This study was performed to investigate the effects of enhanced light transmission on plant growth, photosynthetic ability, and disease tolerance to leaf blight, anthracnose in ginseng (Panax ginseng C. A. Meyer, Araliacease family) during the early growth stage (April to June). The photosynthetic ratio, stomatal conductance, and stem diameter of plants grown under a shade net with 15% light transmission rate showed an increasing trend compared to the control plants (5% light transmission rate) although the growth of the aerial parts were not influenced significantly. Plant height, stem length, and leaf length of treated plants were not significantly different from those of the control plants. Root parameters, such as root length, diameter, and weight of treated plants increased significantly compared to the control. Yield performance (187.4 ㎏• 10 a−1) of treated plants was 55.5% higher than that of the control (150.4 ㎏• 10 a−1). Additionally, disease severity scores of treated plants were lower than those of the control plants, revealing higher survival rates. To retain high yield potential and enhance the level of disease tolerance in ginseng, we suggest the increase of light transmission rate during the early growth stage.

This study was conducted to investigate the effects of sowing density, number of seeds sown per hole, andthinning treatment on growth characteristics and disease occurrence in Panax ginseng under direct sowing cultivation in ablue plastic greenhouse. Seedling were grown from 2 or 3 seeds sown, and the healthiest was only retained, while the restwere thinned out at the foliation stage. NO3-N, P2O5, and organic matter content differed significantly between growthconditions in the plastic greenhouse and in conventional shade in the soil. Disease also tended to be higher in the conven-tional shade than in the plastic greenhouse. Plant height and stem length showed an increasing trend with increasing sowingdensity and number of seeds sown per hole. However, these measures noticeably decreased when thinning treatment wasconducted. Growth of the subterranean part of ginseng was not markedly influenced by sowing density, the number of seedssown per hole, or thinning treatment. Root weight, which is an important factor in yield, was significantly affected by thenumber of seeds sown and thinning treatment. Interestingly, root weight tended to be higher in the thinning treatment plotthan the untreated control plot. Damping-off and root rot increased noticeably as the number of seeds sown increased. Dis-ease also tended to be substantially higher in the thinning treatment plot than the untreated control. However, physiologicaldisorder of the plants did not vary with sowing density, the number of seeds sown, or thinning treatment.