Influence of foliar copper and nickel applications on sugarcane yields in brown rust infested fields in Louisiana

Authors: Johnson, Richard; Grisham, Michael

Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 4/10/2014
Publication Date: 7/1/2014
Citation: Johnson, R.M., Grisham, M.P. 2014. Influence of foliar copper and nickel applications on sugarcane yields in brown rust infested fields in Louisiana [abstract]. Journal of the American Society of Sugar Cane Technologists. 34:57-58.

Interpretive Summary:

Technical Abstract: Sugarcane fields with severe brown rust infections have been documented to show a decrease in sugar per hectare yields of up to 1680 kg/ha ($170/ha). Currently, control of this disease is accomplished with multiple fungicide applications. This is a costly practice for sugarcane producers who are already under economic stress due to low sugar prices. A study was initiated to explore several alternatives to fungicides for the potential control of sugarcane brown rust. Nickel (Ni) and Copper (Cu) compounds were among the very first fungicides used in agriculture, but their use was discontinued when the newer organic fungicides were released. These elements are also essential plant nutrients, which have important roles in plant metabolism. The objective of this study was to determine if foliar applications of nickel and copper fertilizer could prevent yield losses associated with brown rust infestations. In 2013, two tests were initiated in PC fields of cultivars HoCP 96-540 and L 99-226 to determine the influence of Ni and Cu on cane and sugar yields and on the incidence of sugarcane diseases, particularly brown rust. Foliar applications of Ni were applied at several rates ranging from 0 to 0.28 kg Ni/ha using a commercially available Ni fertilizer and foliar applications of Cu at rates ranging from 0 to 2.24 kg Cu/ha using a chelated copper fertilizer. Ni and Cu treatments were compared to an untreated control and a commercial check that received the fungicide Headline®. A similar test that included a fungicide control and untreated control was initiated in 2012, in a PC field on HoCP 96-540 and smaller tests with an untreated control but without a fungicide control were initiated in plant-cane and ratoon fields of HoCP 96-540 and L 99-226 in 2010 and 2011. In 2013, in a plant-cane field of HoCP 96-540 that was infected with brown rust, there was not a significant difference in either cane or sugar yields with Cu or Ni application. There was a trend for increased cane yield with a commercial Ni fertilizer and with the commercial fungicide control. In contrast in an adjacent field of plant-cane L 99-226, an increase in cane yield was observed with Cu (P=0.05) and Ni (P=0.1) application. There was a trend for increased cane and sugar yields with all applied treatments. In 2012, in a plant-cane field of HoCP 96-540 where brown rust was present, both cane and sugar yields increased with Ni fertilizer application (P=0.05). An increase in sugar yield was observed for Cu (P=0.15). In second stubble L 99-226, there was not a significant response to Ni or Cu fertilizer in cane yields. However, an increase in TRS (P=0.05) was observed with both Ni and Cu application. Application of Ni increased sugar yield (P=0.15). In second stubble HoCP 96-540, a significant response to Cu was not observed in cane or sugar yields, but TRS increased (P=0.1) for both Ni and Cu applications. In 2011 in second stubble L 99-226, Cu application increased cane yield (P=0.15), TRS (P=0.15) and sugar yield (P=0.05). Finally, in 2010, an increase in both cane and sugar yields was observed in response to Ni application as compared to the control in plant-cane L 99-226. In first-stubble HoCP 96-540, Cu increased both cane yield (P=0.2) and sugar yield (P=0.15). In second-stubble HoCP 96-540, a significant response to Cu or Ni was not observed. Also in 2010 at a different location, Cu application increased both cane (P=0.05) and sugar yields (P=0.1) in first-stubble, HoCP 96-540. These combined results indicate that both Cu and Ni fertilizers can help improve both cane and sugar yields and possibly offer some protection against yield losses associated with brown rust infestations.