Severe damage on a greenhouse grown lettuce (Lactuca sativa L.) associated with Paratylenchus projectus is described for the first time. There were no marketable lettuce in entire greenhouse after three months of planting. Lettuce roots system appeared corky and most of feeder rootlets disappeared. Population densities of P. projectus were ranged from 320-11,600 nematodes per 100 cm 3 of soil. In an inoculation test in a greenhouse, P. projectus is proved as a causal agent of lettuce damage.

This study was conducted to get the basic data for the eco-friendly cultivation of Chines cabbages that high nitrogen requirements by evaluate the effect of the pollack fish-meal incorporation on growth properties of cabbage and soil chemistry. The study was conducted as pot (1/2,000a) test at the Miryang in Korea from May to August 2017. The treatment was divided into two groups; the amount of fish-meal treated were based by comparing the standard application ratio of nitrogen for Chinese cabbage with the nitrogen content of the fish-meal, and the chemical properties and the growth of the cabbage were compared by the treatments of 50%, 100%, 150%, 200% and 250%. The results obtained are following; the ammonia gas was produced from the after 2nd day of incorporated, and the amount of ammonia gas generated was geometrically correlated with the amount of fish processed. The soil pH level after study was lowered to about the pH 5.1 from 32.1 g/pot (1/2,000a). Due to the fish-meal increased the EC, content of Av. P 2 O 5 acid and inorganic nitrogen, and the pH level did not decrease even when the inorganic nitrogen increased at NO 3 --N content of 5.4 mg/kg and NH 4 + -N was higher than 3.3 mg/kg. The SPAD value at the time of cabbage harvest was positive correlation with the amount of fish-meal treated, and the biomass was similar to that of SPAD. The biomass of Chinese cabbage in fish-meal plots were higher than that of conventional treatments, and the weight of the headed cabbage was the highest in T4 (64.1 g/pot). The number of cabbage leaf was the highest in T3 (53.4 g/pot). Based on the above results, it is thought that if the C/N ratio adjusted plant organic resources, methods of mixing and technologies for minimizing pH drop are supplemented, it will be excellent eco-friendly organic resources instead of synthetic nitrogen.

The study was conducted to investigate the infestation and distribution of plant-parasitic nematodes on Chinese yam (Dioscorea batatas) in Andong, Korea. Root-knot nematodes, Meloidogyne incognita was the most prevalent nematode species which is found from 43 yam fields (81.1%) with high population densities (average of 450 juveniles/300 cm 3). Other nematodes, root-lesion nematode (Pratylenchus spp.) and pin nematode (Paratylenchus spp.) were less problematic. Density of juveniles (J2) of M. incognita was 10 J2/300 cm 3 by August, then increased to 274 in September and 624 in October. The highest J2 density was found at the soil depth between 40 and 50 cm (1,840 J2/300 cm 3). M. incognita was able to infest yam tuber down to a depth of 70 cm and developed galls outside and brown spots inside. The highest number of females were found at 40-50 cm (79 females/10 cm piece) tuber from the top.