Final diagnosis


Grey mould ( Botrytis cinerea)

Rot and mould on a floating seedbed tray. <b><i>Botrytis cinerea</i></b>
Small, brown canker, surrounded by a brown border, starting from a dry leaf used as a nutrient base. <b><i>Botrytis cinerea</i></b>
Brown to dark brown lesion, girdling several centimeters of stem. <b><i>Botrytis cinerea</i></b>
Several brown and moist lesions surrounding the stem and the buried stem portion; they are occasionally covered by a grey mould. <b><i>Botrytis cinerea</i></b> (grey mould)
Tan canker covered by grey mould is developed on a tobacco plant collar. <i><b>Botrytis cinerea </b></i>(grey mould)
The stem is surrounded by a brownish cankerous lesion which weakens the collar. <i><b>Botrytis cinerea</b></i> (grey mold)
A beige spot, with brown irregular and concentric rings. <i><b>Botrytis cinerea</b></i>
On mature leaves the lesions often appear as large, light brown spots with a papery texture. <i><b>Botrytis cinerea</b></i> (Botrytis leaf spot)
Large spot on the lamina edge progressing through the veins. Wet and dark at first, the tissues turn lighter as they become necrotic. <b><i>Botrytis cinerea</i></b> (<i>Botrytis</i> leaf spot)
In unfavourable conditions, we observe beige, leathery spots with fine concentric darker rings surrounded by a well marked chlorotic halo. <i><b>Botrytis cinerea</i></b> (<i>Botrytis</i> leaf spot)
A large beige lesion is formed on a Virginia tobacco leaf from a rotten corolla fallen on it. <i><b>Botrytis cinerea </b></i>(blossom-dead leaf spot)
Browning and rotting of the tip and the midrib of a Virginia tobacco leaf. <b><i>Botrytis cinerea</i></b> (Botrytis leaf spot)
A wet and black rot, covered by a grey mould on a tobacco leaf at the beginning of curing. <i><b>Botrytis cinerea</b></i>
Fresh, wet canker lesion of dark brown to black, covered by a grey mouldy growth in the centre developing on tobacco stem. <b><i>Botrytis cinerea</i></b> (Botrytis leaf spot)
A dark brown canker covered by grey mould starting from the stem of a tobacco plant. <b><i>Botrytis cinerea</i></b>
The corolla of an infected flower, held in the axils of a tobacco leaf stem, is an ideal nutrient base to allow contamination by contact and colonisation of the stem. <b><i>Botrytis cinerea.</i></b>
<i>Botrytis cinerea</i>
Floral parts may be infected; the rotting of these parts is feared by breeders and seed producers. <b><i>Botrytis cinerea</i></b> (grey mould)
When the weather conditions are very humid, the fungus sporulates quickly on lesions forming a grey mould, giving rise to one of the names of the disease. <b><i>Botrytis cinerea</i></b> (grey mould)
Grey mould formed by <b><i>Botrytis cinerea</i></b> is actually composed of numerous branched conidiophores bearing ovoid and hyaline conidia at the tip of sterigmata.
This tobacco plant with a weakened collar starts to wilt slowly. <i><b>Botrytis cinerea</b></i> (grey mold)
Sometimes axillary buds may develop below the cankerous lesion present at the collar. <I> <b> Botrytis cinerea </ b> </ i> (gray mold)