The effect of growth compounds with different doses on physiological characteristics of rice in the treasury

To examine the effect of application of humic acid, folic acid, and seeding treatment with various levels of phosphorous compounds on vegetative characteristics, yield and nutrient uptake capacity of rice (Tarom cultivar) in the nursery at different sowing dates, a split-split plot experiment in a randomized complete block design (RCBD) was performed with three replications in Sari in 2017 and 2018. Experimental factors included an equal combination of humic acid and folic acid as the main factor in the four levels of control and, 3, 6 and 9 g/l, the combination of phosphoric acid solution and monoammonium phosphate as the sub-factor in the four levels of control and 5, 10 and 15 g/l, and the planting date as a sub-sub-factor in three levels in March 10th, March 19th and March 30th. The results revealed that the application of humic acid and folic acid increased root length and the wet and dry weight of the plant compared with the control, and the greatest effect was obtained in the treatment of 6 g/l humic acid and folic acid. The application of humic acid and folic acid caused an increase in the grain and straw nitrogen and the grain phosphorus content but a decrease in the straw phosphorus content. Feeding the seedlings with phosphorus compounds led to a significant increase in the root length and the wet and dry weight of the plant compared with the control. The greatest effect was observed in the treatment of 10 g/l of different phosphorus compounds. Feeding the seedlings with phosphorous compounds increased the nitrogen and phosphorus contents of the grain and straw. Also, the maximum root length and the wet and dry weights of the plant were obtained on the planting dates of March 10th and 19th. In general, it was observed that the greatest dry weight of the plant was 1.017 g, belonging to the treatment of consumption of 6 g/l humic acid and folic acid with 10 g/l of various phosphorus compounds planted on March 10th. The highest amount of white rice (64.18%) was related to the treatment of 10 g/l phosphorus. On planting date, 24 April, more white rice (63.59%) was obtained than the planting dates of 14 April (62.34%) and 4 May (61.28%). The simple correlation between the measured traits showed that the amount of white rice had a positive and significant correlation (at the level of 1% probability) with all measured traits except gel consistency and hard rice and had a significant negative correlation with a gel consistency and hard rice husk.