Effects of different nitrogen rates and seasonal variations on seed yield and yield related traits of kenaf (Hibiscus cannabinus L.) varieties

Abstract

Field experiments were conducted during 2013 and 2014 rainy seasons at the Institute of Agricultural Research
and Training, Obafemi Awolowo University, Moor Plantation, Ibadan to determine the effect of N-application
rates on seed yield traits and seed yield of two kenaf varieties. The experiment was laid out in a randomized
complete block design (RCBD). Kenaf seed of two varieties (Ex-Shika and A -60-282b) were planted in 2013 2
and 2014 with four rates of urea (0, 40, 80 and 120 kg/ha) applied in two splits at interval of 4 weeks. Data were
collected from the two experimental rows and parameters measured include plant height, height of first
capsule, number of capsules per plant, seed number per capsule, one thousand seed weight, seed yield per plant
and seed yield per hectare. The results showed that seasonal variation was significant on all the agronomic and
seed yield parameters measured. However, agronomic and seed yield traits were not significantly affected by
kenaf genotypes and nitrogen fertilizer rates used. The highest plant height was obtained from the control rate
(0 kg of nitrogen/ha). Varietal effect on all the traits measured was not statistically different. This research
demonstrated that kenaf was relatively unresponsive to N application of 120 kg / ha and lower, and at high Nlevel there was a potential risk of decreasing plant height.