Appropriate Harvesting Time and Seed Rates of the first Crop in the Stubble-lodging Rice Ratooning Cropping in the Central Plain

Abstract

Stubble-lodging rice rationing method is so popular that many farmers have put in practice. Survey of stubble-lodging rice rationing method was made in the Central Plain and found that the success of this method was depended on many criteriars. Harvesting time and seed rates in the first crop were so important that studies should be made. Then experiment was conducted at Pathumthani Rice Research Centre in 2003 and was divided into two sub experiments namely appropriate harvesting time and seed rates of the first crop in stubble-lodging rice rationing cropping. It was designed as RCB with 4 replications; plot size was 10x10 m. Rice cultivar named Suphanburi 1 was used in this experiment. Yield, height, yield component of the first crop and stubble-lodging rice rationing crop, number of tiller emerged from stubble and seeding at 7, 14 and 21 days after stubble lodging as well as soil moisture content every 3 days after stubble lodging with metrological data were recorded. The sesult showed that yield harvested at 25, 28, 31 and 34 days after 80% flowering in the first crop were not different from each other as well as seed rate of 15, 20, 25 and 30 kg/rai and didn’t affect yield of stubble-lodging rice rationing cropping in the second crop.