Plant Viruses diseases and Symptoms

Zohaib Ul Hassan

Ataturk University, Erzurum, Turkey zuhaib1144@gmail.com

Banana Bunchy Top Virus

Fiji in 1889. Severity during 1894. Disease intensity rang 20-32.7%. BBTV most sever & widely prevalent in Australia,

Pakistan. India, Borneo, Egypt, Sri lanka, Taiwan, Philippine.

Pathogen BBTV

Symptoms

Irregular, nodular, green streaks (.75mm wide, 2.5 c long), along the veins, on underside of lower portion of leaf blade, midrib & petiole.

TransmissionMechanicalAphid (pentalonis nigronervosa) persistent manner.A single aphid is enough to transmit disease.

Epidemiology

Disease spread quickly in hilly areas due to conducive weather .Rain.

Management Remove infected plant.Use resistance variety.40g of carbofuran 3g granules/ pit before planting.Spray systemic insecticide viz., 0.1%phasphamidon or 0.2%oxydementon methyl or 0.1% monocrotophos 3 times at 3 weeks intervals.

Potato Virus XSymptoms

Inter veinal mosaic.Mottling with stunting.Crinkling.Top necrosis.

TransmissionMechanical.Chewing insects.

ManagementField sanitation with 3% trisodium phosphate or 1% calcium hypohoride.

Potato virus ySymptoms

Mosaic.Necrosis.Leaf drop streaking.Plant Stunting.Bunching or twisting of leaves.Necrosis.

TransmissionAphid (Aphis gossypii) non persistent manner.

ManagementThermotherapy.

Potato Leaf Roll VirusSymptoms

Upper and inward rolling of leaflet.Leaf turning.Dwarfing.Leaflet thick and dry & lower leaf become brown.Smaller size tuber.

TransmissionPlanting infected seed tuber.Aphid (Aphis gossypii) persistent manner. Primary vector Green peach aphid (myzus persicae).

ManagementUse certified seed.Hot water treatment at 55 c for 15- 20 mint. Control aphid pop & other host.

Tomato Spotted Wilt VirusFirst reported from India 1975.

SymptomsSudden browning of leaves.Necrosis. Leaves distortion.Green brown glaze to dark brown almost black glaze area.On ripe fruit red and yellow markings.

Transmission

Tospo virus cause the disease.Thrips (Thrips tabaci)).Vector (Frankliniella occidentalis).Mechanical transmission.Host range:

Ornamental plants, Vegetables, Weeds, Potato, Brinjal, Pea, French bean, Cowpea, Lettuce, Pineapple.

Management

• Prevent from vectors.• Uproot and burn the effected field • Systemic insecticides• Control of weeds• Crop rotation• Plant resistance cultivars

Tomato Leaf Curl Virus

After infection within 20 days disease losses up to 92.4%.

Infection occur after 35 & 50 days after transplanting yield losses would be reduced to 74 & 28% respectively.

Symptoms :• Severe form in September and November• Stunted and excessively branched• Leaves show downward rolling

Cont..

• Curling twisting and chlorosis• Flower drop is common.Transmission:• White fly Bemisia tabaci.Epidemiology:• High temperature and low humidity.

Management:

• Seed treatment with hot water @ 50°c• Field sanitation• Mulching with saw dust.• Yellow sticky traps for controlling of insect

vector.• Bio control agent.• Spray of krishi oil after flower formation.• Eradicate weeds.

Chilli mosaic virus

21-60% yield losses.Symptoms:Vein clearing on leaves.Yellowing of whole leaves, followed by patterns of yellow and green colourDistortion of veins Infected plants produce few fruitsTransmission:Sap transmittedVector Aphis gossypii

Host range:Chilli, Bell pepper, Tobacco, Tomato, Egg plant, Okra, Nicotiana rustica ,N glutinosa , Datura albaManagement:Destruction of infected plantsEradication of weeds from the fieldSpraying of 0.02% methyl parathion for aphid.

Tobacco mosaic virusSymptoms:Greenish yellowing mottling curled in shapeBrown streaking on branchesMottled symptoms on fruitYellow spotting in some fruits.Spots are irregular in shape and sunkenTransmission:Mechanically transmitted virus.Infected seeds of chilli.

Host rangeVery wide host range.Management:Resistance varity. Burn the infected plants.

Cucumber mosaic virusMottling between light and dark portion Upward curlingDark green spots on surface of leavesInfected plants are compactYellow ring are produced on fruits quarter and half inch in diameter.Transmission:Aphis craccivora, A. gossypii. Mechanically transmitted virus.

Management:Removal and destruction of infected plantRemoval of weeds from fieldSpraying of 0.05% nuvacron 0.02% of metasystoxSoil application of carbofuran at1.5 kg/ Ha. Spraying of 1.5-1.8% mineral oil at 5-6 days interval.