Nitrogen Management with Leaf Color Chart (LCC) in Irrigated Rice Varieties of the Central Plain

Abstract

The aim of this study was to develop an appropriate recommendation for nitrogen management in irrigated areas of the central plain by using Leaf Color Chart (LCC). Eleven photoperiod-insensitive and 3 photoperiod-sensitive rice varieties were studied for nitrogen management using LCC. The studies were conducted at Pathum Thani Rice Research Center both in wet and dry seasons during 2006-2007. Factorial in RCB with 4 replications were used which consisted of 2 factors, rice varieties and nitrogen managements. Four methods of nitrogen managements; recommendation, application of nitrogen at LCC£2, LCC£3 and LCC£4were used in the experiments. The results showed that leaf color differs among varieties and seasons. For photoperiod-insensitive rice varieties, at leaf color level of LCC£3 was recommended to apply 4 kg N/rai in most varieties except RD31 in which LCC£4 was recommended. For 3 photoperiod-sensitive rice varieties, at leaf color level of LCC£2 were recommended to apply 2 kg N/rai, and the excess amount of nitrogen could not increase the rice yield due to less nitrogen response.