In open field Komatsuna cultivation in late-summer, the products without chemical pest control were seriously damaged by Lepidoptera or legume leafminer, consequently less than 10 % of the plants were marketable and marketable yield of less than 0.3 kg/m^2 were obtained. The physical barrier of cheesecloth tunnelcovering was successfully introduced and the rate of marketable plant improved to more than 70 % so as the marketable yield to 2.1 kg/m^2 or more. The marketable yield of 1.8 kg/m^2 was obtained when insect pests were controled chemically without barrier. These results indicate that the use of physical barrier would be favorable to late-summer Komatsuna cultivation compared to chemical control. In autumun Komatsuna cultivation, the advantage of the physical barrier of cheesecloth tunnel-covering was considerably decreased because that the number of tunnels into which aphids invaded were increased. The application of cheesecloth tunnel-covering may not be adequate to prevent aphids' attack during the period when the population of aphids in surrounding fields is higher, even if the cheesecloth of smaller mesh (0.6mm) was used. In late-autumun harvesting chinese cabbage cultivation, the products without chemical pest control were also seriously damaged by Lepidoptera or aphids, consequently the marketable yield were about 100 kg/a. The application of cheesecloth tunnel-covering greatly improved the marketable yield up to the same level to chemically controled plots (600 kg/a), provided that early aphid invasion into the compartment of cheeseclothtunnel and subsequent rapid increase of aphids inside were not occurred. As to these three field experiments, the pre-planting soil surface covering with a transparent vinyl seat during summer was useful for weed management and this solarization decreased the aphids problem inside of the cheesecloth tunnel, however, it was not clear how the decrease occurred.