Sridhar Gummadi

Prof. Sridhar Gummadi

International Rice Resarch Instiute (IRRI)
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 January 2022 in Scientific Reports
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SGSridhar Gummadi
Sridhar Gummadi
TDTufa Dinku
Tufa Dinku
PSParesh B. Shirsath
Paresh B. Shirsath
MKM. D. M. Kadiyala
M. D. M. Kadiyala
High-resolution reliable rainfall datasets are vital for agricultural, hydrological, and weather-related applications. The accuracy of satellite estimates has a significant effect on simulation models in particular crop simulation models, which are highly sensitive to rainfall amounts, distribution, and intensity. In this study, we evaluated five widely used operational satellite rainfall estimates: CHIRP, CHIRPS, CPC, CMORPH, and GSMaP. These products are evaluated by comparing with the latest improved Vietnam-gridded rainfall data to determine their suitability for use in impact assessment models. CHIRP/S products are significantly better than CMORPH, CPC, and GsMAP with higher skill, low bias, showing a high correlation coefficient with observed data, and low mean absolute error and root mean square error. The rainfall detection ability of these products shows that CHIRP outperforms the other products with a high probability of detection (POD) scores. The performance of the different rainfall datasets in simulating maize yields across Vietnam shows that VnGP and CHIRP/S were capable of producing good estimates of average maize yields with RMSE ranging from 536 kg/ha (VnGP), 715 kg/ha (CHIRPS), 737 kg/ha (CHIRP), 759 kg/ha (GsMAP), 878 kg/ha (CMORPH) to 949 kg/ha (CPC). We illustrated that there is a potential for use of satellite rainfall estimates to overcome the issues of data scarcity in regions with sparse rain gauges.

5 November 2020 in PLOS ONE
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SGSridhar Gummadi
Sridhar Gummadi
MKM. D. M. Kadiyala
M. D. M. Kadiyala
KRK. P. C. Rao
K. P. C. Rao
IAIoannis Athanasiadis
Ioannis Athanasiadis
RMRichard Mulwa
Richard Mulwa
TATilahun Amede
Tilahun Amede
In this study, we assessed the possible impacts of climate variability and change on growth and performance of maize using multi-climate, multi-crop model approaches built on Agricultural Model Intercomparison and Improvement Project (AgMIP) protocols in five different agro-ecological zones (AEZs) of Embu County in Kenya and under different management systems. Adaptation strategies were developed that are locally relevant by identifying a set of technologies that help to offset potential impacts of climate change on maize yields. Impacts and adaptation options were evaluated using projections by 20 Coupled Model Intercomparison Project—Phase 5 (CMIP5) climate models under two representative concentration pathways (RCPs) 4.5 and 8.5. Two widely used crop simulation models, Agricultural Production Systems Simulator (APSIM) and Decision Support System for Agrotechnology Transfer (DSSAT) was used to simulate the potential impacts of climate change on maize. Results showed that 20 CMIP5 models are consistent in their projections of increased surface temperatures with different magnitude. Projections by HadGEM2-CC, HadGEM2-ES, and MIROC-ESM tend to be higher than the rest of 17 CMIP5 climate models under both emission scenarios. The projected increase in minimum temperature (Tmin) which ranged between 2.7 and 5.8°C is higher than the increase in maximum temperature (Tmax) that varied between 2.2 and 4.8°C by end century under RCP 8.5. Future projections in rainfall are less certain with high variability projections by GFDL-ESM2G, MIROC5, and NorESM1-M suggest 8 to 25% decline in rainfall, while CanESM2, IPSL-CM5A-MR and BNU-ESM suggested more than 85% increase in rainfall under RCP 8.5 by end of 21st century. Impacts of current and future climatic conditions on maize yields varied depending on the AEZs, soil type, crop management and climate change scenario. Impacts are largely negative in the low potential AEZs such as Lower Midlands (LM4 and LM5) compared with the high potential AEZs Upper Midlands (UM2 and UM3). However, impacts of climate change are largely positive across all AEZs and management conditions when CO2 fertilization is included. Using the differential impacts of climate change, a strategy to adapt maize cultivation to climate change in all the five AEZs was identified by consolidating those practices that contributed to increased yields under climate change. We consider this approach as more appropriate to identify operational adaptation strategies using readily available technologies that contribute positively under both current and future climatic conditions. This approach when adopted in strategic manner will also contribute to further strengthen the development of adaptation strategies at national and local levels. The methods and tools validated and applied in this assessment allowed estimating possible impacts of climate change and adaptation strategies which can provide valuable insights and guidance for adaptation planning.

30 September 2020 in Remote Sensing
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HPHoang - Phi Phung
Hoang - Phi Phung
NDNguyen Lam Dao
Nguyen Lam Dao
CPCu Pham-Van
Cu Pham-Van
QXQuang Chau Nguyen Xuan
Quang Chau Nguyen Xuan
VNVu Nguyen-Van-Anh
Vu Nguyen-Van-Anh
TLTrung Le-Van
Trung Le-Van
Food security has become a key global issue due to rapid population growth, extensive conversion of arable lands, and declining overall productivity in some areas because of the effects of floods, water shortage, salinity intrusion, and plant diseases. In this study, we analyzed the relationship between the pattern of salinity intrusion and the spatiotemporal distribution of rice cultivation in the winter–spring crops of 2015, 2016, 2019 and 2020 in coastal provinces of the Vietnamese Mekong Delta. Sentinel-1 (S-1) data were used to extract the spatial distribution information of six rice growth stages based on a rice age algorithm. The classification accuracy of rice crop growth stages was found to have an overall accuracy of 85% and a Kappa coefficient of 0.80 (n = 373). For evaluating salinity intrusion effects, salinity isolines (4 g/L) were used to determine the percentage of rice areas affected. Results show that in the years observed to have severe salinity intrusion such as 2016 and 2020, a strong shift in planting calendar was identified to avoid salinity intrusion, with some areas being sown or transplanted 10–30 days earlier than normal planting. In addition, the lack of irrigation water and salinity intrusion limits rice cultivation in the dry season of coastal areas. Further analysis from the S-1 data confirms that the spatiotemporal distribution of rice cultivation is related to the change in government policy/recommendation affected by salinity intrusion. These findings demonstrate the potential and feasibility of using S-1 data to develop an operational rice crop adaptation framework on the delta scale.

29 December 2021 in Sustainability
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KCkeerthi chadalavada
keerthi chadalavada
SGSridhar Gummadi
Sridhar Gummadi
KKKoteswararao Kundeti
Koteswararao Kundeti
DKDakshina Murthy Kadiyala
Dakshina Murthy Kadiyala
KDKumara Charyulu Deevi
Kumara Charyulu Deevi
STSenthil Kumar T
Senthil Kumar T
Given the wide use of the multi-climate model mean (MMM) for impact assessment studies, this work examines the fidelity of Coupled Model Intercomparison Project Phase 5 (CMIP5) in simulating the features of Indian summer monsoons as well as the post-rainy seasons for assessing the possible impacts of climate change on post-rainy season sorghum crop yields across India. The MMM simulations captured the spatial patterns and annual cycles of rainfall and surface air temperatures. However, bias was observed in the precipitation amounts and daily rainfall intensity. The trends in the simulations of MMM for both precipitation and temperatures were less satisfactory than the observed climate means. The Crop Environment Resource Synthesis (CERES)-sorghum model was used to estimate the potential impacts of future climate change on post-rainy season sorghum yield values. On average, post-rainy season sorghum yields are projected to vary between −4% and +40% as well as +10% and +59% in the near future (2040–2069) for RCP 4.5 and RCP 8.5, respectively, and between +20% and +70% (RCP 4.5) as well as +38% and +89% (RCP 8.5) in the far future (2070–2099). Even though surface air temperatures are increasing in future climate change projections, the findings suggest that an increase in the post-rainy season sorghum yields was due to an increase in the rainfall amounts up to 23% and an increase in the atmospheric CO2 levels by the end of the 21st century. The results suggest that the projected climate change during the post-rainy season over India is an opportunity for smallholders to capitalize on the increase in rainfall amounts and further increase sorghum yields with appropriate crop management strategies.

11 January 2025 in Agronomy
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SSSrinivasan Samineni
Srinivasan Samineni
SGSridhar Gummadi
Sridhar Gummadi
STSUMITHA THUSHAR
SUMITHA THUSHAR
DKDil Nawaz Khan
Dil Nawaz Khan
AGAnestis Gkanogiannis
Anestis Gkanogiannis
RSRakesh Kumar Singh
Rakesh Kumar Singh
Scarce water resources, high temperatures, limited rainfall, elevated soil salinity, and poor soil quality (98% sand) challenge crop production in the desert regions of the Middle East. Proso millet’s resilience under these stresses presents a potential solution for enhancing food security in arid environments. This field study evaluated 24 proso millet genotypes under three environments (100% freshwater, 50% freshwater, and 10 dS/m salinity) in the UAE during normal and summer seasons, aiming to identify genotypes resilient to water, heat, and salinity stresses and to assess genotype-by-environment (G × E) interactions and key traits associated with grain yield. ANOVA indicated significant G × E interactions. Genotypes G9 and G24 displayed high yield and stability across environments during the normal season. In the summer, genotypes G7 and G10 exhibited resilience with high yields under high-temperature stress alone, while combined stresses led to yield reductions across all genotypes, with greater susceptibility under cumulative stress. GGE biplot analysis identified G9 as ideal in the normal season, while G15 and G23 demonstrated stability under combined stresses in the summer season. High chaffy grain yield (CGY) observed under summer stress conditions suggests a shift in resource allocation away from productive grain formation. The reproductive phase was highly vulnerable to heat stress, with 88% of this period experiencing daytime temperatures exceeding 40 °C, with a peak reaching up to 49 °C. These extreme conditions, coinciding with the crop’s critical growth stages, triggered a significant increase in chaffy grain production, substantially reducing overall grain yield. Despite these challenges, genotypes G7, G10, and G12 exhibited notable resilience, maintaining yields above 0.75 t ha−1. Correlation analysis suggested that selecting for increased plant height, forage yield, and 1000-grain weight (TGW) could enhance grain yield under the normal and summer conditions. This study highlights the potential of proso millet genotypes as climate-resilient options for arid regions, providing a basis for developing stress-tolerant varieties and promoting sustainable agriculture in desert climates.

5 February 2025 in Climatic Change
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SGSridhar Gummadi
Sridhar Gummadi
SSSrinivasan Samineni
Srinivasan Samineni
LLLuis Augusto Becerra Lopez-Lavalle
Luis Augusto Becerra Lopez-Lavalle
The sustainability of ecosystems in Central Asia’s semi-arid and arid regions is increasingly threatened by anthropogenic climate change, with shifts in extreme precipitation events playing a pivotal role. Effective adaptation strategies depend on precise forecasting of these changes. This study investigates projected trends in mean and extreme precipitation indices across Central Asia (CA) from 1985 to 2100. Utilizing datasets from the fifth generation of ECMWF Reanalysis (ERA5), the Climate Prediction Center (CPC), and high-resolution National Aeronautics and Space Administration (NASA) Earth Exchange Global Daily Downscaled Projections (NEX-GDDP) derived from Coupled Model Intercomparison Project Phase 6 (CMIP6) models, we analyzed four Shared Socioeconomic Pathway (SSP) scenarios across three distinct time periods. The CMIP6 Multi-Model Ensemble (MME) accurately simulates mean annual precipitation (ANP) for much of the region, though it underperforms in mountainous areas. Specifically, it underestimates days with precipitation exceeding 10 mm (PD10MM) and the Simple Daily Intensity Index (SDII) while overestimating Consecutive Dry Days (CDD) in regions with higher altitudes and more precipitation. Projections indicate a potential increase in mean ANP by up to 50% across most of Central Asia, becoming especially prominent from the mid-century onward. Extremes in precipitation, such as the SDII, the maximum 1-day precipitation amount (RX1DAY), and days with over 10 mm of rainfall, are expected to rise in frequency and intensity across the region. In contrast, while CDD may decrease in eastern CA, it will likely increase in the west by the century’s end. These anticipated changes suggest increased wetness under warming scenarios, with more frequent heavy precipitation events and a reduction in prolonged dry periods, particularly under high-emission pathways. The data provides a foundation for developing effective adaptation strategies to enhance resilience against the impacts of climate change in Central Asia.