Study on growth and development of rice under the influence of different irrigation regimes arranged in greenhouse conditions at Thai Nguyen University of Agriculture and Forestry. The experiment was conducted on Khang Dan 18 rice variety with 5 different irrigation treatments, including flooded treatment during cultivation (F1)
alternate between dry and wet every 4 days (F2), 8 days (F3), 12 days (F4) and 16 days (F5). The results show that the irrigating regime significantly affects the growth of rice such as number of branches, plant height, dry mass, leaves and roots. The best growth of rice is at the 4-day alternating between dry and wet, which has 24.2 - 36.9% higher growth rate than the other treatments. Growth factors, such as leaf stem weight, are strongly correlated with root parameters at tillering, dough and maturity. The root parameters are positively correlated with the growth of stems and leaves in the flowering and maturing stage. The higher number of roots significantly leads to the larger root mass, leaf, stem, and total dry matter weight with a confidence level of 95% or more (P <
0.05). In order for the rice to grow well, it is necessary to manage irrigation for the best root development especially in the main stages such as tillering, panicle initiation, heading, grain filling, and ripening.