209 CONTENTS

Buletinul AŞM. Ştiinţele vieţii. Nr. 2 (314) 2011
118
CHEMICAL CONTROL OF BROOMRAPE AND WEEDS WITH
IMIDAZOLINONE HERBICIDE AND RESISTANT HYBRIDS IN
SUNFLOWER PRODUCTION IN TURKEY
Goksel Evci¹, Nilgun Sezer 2 , Veli Pekcan¹, M. Ibrahim Yilmaz,
Yalcin Kaya¹
¹Trakya Agricultural Research Institute, PO Box: 16, 22100 Edirne, Turkey.
2 Seed Registration and Certi cation Center, Yenimahalle, 06100, Ankara, Turkey.
Correspondent author e-mail: yalcinkaya@ttae.gov.tr
Introduction
Genetica, Biologia moleculară şi Ameliorarea
The applying post emergence IMI (Imidazolinone) herbicide over genetically
IMI herbicide resistant plants as called Clear eld production system promises to
be one of the best tools available for weed control in sun ower [1]. The Clear eld
trait for sun ower was discovered rstly in a soybean eld in Kansas, US in 1997 [2;
3; 13]. It was found in a population of wild sun owers growing with seven years of
continuous ALS-inhibitor herbicide use. Then, this trait was transferred to public lines
with through several backcross generations, and then these public lines made available
to commercial seed companies [4; 8; 11; 13].
The Clear eld system consists of sun ower hybrids with using with IMI herbicide,
delivering broad-spectrum post emergence grass and broadleaf weed control in
sun ower. Best results were obtained with a single foliar treatment with Imazamox
(35 g/l) + imazapyr (15 g/l), 43.75+18.75 g/ha was applied on IMI resistant sun ower
plants at 8-10 true leaf stage both controlling weeds and broomrape (Orobanche. cernua
Loef .) [5; 6; 7; 9; 12]. On the other hand, if sun ower eld has less broomrape and
more invaded by weeds in soil surface, this application should apply at early stage to
get effective weed control. However, if the goal is more broomrape control in mostly
less weed problem elds, the application should perform at 10-12 leaf stages [6; 7; 9].
On the other hand, winter rapeseed and sugar beet should not plant after the sun ower
in the rotation due to residue effect of IMI herbicide [14].
IMI herbicide tolerant sun ower hybrids play an increasing role in the sun ower
production in Turkey, because they control both broomrape and key weeds which
could not controlled by pre-emergence herbicides such as Xanthium strumarium Wallr.
Chenopodium album L., Echinochloa cruss-galli, Sinapsis arvensis L., Amaranthus
spp. Solanum nigrum L., Datura stramonium L. Avena spp. etc. resulting important
yield losses in sun ower [9; 12].
The use of IMI herbicide controlling both key weeds and Orobanche parasite with
using IMI resistant hybrids increase gradually in recent years in Turkey [12] . In recent
years, IMI resistant hybrids were planted about 51 % of sun ower planted area in
Trakya Region which has 70 % of sun ower production in Turkey due to extensive
infested broomrape elds [10]. On the other hand, lower seed yield and oil content
were obtained from IMI type (1694.0 kg / ha) when comparing genetically broomrape
resistant ones (1928.4 kg / ha) [10]. As results, lower income were gained from IMI
type (783.4 US $ / ha) than broomrape resistant ones (888.1 US $ / ha) due to both
higher costs for herbicide use and also lower obtained seed yield. However, farmers