Abstract

Allelopathic impacts of two crops, sunflower (Helianthus annus L.) and caster bean (Ricinus communis L.) were evaluated against dodder (Cuscuta compestris) germination properties. Different plants residue, plant parts (root, shoot, leaf and whole plant), various concentrations of aqueous extract and decay durations were employed as study factors under completely randomized design (CRD) with factorial arrangement by three replications in this study. The results indicated that germination percentage, germination rate, emergence rate, seedling length of dodder was sharply influenced by sunflower and caster bean residue application. Aqueous extract of sunflower inhibited dodder seed germination more efficiently in comparison with caster bean especially in higher concentrations. Moreover, shoot aqueous extract allelochemicals showed substantial potential to the inhibition of dodder germination in contrast with other parts of plants. However, fresh leaf solid residue indicated great potential to dodder germination suppression. Increasing aqueous extract concentration significantly inhibited dodder germination and emergence under controlled conditions. In conclusion, dodder germination can be controlled by sunflower and caster bean allelochemicals. Therefore, allelopathic potential of these two plants can be consider as a sustainable approach in integrated management systems.

Key words: Allelochemicals, aqueous extract, decay duration, Cuscuta compestris