Sunflower response to nitrogen supply and split application

Abstract

Nitrogen is an essential nutrient for the growth of different organs that affect directly or indirectly the final yield. In a field experiment, a sunflower hybrid was supplied with increasing amounts of N, applied either at emergence or splitted, with a second application at the 4^th leaf stage. Splitting did not affect any of the characteristics evaluated. Nitrogen increased leaf area and initial root lenght. Stem height increased with N in early growth stages but by flowering, the taller plants were those with the lower N doses. Achene yield had a small increase with N as did the number of achenes/capitulum.