Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Role of Potassium on Water Relation Behavior of Triticum Aestivum L. Under Water Stress Conditions

M. A. Baque
Department of Agronomy, Sher- e- Bangla Agricultural University, Dhaka, Bangladesh.

M. A. Karim
Dept. of Agronomy, Bangabandhu Sheikh Mujibur Rahman Agril. Univ., Gazipur, Bangladesh.

A. Hamid
Dept. of Agronomy, Bangabandhu Sheikh Mujibur Rahman Agril. Univ., Gazipur, Bangladesh.

Abstract/ Executive Summary:

The study was initiated to evaluate the role of potassium on water stress tolerance, in relation to water relations of wheat plants subjected to water stress. Wheat variety Satabdi (BARI Gam 21) was grown in K deficit soil in pots inside vinyl house under natural Iight. Three levels of each of potassium (39.0, 156.42 and 312.85 kg ha^-1) and soil moisture viz. control [ less than 25% depletion from field capacity (FC)], mild stress (more than 37.5% depletion from FC) and severe water stress (more than 50% depletion from FC) were the treatment variables. Plant water status was severely affected by water stress. Irrespective of soil moisture levels, fertilizer potassium showed beneficial effects on plant water status. Higher doses of potassium in wheat generally showed the maximum relative water content, higher water retention capacity and exudation rate. Higher levels of K significantly reduced the water saturation deficit. Fertilizer potassium, however, made leaf water potential more negative. The beneficial effect of fertilizer potassium on water stress tolerance in wheat plants were more pronounced under water stressed conditions than that under control conditions.

Keywords: Water relations, Exudation rate, Water stress, Potassium, Wheat

Location: Dinajpur area.

Start Date: 00-11-2001

End Date: 00-03-2002

Program Area: Crop-Soil-Water Management

Commodity: Fertilizer

Objectives:

To know the physiological changes in wheat due to water stress and to analyze the role of potassium on water relation behavior of wheat subjected to water stress.

Methodology:

The plants were grown in pot under semi- controlled environmental (inside vinyl house) conditions at tht Environmental Stress Research site of Agronomy Division at the Bangabandhu Sheikh Mujibur Rahman Agricultural University, Salna, Gazipur during winter (November' 2001- March' 2002). The experimental soil was collected from Fulbaria thana under the district of Dinajpur ( AEZ 1 ) for its K deficit character. The soil was sandy-loam in texture and slightly acidic in nature (pH = 5.6) with poor fertility status (Total nitrogen = 0.064%; available P = 27 ppm and exchangeable K = 0.05 meq/100g dry soil). Wheat variety Satabdi was grown in K deficit soil in pots inside vinyl house under natural light. Three levels of each of potassium (39.0, 156.42 and 312.85 kg ha^-1) and soil moisture viz. control (less than 25% depletion from field capacity FC), mild stress (more than 37.5% depletion from FC) and severe water stress (more than 50% depletion from FC) were the treatment variables. Plant water status was measured on the basis of the following: The fully developed flag leaves of four replicated plants per treatment were carefully collected at anthesis stage. Their fresh weights were measured immediately. Thereafter. the leaves were immersed in distilled water lor 24 h at room temperature in the dark. These leaves were weighed after removing excess water by gently wiping with paper towel to determ inc their turgid weight. The leaves were then dried in an oven for 72h at 70°C to determine their dry weights. The fresh, turgid and dry weights of the leaves were used to calculate the following: Relative Water Content (RWC)= (Fresh wt.-Dry wt./Turgid wt. Dry wt.) x 100, Water Saturation Deficit (WSD) = (100-RWC), Water Retention Capacity (WRC)= (Turgid weight/Dry weight). Lear water potential was measured at anthesis of wheat at 6.30 A.M. with the help of Scholander Pressure Bomb apparatus. The top most fully developed leaf was cut carefully with sharp blade from 4 replicated plants of each treatment. The cut leaf was set in the apparatus and pressure was given. When the xylem water came out from the cut end, then the pressure was stopped. This instrument gives pressure in kg/cm² (0.98066 kg/cm² = 1 bar; 10 bar = 1 MPa Mega pascal). Exudation rate was measured at anrhesis, 5 cm above the base of the stem. At first, dry cotton was weighed. A slanting cut on stem was made with a sharp knife. Then the weighed cotton was placed on the cut surface. The exudation of sap was collected for 1 hour at normal temperature. The final weight or the cotton with sap was taken. The exudation rate was measured by using this formula. Exudation rate (mg/h) = (Weight of cotton + sap) - Weight of cotton/ Time (h). Factorial randomized block design (RBD) was used for this experiment. The data recorded on different parameters were analyzed using the help of "MSTAT" program. The differences between the treatment means were compared by Least Significant Difference (LSD) test at 5% level of significance alter performing ANOYA.

Source of Information: Progress. Agric. 13(1 & 2) : 71-75,2002, ISSN 1017-8139

Article Link (Online Journal):

Funding Source:

Total Budget (Tk.) :

Achievement/Findings:

Plant water status was severely affected by water stress. Irrespective of soil moisture levels, fertilizer potassium showed beneficial effects on plant water status. Higher doses of potassium in wheat generally showed the maximum relative water content, higher water retention capacity and exudation rate. Higher levels of K significantly reduced the water saturation deficit. Fertilizer potassium, however, made leaf water potential more negative. The beneficial effect of fertilizer potassium on water stress tolerance in wheat plants were more pronounced under water stressed conditions than that under control conditions.

Knowledge Management: Journal