Investigating the Allelopathic Potential of Turnip and Broccoli to Manage Field Dodder in Eggplant Cultivation by Ecological Means

Purpose: Considering that the field dodder is one of the most dangerous parasitic weeds that causes serious damage to cultivated crops, this study aimed to evaluate the efficiency of different control methods against field dodder and the damage caused by the field dodder to eggplant. As well, to determine the isothiocyanate content of turnip and broccoli plants using GC-MS analysis.
Research Method: This study was conducted during 2020 and 2021. The experiment examined control methods involving turnip and broccoli as pre-cultivation plants, later both incorporated into the soil separately during specific growth stages, and then both covered and uncovered with black polyethylene mulch, and black polyethylene mulch alone. Controls included plots free of field dodder (Control 1) and plots totally infested with field dodder (Control 2). Finally, all plots were cultivated with eggplant seedlings on rows.
Findings: The efficacy of control methods against field dodder in eggplant plots reached 95.81% in TM (turnip+BP mulch) , 92.30% in BM (broccoli+BP mulch), 91.25% in M (black polyethylene mulch alone), 68.26% in T (turnip alone), and 62.58% in B (broccoli alone) treatments. The highest eggplant yield of 8.396 tons/da was achieved in TM treatment. The field dodder caused a yield loss in eggplant by 82.16%, a decrease in eggplant height by 31.12%, and by 58.99% in the number of eggplant fruits in the Con 2 treatment, where the plots were fully infested with filed dodder.
Originality/value: The efficiency of cruciferous plants against field dodder is attributed to their isothiocyanates content as the highest percentage of isothiocyanate compounds was found in turnip by 56.6% and the lowest in broccoli by 30.47%.