CO2 exchange, dry matter accumulation and growth response of sorghum (Sorghum bicolor L. Moench) to terminal drought as affected by potassium and blended-NPSBZn fertilization

Endris, S and Fetene, M and Amede, T (2021) CO2 exchange, dry matter accumulation and growth response of sorghum (Sorghum bicolor L. Moench) to terminal drought as affected by potassium and blended-NPSBZn fertilization. Journal of Agronomy and Crop Science (TSI), 207 (3). pp. 450-464. ISSN 0931-2250

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Abstract

Sorghum production is constrained by terminal drought stress in semi-arid areas of north-eastern Ethiopia. Data from field experiments conducted in the region for two consecutive years (2015 – 2016) were used to investigate the effect of potassium (K) and NPSBZn-blended fertilizer (BF) inputs on the drought response of sorghum through analysis of gas exchange, dry matter accumulation and growth parameters. Leaf gas exchange properties varied strongly with K and BF application both under normal rainfall and drought conditions. Data taken at anthesis in drought-exposed sorghum indicated reduction of net photosynthetic rate (AN) with BF supply. AN declined from 15.7 µmol CO2/m2/s in the control to 13.4 µmol CO2/m2/s with application of 164 kg/ha BF. However, higher total dry matter yield was recorded at maturity in response to blended fertilizer and K inputs. Increasing supply of NPSBZn-blended fertilizer was associated with declining leaf K content, increasing intercellular CO2 concentration and water use efficiency (WUE) during anthesis. Significant variations in crop growth rates were also observed in response to K and BF inputs. At physiological maturity, net assimilation rate (NAR) increased with K and BF inputs both under drought and normal rainfall conditions. In general, K application modulated the response of sorghum to BF input under both normal rainfall and drought conditions. Therefore, grain sorghum could benefit from early supply of K and BF fertilizer in drought prone areas of Northeastern Ethiopia.

Item Type: Article
Divisions: Research Program : East & Southern Africa
CRP: UNSPECIFIED
Uncontrolled Keywords: blended fertilizer, chlorophyll, drought, gas exchange, growth, sorghum
Subjects: Mandate crops > Sorghum
Others > Drought
Others > Fertilizer Applications
Others > Plant Growth
Depositing User: Mr Nagaraju T
Date Deposited: 15 Jan 2025 03:45
Last Modified: 15 Jan 2025 03:45
URI: http://oar.icrisat.org/id/eprint/12906
Official URL: https://onlinelibrary.wiley.com/doi/full/10.1111/j...
Projects: Agricultural Growth Program-II
Funders: Ethiopian Institute of Agricultural Research
Acknowledgement: UNSPECIFIED
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