Invasive Species Compendium

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Abstract Full Text

Aspects of the dispersion and viability of the teosinte seeds (Zea mays ssp.) in the Ebro valley.

Abstract

One of the main concerns associated with the appearance of a new invasive weed species is to prevent its expansion. In this paper we present the results of a study on the possible dispersal routes of teosinte (Zea mays ssp.) firstly detected in the Ebro valley (NE Spain) in 2014. With this purpose, the patterns of plant distribution within maize fields has been studied as well as the possibility of teosinte seeds remaining viable in the milling process for feeding animals and the viability of the seeds as a function of their residence time in pig and dairy slurry. After analyzing the distribution of teosinte plants in 153 fields in Aragon and Catalonia, it has been found that 66.3% of the infested plots could have been probably infested by means of harvest combines. Regarding the milling and grinding process of grains of teosinte and corn together, null viability of seeds has been found using mills with an exterior mesh of 5 and 2.5 mm in diameter, which are commonly used for animal fodder but 2.6% of the seeds remained viable after passing the 8 mm mesh. Finally, the log-logistic model predicted that the mean survival time of the seeds was 11.1 and 16.4 days in pig and cattle slurry, respectively and that the nil viability occurred at 15.7 and 37.4 days for pig and cattle slurry, respectively. It is, thus, necessary to wait at least during this period of time before spreading the slurry in areas with teosinte infestations.