Sugarcane with Si fertilization under water deficit: effects in plant nutrition and biomass yield

Abstract

Silicon (Si) fertilization has shown positive effects against water drought, decreasing the damages, but it is still scarce information in sugarcane crop, which is a Si-accumulating plant of this beneficial element. So, the objectives of this study will evaluate the presence or absence of Si fertilization regarding gases exchange in plants and Si and nutrients uptake by above-ground biomass and root system in sugarcane grown under water deficit. The experiment will be conducted in randomized blocks without and with Si (0 and 1000 kg ha-1 Si), 2 cultivars (drought tolerant: RB86-7515; drought susceptible: RB85-5536), without and with moderated water deficit (100 and 55% soil humidity field, respectively), and 10 replications. Water deficit will be imposed in 5months-old plants. It will be evaluated the height of plants, number of green and dry leaves, SPAD index, leaf area and gas exchange in five evaluations during the water deficit period. At harvest, it will be assessed biometric parameters (height of plants, number of green and dry leaves), physiological parameters (chlorophyll a e b, water relative content, leaf water potential, electrolyte leakage), gases exchange, above-ground biomass, and root system biomass, concentration and accumulation of Si and nutrients and water use efficiency (water applied/plant biomass). (AU)