Pigmentos fotossintéticos como descritores de resposta a adubação organomineral em cana-de-açúcar (Saccharum Officinarum L.)

Sugarcane (Saccharum officinarum L.) comes from the Asian continent. Culture is of enormous importance to the Brazilian economy, being explored throughout the country, with the Southeast, Northeast and South as the largest production centers today. With the growing population, it has been increasingly sought to increase productivity and profitability with the cultivation of sugarcane with the help of agricultural and managerial techniques. Plant productivity is related to photosynthetic efficiency. One of the factors linked to this efficiency is the chlorophyll content, due to its direct connection with the absorption and transfer of light energy. However, the concentration of chlorophylls can be influenced by fertility and fertilization. The objective of this work was to compare the use of chlorophyll meter (Minolta SPAD® 502 and Falker ClorofiLOG® 17 1030) and spectrophotometer for chlorophyll determination in sugarcane fertilized with organominerals and industrial sewage sludge. The experiment was conducted in randomized blocks, with five replications per treatment. The characteristics evaluated were: Cla (chlorophyll a), Clb (chlorophyll b), Car (carotenoids), Clt (total chlorophylls), Cla/Clb (ratio between chlorophyll a and chlorophyll b). All equipment used showed similar responses in terms of chlorophyll concentration in response to fertilization. It was found that, regardless of the treatments, the concentrations of photosynthetic pigments did not vary.