DISEASE AND PEST OF CASHEW NUT | DISEASE AND PEST OF CASHEW NUT AND THEIR MANAGEMENT | PEST OF CASHEWNUT | DISEASE OF CASHEWNUT | DIEBACK OR PINK DISEASE | DAMPING OFF | ANTHRACNOSE | INFLORESCENCE BLIGHT | SHOOT ROT AND LEAF FALL | TEA MOSQUITO BUG | STEM BORER | LEAF MINOR | SHHOT AND BLOSSOM WEBBERS | Diseases of cashew and control measures | major disease of cashewnut

DISEASE AND PEST OF CASHEW NUT

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DISEASE

1. DIEBACK OR PINK DISEASE

Scientific name - Corticium salmonicolor

SYMPTOM

■ A whitish or pink growth of the fungus may be seen on the affected branches.

■ Shoot death from top to bottom, hence the name regressive death.

■ After a heavy rain on the branches, a silky film of the mushroom thread is seen.

■ In an advanced stage, the cortex splits and falls off.

■ Sometimes only one branch is affected, but many of them turn yellow and shade a part of the tree that looks sterile.

ADMINISTRATION

■ Prune the affected branches well below the site of infection and destroy them.

■ Protect the cut surfaces by applying Bordeaux paste.

■ If the disease is severe, it is recommended to spray a 1% Bordeaux mixture.

■ spraying must be done twice once, May June and the second in October. Collect all dry and effective branches to reduce the source of inoculum.

2. DAMPING OFF

Scientific name: Phytophthora palmivora

SYMPTOM

■ Occurs in nurseries where drainage conditions are poor.

■ The organism attacks the root or the coldest region of the seedling or both regions and causes its death. When the seedlings become infected with Pythopthora palmivora, they turn pale.

■ A water-soaked lesson may be observed in the neck region darkening and encircling the stem.

■ The seedling falls off and eventually the plant dies.

■ On the leaves, in severe cases, a water-soaked lesion can be seen.

■ These lesions spread and merge, often covering the entire leaf blade.

ADMINISTRATION

■ Provide adequate drainage for beds and poly bags.

■ Soak the beds / bags with 0.1% agallol to obtain a 1% boardex blend.

3. ANTHRACNOSE

Scientific name: Gloeosporium gloeospocioides

SYMPTOM

■ The Tamilnadu epidemic causes severe losses in Brazil.

■ Fungi infest young leaves, twigs and form a reddish-brown, water-soaked lesson. Resin exudation may be observed in the affected region.

■ The lesson enlarges and kills the shoots, the young leaves wither and the fruits wither. Infected inflorescence turns black, repeated infection of the terminal shoots leads to the death of the tree over time.

ADMINISTRATION

■ Destroy all affected branches.

■ Spray the plant with a mixture of 0.5% boardex and 0.25% mancozeb.

4. INFLORESCENCE BLIGHT

Scientific name: Gloeosporium Gloeosporiodes

SYMPTOM

■ This is also a common disease in Kerala, especially during the monsoon period.

■ The characteristic symptom is the drying of the flower branches.

■ Symptoms manifest as small waters of lesion on the primary spine and secondary spine.

■ The lesion is pinkish-brown in color, enlarges and soon becomes crusty.

■ Rubbery exudates may be present in the affected region.

■ The lesion develops in larger patches and causes the inflorescence to dry out. The incidence is very severe when cloudy weather prevails.

ADMINISTRATION

■ A combined spray of a dimecron fungicide and insecticide is recommended.

■ It is often claimed that the main cause of the disease is the tea fly and that the fungi are only secondary organisms.

5. THE SHOOT ROT AND LEF FALL

Scientific name - P. nicotianae var. nicotianae

SYMPTOM

■ During the southwest monsoon month of June and August, extensive symptoms of fall and shoot rot are observed.

■ Elongated black lesson that first developed on the exuding gingival stem. later, the infection accumulates up and down, causing the tender stem to collapse and wrinkle the tender leaves.

■ The lower mature leaves are also infected with an elongated black lesion on the midrib, which then spreads to the main lateral veins and leaf blade.

■ Infected licenses will be removed shortly.

ADMINISTRATION

■ Spring with 1% Bordeaux mixture before the onset of the monsoon will control the spread of the disease.

PEST

1. TEA MOSQUITO BUG

Scientific name- Helopeltis antonii

SYMPTOM

■ The nymph and the adult suck the sap from the leaves and inflorescences.

■ The leaves are deformed and show angular lesions, particularly along the rib where they can fall.

■ In the flowering phase they cause the joy of the inflorescences.

■ Feeding the stem with young shoots causes an elongated green lesion which is sometimes accompanied by oozing from the gums.

■ Severe damage shoots regressively due to the effect of insect saliva in combination with fungi, which enter plant tissue through food injury, the subsequent development of numerous auxiliary shoots causes clustered terminal growth known as witch's broom.

■ In the event of a severe infestation, the trees may appear to have been caused by a fire.

■ Feeding insects with developing apples and nuts causes a sunken brown spot.

■ Tree growth is severely retarded and fruiting of the attacking flower seed is reduced.

ADMINISTRATION

■ Shade adjustment pruning is performed to facilitate adequate penetration of sunlight into the canopy.

■ Spray the following insecticide, completely covering the foliage and bark during the early morning hours.

■ Monocrotophos 36 SL 3.0 l in the new rinsing formation.

■ Spray endosulfan at 35 c and Carbaryl 50 WP 3.0 kg in 1500-200 liters of water per hectare.

■ Do not mix cashews with crops that contain most hellopeltis insects, such as cotton, tea, sweet potato, guava, and mango.

2. STEM BORER

Scientific name: Plocaederus obesus

SYMPTOM

■ Heartwood edge of broad-leaved conifers.

■ Making irregular tunnels in the heartwood under the bark.

■ Excreta outside the cortex may indicate larval adaptation, but not until the adult has obvious symptoms of the attack.

ADMINISTRATION

■ Collection and destruction of affected shoots.

■ Scrape the bark from the exposed root and sprout with carbaryl 250 wp 2 grams per liter.

■ Root feeding with monochotophos 36 wsc 10 ml + 10 ml of water kept in a polyethylene bag on one side of the tree and keep the same amount on the other side of the tree.

■ Remove early stage larvae from the tree and soak the damaged part with 0.2% chloropyrifos at 10 ml per liter or 5% neem oil.

3. LEAF MINOR

Scientific name - Acrocercops syngramma

SYMPTOMS

■ Maning of the leaves of caterpillar.

■ The thin epidermal peel swells in the mind area and appears as whitish spots on the surface of the leaves.

■ In old ones, allow these blisters to dry out and fall into large living holes.

ADMINISTRATION

■ Spray 2.0 kg of carbaryl 50 WP or 1.25 L of malathion 50 EC or 1.5 L of endosulfan 35 EC between 1500 and 2000 s and water per hectare.

4. SHOOT SND BLOSSOM WEBBERS

Scientific name - Macalla momcousalis

SYMPTOM

■ The larvae collect young leaves and INFLORESCENCE and feed on them.

■ Apples and walnuts are also covered with a spider web and their surface tissue is discarded.

ADMINISTRATION

■ Collect and destroy damaged parts of the plant.