pots filled with steam-sterilized propagation
substrates. Propagation sub- strate was composed of peat, vermiculite, and soil from vegetable fields (2:1:1, volume basis) and was steam sterilized at 134 °C for 30 min. Seedlings were placed in a growth cham- ber held at 25/20 °C day/night with a 16-h photoperiod. Illumi- nationwas providedbyhigh-pressure sodiumlamps at50 WÁm–2.