EFFECT OF NITROGEN AND FOLIAR APPLICATION OF PHENOLIC COMPOUNDS ON FLAG LEAF PIGMENTS AND GRAIN YIELD OF SPRING WHEAT (Triticum aestivum L.) GENOTYPES

Abstract

Application of phenolic compounds such as proline, glycinebetaine, silicon, cytokinins, methanol etc. are getting important consideration in modern agricultural research for managing plants to get maximum yield under different environmental conditions. However there is a lack of knowledge about the effects of these phenolic compounds on grain yield, yield components and physiological properties such as leaf photosynthetic pigments. In the context the the present study was conducted during 2015-2016 growing season at the experimental field in the faculty of agriculture, University of Cukurova, Adana, Turkey to evaluated the effects of some phenolic compounds such as proline, glycinebetaine, silicon, cytokinins, methanol etc on chlorophyll (Chl) as well as total carotenoid contents of four bread wheat genotypes (‘Adana-99’, ‘FSD-2008’, ‘Basribey-98’ and ‘Seher-06’) under two nitrogen levels viz., low nitrogen level, LN: 60 kg N ha -1 and high nitrogen level, HN: 180 kg N ha -1 under well-watered condition. The results of the LN showed that the grain yield was only significantly correlated with Chl a/b (r=-0.751**) of wheat genotypes. While, under HN, Chl a , Chl b , carotenoid and Chl a/b were strongly correlated with grain yield (r=0.422*, r=0.635**, r=0.444* and r=-0.590**) respectively. Among the phenolic compounds, proline highly sitimulated the relationships between grain yield and Chl b , carotenoids and Chl a/b (r=0.795*, r=0.795* and r=-0.811*), respectively. Similary, methanol effects were strongly correlated with grain yield and Chl b and Chl a/b (r=0.844** and r=-0.772*), respectively. Therefore it is concluded that foliar application of methanol and proline were significantly increased the flag leaf Chl b concentration which ultimately lead to increase the grain yield of wheat genotypes. field N, 35°21′ E, 29 m above sea level), The soil type is a fine loamy, montmorillonitic typic xerofluvent, low in organic matter and slightly alkaline (pH 7.1–7.6). Treatments were with a similar developmental pattern of four spring bread wheat genotypes viz., ‘Adana-99’, ‘FSD-2008’, ‘Basribey-95’ and ‘Seher-06’ ; two nitrogen levels viz., low nitrogen level, LN: 60 kg N ha -1 and high nitrogen level, HN: 180 kg N ha -1 and foliar application of five phenolic compounds viz., Cytokinins, 40µM,; Silicon, 6 mM; Glycinebetaine, 100mM; Proline, 100mM; Methanol, 20% (v/v)). The experiment was conducted with split-split plot design with three replications. Nitrogen levels were assigned in main plots, phenolic compounds were in sub plots and genotypes were arranged in sub-sub plots. Phenolic compounds tratments were applied in three times at Zadok’s growth stages (ZGS) 20, 30 and 60 (Zadoks et al. 1974). The sowing density was 500 viable seeds m −2 . Every plots consisted of 6 m long 8 rows with a row spacing of 0.15 m.