Effectiveness of Diquat, Copper Hydroxide, Copper Oxychloride and their Association in Control of Submerged Macrophytes Ceratophyllum demersum

Abstract

-The aims of this study were to evaluate the effectiveness of diquat, copper hydroxide, copper oxychloride and their associations diquat + 0.1% copper oxychloride and diquat + 0.1% copper hydroxide to control Cerathophyllum demersum. Therefore, the concentrations used were 0.1, 0.3, 0.5, 0.7, 1.0 and 1.5 mg L -1 oxychloride and copper hydroxide and 0.2, 0.4, 0.8 and 1.2 mg L -1 diquat and their associations with 0.1% copper oxychloride and 0.1% copper and a control hydroxide. The experimental design was completely randomized with ten replications for 45 days. For evaluation we used a scale of 0-100% control of notes and rated the weight (g) and length (cm) of pointers at the end of the trial period. Diquat showed 100% efficacy at 30 DAA, associations in 21 DAA and copper sources promoted regrowth of C. demersum. Diquat and its associations were more effective in controlling C. demersum. The use of herbicide in combination with a copper source is more efficient for the control of submerged weeds because it potentiates the effect of the herbicide in weed control Keywords: aquatic plants, algaecide effect, chemical management. de 0,1, 0,3, 0,5, 0,7, 1,0 RESUMO -O objetivo

EFFECTIVENESS OF DIQUAT, BOTH ISOLATED AND ASSOCIATED WITH COPPER SOURCES IN CONTROLLING THE Hydrilla verticillata SUBMERGED MACROPHYTES AND ANKISTRODESMUS Gracilis microphyte

“…On day 7 and 11 DAA, there was branch chlorosis in all the tested concentrations; on day 21 DAA it was possible to observe the loss of sustainability capacity of the young branches; and on day 30 DAA there was total necrosis of the young branches in all concentrations (Table 1). These phyto-intoxication signs also occurred with Elodea canadensis, Elodea nuttallii and Potamogeton crispus when exposed to asulam herbicide (Arts et al, 2008) and with C. demersum when exposed to diquat (Garlich et al, 2016b).…”

“…This effect was also described by Sutton et al (1970), with the addition of 0.1 to 2.0 mg L -1 copper sulphate to diquat herbicide, in order to control E. densa, Najas guadalupensis and H. verticillata; according to Pennington et al (2001), with a mixture of 1.0 to 3.0 mg L -1 endothall + 0.5 mg L -1 copper, with similar control results (> 99%) over H. verticillata; according to Garlich et al (2016b) with diquat, either isolated or associated with 0.1% copper oxychloride and hydroxide, for C. demersum.…”

“…Total biomass reduction also occurred with the use of diquat, both isolated and associated with 0.1% copper oxychloride and hydroxide. It controlled 100% of Ceratophyllum demersum (Garlich et al, 2016b).…”

“…Diquat has been vastly evaluated for macrophyte control, especially to promote fast control over many species (Martins et al, 2008;Garlich et al, 2016b). This is a photosystem-I inhibitor herbicide, that reduces the effectiveness in electron transfer; this system can be found both in macrophytes and algae.…”

“…Studies on its effectiveness were performed with Hydrilla verticilata, Egeria densa and Egeria najas (Henares et al, 2011) and Ceratophyllum demersum (Garlich et al, 2016b).…”