ABSTRACT Cynanchum acutum is an invasive perennial in Iranian citrus orchards that resprouts from deep fibrous roots and climbs trunks, rendering manual removal and common herbicides (e.g., glyphosate, glufosinate) ineffective. We evaluated transparent polyethylene solarization mulch as a low‐cost physical control in a two‐season field study (Solar Hijri 1403–1404; mid‐March–late‐September 2024–2025) in Juyim, Fars Province, and report complete above‐ground suppression of C. acutum under mulched trees. Three sour lemon orchards were used; each contained 25‐year‐old trees heavily infested with C. acutum . In treated plots vines were cut at the stem base, soil was tilled and amended with composted manure and balanced fertilizer, and drip lines were laid beneath a transparent polyethylene film (150–200 μm). The film covered the row beyond the canopy from mid‐March to late‐May for solarization; ~5 cm of local soil was then applied over the film to block light for longer‐term suppression. Irrigation ran every other day to maintain near‐field‐capacity moisture. Control plots received conventional weeding only (monthly manual removal of above‐ground C. acutum shoots using hand tools; no herbicide application was performed). After two seasons, mulched plots showed complete suppression of above‐ground C. acutum emergence; control plots remained heavily infested. Mulched trees exhibited greater vigor and higher fruit yield, consistent with soil heating, reduced soil‐borne pests, and improved nutrient availability under the clear film. Clear polyethylene proved practical with existing drip systems, but multi‐site and longer‐term trials are needed before wide‐scale recommendations.
Seyed Ali Akbar Bagherian (Wed,) studied this question.