Revista Brasileira De Herbicidas 2016; 15(2): 184-194
Morpho-anatomical aspects and technological quality of saccharine sorghum submitted to plant regulators
With the increase in the demand for renewable fuels, the sugarcane industry must seek a way of increasing agro-industrial productivity while reducing production costs. Currently, there are few reports on the use of plant growth regulators in saccharine sorghum crops. The objective of this study was to evaluate the effects of the application of chemical ripening agents on the technological quality and the morphological and anatomical aspects of saccharine sorghum. The experiment was conducted at the Cerradinho Mill in Catanduva, São Paulo state. Plant growth regulators applied were etephon at 1.32, 0.66 and 0.33 L ha-1, sulfometuron-methyl at 20.0, 10.0 and 5.0 g ha-1, thiadizuron at 0.150, 0.100 and 0.50 L ha-1, ethyl-trinexapac at 0.80, 0.40 and 0.20 L ha-1 and a control treatment. The experiment was conducted in randomized blocks with a subplot design with four replications. The following technological parameters were evaluated: juice purity, reduced sugars, total recoverable sugars, juice brix, juice pol, theoretical recoverable sugars and fiber (%). The thickness of the upper face or adaxial epidermis (AdE), the thickness of the lower face or abaxial epidermis (AbE), sclerenchyma diameter (SD), mesophyll thickness (MT), diameter of xilematic vessels (DX) and diameter of phloematic vessels (DP) were evaluated. It is concluded that saccharine sorghum showed a significant increase in technological quality when etephon was used at dose of 0.33 L ha-1, and at 0.66 L ha-1 between 37 and 44 days after the application of chemical ripening agents. For the technical characteristics, the chemical ripening agent sulfometuron-methyl and etephon in doses of 5 g. ha-1 and 0.33 L ha-1, respectively, promoted the best results from the 37 days after application. For anatomic characteristics of saccharide sorghum plants, the chemical ripener agent thiadizuron in dose of 0.100 L ha-1 showed the best results at 44 days after application.
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