Taro is an important vegetable in Miaoli, and is mainly produced in Gongguan and Tongluo. The AG.STATISTICS YEARBOOK 2012 of Agriculture and Food Agency showed a total taro planting acreage of 2,346 hectares, of which 519 hectares are in Miaoli County, second only to Taichung. The total production of 10,541 metric tons also puts the county in second place while the production per unit of land is the highest in the nation.

The prevailing taro planting practice heavily utilizes fertilizers and pesticides. That raises not only production costs but also brings out the issues of food safety and environmental impacts. Therefore, we have conducted research on health management of taro, including sterilizing taro cormel, cultivation management, investigations of weeding, and pest control and experiments of pruning in response of typhoon damage. We hope to develop a cultivation management model that is suitable for Miaoli, improve food safety, and reduce environmental impacts.

Our observation and experiments indicate that weeds in taro fields have shown differences between years since 2005, when we started this investigation. Bolboschoenus planiculmis and perennial grass predominated in 2008-2009, making it a tough weeding problem. Our experiments suggest that taro fields where Bolboschoenus planiculmis is rampant can be treated with sulfonylurea-based herbicides which are used for rice planting. This effective treatment quickly cuts down underground tuber reproduction. In 2010, weeds mainly included Poa annua,Fimbristylis littoralis Gaudich.,Emilia sonchifolia (L.) DC. var. javanica (Burm. f.) Mattfeld,Conyza sumatrensis (Retz.) Walker,Ranunculus sceleratus L.,Alopecurus aequalis Sobol. var. amurensis (Komar.) Ohwi , among which Poa annua and Fimbristylis littoralis Gaudich were predominating. Preliminary experiments show that pruning can affect the gross weight of the corm of taro, reducing incidence of Phytophthora blight. However, we still need more experiments to support subsequent use of fertilizers and chemicals.