Weed control in rose-scented geranium (Pelargonium spp)

Area of Science:

• Agronomy
• Horticulture
• Weed Science

Background:

• Weed competition significantly reduces essential oil yield in rose-scented geranium (Pelargonium spp).
• Broad-leaf weeds are the predominant species, impacting crop productivity.
• Effective weed management strategies are crucial for maximizing geranium cultivation.

Purpose of the Study:

• To evaluate the efficacy of chemical (oxyfluorfen, pendimethalin) and cultural weed control methods in rose-scented geranium.
• To assess the impact of different weed control treatments on geranium oil yield and quality.

Main Methods:

• Field investigations conducted in 1999 and 2000.
• Treatments included pre-emergence application of oxyfluorfen and pendimethalin at various rates.
• Cultural practices evaluated: mulching with spent lemon grass, successive hand weeding, hoeing, and multiple hand-weedings.

Main Results:

• Pre-emergence pendimethalin (0.75-1.00 kg AI ha(-1)) or oxyfluorfen (0.25 kg AI ha(-1)), mulching, and three hand-weedings were highly effective.
• These methods significantly reduced weed density and dry weight, yielding oil comparable to weed-free conditions.
• Lower herbicide rates (oxyfluorfen 0.15-0.20 kg AI ha(-1), pendimethalin 0.50 kg AI ha(-1)) showed reduced efficacy.
• No tested herbicides negatively impacted the essential oil quality (citronellol, geraniol content).

Conclusions:

• Effective weed control in rose-scented geranium is achievable through integrated approaches.
• Optimized herbicide application (pendimethalin, oxyfluorfen) and cultural practices ensure high oil yield without compromising quality.
• Further research may explore integrated weed management for sustainable geranium production.