Performances of Boro Rice as Affected by Different Concentrations of Marine Water

Abstract

Salinity is one of the most devastating abiotic stresses limiting crop production. Considering this issue, a pot experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the boro season (2017-2018) using two rice(Oryza sativa L.) varieties, namely BRRI dhan28 (salt sensitive) and BRRI dhan47 (salt tolerant),to assess the effects of varied salinity levels on the growth and the performance of the rice varieties under salt stress conditions. Four salinity treatments were used in this experiment, viz. control S0 (only freshwater), quarter-strength marine water S1 (three-parts freshwater and one-part marine water; 7.5 ds m−1), half-strength marine water S2 (half freshwater and half marine water; 15 ds m−1), and full-strength marine water S3 (only marine water; 30 ds m−1).These mixtures were used for irrigation purposes throughout the life cycle of the plants. Salt stress significantly decreased the plant height, relative water content (RWC) of leaves, number of effective tillers hill−1, number of filled grains panicle−1, 1000-grain weight, grain yield, straw yield, and biological yield of the rice. In both rice types, plant growth and yield were reduced as the salinity level increased. Grain yields decreased by 50, 90, and 100% in BRRI dhan28 when irrigated with quarter strength, half strength, and full-strength seawater, respectively, but decreased by 27, 50, and 72%, respectively, in BRRI dhan47. Similarly, other yield attributes had higher reductions in BRRI dhan28 under salt stress conditions than BRRI dhan47. However, irrigation with marine water in rice might lead to some straw yield but produced little to no grain.

Response of Biochar on Growth and Yield of Aman Rice Under Salt Stress

“…Imposition of 2800 ppm NaCl caused death of all plant at harvesting time as a result reduction of total grains panicle −1 was 100% under this treatment. These results were in line with previous studies (Nahar et al, 2009;Islam et al, 2022) who reported that salinity decreases number of grains in rice.…”

“…Upon exposure to 2800 ppm NaCl, the plant height of rice declined by 19, 48, 71 and 100% at 40, 60 and 80 DAT, and at harvest, respectively, compared with untreated control. Our results in agreement with Islam et al (2022) who stated that salinity decreased plant height of rice and magnitude of decreases increased with the advancement of the growth period. Under saline conditions, Na + enter into shoot of rice through apoplastic pathway which disrupts cell division and cell elongation and ultimately reduced growth of rice (Hussain et al, 2017).…”

“…Exposure to 1600 and 2800 ppm NaCl decreased grain yield by 28 and 100%, respectively, compared with control (Table 3). Salinity reduced grain yield in rice by decreasing yield attributes including effective tillers, number of grain and 1000-grain weight (Islam et al, 2022). The present study revealed that salinity decreased grain yield by decreasing the number of effective tiller hill −1 , total grains and filled panicle −1 which is in line with previous studies (Zeng et al, 2002;Islam et al, 2022).…”

“…Upon exposure to 1600 and 2800 ppm NaCl, straw yield of rice declined by 18 and 100%, respectively, compared with control. Salinity drastically reduced the straw yield of rice by decreasing photosynthesis, nutrient uptake (Siddique et al, 2015), and tiller number (Islam et al, 2022).…”

“…Salinity in the plant root region creates osmotic, ionic and oxidative stress in plants (Munns and Tester, 2008;Hussain et al, 2017) which ultimately reduced growth and yield of plant (Hasanuzzaman et al, 2013;Rahman et al, 2016a;Rahman et al, 2016b). Salt induced stress reduced plant height, tiller number, effective tillers, filled grain, grain yield, straw yield even causes death of plant (Hasanuzzaman et al, 2013;Islam et al, 2022).…”