옥상 텃밭에서 방향성 식물과의 동반재배가 케일의 생육 및 해충방제에 미치는 영향

Abstract

Companion cropping of aromatic ornamental plants provides an environmentally benign route to improving main crops and reducing pest damage in agro-ecosystems. Aromatic plants are frequently used as companion plants, but their effects on growth and pest control remain unclear in a rooftop vegetable garden. Here, we evaluated the effects of aromatic plants on the growth and pest control of kale (Brassica oleacea var. viridis) in a rooftop field experiment. Kale were companion cropped with four aromatic plants (2 Lamiaceae, 2 Asteraceae), curry plant (Helichrysum italicum), apple mint (Mentha suaveolens), lavender (Lavandula augustifolia), or marigold (Tagetes patula) at a 1:1 planting ratio. Accordingly, five treatments were set up in a rooftop vegetable garden: KC, kale control; KI, kale + curry plant; KA, kale + apple mint; KL, kale + lavender; KM, kale + marigold. Over time, growth parameters such as plant height, leaf size, number of leaves, and dry weight were highest in the KC, while the KA treatment showed the lowest values. Except for chlorophyll content, kale growth generally declined under companion cropping, likely due to competition with the aromatic ornamental plants. Companion cropping showed a stronger pest suppression effect compared to kale alone, although the difference among plant species diminished over time. In rooftop vegetable gardens, companion cropping may be more effective for pest control than for promoting crop growth. Future applications should consider interspecific interaction to optimize eco-friendly cultivation strategies.