Assessment of nonchemical weed management of windmill palm (Trachycarpus fortunei) nursery

Abstract

The windmill palm is a distinctive outdoor ornamental palm adapted to cooler climates. Weeds pose significant challenges in palm nurseries, particularly during seedling and establishment stages. This research was conducted in a nursery with 5,500 windmill palm seedlings, starting in April 2014 when the palm trees were three years old. Experiments were terminated in October 2018 when weed control was no longer necessary due to the advanced growth stages of the palm trees. The objectives were to determine the weed composition and diversity, elucidate the effects of mechanical weed management (MWM) on growth rate of palm, and develop a sustainable program to maximize palm tree growth through effective weed management and soil tillage. Owing to the lack of registered nursery herbicides in Türkiye, weed control was performed mechanically using garden hoeing machines between rows and hand hoeing for intra-row strips. The most common and dense weeds were purple nutsedge, annual mercury, and common purslane in summer-autumn, and burning nettle in winter-spring. In 2014, weed densities were 100, 127, and 145 weeds m^–2 for MWM, hand-weeding (HW), and nontreated (NT), respectively. Transplanted palm seedlings required at least two, ideally three growing seasons of intensive weed control until the palm tree crowns block sunlight and suppress weed growth. The research indicated palm trees in the MWM treatment had approximately 84 leaves and a height of 210 cm by October 2018, compared to 54 leaves and 136 cm for HW, and 40 leaves and 100 cm for NT. These results highlight the critical role of MWM in promoting optimal growth of Chinese windmill palms. Effective and sustainable weed management, combining MWM and HW, is essential for producing high-quality palm trees, which are valuable insights for nursery managers and contribute to best practices for cultivating windmill palm trees in similar climatic regions.