The factors influencing weed seed longevity in buried packet trials

Abstract

Since 2008, a series of trials have studied weed seed longevity by burying packets of seeds in a field research enclosure and retrieving them over time. This paper overviews the results of the completed species where the results have been published by past researchers; Andropogon guyanus, Calotropis procera, Casabella thevetia, Leucaena leucocephala, Stevia ovata, and Ziziphus mauritiana. Completed trials of several species (Azadirachta indica, Lantana camara, Parthenium hysterophorus, Tecoma stans, Prosopis pallida and Vachellia nilotica) are unpublished, but are also summarised. Over 1 to 13 years, seeds of each weed species have been subject to different soil, ground cover and depth treatments. This paper summarises the predominant treatment effects on the seed longevity of each species. Results are presented in terms of a percent (%) reduction in viable weed seed to provide decision makers with relative risk-based information on which to base feasible weed management strategies.