Combinations of Dilwet, an organosilicone surfactant, and ethephon, a hormonal compound often applied to fruit trees to thin the crop, were applied at full bloom to prevent fruit development in two young vineyards differing in elevation by 600 m. Each vineyard was planted with the same 19 red and 10 white grape cultivars from a range of countries of origin. Vineyard elevation did not affect response to treatment. A combined spray of 0.5% Dilwet with 0.04% ethephon reduced cluster number by an average of 85%, while weight of the remaining clusters was reduced by 63%, compared to unsprayed controls. Increasing the concentration of Dilwet to 1% reduced cluster number by 93% and cluster weight by 76%. There were significant differences in the response of cultivars to the treatments, depending on country of origin, with grapes originating in France responding better to higher concentrations of Dilwet. White grapes were more responsive than red grapes. These results highlight the need to test different cultivars and genetic origins of crops when examining the effects of new agricultural chemicals.

Willow (Salix spp.) trees, found worldwide, contain secondary metabolites that are valuable as dietary supplements for animal feed and as anti-parasitic compounds. We quantified secondary metabolites (phenolic, flavonoids, and salicylic acid) in ethanolic extracts from leaves and branches of three Salix acmophylla genotypes and investigated their potential to inhibit Eimeria sp. sporulation, a major concern in ruminants. The total phenolic content of willow leaves and branches was similar in two of three different genotypes. The total flavonoid content of the branches was significantly higher than that of leaves of the same genotype; however, the salicylic acid content was significantly higher in leaves than in branches. Importantly, all extracts exhibited significant inhibition of Eimeria sporulation, where over 70% inhibition was obtained at concentrations as low as 750 ppm. The sporulation inhibition by branch or leaf extracts exceeded 80% for leaves and 90% for branches at concentrations above 1250 ppm. The study highlights the potential of using Salix extracts as bioactive compounds for biological control of coccidiosis in ruminants and emphasizes the importance of genotype-specific variations in secondary metabolite profiles. We conclude that all parts of S. acmophylla can provide secondary metabolites that act as a coccidiostat to treat Eimeria in goats.