By P.Kandasamy BTE – 06 -014

K= empirical seasonal consumptive use coefficient for the growing season

F= sum of the monthly consumptive use (f) for the growing season

k = empirical consumptive use crop co efficient for the month

f = t x p/100 t = mean monthly temperaturep = monthly daylight hours expressed

as per cent of daylight hours of the year.

CROP M O N T H S

JAN FEB MAR APR MAY JUNE

JULY

AUG SEP OCT NOV DEC

Rice 0.85 1 1.15 1.3 1.25 1.1 0.9

Maize 0.5 0.6 0.7 0.8 0.8 0.6 0.5

Wheat 0.5 0.7 0.75 0.7

Sugar cane

0.75 0.8 0.85 0.85 0.9 0.95 1 1 0.95 0.9 0.85 0.75

Cotton 0.5 0.6 0.75 0.9 0.85 0.75 0.55 0.5 0.5

Vegetables

0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.8 0.7 0.6 0.55 0.5

Citrus 0.5 0.55 0.55 0.6 0.6 0.65 0.7 0.7 0.65 0.6 0.55 0.55

Months Mean monthly temperature, oF (t)

Monthly crop co-efficient (k) from table

Percent day light hrs (p) from table

Monthly consumptive use (inches) k.t.p/100

Jan 77.36 0.5 8.11 3.13

Feb 81.9 0.55 7.4 3.33

Mar 82.67 0.6 8.44 4.18

Apr 88.2 0.65 8.43 4.83

May 90.7 0.7 8.81 5.59

June 89.46 0.75 8.57 5.75

July 88.38 0.8 8.84 6.25

Aug 86.315 0.8 8.74 6.03

Sep 87.215 0.7 8.26 5.04

Oct 84.92 0.6 8.29 4.22

Nov 80.51 0.55 7.89 3.49

Dec 81.41 0.5 8.08 3.28

U= 55.12 inches = 140cm

http://books.google.co.in/books?id=yANwmTjf588C&pg=PA103&lpg=PA103&dq=blaney+criddle+method&source=bl&ots=64j68csYbW&sig=cDIpxuNIWiWntQAqFRbkauXo-YE&hl=en&ei=YvXISZnmIsOGkQWkm4XmAg&sa=X&oi=book_result&resnum=9&ct=result

www.nih.ernet.in/Method3.htm Irrigation theory & practice by A M Michael