Evaluating the Effect of Smoke-water and Nitrogen Fertilizer on Wheat (Triticum aestivum L.) Ecophysiological Traits

Fire and smoke have been used in traditional agricultural systems for centuries. In recent years, biologically active compounds have been isolated from smoke with potential uses in agriculture and horticulture. It has been reported that smoke plays an important role in many aspects of plant biology such as seed germination, plant growth and flowering. Smoke contains several thousand compounds such as phenolic compounds, alcohols, lactones, aldehydes, acid, ketones, alkaloid and hydroxybenzenes. A biologically active butenolide (3-methyle-2H-furo [2,3-c]pyran-2-one=KAR1) was isolated from plant-derived smoke. This bioactive compound displays activity in a variety of species concentration as one-part-per-billion. The role of smoke-isolated compound KAR1 in promoting seedling growth has been reported in many plant species. Also smoke-derived butenolide has both cytokininandauxin-like activities when applied at low concentrations. Although most research has focused on smoke as a germination cue for the release of seed dormancy, there is increasing evidence that smoke also has post-germination effects. Moreover, the smoke-water solution is acidic and contains substantial of plant nutrients such as high level of NH4, an important source of nitrogen for plant growth. Nitrogen is an essential element for growth and development of plants, especially wheat that it is the most important and strategic cereal crop in world commerce. The objectives of the present study were (1) to evaluate the effect of urea fertilizer and smoke-water on some eco-physiological traits of wheat, (2) to characterize and identify the interaction between smoke-water and usage of different fertilizer levels on crops traits.
In order to evaluate the effect of smoke-water and nitrogen fertilizer on wheat (Triticum aestivum L. var. Pishtaz) ecophysiological traits, a field experiment was conducted as a split plot based on complete randomized block design with three replications. This experiment was conducted in research farm of Agricultural Faculty of Razi University during 2015 to 2016. In this study application of nitrogen fertilizer in four levels (included 90, 180, 300 and 360 kg.ha-1) were assigned to the main plots and five smoke-water concentrations (included 0, 0.001%, 0.01%, 0.1% and 1% v/v) were assigned to the sub plots. Smoke-water is one of the most convenient means of application and its biologically active compounds are readily dissolved in water. The smoke produced by combusting variety of dry plant materials in a controlled system and bubbling it through water to produce smoke-saturated water. Smoke-water for foliar-application treatment was prepared by diluting this stock solution with distilled water to obtain four concentrations. Foliar treatment consisted of spraying wheat plants at three times (from before anthesis stage to final milk stage) with smoke-water concentrations. The control plots were sprayed with distilled water. Before spraying, one drop of Tween 20 as a surfactant was added to 250 mL test solution, including control.
Results indicated that leaf area index, light absorption, total dry weight yield, radiation use efficiency, grain yield and harvest index of wheat increased in high levels of nitrogen fertilizer treatments in comparison with low levels. Most of these traits significantly affected by increasing of smoke-water concentration compared to control treatment. In this study applying high level of smoke-water foliar raised leaf area index, light absorption, total dry weight yield and radiation use efficiency of wheat and eventually influenced grain yield. So that the highest radiation use efficiency (1.65 g.MJ-1) was obtained from usage of 350 kg.ha-1 urea fertilizer and smoke-water at concentration of 1% v/v. also the highest grain yield (922 g.m-2) was obtained from usage of 350 kg.ha-1 urea fertilizer and smoke-water at concentration of 1% v/v and lowest grain yield (339 g.m-2) was recorded for application 90 kg.ha-1 urea fertilizer and foliar with distilled water.
Considering all the results presented, it can be concluded that application smoke-water led to increase wheat grain yield. Our results showed that smoke-water as an organic compound improved all wheat traits in all levels of urea fertilizer. Although, smock-water had more effect in low nitrogen fertilizer level compared to high nitrogen fertilizer level. Therefore, it seems that using of smoke-water in the wheat farm may be lead to decrease the excess use of nitrogen fertilizers.