Microbial metabolites have been identified as a promising class of natural herbicides due to their effective control against weeds and a relatively low environmental impact. Here we report on the potency and crop safety of a natural compound with herbicidal properties, the metabolite SPRI-70014 from Streptomyces griseolus CGMCC 1370. The compound showed excellent herbicidal activities on various broadleaf and gramineous weeds in both greenhouse and field trials. In germination inhibition experiments, SPRI-70014 inhibited the emergence of both root and shoot at 1 mg L−1. At a dose of 31.3 g ai ha−1, SPRI-70014 provided effective control over most broadleaf weeds in greenhouse trials. Observations on absorption and translocation using a cucumber plant model system indicated that SPRI-70014 could be absorbed by the root but only partly by the stem. Field trials showed that SPRI-70014 provided effective control over most weed species tested at a dose of 1,000 g ai ha−1. Crop safety experiments showed that the compound had no harmful effect on peanut or wheat plants at doses up to 2,000 g ai ha−1. These results indicated that this compound could be developed as a potential POST herbicide for control of broadleaf weeds in peanut and wheat fields.
Nomenclature: Cucumber, Cucumis sativus L.; peanut, Arachis hypogaea L.; wheat, Triticum aestivum L.