Quantification of palmer amaranth seed number using a computerized particle analyzer

Abstract

Abstract We evaluated the accuracy of a computerized particle analyzer (CPA) for high‐throughput counting of Palmer amaranth (Amaranthus palmeri S. Watson) seeds and subsequently used the CPA to verify the accuracy of two subsampling methods for estimation of Palmer amaranth seed production. To determine accuracy of the CPA, 55 hand‐counted samples, ranging from 500 to 5000 Palmer amaranth seeds, were drawn from field samples and counted with the CPA. The relationship between hand and CPA seed counts was described by a linear model (R2 = 0.99) with a slope of 0.987 and a y‐intercept of 3.49. Thus, very little discrepancy exists between seed counts conducted by hand or the CPA. Additionally, two published methods for estimation of Palmer amaranth seed production were compared to the CPA and proven to be highly accurate. We conclude from these findings that the CPA offers a high‐throughput alternative for weed scientists who frequently count large quantities of seed.