Influence of harvest date on seed yield and quality in forage kochia

Authors: CREECH, CODY - University Of Nebraska; Waldron, Blair; RANSOM, COREY - Utah State University; ZOBELL, DALE - Utah State University; CREECH, J - Utah State University

Submitted to: Frontiers of Agricultural Science and Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2017
Publication Date: 3/21/2018
Citation: Creech, C.F., Waldron, B.L., Ransom, C.V., Zobell, D.R., Creech, J.E. 2018. Influence of harvest date on seed yield and quality in forage kochia. Frontiers of Agricultural Science and Engineering. 5:71-79. https://doi.org/10.15302/J-FASE-2017196.
DOI: https://doi.org/10.15302/J-FASE-2017196

Interpretive Summary: Forage kochia (Bassia prostrata) is used to reclaim rangelands and provide forage for livestock and wildlife. Limited research has been conducted on its seed production. This research evaluated the affect of harvest date on seed weight, germination, and seed production of two forage kochia subspecies. Seed was harvested from field-grown plants for three years during the first week of October, November, and December. October harvests resulted in the lightest seed weights, with November harvests slightly heavier than December, for most populations. The new cultivar Snowstorm and an experimental line Sahsel, had the highest seed weights in November of 154.7 and 143.3 mg respectively, whereas, Immigrant, the standard of forage kochia, ranked among the lowest in seed weight. For most forage kochia populations, germination was low from the October harvest (11 to 43%), with higher germination of November and December seed (43 to 64%). Total and viable seed yields were highest in November with the exception of two forage kochia populations, which peaked in October, indicating they mature earlier. Results indicate that forage kochia uaually reaches optimum seed maturity by early November, but earlier maturing populations exist in both subspecies virescens and grisea. The high December germination, but corresponding low viable seed yields, suggests that germination per se is inadequate to determine maturity for this indeterminate species. These results demonstrate seed trait differences and confirm the importance of selecting an ideal harvest date to maximize seed yield and viability of forage kochia.

Technical Abstract: Forage kochia (Bassia prostrata) is used to reclaim rangelands and provide forage for livestock and wildlife. Limited research has been conducted on its seed production. This research evaluated the affect of harvest date on 100-seed weight, germination, and total and viable seed yield of two forage kochia subspecies. Seed was harvested from field-grown plants for three years during the first week of October, November, and December. October harvests resulted in the lightest 100-seed weights, with November harvests slightly heavier than December, for most accessions. The new cultivar Snowstorm and breeding line Sahsel, both subspecies grisea, had the highest (P < 0.05) 100-seed weights in November of 154.7 and 143.3 mg respectively, whereas, Immigrant (subspecies virescens), the standard of forage kochia, ranked among the lowest in 100-seed weight. For most accessions, germination was low from the October harvest (11 to 43%), with higher (P < 0.05) germination of November and December seed (43 to 64%). Total and viable seed yields were highest in November with the exception of two accessions, which peaked in October, indicating they mature earlier. Results indicate that forage kochia usually reaches optimum seed maturity by early November, but earlier maturing accessions exist in both subspecies virescens and grisea. The high December germination, but corresponding low viable seed yields, suggests that germination per se is inadequate to determine maturity for this indeterminate species. These results demonstrate seed trait differences and confirm the importance of selecting an ideal harvest date to maximize seed yield and viability of forage kochia.