Effect of nitrogen compounds and tricyclazole on some biochemical and morphological characteristics of waterlogged-canola

ABSTRACT: Waterlogging causes deleterious physiological changes which restrict canola growth and yield. The objective of this work was to compare the effects of the foliar applications of urea, calcium nitrate, potassium nitrate and tricyclazole at different times on selected biochemical and morphological characteristics of canola plants (Brassica napus L. cv. Hayola 401) under waterlogging stress conditions. Plants in the 5-leaf growth stage were exposed to the flooding conditions for two weeks. The results showed that the content of chlorophyll a, chlorophyll b, chlorophyll a/b ratio and carotenoid in the leaves of canola were reduced after this stress. The flooding stress also significantly decreased the grain yield, number of siliques per plant, plant height, stem width, number of branches and branching position. The higher pigments content in the leaves, the increase in the number of siliques per plant (which was responsible for the significantly greater grain yield over the waterlogged control) and increase in other morphological characteristics were obtained by foliar application of calcium nitrate, potassium nitrate and tricyclazole. The foliar spray of urea caused a less significant increase for these characteristics. The foliar application before the stress was more beneficial than the foliar spray after waterlogging. The foliar spray twice (before and after the stress) was slightly superior to the foliar spray before or after waterlogging stress. However, we concluded that the foliar spray of calcium nitrate, potassium nitrate and tricyclazole before or after the waterlogging stress was more applicable and cost efficient than the foliar application twice and are advisable to alleviate the flooding damage in canola.