Evaluation of Striga emergence under natural field
infestation
Sixteen (16) sorghum genotypes consisting of 12 SAP lgs1 mutants,
2 LGS1 lines, and a resistant and susceptible check (SRN39 and
Shanqui Red) were evaluated in a Striga infested field in Alupe,
Kenya (0.45°, 34.7°). The sorghum entries were planted in four-row plots
measuring 4 x 3.2 m. Each plot was surrounded by 1 m path. Spacing was
set at 80 cm between rows and 20 cm between plants and the 16 entries
were laid in lattice design replicated three times. To ensure uniform
distribution of Striga seeds in the sick plots, each planting
hill was augmented with approximately 3000 Striga seeds. 2 g of
diammonium phosphate (DAP) fertilizer were applied per hill. Twenty-one
days after sowing plants were weeded using a hoe and subsequently
thinned leaving 8 plants per row. To avoid disturbing the emergingStriga plants, second and third weeding was done by hand pulling.
The same experimental set up was used on non-infested (Strigafree) plots.
Sorghum agronomic traits and Striga data parameters were
measured. The number of emerging Striga plants was counted at 42,
56, 70, 84 and 98 days after sowing in each plot. Data on sorghum
included days to 50 % flowering, plant height, weight of 100 grains
(HGW). Sorghum panicles were sun dried, threshed and kernel yield was
determined.