Description:Grey, cobwebby fungal growth sometimes with tiny black spore bodies. Underlying plant tissue is usually soft.
CyclamenThe infection usually starts near ground level.
GrapesBerries are most commonly affected. They go soft and a grey fungal growth appears soon after. Berries damaged by insects or hail are very susceptible to infection by wind borne spores. Infection can occur at flowering. The disease may develop after picking in storage.
LiliesRound to oval, yellow to reddish brown spots appear on both sides of the leaf. Their colour may fade with time and the leaf may be destroyed as the spots grow and join. Stems may be spotted and break at the lesion. Infected buds may wither and turn brown or produce distorted flowers. These symptoms may also be caused by Botrytis elliptica.
LettuceA soft rot that may be edged with red and have grey furry hyphal growth with black sclerotia occurs on the lower leaf stalks and may rot the base completely leading to death or stunting in less severe cases.
PearsDying flowers are often infected and the disease spreads to the fruit. A soft rot appears on the fruit followed by a grey, powdery growth of spores.
PelargoniumMainly affects flowers that fade or wither and brown. A furry growth appears on the dead petals that may be matted together. Infected petals may fall onto leaves below and infect them.
RosesMainly affect flowers and buds and occasionally leaves. Buds turn brown and rot and the infection may travel down to the stem. Pink rings are produced on petals. It usually lives on dead material and only attacks living material in cool and humid conditions and if these conditions persist the grey hyphal growth may be seen.
Species Affected:Brassicas, Ornamentals, Pelargonium(Regal, Ivy and Zonal).
Biology:Favoured by cool, wet, humid conditions.
Life Cycle:Origin and History:
Management and Control:Decrease humidity.
OnionsHarvest onions carefully at the right stage, then cure them correctly in well ventilated areas.
Brassica cropsDispose of crop residues by burial or burning.
FruitDip fruit in fungicides.
GrapesPrune to increase are circulation and let in sunlight.
LettuceIncrease air circulation. Reduce planting density.
PelargoniumRemove and destroy infected flower heads and leaves immediately.
RosesRemove and destroy infected buds, flowers and stem.
StrawberryUse plastic or other mulch to prevent soil contact with fruit.
Related and Similar Species:References:
Acknowledgments:Collated by HerbiGuide. Phone 08 98444064 for more information.