Growth and yield response of a sunflower hybrid FH-81 to different irrigation and nitrogen management strategies

A study pertaining to determine the effect of different irrigation and nitrogen management strategies on growth and yield of sunflower hybrid FH- 81 was investigated at the Agronomic Research Area, University of Agriculture, Faisalabad during 2001 autumn growing season. The treatments were four irrigation level i.e. Io (irrigation at establishment), I1 (Establishment + vegetative stage), I2 (Establishment + flowering stage) I3 (Establishment vegetative + seed development) and three nitrogen rates i.e. No (control), N1 (100 kg ha-1), N2 (200 kg ha-1). The split plot design with three replications was used keeping irrigation level randomly in plain plots and nitrogen in sub plots. The plot size was 2.4x6 m having four rows with row to row distance of 60 cm and plant to plant distance of 20 cm. The crop was sown on August 27, 2000 and was harvested on 27 November 2001. The results obtained are summarized as under. 1. I3 irrigation level showed significantly high biological yield (8.741 t ha-1) over all other treatments N2 and N1 showed non significant but significantly higher biological yield of 7.217 and 7.155 t ha-1 respectively over control (6.464 t ha-1). 2. The treatment I3 gave significantly highest seed yield (1.909 t ha-1) over all other treatments. Significantly lowest see yield (1.121 t ha-1) was obtained in I degree. Non- significant differences were found in seed yields of N2 (1.576 t h-1) and N1 (1.556 t ha-1) but both of them showed significantly, higher seed yield over control (1.344 t ha-1). 3. Irrigation levels exhibited non- significant affects on harvest index. The difference between the effect of N2 21.78%) and N1 (1.73%) on the harvest index was non-significant but both of them were significantly higher over control. 4. Plant height of 13 (123.8 cm), 12 (121.0 cm) and I1 (118.8 cm) was non-significant but significantly higher than I degree (110.2 cm). Both N2 (122.7 cm) and N1 (120.2 cm) showed significantly higher plant height over control (112.4 cm). 5. Stem girth of 13 (1.691 cm) was significantly higher than all other treatments. Stein girth shown by N2 (1.631) and N1 (1.605 cm) was non- significant but significantly higher over control (1.498 cm). 6. Both I1 and 13 took equal but significantly more number of days to flowering than I0 and I1. Days taken by N2 and N1 to flowering were significantly more than control. 7. I3, I2 and I1 shown statistically similar but significantly higher head diameter than I0. Head diameter shown by N2 (13.92 cm) and N1 (13.83 cm) was non-significant but significantly higher than control. 8. No. of achenes per head showed by I3 (711.7) and I2 (685.2) were statistically similar but significantly higher than all other treatments. Regarding effect of nitrogen both N2 (670.5) and N1 (663.5) shown non-significant but significantly higher no of achenes/head over control (626.4) 9. I3 treatment showed significantly higher 1000 seed weight over all other irrigation treatments. Both N2 and N1 shown, significantly higher 1000-seed weight over control. 10. Irrigation level I3 exhibited significantly highest leaf area duration (77.62 days) over all other treatments. Non- significant differences were found in the LAD exhibited by both N2 (65.95) and I1 (67.58. days) but both of them were significantly higher than control. 11. Both irrigation and nitrogen significantly affected crop growth rate. Significantly highest CGR (13.01 g-2 m-2 d-1) was shown I3 treatment over all other irrigation levels. Both N2 and N1 shown statistically similar but significantly higher CGR over the control. 12. Both irrigation and nitrogen exhibited significant effect on LAI. Maximum values of leaf area index was observed in all the treatments on 53 DAS. I3 treatment exhibited significantly highest LAI over all treatments. Similarly LAI shown by N2 and N1 was non-significant but significantly higher over control on 53 DAS and there after. 13. Both irrigation and nitrogen exhibited non-significant effect on the net assimilation rate. 14. I3, I2 and I1 irrigation levels exhibited statistically similar effect on seed oil content. But both 13 and I1 significantly increased the seed oil content over I degree which in turn was statistically at par with I2 level. Highest seed oil content was observed in N1 but it was at par with No and both of them were significantly higher than N2.