Assessment of water requirement of tobacco at Rajamundry (Andhra Pradesh)

Abstract

Water use, Water Use Efficiency (WUE) and Water Requirement Satisfaction Index (WRSI) of
tobacco varieties grown during rabi 1979 to 1988 at Rajamundry had been studied. The yield of tobacco was linearly and
significantly correlated with amount of rainfall, water use and WRSI. The total amount of rainfall during growing season
was inadequate to meet the crop water requirements and these were partially met from stored soil moisture from previous
kharif season. The excess rain during ripening stage of tobacco adversely affected the leaf yield and quality.
The amount of water consumed varied between 110.0 to 186.6 mm for CTRI Special, 86.8 to 184.0 mm for
Jayashri. The mean WUE was found to be 6.1 and 6.4 kg/ha/mm respectively for CTRI Special and Jayashri. The
maximum amount of water consumed was 81.2 mm (i.e., 58.7%) during grand growth stage, followed by 36.5 mm
(26.5%) during establishment stage and comparatively less (20.6mm) during maturity stage (14.8%). The average Kc
value was maximum (0.5) during grand growth stage. WRSI showed decreasing trend from sowing towards maturity and
the rate of decrease was high in grand growth stage due to peak water consumption and less rainfall.