Agronomic characteristics, insect pollinators, and seedbank persistence of a novel oilseed crop, chia (Salvia hispanica L.) in eastern China

Abstract

Chia (Salvia hispanica L.), a member of the Lamiaceae family, is a newly emerging crop species in China, gaining extensive attention worldwide as a potential dietary oil and pharmaceutical resource. However, there are few reports on the cultivation or field evaluation of chia in China. The present study was conducted to evaluate the agronomic performance of chia, including the determination of the suitable seeding window and seed yield potential. Data were also collected on flower-visiting insects, flowering phenology, and seedbank persistence of chia for providing baseline information on weed risk assessment for the potential of crop introduction in China. Results showed that chia seeded between late-Apr. and middle-May produced a greater seed yield (mean: 686.6 kg ha−1; ranges: 324.5–1034 kg ha−1) compared to that of seeded at other dates (mean: 136.6 kg ha−1; ranges: 0–311.0 kg ha−1). While the content of individual saturated and unsaturated fatty acids of the chia seed oil varied with seeding date and genotype, the unsaturated fatty acids, including C18:1 (oleic acid), C18:2 (linoleic), and C18:3 (linolenic) were the most abundant fatty acid in chia seed oil, accounting for approximately 87 % of the total oil content. At the present location, even though the chia seeding dates varied from mid-Mar. to end-Jun., the plants could still complete the whole crop lifecycle with similar dates for the specific phenological stage. Moreover, chia flowers attracted a diverse group of pollinating insects from the Hymenoptera, Diptera, Lepidoptera, and Coleoptera. Eastern honeybees (Hymenoptera) and syrphid flies (Syrphidae) were the most abundant insect species, accounting for 25.4 % and 25.8 % of all insect pollinators, respectively. While the chia cannot persist in the seedbank during the spring growing season, the seeds from the late fall harvest could be partially dormant in the soil seedbank with the potential for generating the weed control problem in the subsequent crops. The baseline information obtained from this study would help understand the potential ecological risk of chia and serve a valuable reference for introduction of chia production in China.