Optimizing Weed Control Practices and Irrigation Intervals for Tomato Production in Broomrape-Infested Fields

Parasitic plants, such as branched broomrape (Orobanche ramosa L.), pose significant challenges to tomato cultivation, leading to substantial yield and quality losses. This two-year field experiment, conducted over two consecutive growing seasons (each lasting approximately 120 days), was laid out in a split-plot arrangement under a randomized complete block design with three replications. The study evaluated the impacts of five weed control practices (black polyethylene mulch, transparent polyethylene mulch, pendimethalin, glyphosate, and an untreated weedy check) and three irrigation intervals (irrigation every 3 (D3), 6 (D6), and 9 (D9) days after transplanting until first fruiting) on weed suppression, broomrape infestation, tomato growth, yield, and quality. On average of irrigation intervals, black polyethylene mulching significantly (p ≤ 0.05) reduced weed density by 89% (to 4.2 plants m–2) and Orobanche intensity by 61% (to 1.5) compared with control, thus resulting in a 132% increase in tomato yield (22.3 t ha–1) and an improved cost–benefit ratio. Among irrigation treatments, D6 significantly (p ≤ 0.05) increased the tomato yield (19.0 t ha–1) by 30% compared to D9, achieving the highest cost–benefit ratio. Weather variations between years influenced the efficacy of irrigation and weed management practices. Notably, D6 combined with black polyethylene mulching and pendimethalin significantly (p ≤ 0.05) increased the fruit yield by 286% compared with control. Overall, a 6 day irrigation frequency combined with black polyethylene mulching or D6 combined with pendimethalin may represent an economical and effective weed management strategy for mitigating yield losses caused by branched broomrape in tomato cultivation.