Verification of the selective efficacyand effect of the applicationof the pre-emergence herbicide Stomp (Pendimethalin) on shoot growth in young ornamental woody plants using privet and European Bladdernut as an example

Abstract

The research was carried out on newly planted bare-root plants at an early stage of their cultivation. The scope of the growth responses of woody plants was verified in relation to the recommended herbicide rate, namely for herbicide solution application rates of 0.825% and 1.025%. The new increment of the longest shoot and the mortality rate were evaluated. The selective efficacy on weeds was observed. Data collection took place at 2, 4, 8, 12 and 24 weeks after application. The experiment followed the manufacturer's recommendations for application. It was conducted on an experimental area of loamy sand soil in 2019 and it was not affected by extreme weather conditions. The application of the herbicide to privet (Ligustrum vulgare) showed a small inhibitory effect, reducing the average increment of the longest plant shoot by 4.7% and 8.3%, respectively, by the end of the study period compared to the control. By contrast, in the case of the European Bladdernut (Staphylea pinnata), the application was found to have an adverse effect. The role of the application rate was secondary. The average increment of the longest shoot was reduced by 45.68% and 50.13%, respectively, and the mortality rate of the treated woody plants reached 10% at the end of the study period. The highest inhibitory effect of the herbicide on the ornamental woody plants that had been treated was observed in the first 2 and 4 weeks after treatment, respectively. The application of the herbicide proved ineffective against horseweed (Conyza canadensis) and groundsel (Senecio vulgaris).