Page 27 - Volume 7, Issue 1, January 2014

1

Department of Agricultural Development, Democri-

tus University of Thrace, GR-682 00 Orestiada, Greece

Corresponding author:

damalas@mail.gr;

cdamalas@agro.duth.gr

Hellenic Plant Protection Journal

7:

25-29, 2014

SHORT COMMUNICATION

Occurrence of European field pansy (

Viola arvensis

) in

Orestiada, Greece

C.A. Damalas

1

, S.D. Koutroubas

1

and S. Fotiadis

1

Summary

The European field pansy (

Viola arvensis

Murray), an annual broadleaf weed, occurs with in-

creasing frequency over the last few years in arable land of the Farm of Democritus University of Thrace

in Orestiada. Naturally-occurring weed populations were observed in densities from 5 to 20 plants per

m

2

mostly in irregular patches, in the margins (edges) of a winter wheat field and at points of the field

with low wheat density, in minor spring-sown legumes such as lentils, faba beans, lupine, and winged

vetchling, and in parts of the fields without crop. The occurrence of the species in the area is proba-

bly associated with the absence of chemical weed control (no use of herbicides) coupled with the in-

creased nitrogen availability in the soil, which favors the overall productivity of plants (i.e. biomass ac-

cumulation, seed production and seed dispersal) in subsequent generations. In this report, basic mor-

phological traits at different stages of the life cycle of the species are presented.

Additional keywords

: identification, morphology,

Viola arvensis

The European field pansy (

Viola arvensis

) oc-

curs with increasing frequency over the last

few years in arable land (at an acreage of

15 ha) of the Farm of Democritus Universi-

ty of Thrace in Orestiada. Increasing densi-

ties of plants were confirmed by systemat-

ic visual observations in the area. According

to the literature, this species is mentioned

as an annual weed mainly of cereals and oil-

seed rape in northern Europe (Vanaga

et al.

,

2010; Salonen

et al.

, 2011; Andreasen and

Stryhn, 2012; Hanzlik and Gerowitt, 2012),

in New Zealand (Bourdôt

et al.

, 1998), and

in Canada (Degenhardt

et al.

, 2005a, 2005b,

2005c). It appears that this weed is consid-

ered to be a minor threat in agroecosystems

(Degenhardt

et al.

, 2005c) and a rather easy

weed species to tackle, particularly with the

use of herbicides, depending on the avail-

able herbicides and the crop management

system (Huggenberger and Gueguen, 1987;

Degenhardt

et al.

, 2005a, 2005b; Becker

et

al.

, 2008; Koo and Caseley, 2008; Richardson

and Zandstra, 2009). In general, identifica-

tion of a weed is the first step towards find-

ing potential practices for effective manage-

ment (Dekker, 1997). However, information

about the performance of this weed under

Greek conditions does not exist. Thus, the

aim of this study was the depiction of basic

morphological traits of European field pan-

sy to assist correct identification and also

to provide basic information on its occur-

rence from the area of Orestiada in Greece.

To our knowledge, European field pansy has

been reported previously as a minor weed

of wheat fields in Greece (Damanakis, 1983)

and it is also mentioned as a herb in FILOTIS

database, a Greek information system for

the natural environment of Greece (FILOTIS

DATABASE, 2014). However, further informa-

tion lacks in the Greek literature.

A field survey was conducted in 2011

at the Farm of Democritus University of

Thrace in Orestiada, Greece (41

o

30’N lat-

itude, 26

o

32’E, 22 m asl), where the spe-

cies was initially recorded. The soil was silty