CULTIVAR AND WEED CONTROL STRATEGY INFLUENCING THE PRODUCTIVITY OF ROSELLE (HIBISCUS SABDARIFFA L.) IN A SEMI-ARID ENVIRONMENT OF NIGERIA.

Field trial was conducted during the 2019/2020 cropping seasons to determine the effect of cultivar and weed control strategies on the productivity of roselle in a semi-arid environment. The trials comprised of two cultivars (deep red and white) and seven weed control strategies (pendimethalin at 2.0, butachlor 2.0, butachlor 1.5 + pendimethalin 1.5 kg a.i. ha-1, butachlor 1.5 kg a.i. ha-1 + SHW at 6 WAS, pendimethalin 1.5 kg a.i. ha-1 + SHW at 6 WAS, hoe weeded twice at 3 and 6 WAS, and weedy check) which were factorially combined and replicated thrice in a Randomized complete block design. The application of pendimethalin at 2.0 kg a.i. ha-1, as well as the deep red roselle cultivar, resulted in significant (P<0.01) increase in the number of days to 50% emergence, crop injury scores, and lowest stand count. The weedy check, on the other hand, recorded the lowest crop vigor score, plant height, number of leaves plant-1, leaf area, and leaf area index. Similarly, weedy check had the lowest fresh fruit weight, fresh capsule weight, dried capsule weight, seed weight, seed yield, and 1000 seed weight when compared to the other weed control strategies. Weed cover and weed density were similar in weedy check compared to the other weed control strategies, but treatment efficiency index was significantly (P<0.01) higher with application of two hoe weeding's at 3 WAS and 6 WAS, butachlor 1.5 kg a.i. ha-1 + SHW at 6 WAS and pendimethalin 1.5 kg a.i. ha-1 + SHW at 6 WAS. Deep roselle cultivar outperformed white roselle in terms of growth and yield characters. Therefore, the cultivation of deep red roselle with butachlor and pendimethalin at 1.5 kg a.i. ha-1 + SHW at 6 WAS can be adopted in place of hoe weeding for season long weed control in the study area. [ABSTRACT FROM AUTHOR]