EFFECT OF SOWING DATE AND CHITOSAN RAW MATERIAL POWDER ON BORO RICE (BRRI dhan88)

Abstract

A pot experiment was conducted under the net house of Sher-e-Bangla Agricultural University (SAU), Dhaka, Bangladesh, during November 2019 to April 2020, to investigate the effect of sowing date and chitosan raw material powder on Boro seedling character. The experiment was consisted of two factors with three replications following Completely Randomized Block Design (RCBD). Factor A: Different sowing dates (08) viz: S 1 i

= 23 Nov, 2019 S 2 = 25 Nov, 2019 S 3 = 27 Nov, 2019 S 4 = 29 Nov, 2019; S 5 = 01 Dec, 2019; S 6 = 03 Dec, 2019 S 7 = 05 Dec, 2019 and S 8 = 07 Dec, 2019. Factor B: Level of chitosan raw material powder (w/w) (06) viz: T 1 = 0.1%, T 3 = 0.2%, T 4 = 0.3%, T 5 = 0.4% and T 6 = 0.5%. A significant variation was observed in the Boro seedlings characters including seedling height, fresh weight, oven dry weight, seedling strength and chemical properties of the seedbed soils in all the sowing dates. Seedling characters values in all the sowing dates were lowest in the control against the treatments. Seedbed application of the chitosan raw material powder significantly improved the Boro seedling characters at 25 days after sowing (DAS), 30 DAS, and 35 DAS in the different sowing dates. The seedling height, fresh weight, oven dry weight and seedling strength were increased in a dose dependent manner with the application of chitosan raw material powder up to sowing date S 8 . In the 1 st sowing date values of the seedling characters were maximum then gradually decreased and lowest value was found in the last (8 th ) sowing dates. Seedlings produced in the 1 st sowing date at 35 DAS were performed superior than the seedlings of 30 DAS and 25 DAS. But the some treated seedlings of the 25 DAS and 30DAS were performed significantly better than control seedlings of the 35 DAS. Grain yield production of the S 1 seedlings (25, 30 and 35 days old seedlings) was higher in the treated seedlings over the control seedlings. 35 day aged seedling treated with 0.3% chitosan raw materials powder (35DT 3 ) was shown higher yield pot -1 (65.02 g) performance which 21% yield increase over control. On the other hand, a significant improvement was observed on the seedbed soil properties including organic carbon, organic matter, soil pH and total nitrogen content. The maximum value of the seedbed soil properties was recorded in the T 6 treatment and minimum level was recorded in the control treatment (T 1 ). The increments of the organic matter content and total nitrogen content were in a dose dependent manner. The results indicated that chitosan raw material powder could play a significant role in the improvement of Boro seedling characters and yield performance under the optimum sowing dates and also after the optimum sowing dates. Chitosan raw material treated 30-35 days old Boro seedling could be recommended for the farmers use. Low temperature induced seedling growth reduction could be manipulated through using CHT raw material powder in seedbed.