Browsing by Author "Ratnasekera, Disna"

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Drought and salinity stresses in barley: Consequences and mitigation strategies
(2019) Kızılgeçi, Ferhat; Hossain, Akbar; Islam, Md. Shohidul; Barutçular, Celaleddin; Hussain, Saddam; Hassannuzzaman, Mirza; Akram, Tauseef; Mubeen, Muhammad; Nasim, Wajid; Fahad,Shah; Kumar, Narendra; Meena,Ram Swaroop; Kızılgeçi, Ferhat; Yıldırım, Mehmet; Ratnasekera, Disna; Saneoka, Hirofumi
Recent trends show reductions in crop productivity worldwide due to severe climatic change. Different abiotic stresses significantly affect the growth and development of plants, leading to decreased crop yields. Salinity and drought stresses are the most common abiotic stresses, especially in arid and semi–arid regions, and are major constraints for barley production. The present review attempts to provide comprehensive information related to barley plant responses and adaptations to drought and salinity stresses, including physiological and agronomic, in order to alleviate the adverse effect of stresses in barley. These stresses reduce assimilation rates, as they decrease stomatal conductance, disrupt photosynthetic pigments, reduce gas exchange, enhance production of reactive oxygen species, and lead to decreased plant growth and productivity. This review focuses on the strategies plants use to respond and adapt to drought and salinity stress. Plants utilize a range of physiological and biochemical mechanisms such as adaptation strategies, through which the adverse effects can be mitigated. These include soil management practices, crop establishment, as well as foliar application of anti-oxidants and growth regulators that maintain an appropriate level of water in the leaves to facilitate adjustment of osmotic and stomatal performance. The present review highlighted the adverse effect of drought and salinity stresses barley and their mitigation strategies for sustainable barley production under changing climate. They review also underscored that exogenous application of different antioxidants could play a significant role in the alleviation of salinity and drought stress in plant systems.
Normalized Difference Vegetation Index and Chlorophyll Content for Precision Nitrogen Management in Durum Wheat Cultivars under Semi-Arid Conditions
(Sustainability (Switzerland), 2021) Kızılgeçi, Ferhat; Yıldırım, Mehmet; İslam, Mohammad Sohidul; Ratnasekera, Disna; Iqbal, Muhammad Aamir; Sabagh, El Ayman
To impart sustainability to modern intensive farming systems, environmental pollution caused by nitrogenous fertilizers needs to be reduced by optimizing their doses. To estimate the grain yield and nutrtional quallity of wheat, the normalized difference vegetation index (NDVI) and chlorophyll content (SPAD) are potential screening tools to identify the N deficiency and screen out the promising cultivars. The two-year field study was comprised of five levels of nitrogen (N) (control, 50, 100, 150 and 200 kg N ha-1) and two durum wheat genotypes (Sena and Svevo). The experimental design was split-plot, in which N levels were placed in the main plots, while wheat genotypes were arranged in sub-plots. To predict the yield and quality traits, NDVI and SPAD values recorded at heading, anthesis and milky growth stages were taken as response variables. The results revealed that N fertilization significantly influenced SPAD and NDVI attributed traits of durum wheat, except NDVI at milky stage (NDVI-M) during the first year. The maximum value of NDVI was recorded by 150 kg N ha-1, while control treatment gave the minimum value. The grain yield was increased with the increasing dose of N up to 100 kg N ha-1 (4121 kg ha-1), and thereafter, it was declined with further increased N levels. However, the variation between genotypes was not significant, except NDVI and SPAD values at the milky stage. The genotype Svevo had the highest NDVI values at all growth stages, while the genotype Sena recorded the maximum SPAD values during both years. Similarly, N levels significantly influenced the quality traits (protein, wet gluten, starch test weight and Zeleny sedimentation) of both genotypes. The highly significant relationship of SPAD and NDVI with the grain yield and yield attributes showed their reliability as indicators for determining N deficiency and selection of superior wheat genotypes for ensuring food security under climate change scenario.