تعيين كاراترين شيوه ي تقسيط كود نيتروژن با استفاده از نمودار رنگ برگ (LCC) و كلروفيل متر (SPAD) در برنج

Determination of best method of partitioning N fertilizer by using Leaf Color Chart (LCC) and chlorophyll meter (SPAD) in rice

In order to determination of partitioning N fertilizer by using of Leaf Color Chart (LCC) and Chlorophyll meter (SPAD) in rice an experiment was conducted as split plot under randomized complete block design with three replications during 2006 and 2007 at Rice Research Institute of Iran. Main plots were contained cultivars in three levels (GRH1, Khazar and Hashemi) and sub plots were contained six time of application N fertilizer as LCC<3 (application of N fertilizer after observation of 3 degree in Leaf Color Chart), LCC<4 (application of N fertilizer after observation of 4 degree in Leaf Color Chart), SPAD<35 (application of N fertilizer after time that degree in SPAD was under 35), SPAD<38 (application of N fertilizer after time that degree in SPAD was between 38 and 35), common method (application of 150kg N fertilizer in tillering, panicle initiation and flowering) and no fertilizer. Significant deference was detected between cultivars for all of the traits in 1% probability level. Also, significant deference was identified between tools for all of the traits (unfilled grains and thousand grain weight) in 1% probability level. Significant deference was showed between SPAD<38 and LCC4 with other methods of partitioning, whether non significant deference was detected between common method with LCC<3 and SPAD<35. According to these result, level of optimum SPAD was identified 35 for Hashemi. Also, levels of optimum LCC and SPAD were identified 4 and 38 for GRH1 and Khazar, respectively. Result of this study were showed when LCC and SPAD values were under than optimum level, N fertilizer should be used as 35 (for Hashemi) and 40 (for GRH1 and Khazar) kg N fertilizer per hectare.