Delineation of thermal requirements of rice (Oryza sativa L.) staggered in different transplanting windows and their validation
Loading...
Date
2021
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University, Ludhiana
Abstract
The present study entitled “Delineation of thermal requirements of rice (Oryza sativa L.) staggered in
different transplanting windows and their validation” was carried out during Kharif season 2019-20 at
research farm of Department of Climate Change and Agricultural Meteorology. The experiment was
conducted with three rice varieties (PR115, PR118 and PR124) under three dates of transplanting dates
(13th June, 21st June and 29th June) in Randomized block design with three replications. The results of
phenological studies revealed that the crop transplanted early (13th June) took more number of days
(137) to reach physiological maturity and accumulated more heat units as compared to delayed
transplanting (21st June and 29th June). Historical analysis of accumulated growing degree days
(AGDD) of rice in Punjab from 1990-2019 under transplanting window I, II and III showed that there
was increasing trend of AGDD in all the districts except the Ludhiana and Bathinda where no such
prominent increasing trend was found. Among all the districts, the highest rate (23.85°C day year-1) of
AGDD increased was in S.B.S. Nagar. The lowest rate (2.29°C day year-1) of increase was in
Ludhiana. In the whole state, to complete different phenological stages during different pentads under
three transplanting windows, the highest heat units were accumulated by the crop at Muktsar during
period P1 (1990-1994) to P6 (2015-2019). The lowest heat units were accumulated by S.B.S. Nagar
from pentad P1 (1990-1994) to P4 (2005-2009) and by Jalandhar in P5 (2010-2014) and by Ludhiana
in P6 (2015-2019). Trend analysis of heat use efficiency (HUE) of rice from 1990-2018 showed that
under three transplanting windows the highest rate of increase in HUE was in Ludhiana. The
decreasing rate was found in Rupnagar, S.B.S. Nagar and Amritsar under transplanting window I and
in Rupnagar and Amritsar under transplanting window II and III. Spatio-temporal interpolation of
variability of thermal requirements of rice in different districts of Punjab had been demarcated using
geospatial technology. The results showed that growing degree days accumulation had increased in all
the districts of Punjab from 1990-2019. Maximum accumulation of heat units is in first transplanting
window followed by second and then in third. Results of validation of historical thermal requirements
with actual experimental data under staggered transplanting were, the most positive deviation at
maximum tillering, anthesis and physiological maturity occurred in North-east districts (S.B.S Nagar
and Hoshiarpur) and most negative deviation at Muktsar during different Pentads. Study of predicted
temporal variability in thermal requirements of rice under three transplanting windows showed that
most positive deviation at tillering, anthesis and physiological maturity during different pentads
occurred at Muktsar during F6 (2045-2049) and lowest deviation at Hoshiarpur during F1 pentad. So
the present study may help in the deciding the right time of transplanting and match phenology of crop
in specific environment to achieve higher yield.
Description
Keywords
Citation
Manhas, Upasna (2021). Delineation of thermal requirements of rice (Oryza sativa L.) staggered in different transplanting windows and their validation (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.