PATH 372 Diseases of Horticultural Crops
PATH 372 Diseases of Horticultural Crops
PATH 372 Diseases of Horticultural Crops
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Survival and spread<br />
Infected tubers<br />
Spread by aphids, Myzus persicae and Aphis gossypii<br />
Management<br />
Disease free seed tubers for planting<br />
Rouging <strong>of</strong> diseased plants<br />
Aphid control<br />
c) Leaf roll – Potato leaf roll virus<br />
Symptoms<br />
Upward rolling <strong>of</strong> leaves, which have a stiff leathery texture<br />
Plants stunted and have a stiff upright growth<br />
Phloem necrosis <strong>of</strong> tubers in some varieties<br />
Spread<br />
Infected seed tubers or by aphids<br />
Management<br />
Disease free seed tubers for planting<br />
Aphid control<br />
7) Potato spindle tuber – Viroid<br />
Symptoms<br />
Plants appear erect, spindly and dwarfed<br />
Leaves small, erect and leaflets dark green<br />
Tubers elongated with tapering ends<br />
Tuber eyes are numerous and more conspicuous<br />
Spread<br />
Infected seed tubers<br />
Mechanically spread by knives used to cut seed tubers<br />
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