The gelatin capsule (gel cap) formulation of 1,3-dichloropropene (1,3-D) is a new concept to reduce the environmental release, transport, and hazard potential of the use of 1,3-D to control soilborne diseases and nematodes. The objective of this study is to evaluate the biological efficacy of the 1,3-D gel cap formulation under laboratory and greenhouse trial conditions. Greenhouse experiments were carried out in suburbs of Beijing and Hebei Province of China in 2007 and 2008, focused mainly on tomato and Bellis perennis L. (daisy) crops. Results showed that 1,3-D gel cap application at a rate of 16.8 g of active ingredient m(-2) was as effective as 1,3-D liquid injection treatment. Crop yields in plots treated with 1,3-D gel cap and 1,3-D liquid were significantly higher than those in untreated control. The present study confirms that the 1,3-D gel cap formulation is a promising new formulation with good field efficacy.