Title: Determination of the most suitable transplanting distance and the amount of nitrogen fertilizer for the promising line of the TH3 rice
Author: Abbas Shahdi Kumleh
One of the effective factors to increase rice production is considering the principles of agriculture, including achieving the desired density per unit area and the optimal use of nitrogen as a bottleneck for plant growth. For this aim, a two-year factorial experiment was conducted in a randomized complete block design with three replications at Rice Research Institute of Iran in Rasht during the farming year 2020-2021 to determine the most appropriate planting density and nitrogen fertilizer recommended for the promising rice line of TH3. Experimental factors composed of nitrogen fertilizer application in four levels (N0-N60-N75-N90 kg/ ha) and planting density in three levels (10 cm× 20 cm, 15 cm× 20 cm, 20 cm× 20 cm). Results showed that for the TH3 promising rice line the highest plant height (132.5), number of panicles per square meter (156.3), number of filled grain per panicle (126.7), 1000-grain weight (26.3 gr), paddy (5266.6 kg/ ha) and biological yield (14529.3 kg/ ha) and the percentage of harvest index (37 %) were obtained with consumption of 90 kg N/ ha which was not significantly different from the treatment of 75 kg N/ ha. Also, the planting density of 15 cm × 20 cm with the highest paddy (4706.4 kg / ha) and biological yield (13845.4 kg/ ha) was superior compared to the other planting distances. Therefore, to achieve the yield potential of rice promising TH3 line, reduce the economic costs of production per unit area, and also reduce the harmful effects of chemical fertilizers, using 75 kg of nitrogen per hectare with a cultivation distance of 15 cm× 20 cm is recommended.
Keywords: Rice varieties, Crops improvement, Potential yield, Plant density, Yield