Effect of plant density and nitrogen on the agronomic performance of sunflower on dry land

Abstract EN

Field experiments were conducted for 2 years to determine the effccts of planting density and nitrogen level on late sown sunflower, seed yield and other characteristics under the dry conditions of the central Sudan.

In Exp.

I.

two cultivars (Hungarian A and Cerninka) w'ere estab- lished at 83.333 and 166.666 plants ha and 3 levels of nitrogen (0.

40 and 80 kg N ha ').

In Exp.

II.

two cultivars (Bolero and C erninka) were estab- lished at the same levels of nitrogen at 83,333 and 41.666 plants ha 1 In both experiments, cultivars differed significantly from one another in seed yield.

The average yields of Hungarian A and Bolero, being 1131 and 1008 kg ha .

were 32.7 and 29.1%.

respectively, over that of Cerninka in the re- spective trials.

Under the conditions of tiie first experiment, seed yield, plant height, number of harvested plants ha .

head diameter and 1000 seed weight were significantly increased by the 40 kg N ha .

Lower plant- ing density (83.333 plants ha ') in contrast to higher density (166.666 plants ha ') significantly increased seed yield ha ! and 1000-seed weight and de- creased number of plants ha In the second experiment, application of 40 kg N ha 1 significantly reduced plant height, whereas planting density (41,666 plants ha ') significantly reduced the actual number of harvested plants ha \ In both trials, application of 80 kg N ha" 1 had no significant ef- fect on any of the traits evaluated.

Apart from number of filled seeds head (Exp.

I), all the first order interactions (Exp.

I) and the second order in- teractions (both trials) evaluated for the different traits among the three factors were significant, indicating that, in the course of a selection prog- ramme, testing of sunflower lines at several nitrogen levels and planting de- nsities would be necessary for their best assessment.

Apparently, a minimum number of 83,333 plants ha 1 and maximum dose of 40 kg N ha "1 would prove to be adequate for achieving maximum seed yield in late sown sunflower in the dry tropics.