Physical and Cultural Weed Control Working Group of - European ...

9 th EWRS Workshop on Physical and Cultural Weed Control 47
Samsun, Turkey, 28 – 30 March 2011
Effect of different temperatures on seed germination of susceptible and
herbicide-resistant populations of Avena sterilis L.
P. Molei 1 , S. Turkseven 1 , Y. Nemli 1 , F. Erbas 1 , and A. Uludag 2
1 Faculty of Agriculture, Ege University, Bornova, Izmir, Turkey E-mail: molaei.p59@gmail.com
2 Faculty of Agriculture, Igdir University, Igdir, Turkey.
Herbicide resistant weeds are one of the main problems in agriculture worldwide. Several
herbicide resistant weed species were documented in Turkey as well. Sterile oat (Avena sterilis L.)
is a miserable weed species in cereals and in some other crops such as lentil, onion etc, which are
rotated with cereals. Herbicide resistant wild oat populations were determined in several regions of
Turkey. Knowledge on weed biology and ecology is one of the factors preparing integrated weed
management programs which includes physical and cultural weed control techniques. Difference in
fitness between wild and resistant populations of weeds has been already suggested to manage
resistant weed populations. Germination rates under different regimes of susceptible and resistant
sterile oat were compared.
Populations were collected from Eastern Mediterranean (starting with K) and Southern
Marmara (starting with A) Regions. Resistant populations (AKR2, AV14) that are already proved
resistant to both APP (Aryloxy-phenoxy-propionate) and CHD (cyclohexanadione) herbicides were
compared with four susceptible populations (KTA, KRL3, AV01, AV02) that are from fields or
non-crop areas. Experiments were carried out in petri dishes with 25 seeds in incubators under 10,
15, 20, 25, or 30 °C constant temperatures. Experimental design was RCBD with four replications.
Germination rate was recorded daily.
The data from two experiments pooled and total number of germinated seeds at the 12th day
were presented in table 1. Southern Marmara populations were germinated higher under lower
temperatures while Eastern Mediterranean populations germinated higher under higher temperatures
regardless their resistance status. There was no difference in germination rate among Southern
Marmara populations. Resistant Mediterranean population (AKR2) germinated higher than two
susceptible Mediterranean populations of which germination delayed approximately 2 days. There
is a need for further investigation at biotype level which has different resistant patterns. However, it
can be concluded that there is no fitness penalty for populations investigated. These results suggest
that physical weed control method would be one of the most prominent ones to control herbicide
resistant weeds, which resulted from solely relying on chemical control methods.
Table 1. Germination rates of sterile oat populations under different temperatures
Temperature
Sterile oat Populations
( 0 C) AV01 AV02 KTA AKR2 AV14 KRL3
------------------------------------- The Number of Germinated Seed -------------------------------------
10 24.88 23.50 10.25 24.25 24.62 17.38
15 22.50 23.50 17.38 24.12 22.38 21.38
20 20.38 20.88 17.38 24.50 17.50 21.50
25 17.38 19.50 20.25 24.25 21.12 19.88
30 10.12 7.75 11.38 23.38 5.62 18.38