Longevity of Weed Seeds After 5.5 Years in the Stoneville 50-Year Buried-Seed Study

Abstract

Seeds of 20 weed species buried at depths of 8, 23, and 38 cm in 1972 and 1973 were exhumed at regular intervals and tested for viability and germination. Burial depth had little to no significant influence on longevity. After 5.5 yr 48% of johnsongrass [Sorghum halepense(L.) Pers.], 36% of velvetleaf (Abutilon theophrastiMedic.), 33% of purple moonflower (Ipomoea turbinataLag.), 30% of spurred anoda [Anoda cristata(L.) Schlecht], 18% of hemp sesbania [Sesbania exaltata(Raf.) Cory], and 13% of pitted morningglory (Ipomoea lacunosaL.) seeds were still viable. No more than 6% of the original population for any other species was viable at 5.5 yr. Hard seeds comprised a high percentage of the longer-lived seeds. Seeds of longest-lived species were losing viability at an average of 26% of the existing population each year from 3.5 to 5.5 yr.