The experiment was conducted at the Research Field of Patuakhali Science and Technology University, Dumki, Patuakhali, during the period from January 2015 to March 2015 to find out the effect of Gibberellic Acid on growth and yield of Mungbean.
Planting materials
Two varieties of Mungbean used in this study were:
- V1 : BARI Mung 6
- V2 : BARI Mung 5
The seeds of these varieties were collected from Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur.
Application of GA3
In each block there were eight plots, four for each variety and each variety received treatments in the following manner at 20 days after sowing (DAS),
i) C0 = Control
ii) C1 = 50 ppm GA3
iii) C2 = 100 ppm GA3
iv) C3 = 150 ppmGA3
A 150 ppm solution of GA3 was prepared by dissolving 150 mg of GA3 in 1L of distilled water. The distiled water was added to make the volume 1liter to get 150 ppm solution which was used as concentration 4. Similarly other volumes of GA3 were prepared.
Experimental design and layout
Two factors were considered in this experiment. The concentrations of GA3 was considered as factor A and two varieties as factor B. The experiment was laid out in Randomized Complete Block Design (RCBD). There were three replications. Each treatment was randomly accommodated oncen each block. i
Sampling and data collection
The first crop sampling was done on 15 days after sowing (DAS) and it was continued till physiological maturity of 60 DAS and at harvest. Five plants were selected randomly in such a way so that the border effect could be avoided. For this reason, the outer two lines and the outer plants of the middle lines in each unit plot were avoided. Data were recorded periodically from the sample plants at 15 days interval. Yield data were also collected after harvest. The plants were separated into shoot and roots and then their dry weight were recorded after drying them in oven at 80±20C for 72 hours.
Growth characters
Total dry matter (TDM)
The plant parts such as shoot including leaves and roots were detached and were kept separately in oven at 80±20C for 72 hours. The oven dried samples were weighed for dry matter production. The total dry matter production was calculated from the summation of shoots and roots.
Crop Growth Rate (CGR)
The crop growth rate values at different growth stages were calculated using the following formula–CGR = × g m–2day–1
Where, W1= Total dry matter production at previous sampling date
W2= Total dry matter production at current sampling date
T1= Date of previous sampling
T2= Date of current sampling
GA= Ground area (m2)
Relative Growth Rate (RGR)
The relative growth rate (RGR) values at different growth stages were calculated using the following formula–
RGR = g cm–2day–1
Where, W1= Total dry matter production at previous sampling date
W2= Total dry matter production at current sampling date
T1= Date of previous sampling
T2= Date of current sampling
Loge= Natural logarithm