2016 Volume 60 Issue 3 Pages 146-154
In the highlands of central Vietnam, producers attempt to cultivate profitable temperate crops that could not grow in the lowlands. We, therefore, examined the possibility of strawberry (Fragaria × ananassa Duchesne) cultivation under a rain shelter in the highlands (1,320 m AMSL) of Bạch Mã Mountain. Strawberries grew vigorously in the dry season from March to September. We observed flowering, fruiting and runner growth. Many fruits were malformed or unfertilised, but normal fruits were produced by artificial pollination. In the rainy season from October to February, the plant growth was stagnant. Lower leaves turned brown and wilted, and many plants died. The analysis of climate data and comparison of cultivation methods suggested that the stagnant growth and death of the strawberry plants were related to the light intensity and relative humidity rather than to the air temperature. We investigated plant responses such as stomatal conductance under variable light intensity and humidity conditions at different leaf positions using a portable photosynthesis system in a phytotron. The stomata of the mature leaves tended to close in response to a low light intensity and high humidity. When the light intensity was increased, the transpiration rate of the mature leaves remained markedly low. The difficulty to grow strawberries in areas with frequent rain is attributed to prolonged low light intensity and high humidity, which lead to stagnant water flow in plants. We discussed the possibility of strawberry cultivation in tropical highlands with high rainfall.
