MZ Hossain
Soil, Water and Environment Discipline, Khulna University, Bangladesh
S Sikder
Soil, Water and Environment Discipline, Khulna University, Bangladesh
A Husna
Soil, Water and Environment Discipline, Khulna University, Bangladesh
S Sultana
Soil, Water and Environment Discipline, Khulna University, Bangladesh
S Akhter
Soil, Water and Environment Discipline, Khulna University, Bangladesh
A Alim
Soil, Water and Environment Discipline, Khulna University, Bangladesh
JC Joardar
Soil, Water and Environment Discipline, Khulna University, Bangladesh
Rice, Water Stress, Morphology, Physiology, Yield
Soil, Water and Environment Discipline, Khulna University, Bangladesh
Crop-Soil-Water Management
Water management, Rice
The experiment was conducted in front of the net house of field laboratory of Soil, Water and Environment Discipline, Khulna University, Bangladesh which is geographically located at N: 22"10' north latitude and 89"20' east latitude. The experimental site has silty clay texture. Surface soil (0-15 cm) was collected from this site and the characteristics of experimental soil. The collected soil was dried under the sun followed by crushing, mixed thoroughly and 8 kg soil was put in each of the 12L plastic pots. The pot soil was fertilized with urea, Triple Super Phosphate (TSP), Muriate of Potash (MOP) and gypsum as sources of N, P, K and S at the rate of 100 kg N, 60 kg P2O5, 75 kg K2O and 20 kg S ha-1, respectively (BARC, 2012). The whole amount of TSP, MOP, gypsum and 1/3rd of urea was applied prior to final preparation of the pots. The remaining 2/3rd urea was top dressed in two equal installments at 25 and 50 days after transplanting. Irrigation was done very carefully when needed to maintain the water stress according to the treatments and weeding was done regularly. To simulate the conditions of the local farming in Khulna region, 27 days old rice seedlings in regular cultivation Banglamoti (BRRI dhan 50), Vittiatash (BRRI dhan 28 selected) and Atash balam (BRRI dhan 28) were selected for transplanting into the pots. Three seedlings were transplanted in each pot which were arranged according to completely randomized design (CRD). In growth experiment, plants were subjected to five degrees of water stresses: T1 = pots containing soil are ponded with water up to 5 cm above the soil surface, T2 = pots containing soil are ponded with water up to 3 cm above the soil surface, T3 = pots containing soil are saturated with water, T4 = soils in the pot contain water @ of 75% of saturation, T5 = soils in the pot contain water @ of 50% of saturation. Each treatment was replicated three times. Data on some morphological parameters such as plant height, tiller number, panicle number, and dry weight; yield attributes such as grain panicle-1, grain weight panicle-1, 1000 grain weight, and harvest index were measured according to standard methods (Jahan et al., 2013). Two physiological characteristics like Water Use Efficiency (WUE), Relative Water Content (RWC) were recorded by following methods. After collecting the leaves from the top, the RWC was calculated according to the following formula: RWC = x 100. Where, FW = fresh weight of leaves, TW = turgid weight of leaves, DW = dry weight of leaves; To avoid moisture loss from the leaves, the FW was taken as soon as possible after leaf collection. For obtaining the TW, the leaves were kept into a container filled with distilled water for 12 hours until the leaves reach a constant weight which was considered as 100% hydration. The TW was determined immediately after removing the leaves from water. The DW was taken after oven drying of fully turgid leaves for 48 hours at 700C (Turner, 1986). WUE was calculated as total dry weight divided by total amount of transpiration for each water treatment. WUE was calculated by using the following formula after observing the amount of water loss from the potson daily basis. Where, W2 and W1 are the total plant dry weights after 2nd and 1st harvest respectively. Water stresses were imposed by simply weighing the soil added to the pot (dry weight), the amount of water started with and all other objects (weight of pot, etc.). Finally, weighing each pot once a week to measure evaporation and add evaporated water. The collected data were taken under the analysis of variance (ANOVA) using Minitab’s ANOVA (version 17.0) and Duncan’s New Multiple Range Test (DNMRT) was used to compare treatments.
SAARC J. Agri., 18(1): 61-71 (2020)
Journal