Effect of chitosan foliar application on the performance and yield of soybean and maize under field conditions.
Abstract Chitosan is a natural heterogeneous polymer, non-toxic and find many potential applications in agriculture. The search of a biopolymer to replace the synthetic agrochemicals, the effects of foliar application of chitosan solution on agronomic performance under field experiments have been investigated in two consecutive harvests (2014/2015 and 2015) of soybean and maize. Two chitosan concentrations (0.5 and 1%) were sprayed four times during the culture development and the evaluation was based on morphological characteristics, growth and yield components. Seeds were collected to determine the content of macro- and micronutrients. Results revealed that most of the morphological and growth parameters (plant height, leaf number per plant) and yield attributes were not increased with the chitosan treatment in soybean and maize. The soybean treated with foliar application of chitosan 0.5% increased the accumulation of nitrogen by 9.14% when compared with the water treatment, but the effect was not consistent in both seasons and cultivars. The values of the other nutrients did not change the content. Maize plants treated with chitosan (0.5% or 1%) significantly decreased the boron concentration by 66.7% in the grains analyzed and may have influenced the plant development (height) without altering the other agronomic parameters. Therefore, whereas the climatic conditions in these two seasons were stable and biotic or abiotic stresses were not observed, foliar application of chitosan solution did not present differences that could establish a pattern of behavior in field experiments conducted by two harvests.