Question

The mean monthly temperature and monthly percentage of annual day-time (hr) are tabulated below :
$\begin{array}{ccc}\text{Month}& \text{Temperature}{(}^{\circ }C)& \text{Monthly percentage of}\\ & & \text{annual day time 9 hr}\\ \text{Nov}& 16& 7.2\\ \text{Dec}& 11.5& 6.9\\ \text{Jan}& 9.5& 7.0\\ \text{Feb}& 13.5& 8.1\end{array}$


Wheat is grown in the season Nov-Feb, the potential evapotranspiration in this season will be ______ mm.
(Take k = 0.6 and and use Blaney Criddle formula)

• A. 244.1

Answer 1

The correct option is A 244.1
$\begin{array}{ccccc}\text{Month}& \text{Temperature}& \text{Temperature}& Pn& \frac{P_n{T}_f}{100}\\ & {(}^{\circ }C)& {(}^{\circ }F)& & \\ \text{Nov}& 16& 60.8& 7.2& 4.38\\ \text{Dec}& 11.5& 52.7& 6.9& 3.64\\ \text{Jan}& 9.5& 49.1& 7.0& 3.44\\ \text{Feb}& 13.5& 56.3& 8.1& 4.56\\ & & & \Sigma =& 16.02\end{array}$

$T_f=1.8T_c+32$

From Blaney-criddle formula,
$PET=2.54k\Sigma \frac{p_n{T}_f}{100}$

$=2.54\times 0.6\times 16.02cm$

$=24.41cm=244.1mm$