ABSTRACT

June-bearing strawberry cultivars have been widely grown in Japan. Since they are harvested in winter and spring, little produce is available in summer and autumn. To achieve stable year-round supply, we need to expand the production area of ever-bearing cultivars. Here, we examined whether it is possible to increase dry matter (DM) production and fruit yield by increasing the CO₂ concentration within the plant canopy through local application to promote photosynthesis in summer and autumn protected culture. We investigated the CO₂ concentration in the plant canopy, DM production characteristics, yield characteristics, fruit quality, projected leaf area, cumulative light interception, and light use efficiency. We confirmed that the CO₂ concentration within the plant canopy could be increased in summer and autumn (Control; 398 ppm, CO₂; 1280 ppm), significantly increasing DM production and total yield (Control; 349 g, CO₂; 447.5 g). We consider that local application of CO₂ increased the projected leaf area and thus cumulative light interception. This method may help to increase fruit yield in summer and autumn protected culture.

摘要

六月草莓品种已在日本广泛种植。由于它们是在冬季和春季收获的，因此夏季和秋季的农产品很少。为实现全年稳定供应，我们需要扩大常产品种的产区。在这里，我们研究了是否可以通过局部施用增加植物冠层内的 CO ₂浓度来促进夏季和秋季保护栽培中的光合作用，从而提高干物质 (DM) 产量和果实产量。我们研究了植物冠层中的CO ₂浓度、干物质生产特性、产量特性、果实品质、投影叶面积、累积光截留和光利用效率。我们确认了 CO ₂夏季和秋季植物冠层内的浓度可以增加（对照；398 ppm，CO ₂；1280 ppm），显着增加干物质产量和总产量（对照；349 g，CO ₂；447.5 g）。我们认为 CO ₂的局部应用增加了投影叶面积，从而增加了累积的光拦截。这种方法有助于提高夏秋保护栽培的果实产量。