The Use of Genetically Tolerant Maize (Zea mays L.) in the Control of Striga hermonthica in Northern Côte d’Ivoire

Aim: To use host plant tolerant maize (Zea mays L.) to control Striga hermonthica in northern Côte d’Ivoire and to test the infectivity of seeds of S. hermonthica populations on maize.

Study Design: Two-way factorial experiment on a randomized complete block design with three replications.

Place and Duration: Ferkessédougou research station of the National Center of Agricultural Research (CNRA), one year in 2011.

Methodology: The first factor was maize variety with two levels (IWD STR and GMRP-18). The second factor was S. hermonthica populations with six levels (StMi1, StMi2, StMa1, StSo, StMa2 and StMa3). A plot consisted of 2 rows, 5 m long, spaced 0.80 m apart with 0.50 m spacing between plants within the row. Data were collected on 18-maize competitive plants per plot.

Results: The Striga-tolerant IWD STR produced up to 51% more grain (P<.001) than the susceptible variety. Three out of the six populations tested were able to significantly reduce grain yield (P=.005) by 38.5 to 58.7%. The difference in virulence of S. hermonthica populations followed a north-south gradient, with the highly virulent populations coming from the Northern Sudan Savanna zone. There was no strain specialization in the S. hermonthica populations tested.

Conclusions: Host plant tolerance is a useful control measure to combat the menace of S. hermonthica infestation in Côte d’Ivoire. The genetic development of Striga tolerant maize can be done without developing tolerant varieties to a particular strain of the parasite. Further studies should be carried out to determine the genetic diversity of S. hermonthica in Côte d’Ivoire and to understand the difference in virulence among populations