WHEAT IN BANGLADESH: YIELD GROWTH, PRODUCTION PERFORMANCE AND DETERMINANTS - Soybean and Wheat Crops: Growth, Fertilization, and Yield - page 217

between the potential and actual yields in farmer's own production environment (De Datta et
al., 1978). The yield Gap-I exists mainly because of the differences in the production
environment between the experiment station and the average farm. Also, there may be
components of experiment station technology that are not transferable to farmers' field. By
definition, the yield GAP-II exists because of individual farmer's use of inputs or practices
resulting in lower yields than potentially possible on his/her farm.

Table 6. Constraints affecting production performance of wheat farmers

Factors N Actual yield

(kg/ha)

Yield loss
(kg/ha)

TE

Educated farmers vs. 199 2572.46 465.12 0.85
Farmers with no education 94 2396.44 606.03 0.80
t-test for mean differences 3.29*** -5.77*** 6.30***
Suitable land type vs. 193 2703.01 487.96 0.85
Unsuitable land type 100 2155.03 553.50 0.79
t-test for mean differences 12.05*** -2.65** 6.72***
No loss due to poor soil fertility vs. 202 2720.48 497.75 0.85
Loss due to poor soil fertility 91 2062.07 538.23 0.79
t-test for mean differences 15.62*** -1.61 6.48***
Timely fertilization vs. 232 2584.11 490.70 0.84
Delay in fertilization 61 2256.89 584.96 0.79
t-test for mean differences 4.53*** -3.36*** 5.15***
Seed procured from Research Station vs. 37 2734.22 410.64 0.87
Seed procured from neighbours or market 256 2484.45 524.74 0.82
t-test for mean differences 5.11*** -3.00*** 4.06***
Timely sowing vs. 85 2816.21 405.86 0.88
Delay in sowing 208 2393.30 553.02 0.81
t-test for mean differences 10.21*** -5.76*** 8.33***
Use of mechanical power vs. 180 2576.99 424.38 0.86
No use of mechanical power 113 2418.81 647.24 0.79
t-test for mean differences 3.12*** -10.03*** 9.52***
Received training vs. 42 2716.52 405.24 0.87
No training 251 2482.43 527.91 0.82
t-test for mean differences 3.26*** -3.72*** 4.23***
Four or more sources of information vs. 19 2786.32 418.50 0.87
Three or less sources of information 274 2497.24 516.69 0.83
t-test for mean differences 4.46*** -2.38*** 3.44***
All farms 293 2515.98 510.33 0.83
Note: Yield loss = Maximum possible yield - actual yield. The maximum yield is computed by
dividing the actual yield by the technical efficiency score.
*** Significant at 1 % level (p<0.01).

The first step in estimating yield gap in wheat production is to determine the yield levels
at different phases. In this study, experiment station yields were obtained from the WRC for
the year 2000 (WRC, 2000). On the other hand, potential farm level yields were estimated
from the actual farm level data and the computed technical efficiency scores (Table 4). For