Planta Daninha (2010) 28, 575-584

S.J.P. Carvalho, A.C.R. Dias, G.M. Shiomi and P.J. Christoffoleti (2010)
Adição simultânea de sulfato de amônio e ureia à calda de pulverização do herbicida glyphosate
[Simultaneous addition of ammonium sulfate and urea to glyphosate spray solution]
Planta Daninha 28 (3), 575-584
Abstract: Two trials were carried out under greenhouse conditions to evaluate the efficacy of glyphosate on Digitaria insularis plants when urea (U; 5 g L-1); ammonium sulfate (AMS; 15 g L-1) or U+AMS (2.5 + 7.5 g L-1) were used as spray solutions. At 28 days after application, according to dose-response curves (first trial), 409 g ha-1 of glyphosate application were necessary to obtain 50% of weed control (C₅₀) when water without adjuvants was used as spray solution. To reach the same 50% of weed control, glyphosate rates were reduced to 373, 208 and 189 g ha-1, when the herbicide was sprayed using a solution of U, AMS or U+AMS, respectively. Reduction in the dose of glyphosate combined with U+AMS was also observed for controls of 80% (C₈₀). In the second trial, the addition of U+SA to glyphosate spray solution increased the control obtained at the lowest glyphosate rate (360 g ha-1), leveling it to the highest rate application (720 g ha-1) without adjuvants. These results show the complementary action of U and AMS to increase glyphosate efficacy to control D. insularis.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
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Database assignments for author(s): Pedro Jacob Christoffoleti

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Digitaria insularis (weed)