Abstract
Growth characteristics and establishment of the seeds of horsenettle was examined on effects of chemical and shading treatment in the experiments of small container and cornfield. Chemical treatment of atrazin-metolachlor (3lha^<-1>) decreased shoot and root growth of the seedlings, whereas it was limited at early growth stage as shown by about 3 mm diameter of taproot at a corn harvest time. Dry matter production of the weed was not decreased by shading 50% of sunlight, while it dropped by more than 75% shading of the sunlight. Under such severe shading conditions most of the seedlings survived and grew to a 1.8mm diameter of the taproot. The seedlings of 18 days after germination needed 15-18 days for regrowth, while the seedlings of over 26 days were 11-12 days. The regrowth of the taproots and root fragments was also closely associated with the size of root diameter, suggesting the minimal of 1.5mm diameter in cases of 10cm long taproot and root fragments. The results showed that seedlings of horsenettle was resistant to shading and chemical treatment and thereby led to greater growth and appearance in the cornfield.
