Uptake of Ivermectin from Growing Substrate to Plant Species

IGLESIAS LUCÍA E.; SALLOVITZ JUAN M.; SAUMELL CARLOS A.; FERNÁNDEZ ALICIA S.; JUNCO MILAGROS; SAGÜÉS MARÍA F.; ZEGBI S.; LIFSCHITZ ADRIÁN L.

MADISON

Conferencia; 27th Conference of the World Association for the Advancement of Veterinary Parasitology; 2019

World Association for the Advancement of Veterinary Parasitology

Ivermectin (IVM) is a worldwide-used antiparasitic drug. However, its high level of faecal elimination together with its transfer from dung pats to the underlying soil as well as the common practice of using manure for soil amendement represents a potencial risk to plants growing in these substrates. Two trials were conducted to evaluate the uptake of IVM to: 1) a crop of ryegrass (Lolium multiflorum) and clover (Trifolium repens) growing for 120 days post treatment (dpt) in IVM-spiked soil at 3000 (High group, HG) and 90ng/g (Low group, LG); and 2) a crop of radish (Raphanus sativus) and lettuce (Lactuca sativa) growing for 60 dpt in a mix of soil and 10% IVM-spiked manure at 3000ng/g. Soil, soil-manure mix and plants were sampled starting at 15 dpt and at the end of each trial. All matrices were analyzed by HPLC to quantify IVM concentration. Trial 1: In HG, IVM concentration in soil decreased from 2154 ng/g to 225 ng/g; mean IVM concentration in ryegrass ranged between 378.65ng/g and 21,74ng/g. Strikingly, clover development was delayed until 30 dpt and IVM concentration in this specie ranged between 94,09 ng/g and 4,56ng/g. Significant differences were detected between species (p=0,0374). In the LG, IVM concentration was between 22,26ng/g and 1,02ng/g in ryegrass, and between 10ng/g and 1,02ng/g in clover, without statistically significant differences between species (p=0,8301). Trial 2: IVM was detected in both plant species at significant levels (p>0,05) in all the sampling times; mean IVM concentration was between 10ng/g and 5ng/g in radish, and 17,70ng/g and 6,55ng/g in lettuce. IVM concentration in the substrate decreased from 1311ng/g to 116ng/g. In conclusion, IVM concentrations in soil or composted substrate are transferred to plants during growth period, and could be incorporated into the food chain of both livestock and humans.