Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges &
Opportunities during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
Results showed that variation in the simulated yield obtained is affected by different sowing
dates. The highest yield was obtained in
crop sown during the first fortnight of
July. It may be due to no moisture stress
coinciding with the critical stage of crops
in crop sowing in this period. The critical
stages identified are the vegetative stage,
the flowering stage, the peg development
and pod formation stage, and the pod
filling stage (Nageswara Rao et al., 1985,
1989). The crop sown in June has not
received excess rainfall during the stage of vegetative growth and the initial dry spell after
sowing helped in profuse flowering and synchronized peg formation may cause in reducing
yield.
The crop sown from 7 July-22 July is identified as the optimum sowing date which can give
maximum yield because the crop sown during this period received rains during the vegetative
stage after sowing and not allowing the crop to undergo initial moisture stress which is good
for groundnut for synchronize and produce flowering. Crop sown on normal sowing date gives
maximum yield because there is less water stress found during critical stages of Kharif
groundnut. The figure showed that the sowing date (15 June, 22 June, 30 June, 07 July, 15 July,
22 July, 28 July, 04 August, and 15 August) is simulated using the DSSAT crop simulation
model to estimate the crop water stress at different crop phenological stages. Maximum water
stress was found in early sown June and late August sown crops in comparison to normal
sowing time (7-Jul, 15 July, and 22 July), which coincides with critical stages of groundnut. In
June sown crop, maximum water stress was found in the first flower to first seed stage i.e.,
(>0.5) (50 %) and in the August sown crop maximum water stress was found > 0.5 (50%) in
the first seed stage to physiological maturity. These stages are crucial for yield determination.
Conclusion
A crop sowing window is an important factor to understand the impact of crop growth and
development. Rainfall plays a vital role for Kharif crops to supply water to the crops and soil
moisture. For early sowing dates of June (15, 22, 30) and August (4, 11 15), late sowing of the
Kharif groundnut crop shows high crop water stress during critical stages over the 2009-2019
year.
References
Nageswara Rao, R. G., Singh, S., Sivakumar, M. V. K., 1985. Effect of water deficit at different
growth phases of peanut I. yield responses. J. Agron. 77, 782–786.
84 | Page Resilience through land and water management interventions, water management and governance