Effect of Nicosulfuron on Biological Production of Xanthium Strumarium L

Effect of nicosulfuron on biological production of Xanthium strumarium L.

D. Bozic1, S. Vrbnicanin1, M. Saric1, E. Onc-Jovanovic2, D. Pavlovic3

1University of Belgrade, Faculty of Agriculture, Belgrade, Serbia Email:

2Institut PKB Agroekonomik, Padinska Skela, Belgrade, Serbia

3Institute for Plant Protection and Environment, Belgrade, Serbia

Understanding effects of different components (including effects of non-target herbicides used for other species control) on weed suppression is necessary for evaluating best strategies for weed control. In Serbia, in many corn fields Xanthium strumarium L. and Sorghum halepense L. (Pers.) at the present are dominant weeds. As it is well known nicosulfuron effectively controls S. halepense in corn. One of the components of X. strumarium control in corn can be a reduction of biological production by this herbicide application. As can be expected, this measure can lead to the reduction of competitive ability of X. strumarium and its seed bank in the soil.

The experiment was conducted in Padinska Skela PKB Agroekonomik near Belgrade in 2008 and again in 2009 on alluvial black marsh soil. X. strumarium was sown in containers and transplanted to the field when the first pair of leaves developed. Experimental design was a completely randomized block design with four replications. Plot size was 5x4.2 m (21 m2). Interrow spacing was 70 cm and the distance between rows 24 cm. Plants were treated with herbicide in two pairs of leaves. Nicosulfuron (Motivell, 40 g a.i.L-1, SC, BASF, Germany) was applied in the amounts of 0 (control), 20, 40 and 80 g a.i.ha-1. Plant height, fresh weight, and leaf area were measured and leaf area index (LAI) was calculated just before herbicide application and 14, 30, 47 and 63 days after herbicide treatment (DAHT) in 2008 and 16, 33, 48, 64 DAHT in 2009. After the maturity burs production (burs weight plant-1 and burs number plant-1) was measured. All data was analyzed using a one-way ANOVA (F-values). Data from each year was analyzed separately because of the different agroecological conditions between the years.

The recommended, as well as, double field rate of nicosulfuron were not enough to cause mortality of X. strumarium, but nicosulfuron exhibited significant effects on X. strumarium. Namely, increasing rates of nicosulfuron significantly reduced all measured vegetative parameters (height, fresh weight, leaf area and LAI). Levels of reduction above measured parameters depend on herbicide rate, assessment and the year. Fresh weight was the most sensitive, while plant height was the least sensitive parameter to nicosulfuron. Nicosulfuron reduced burs production (weight plant-1 or number plant-1) of X. strumarium, but its effect were not so distinct as effects on vegetative parameters. Burs production was decreased when rate of nicosulfuron increased, however reduction of burs weight and number plant-1 was higher in 2008 than in 2009. Namely, effect of nicosulfuron on both parameters was very significant (P<0.01) in 2008, while in 2009 significant effect (P<0.05) was confirmed for burs weight plant-1 only. Those results indicate that plant growth and burs production are not parallel.

Acknowledgements

We thanks the Ministry of Education and Science of Serbia for support in this investigation, Project III46008.