculture is the use of tolerant cultivars. The physiological evaluation of plants through the potential quantum efficiency of  photosystem II (Fv/Fm) and estimated chlorophyll content (SPAD index) can be an effective tool in the selection and recommendation of water deficit-tolerant cultivars. Within this context, the aim of this study was to evaluate the physiological responses of sugarcane cultivars classified as tolerant or susceptible to water deficit. The experiment was carried out near the city of Jaú, SP, Brazil in a greenhouse, between July and December 2013. The experimental design was completely randomized in a 4 x 2 factorial arrangement, with four replications. We studied four sugarcane cultivars: RB72454, RB855453 (prone to WD), SP81-3250 and SP83-2847 (WD-tolerant) in two water management regimes (with and without deficit). WD reduced stems dry mass of all cultivars, however, the greatest decreases were observed in susceptible cultivars to WD, where the decrease was 58.3 and 74.5% for cultivars RB855443 and RB72454, respectively. As for the SP81-3250 and SP83-2847 cultivars (tolerant), the reduction was 44.1 and 47.7%, respectively. For water deficit-tolerant cultivars, there was lower reduction in potential quantum efficiency of photosystem II and SPAD index; therefore, the physiological characteristics (Fv/Fm and SPAD index) are features that can aid the identification and selection of water deficit tolerant cultivars, and also help the  recommendation of these cultivars for harsh environments, minimizing the effects of water
deficit on stem yield on the sugarcane crop.


2017 - Physiology and Productivity of Sugarcane as Affected by Nitrogen Applied
Via Subsurface Drip Irrigation

Marcelo de Almeida Silva, Andressa Freita de Lima Rhein, Alexandrius de Moraes Barbosa
Journal of Environmental and Agricultural Sciences - v. 11, p. 15-28.

Most of sugarcane cultivation in Brazil is carried out under non-irrigated conditions, restricting crop yield due to lack of water. Nitrogen (N) fertilization via subsurface drip irrigation can promote the physiological processes of plants and increase the stalk and sugar yield of sugarcane. This present study aimed to evaluate irrigation and N use in sugarcane ratoon, and assess how this might affect physiological parameters and crop yield. We used cultivar SP80-3280 under subsurface drip irrigation and non-irrigated systems and two N levels (0 and 150 kg N ha-1). Irrigation and N fertilization rendered positive effects for stalk and sugar yields, as well as for plant physiological parameters. Our results showed that irrigation had positive effects over physiological parameters of sugarcane plants, generating great increase in water use efficiency for stalk and sugar production. It was also observed that the supplementary application of 25% water at the highest water deficit period for the crop has increased stalk yield in 84-94% and sugar yield in 86-100%. Nitrogen fertilizer showed increased efficiency in irrigated crop as well, promoting 84% gain in stalk yield. Therefore, subsurface drip irrigation is a great technique to increase crop yield and/or reduce the effects caused by drought.


2015 - Biomass and bioenergy partitioning of sugarcane plants under water deficit

Alexandrius de Moraes Barbosa, Kézia Aparecida Guidorizzi, Tiago Aranda Catuchi, Tadeu Alcides Marques e Gustavo Maia Souza
Acta Physiologiae Plantarum - v. 137, n132, p. 01-08.

This study assessed the photosynthesis, biomass, and phytoenergy production in sugarcane plants subjected to water deficit during the initial stages of development. We hypothesize that the limitations imposed by water deficit on photosynthesis proportionally affect carbon balance, growth, and partitioning of phytoenergy in sugarcane. This study was carried out during 5 months in a growth chamber and water deficit was induced by maintaining soil moisture at 20 % of the maximum water holding capacity (WHC). As control, one group of plants was maintained at 100 % WHC. Water deficit reduced the carboxylation of Rubisco and PEPCase significantly, which were the main limiting factors for photosynthesis. As consequence, the daily leaf carbon balance was significantly reduced by drought. The total accumulated dry matter in well-watered plants was 3.6 times higher than in drought-stressed ones. Water deficit reduced the energy accumulated in sugarcane plants by approximately threefold. Regardless of water regime, a large fraction of the converted energy was not found in stalks. Under water deficit, less than 20 % of the energy is stored in stalks. Since only a tiny fraction of solar energy is used for the production of first generation ethanol, our study reinforces the importance of evaluating strategies to optimize the use of sugarcane, for example, harvesting plant organs other than stalks.


2014 - Efeitos da temperatura do ar na fotossíntese da cana-de-açúcar na fase inicial do desenvolvimento

Anderson Guerra, Alexandrius de Moraes Barbosa, Kézia Aparecida Guidorizzi e Gustavo Maia Souza
Revista Agrarian - v7, n24, p. 36-42

Frente às mudanças climáticas faz-se necessário não somente conhecer os efeitos da temperatura do ar no desenvolvimento das plantas, mas, também, conhecer quais fatores fisiológicos estão relacionados à redução e/ou aumento da fotossíntese. O objetivo deste trabalho foi avaliar o efeito da temperatura do ar sobre a fotossíntese e o desenvolvimento na fase inicial de crescimento da cana-de-açúcar. O experimento foi conduzido em câmara climatizada tipo fitotron com controle de temperatura, fotoperíodo e irradiância. O delineamento experimental foi inteiramente casualizado com oito repetições e três regimes de temperatura: temperaturas baixas (19 ºC diurna e 13 ºC noturna); temperaturas médias (29 ºC diurna e 23 ºC noturna) e temperaturas altas (33 ºC diurna e 27 ºC noturna), durante 150 dias. Aos 120 dias após o plantio (DAP) foi realizado, nas folhas +1, avaliações de parâmetros fisiológicos relacionados à fotossíntese. Aos 150 DAP foi avaliado o número de folhas, a altura, o diâmetro e a massa do colmo. Baixas temperaturas reduziram a eficiência fotossintética das plantas de cana-de-açúcar, como também o desenvolvimento e crescimento (altura das plantas, massa seca e diâmetro do colmo), tendo como causa principal uma limitação bioquímica pela redução da atividade enzimática da Rubisco. Altas temperaturas não afetaram a eficiência fotossintética das plantas de cana-de-açúcar, as quais apresentaram aumento em altura e redução do diâmetro do colmo.

2014 - How the components of bioenergy and technological traits are affected by water deficit in sugarcane

Tadeu Alcides Marques, Jane Rodrigues Vasconcelos, Alexandrius de Moraes Barbosa, Gustavo Maia Souza e Patrícia Angélica Alves Marques
Applied Research & Agrotecngnology -v.7, n2, p. 07-13

To study the effect of water stress on the production of bioenergy and on the biometric and technological parameters that comprise bioenergy in sugarcane, two treatments were
tested: 100% replacement of evapotranspiration and 20% of evapotranspiration, with 10 replicates, using a total of 20 plots, and in a completely randomized design. Biometric, technological and calorimetric analyses were done. Under water stress there was a reduction of biomass and for all the analyzed components (TRS, Pol, Brix and Fiber). The total bioenergy of the system was reduced in the same proportion as the biomass, presenting changes in its composition. The simple sugars (glucose and fructose) showed minor reduction than other components of bionergy.