Reactive oxygen species

In the growth condition(s) of plants, numerous secondary metabolites (SMs) are produced by them to serve variety of cellular functions essential for physiological processes, and recent increasing evidences have implicated stress and defense response signaling in their production. The type and concentration(s) of secondary molecule(s) produced by a plant are determined by the species, genotype, physiology, developmental stage and environmental factors during growth. This suggests the physiological adaptive responses employed by various plant taxonomic groups in coping with the stress and defensive stimuli. The past recent decades had witnessed renewed interest to study abiotic factors that influence secondary metabolism during in vitro and in vivo growth of plants. Application of molecular biology tools and techniques are facilitating understanding the signaling processes and pathways involved in the SMs production at subcellular, cellular, organ and whole plant systems during in vivo and in vitro growth, with application in metabolic engineering of biosynthetic pathways intermediates.

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Stress and defense responses in plant secondary metabolites production

Stable isotopes and plant carbon-water relations

http://www.davidramirezc.com/uploads/7/3/6/9/7369149/monneveux_et_al_plant_science_2013.pdf

Drought tolerance in potato (S. tuberosum L.): Can we learn from drought tolerance research in cereals?

Impact of irrigation volume and water salinity on winter wheat productivity and soil salinity distribution

Impacts of irrigation regimes with saline water on carrot productivity and soil salinity

A two-year study was conducted in arid region of Tunisia to evaluate the effects of deficit irrigation regimes with saline water on soil salinity, yield, and water use efficiency of onion grown in a commercial farm on a sandy soil and drip-irrigated with water having an EC𝑖 of 36 dS/m Irrigation treatments consisted in water replacements of accumulated ET𝑐 at levels of 100% (SWB-100, full irrigation), 80% (DI-80), 60% (DI-60), when the readily available water in the control treatment (SWB-100) is depleted, deficit irrigation during ripening stage (SWB100-MDI60) and farmer method corresponding to irrigation practices implemented by the local farmers Results on onion production and soil salinization are globally coherent between the two-year experiments and show significant difference between irrigation regimes Higher soil salinity was maintained in the root zone with DI-60 and farmer treatments than full irrigation (SWB-100) SWB100-MDI60 and DI-80 treatments resulted also in low EC𝑒 values No significant differences were observed in bulbs fresh and dry yields, bulbs number·ha−1 and weight from the comparison between full irrigation (SWB-100) and deficit treatments (DI-80, SWB100-MDI60) DI-60 irrigation treatment caused significant reductions in the four parameters considered in comparison with SWB-100 The farmer method caused significant reductions in yield components and resulted in increase of water usage 45 and 33% in 2008 and 2009, respectively Water use efficiency was found to vary significantly among treatments, where the highest and the lowest values were observed for DI-60 and farmer treatments, respectively The full irrigation (SWB-100) and deficit irrigation (DI-80 and SWB100-MDI60) strategies were found to be a useful practice for scheduling onion irrigation with saline water under the arid Mediterranean conditions of southern Tunisia

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Yield Response of Drip-Irrigated Onion under Full and Deficit Irrigation with Saline Water in Arid Regions of Tunisia

Soil Salinity and Yield of Drip-Irrigated Potato under Different Irrigation Regimes with Saline Water in Arid Conditions of Southern Tunisia

Modeling and optimization of capsaicin extraction from Capsicum annuum L. using response surface methodology (RSM), artificial neural network (ANN), and Simulink simulation

Field studies were conducted on a sandy soil during autumn of 2010 and 2011 in an arid region of Tunisia to investigate the effects of nitrogen and irrigation regimes with saline water on yield and water productivity (WP) of potato (Solanum tuberosum L. cv. Spunta) and soil salinity. For the two years, irrigation treatments consisted in water replacements of cumulated crop evapotranspiration (ETc) at levels of 100% (I100, full irrigation), 60% (I60) and 30% (I30), when the readily available water in I100 treatment was depleted, while the nitrogen treatments (N) were 0, 100, 200, and 300 kg/ha (No, N100, N200, and N300). Results showed that soil salinity values remained lower than those of electrical conductivity of irrigation water (ECiw) and were the lowest under treatment I100 and the highest with I30 treatment. Relatively low ECe values were also observed under I60 treatment. The highest potato yields for the two years were obtained with I100 treatment. Compared to I100, significant reductions in potato yields were observed under I60 and I30 deficit irrigation treatments resulting from a reduction in tubers number/m2 and tuber weight. The water productivity (WP) was found to significantly vary among treatments, where the highest and the lowest values were observed for I30 and I100 treatments, respectively. Potato yield and WP increased with an increase in nitrogen rates. The rate of 300 kg N/ha was seen to give good yield and higher WP of potato under full (I100) and deficit (I60) irrigation treatments. However, application of N adversely affected potato yield and WP, when N level applied above 200 kg N/ha at I30. The WP was improved by N supply, but its effect decreased as the irrigation level increased. The IWP at I100, which produced the highest potato yield, was 8.5 and 9.9 kg/m3 with N300 but this increased to 11.9 and 15.6 kg/m3 at I30 with N200, in 2010 and 2011, respectively. These results suggested that potato in arid region could be cultivated with acceptable yields while saving irrigation water and reducing nitrogen supply but it was essential to exploit the interaction effect between these two parameters to maximize resource use efficiency.

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Kamel Nagaz

Papers

Impacts of irrigation regimes with saline water on carrot productivity and soil salinity

Yield Response of Drip-Irrigated Onion under Full and Deficit Irrigation with Saline Water in Arid Regions of Tunisia

Soil Salinity and Yield of Drip-Irrigated Potato under Different Irrigation Regimes with Saline Water in Arid Conditions of Southern Tunisia

Modeling and optimization of capsaicin extraction from Capsicum annuum L. using response surface methodology (RSM), artificial neural network (ANN), and Simulink simulation

Yield and Water Productivity of Drip-Irrigated Potato under Different Nitrogen Levels and Irrigation Regime with Saline Water in Arid Tunisia