Effect of some mulch materials against to weeds problem in outdoor ornamental plants

Weeds cause problems such as decreasing plant growth and quality and increasing production cost in outdoor ornamental plant production areas. This study was conducted in Sakarya Province in 2021-2022 to evaluate the possibility of using some plant wastes as mulch material against weeds in outdoor ornamental plant production areas in Sakarya Province. The effectiveness of hazelnut pulp, nutshell, maize stalk, wheat straw, and wood chips for controlling weeds and plant growth in three years old Japanese spindle tree (Euonymus japonicus Aurea) and four years old Leyland cypress (Cupressocyparis leylandii Spiralle) was investigated. For this purpose, a pot experiment was conducted with 8 characters and 6 repetitions. The effects of the applications were evaluated with the number of overall weeds in each pot, the number of dominant weed species in each pot, weed cover area (%), effect rate (%), plant width (cm), plant height (cm) and stem diameter (cm). The most dense weed species in the experiment are Cyperus rotundus L. (Purple nutsedge), Euphorbia peplus L. (Petty spurge), Poa annua L. (Annual meadow grass) in Japanese spindle tree pots whereas Setaria viridis (L.) P. Beauv (green hedgehog millet) and Poa annua L. (Bluegrass) in Leyland cypress pots. As a result of the study, black polyethylene cover was the most effective application in terms of effect on weeds and plant growth in both ornamental plants. The effects of the applications on weeds varied between 75-97% in Japanese spindle tree and 70-97% in Leyland cypress and the most effective applications in both plants were ranked black polyethylene cover (97%), hand weeding (95%) and wheat straw (85%), respectively. As a result, it is recommended to apply synthetic or plant waste mulches, which are determined to be effective in the ornamental plants.