Evaluation of Chloropicrin as a Soil Fumigant against Ralstonia solanacarum in Ginger (Zingiber officinale Rosc.) Production in China

Background: Chloropicrin (Pic) offers a potential alternative to methyl bromide (MB) against Ralstonia solanacarum in ginger (Zingiber officinale Rosc.) production. MB is scheduled to be withdrawn from routine use by 2015 in developing countries. Methods: Pic treatments were evaluated in a laboratory study and in three commercial ginger fields. Results: Laboratory studies showed that the EC50 value and EC80 value of Pic were 2.7 and 3.7 mg a.i. kg(-1) soil, respectively. Field trials in highly infested soil revealed that treatments of Pic at the dose of 50 g m(-2) covered with totally impermeable film (TIF) or polyethylene film (PE) sharply reduced Ralstonia solanacarum and maintained high ginger yields. Both of the Pic treatments provided results similar to, or in some cases slightly lower than, MB with respect to Ralstonia solanacarum control, plant survival, plant growth and yield. All of the fumigant treatments were significantly better than the non-treated control. Conclusions: The present study confirms that the Pic is a promising alternative with good efficacy against Ralstonia solanacarum for ginger production and could be used in integrated pest management programs in China.