[Planting density of Perilla frutescens PA-type].

Two medicinal PA type Perilla germplasms were planted at five planting densities(D1,2 500 plants/Mu;D2,5 500 plants/Mu;D3,8 500 plants/Mu;D4,11 500 plants/Mu;D5,14 500 plants/Mu;1 Mu≈667 m~2). A total of 17 traits, including leaf shape, plant type, yield, volatile oil content and composition, were recorded and studied. With the planting density increased, the leaves appeared narrow, plants small, the deciduous leaves increased, and the leaf yield per plant was low, but the leaf yield per Mu increases significantly with the planting density, and was basically stable after reaching D4. The extraction rate of volatile oil from leaves at planting density D2-D5 was about 0.1% higher than that of D1, and there was no significant difference in the relative content of perillaldehyde, among 5 density. In order to achieve high leaf yield, it is recommended to plant at a density of D4, 11 500 plants/Mu(plant spacing is 15 cm, and row spacing is 40 cm); while comprehensive leaf yield and leaf morphology are recommended to be planted at a density of D2, 5 500 plants/Mu(plant spacing is 30 cm, and row spacing is 40 cm). At the same time, dense planting resistance of two germplasms were different. Number of secondary branches, first section with leaves and plant types were most important feature for the evaluation of the density tolerance of PA-type Perilla. This study provided a reference for the suitable density of PA-type Perilla, and laid a foundation for further study of the tolerance characteristics of different Perilla.