The Effects of Fresh Water Storage on the Germination of Certain Weed Seeds

Abstract

and Summary. Some seeds of Cicuta douglasii (DC.) Coult. & Rose (western waterhemlock), Cuscuta planiflor-a Tenore (smallseed dodder), Cuscuta indecora Choisy (largeseed dodder), Linaria dalmatica Mill. (Dalmatian toadflax), Asclepias speciosa Torr. (showy milkweed), and Halogeton glomeratus (M. Bieb.) C. A. Mey (halogeton) (brown seeds) still germinated after 12 months of submergence at 12and 48-inch depths in canal water. Black seeds of halogeton were not viable after 6 months. In another test, 35 percent of the seeds of Polygonum persicaria L. (ladysthumb) remained firm and 24 percent germinated after 5 years. Seeds of Cichorium intybus L. (chicory) and Swainsona salsula (Pall.) Taub. (swainsonpea) were not decomposed and devitalized in toto until after 5 years. No seeds of Avena fatua L. (wild oat), Blassia hyssopifolia (Pall.) Kuntze (fivehook bassia), and Rumex crispus L. (curly dock) sprouted after 6, 18, and 42 months, respectively. No seeds of Salsola kali L. var. tenuifolia Tausch (Russian thistle) and few seeds of Sonchus aruensis L. (perennial sowthistle) germinated after 3 months.