The objective of this study was to compare the economic threshold (ET) of Pratylenchus penetrans in radish fields of andosols using the Baermann method and the combination method of soil compaction and real-time polymerase chain reaction (PCR). Soil samples were collected from 26 plots at depths of 0 to 30 and 30 to 60 cm before seeding of radishes. The number of P. penetrans in each sample was estimated by the Baermann method and the combination method. No P. penetrans was detected in 13 plots by the Baermann method, while the number of plots in which no P. penetrans was detected was only two by the combination method. The number of spots caused by P. penetrans on radishes harvested from the plots was also counted. It was difficult to determine the ET of P. penetrans estimated by the Baermann method, based on whether severe damage (more than 10 spots on average per radish) was seen. However, the ET of P. penetrans estimated by the combination method was determined at 5.3 J2 equivalents per 20 g dry soil. In plots with P. penetrans densities lower than the ET as evaluated by the combination method, the ratio of plots with no damage was 87%. The results suggest that the combination method has an advantage in the estimation of damage to radish by nematode.

We developed a new culture system to facilitate the indoor use of bedding plants. In this system, lightweight organic culture medium is wrapped in a flat cloth container made of a discarded school uniform. In this study, the composition and volume of culture medium appropriate for this culture system were investigated. Marigold and dianthus planted in coir or a mixture of coir and peat moss grew as well as those in the standard mixed red clay soil, while peat moss alone inhibited growth. Plants grown in the cloth container were slightly smaller than those grown in a usual plastic pot, presenting no problem for practical production. The appropriate volume of the medium was 200 mL or more, because a smaller volume such as 100 mL caused growth inhibition. Fungus often grew on the cloth container, which should be controlled to maintain the commercial value. It was classified as the genus Simplicillium on the basis of ITS sequence analysis.

No abstract

No abstract

No abstract