EVALUATION OF CULTURE MEDIA AND SHADING ON CONTAINER-GROWN ORIENTAL PEARS IN TAIWAN LOWLAND

Supraoptimal temperature in summer and insufficient chilling in winter are the major bottle-necks of cultivation of high chilling Oriental p ears in the warm area. Container cultivation of plants has several ben efits, which include feasibility for moving plants to the appropriate environment. In an attempt to grow high chilling pears in Taiwan's low lands, the studies by using 'Shinseiki' pear (Pyrus serotina) as mater ials were designed to evaluate the practicability of container growing . Its related factors included container, medium, irrigation, and shad ing, etc. The results showed that the temperature of media was affecte d significantly by the proper combination of media and containers. The fluctuation of temperature of media prepared by the combination of pe at and bark compost (1:1 on volume basis) has the lowest temperature a mong the six tested media.The temperature of media filled in a white n onwoven bag was lower than that of media being filled into the three o ther kinds of containers. The records of the media temperatures at the vertical site of bags showed that the upper portion of media (around 10 cm in thickness) was significantly higher than the temperature of a lower portion of media. Drip irrigation did not significantly affect media temperatures. Shading also reduced the temperature of the media and leaf surfaces. The treatment of 25% shading reduced the temperatur e by more than 2-degrees-C as compared to the control. In the treatmen t with the combination of white nonwoven bag, peat + bark compost as m edia, drip irrigation, and 25% shading during summer, the net incremen t of trunk cross section of 'Shinseiki' pear was 180 mm2 from July to September.