Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 4/19/2017
Publication Date: 6/14/2017
Citation: Da Silva, D.P., Richard, K.A., King, B.G., Johnson, R.M. 2017. Effect of growth regulators, boron and molybdenum on sugarcane grown in the greenhouse [abstract]. Journal of the American Society of Sugar Cane Technologists. 34:47.
Technical Abstract: Tillering is an important characteristic in determining sugarcane yields. An experiment was conducted in the greenhouse using LCP 85-384 to determine the influence of the growth regulator Moddus, alone and in all possible combinations with boron and molybdenum, on the growth and development of young sugarcane plants (60 days). The experiment was designed as a randomized complete block design with five replications and seven treatments. The seven treatments were: 1) Control, 2) Sugar Mover™ 4.7 l/ha (8% + Molybdenum 0.004%), 3) Nitrate Balancer™ 18.7l/ha (9% + Molybdenum 0.005%), 4) Moddus™ 0.35 kg/ha (Trinexapac-ethyl), 5) Moddus 0.35 kg/ha + Sugar Mover 4.7 l/ha, 6) Moddus 0.35 kg/ha + Nitrate Balancer 18.7 l/ha, and 7) Moddus 0.35 kg/ha + Nitrate Balancer 18.7 l/ha + Sugar Mover 4.7 l/ha. All treatments were applied foliar, 5 and 12 days after sugarcane seedlings (60 days) were transplanted into pots. Experimental evaluations were carried out at 7, 14, 21, 28, 35 and 42 days after the first application. The biometric variables evaluated were height, number of leaves and number of tillers and the physiological variables were stomatal conductance and SPAD index. The results showed that Moddus alone, at 42 days after treatment, increased tillering (50%), leaf number (21%), stomatal conductance (75%), and chlorophyll levels as estimated by a SPAD meter (36%), but did decreased plant height (42%), when compared to the control. When either formulation of boron and molybdenum (Sugar Mover or Nitrate Balancer) was applied alone, increases were observed in: height (0-38%), number of tillers (0-25%) and stomatal conductance (33-50%), but not in the SPAD index or number of leaves, as compared to the control 42 days after treatment. When Moddus was tank-mixed with boron or molybdenum formulations, increases were observed in number of tillers (25%), leaf number (13-23%), stomatal conductance (11-47%), and SPAD index (24-36%), but not in plant height, when compared to the control 42 days after treatment. However, when Moddus was tank-mixed with both formulations increases were observed in number of leaves (23%), number of tillers (25%) and SPAD Index (36%), but not in stomatal conductance or plant height, as compared to the control 42 days after treatment. These results suggest that Moddus alone can provide modest benefits to sugarcane in Louisiana; however, these benefits may be significantly expanded by tank-mixing Moddus with boron and molybdenum. Future research will investigate these effects in field experiments and attempt to optimize levels of boron and molybdenum.