The Effect of Glyphosate on Anatomical and Physiological Features of Alfalfa Infested with Field Dodder (Cuscuta campestris Yunck.)

Abstract

Field dodder (Cuscuta campestris Yunck.) is a very harmful parasitic weed species worldwide which infests many crops, including alfalfa as a foremost forage crop. Glyphosate has been an effective herbicide for field dodder control even though side effects occasionally occur in alfalfa plants. To find out and quantify the effects of glyphosate (288 and 360 g a.i. ha(-1)) on field dodder control, alfalfa forage yield, and physiological and anatomical features of alfalfa plants under controlled conditions were aims of the study. Physiologic (chlorophyll a, chlorophyll b, total carotenoids); and anatomic parameters were measured. Leaf anatomic parameters were thicknesses of upper epidermis, palisade and spongy tissues, mesophyll and underside leaf epidermis, and diameter of bundle sheath cells. Stem anatomic parameters were thicknesses of epidermis and cortex, and diameters of stem and central cylinder (pith). Both rates of glyphosate caused recovery of the harmful effects of field dodder on alfalfa, which shows that glyphosate can control field dodder at early stages of infestation on alfalfa.