Abstract:
This investigation was carried out in West Kordufan State, at Elfula. Where the
soil is of low fertility and is highly infested with Striga hermonthica. Field and
laboratory studies were undertaken to investigate the best control methods for
Striga. In the study the effects of neem seeds powder, neem leaf and seed
extract, urea and 2, 4-D on Striga incidence on millet and on millet roots length
and Striga germination were determined. Treatments were arranged in
randomize complete block design (RCBD) with four replicates.
Field results showed that, neem seed powder, urea and 2, 4-D reduced Striga
emergence by 25 to 75%. Neem seed powder at 126 and 168 kg/fed in
combination with urea and 2, 4-D reduced Striga emergence by 25 to 66%. 2, 4-
D applied subsequent to urea reduced Striga emergence significantly. Neem
seed powder at 168 kg/fed plus urea, as single and split dose increased crop
height significantly. 2, 4-D in combination with urea or neem seed powder at
168 kg/fed did not affect millet height in one season, but a significant increase in
height was realized in the second season. 2, 4-D applied subsequent to urea as
single and split dose increased millet height significantly.
Neem seed powder at 168 kg/fed reduced grain yield significantly. Neem seed
powder at 126 kg/fed, 2, 4-D alone, irrespective of dose, urea as single and split
dose, the combination of neem seed powder and urea, neem seed powder and 2,
ii
4-D, urea and 2, 4-D increased grain yield, albeit not significantly.
Laboratory experiments showed that, neem leaf and seed extract, irrespective of
dilution, reduced millet root length significantly. However, the attained
reductions decreased with decreasing concentration.
Neem leaf and seed extract at 1.25, 2.5 and 5% (g/100ml), applied to Striga
seeds conditional in water reduced Striga germination significantly, and reduced
Striga radical length, considerably. 2, 4-D and urea increased germination of
Striga seeds significantly and reduced radical length considerably.
Striga seeds conditioned in neem leaf extract, neem seed extract and urea
displayed low germination when placed in the vicinity of millet roots. Striga
seeds conditioned in 2, 4-D or GR24 in water and subsequently treated with root
millet, displayed high germination, when placed in close proximity to millet
roots.
The study showed that neem leaf and seed powder, urea and 2, 4-D have
negative effects on Striga parasitism on pearl millet. Reduced parasitism may be
attributed to reduced germination and reduced length of Striga radical and millet
roots. Other possibilities including inhibition of haustorium initiation and/or
induction of pre-mature haustoria cannot be ruled out.
