T. Tamado et P. Milberg, Weed flora in arable fields of eastern Ethiopia with emphasis on the occurrence of Parthenium hysterophorus, WEED RES, 40(6), 2000, pp. 507-521
An exploratory weed survey was carried out on 240 crop fields in eastern Et
hiopia to assess the influence of some environmental and crop management fa
ctors on weed species composition and distribution, and to investigate the
association of the recently introduced Parthenium hysterophorus L. with oth
er components of the weed flora. A total of 102 weed taxa belonging to 36 p
lant families were recorded. Asteraceae. Poaceae and Fabaceae were the most
abundant families based on the number of species recorded. Digitaria abyss
inica (Hochst. Ex A. Rich) Stapf was the most frequent species (63%) and Pa
rthenium hysterophorus the second most frequent (54%). The latter species w
as ranked as the most important weed by 90% of the farmers in the lowlands
while 86% of the farmers in the highlands ranked the former species as the
worst weed. According to a partial canonical correspondence analysis (pCCA)
, altitude, rainfall, month of planting, number of weedings and soil type w
ere the major environmental/crop management factors influencing the species
distribution in the study area. The first pCCA axis clearly structured hig
hland and lowland weed species while the second axis distinguished those sp
ecies that grow on sandy soils. Parthenium hysterophorus has, in a very sho
rt time period, emerged as one of the most troublesome weed species in east
ern Ethiopia.