Selective control of Orobanche ramosa in potato with sub-lethal doses of glyphosate and other soil treatments -

Abstract

Greenhouse and field experiments were conducted during 2009-2010 at the greenhouse area of the Faculty of Agriculture and Food Sciences (FAFS) and Agriculture and Research Center (AREC) of the American University of Beirut, to test for methyl bromide alternatives such as ammonia gas, phosphoric acid and sulfuric acid for the Orobanche ramosa control and to examine Orobanche ramosa control with sub-lethal doses of glyphosate and on the yield and quality of potatoes such as size, knobbiness and cracking of tubers. Data were collected on Orobanche shoot number and dry weight, potato plant height, vigor, tuber number and marketable and non-marketable yield. Results regarding Orobanche total infestation showed that (unlike methyl bromide), the use of phosphoric acid, sulfuric acid and ammonia gas had no significant effect on the level of Orobanche infestation as compared to the control. The best results considering both Orobanche control and selectivity in potato was obtained by sub-lethal doses of glyphosate. At all tested rates, glyphosate significantly reduced Orobanche infestation as compared to the control. However, the increase in the glyphosate rate decreased the number of marketable potato tubers.