Influence of a Triazole Plant Growth Regulator on Root and Shoot Development and Nitrogen Utilisation of Oilseed Rape (Brassica napus L.)

Abstract

AbstractA factorial experiment with 3 nitrogen (N) levels and 4 application rates of the triazole type plant growth regulator (PGR), BAS 111 W = l‐phenoxy‐3‐(1H‐1,2,4‐triazol‐1‐yl)‐4‐hydroxy‐5,5‐dimethylhexane, was conducted in hydroponics to study the influence on N uptake and morphological changes of oilseed rape. The following results were obtained:–Increased N level of the nutrient solution increased plant height and root and shoot weight. Enhanced N uptake caused a higher N concentration of root and shoot.–Increasing PGR application rates reduced plant height and shoot biomass production; this reaction was stronger at higher doses of N.–Root weight, root length, root diameter and root surface area were increased by N application. None of these parameters was significantly altered by the PGR. This resulted in increased root‐shoot‐ratios at higher PGR rates.–As a consequence of reduced shoot production PGR application resulted in increased concentrations of N. The root reacted similarly but to a lesser degree.