Effects of Seed Placement in Soil on Virulence of Orobanche crenata on Faba Bean

Hamad E. A [1], Hamid, S. A. [2] Babiker, A. G. T[3]
Page No. 141-149

Orobanche crenata Forsk, a major constraint to faba bean (Vicia faba L.) production, albeit
recently introduced into Sudan, is widely distributed and has become a pest of national importance.
The present investigation, undertaken at the College of Agricultural Studies, Khartoum North, was
set to investigate the effects of seed placement in soil on the parasite virulence and influence on
selected faba bean growth attributes. Seeds buried at a depth of 5 cm resulted in the heaviest
infestation and highest emergence of the parasite. Seed placement at 10 and 15 cm soil depths did
not impair attachment of the parasite, but curtailed emergence. O. crenata from seeds placed in the
surface soil displayed late emergence and produced no seeds, whereas those from seeds buried at 5
and 10 cm depths produced considerable number of capsules (16-29 capsules/plant). O. crenata
from seeds placed at 15 cm soil depth remained subterranean and produced no seeds. O. crenata
infestation from seeds placed in the surface soil had no adverse effects on faba bean growth
attributes. However, those from seeds buried at 5, 10 and 15 cm reduced all measured growth
attributes and infestation resulting from seeds placed at 5 cm depth was, invariably, the most
damaging. The results suggest that in newly infested areas soil inversion or adoption of no-till
curtail replenishment of the parasite seed bank and reduce crop damage.
Keywords : Orobanchaceae, Vicia faba- soil depth.