Competitive ability of sugarcane (Saccharum officinarum L.) cultivars to weed interference in sugarcane plantations of Ethiopia

The competitiveness of sprawling (30–50° leaf angle), intermediate (50–70° leaf angle) and erect (70–90° leaf angle) sugarcane cultivars (‘B41227’, ‘B52298’ and ‘NCo334’) was studied for two cropping seasons under 0, 3, 6, 9, 12, 15 weed-free weeks after planting (WAP) of sugarcane and weed-free conditions at three sugarcane plantations in Ethiopia. The study showed highly significant (P < 0.01) effects of cropping season, cultivar, duration of competition as well as the interaction effects of cultivar by durations on weed dry weight, milleable cane yield and sugar yield. Among the cultivars, ‘B41227’ suppressed weed population the most and gave the highest tiller number, cane yield and sugar yield. The highest rates of cane and sugar yield increase were recorded for weed free periods of 3 WAP to 12 WAP, while weeds emerging before 3 WAP and beyond 12 WAP had less effect. The extent of cane and sugar yield loss varied with season, plantation and cultivar. Sugar yield loss of the unweeded treatment (0 WAP) compared with weed-free (WF) treatment ranged from 74.1% for cultivar ‘B41227’ at Metahara to 90.5% for cultivar ‘NCo334’ at Wonji-Shoa plantations. Thus, the sprawling sugarcane cultivar ‘B41227’ appeared to be most competitive and the critical period for weed control should be between 3 and 12 WAP to prevent substantial cane and sugar yield loss due to weed competition.

► The paper evaluates 3 cultivars of sugarcane and 7 durations of weed interference.
► Effects of cultivars and durations were significant on weed biomass and cane yield.
► Sprawling sugarcane cultivar ‘B41227’ was found to be most competitive.
► Weeds have to be controlled during 3–12 weeks after planting of sugarcane.