換気窓開放時の大規模温室でのCO₂施用がトマトの成長および収量に及ぼす影響

抄録

The present study examined the effect of CO₂ enrichment on the growth and yield of tomato plants cultivated in a large-scale greenhouse with a high- ventilation rate. In this study, CO₂ enrichment referred to maintaining the CO₂ concentration inside the greenhouse at the same level as the atmospheric CO₂ level. Tomato plants (Solanum lycopersicum L.) were cultivated under 2 different CO₂ conditions —one group of plants was cultivated under CO₂ enrichment, and the other was cultivated under CO₂ non-enrichment— during the spring-summer and summer-autumn periods. In the spring-summer crop, leaf dry weight and leaf area of the tomato plants cultivated under CO₂ enrichment were greater than those of the tomato plants cultivated under CO₂ non-enrichment. In both the spring-summer and the summer-autumn crops, the total fruit yield per plant increased because of CO₂ enrichment. In the spring-summer crop, CO₂ enrichment led to increase in both the total fruit yield and the normal fruit yield. However, in the summer-autumn crop, the total fruit yield increased and the ratio of the normal fruit yield to the total fruit yield decreased because of CO₂ enrichment. These results reveal that CO₂ enrichment might increase the incidence of fruit malformation according to the cropping season. The effect of CO₂ enrichment on the fruit yield was influenced by differences in the environmental conditions during the cultivation periods. In conclusion, it is therefore necessary to assess whether the environmental conditions inside the greenhouse are suitable for plant growth under CO₂ enrichment.