Different developments of rice leaf and their response to nitrogen

Abstract

The study evaluates and compares the leaf number (LN) of two rice types, Hybrid Indica (HI) and Japonica (J), and their response to three different nitrogen rates. A split plot experiment was conducted in Danyang District, Jiangsu Province in China, from 2017 to 2018 both rice growing seasons. It was carried out using the Transplanting machine, and the spacing was 17 cm × 30 cm. A split zone design was adopted, with three different levels of nitrogen: N0-0, N1-150 kg hm−2 and N2-300 kg hm−2. The areas were isolated with a brick wall to ensure that each main area drained separately. Urea appliance: tiller fertilizer: panicle fertilizer = 4:3:3, P2O5 - 150 kg hm−2 were used as base fertilizer, Potassium chloride 300 kg hm−2: panicle fertilizer = 5:5. Nitrogen rates (N) significantly influenced the LN of Hybrid Indica cultivars. The first year N0 = 15.5, N150 = 15.7, N300 = 15.9 and the second year N0 = 15.9, N150 = 16.3, N300 = 16.5 with a significant difference between both years. However, Japonica rice cultivars were not as responsive to N as Hybrid Indica's were. The Japonica LN on N0 = 16.2, N150 = 16, N300 = 16.8, and N0 = 16.4, N150 = 16.6, N300 = 16.5 for 2017 and 2018 respectively, with a significant difference in the first year only at N300. The results revealed that LN varies greatly among varieties, furthermore the nitrogen fertilizer and the year of the experiment played a major role on LN outcome.

Keywords

• nitrogen (n) rates
• leaf number (ln)
• leaf appearance rate (lar)
• duration from transplant up to panicle initiation (dtp).