INSECT- PESTS and DISEASES in apple.

1.Insect- pest :- 

The insects like san jose scale, wooly apple aphid, red spider mite, tissue borers and defoliating beetles and caterpillars in apple are important insects, which causes great damage to plants.

1. San Jose scale (quadraspidiotus perniciosus)

∆It is a polyphagous pest which feeds on apple plants. The insect is covered with deep gray armature.

∆ By lifting the armature, a yellow coloured insect underneath is seen. The nymph and adults suck sap from aerial parts

∆ Heavily infested trees have bark covered with deep gray overlapping scales. The plant vigor is reduced which results in poor fruit setting and quality.

Control:- 

1.Spray 2 per cent dormant oil ( Servo orchard spray oil/ Hindustan petroleum spray oil ) or 1.5 per cent summer oil like orchex 796/ IPOL/shelter909 at half leaf to tight cluster stage.

2.If oil spray is not applied then spray with 0.04 % chlorpyriphos ( 200ml durmet in 100 L water) after petal fall to kill the crawlers and newly settled scale.

(b).Wooly apple aphid (Eriosoma lanigerum) :

∆ It feeds on apples and lives in colonies on the aerial parts and roots of plants.

∆ In the aerial parts, it is seen as white wooly mass.

∆ Damage is caused by sucking of sap from stem, twigs and roots resulting in gall formation, and plants remain stunted.

∆Fruit set and quality also reduced under severe infestant.

Control:-  

1.Spray infested trees with 0.04% chlorpyriphos( 200ml durmet in 100 L water) during May-June and again in October.

2.Aphid infestation on roots can be reduced by drenching the collar region of the tree with chlorpyrifos (0.1%) in October- November using 10-15 liter solution per tree.

3.Use Malling Merton (MM) series clonal rootstocks for raising nursery plants, which are resistant to wooly aphids.

(c) European red mite (Panonychus ulmi):

∆ This is a serious pest in apples and causes damage by feeding on green matter of leaves.

∆ The leaves turn bronze in color and upward cupping, followed by leaf drop and weakening of fruit bud.

∆The maximum population is observed during May-July. 

∆ The mites complete 5-7 generations in a year. 

Control:- 

1.Spray 2 per cent dormant oil ( Servo orchard spray oil/ Hindustan petroleum spray oil ) at half leaf to tight cluster stage. 

2.Dormant oil spray as suggested for scale is effective against mites.

3.Spray 1 percent summer oils like orchex 796/ IPOL/shelter909@ 1 % at petal fall and again at the walnut stage of fruit.

4.If population is high, spray with fenazaquin ( 25 ml Magister 10 EC/100 L) or propargite (100 ml Omite/ 100 L water) twice at 20 days interval in June- July.

(d) Defoliating Caterpillars

They feed on newly emerged leaves and defoliate the trees. The growth of plants is retarded .

Control:-

1.Spray 0.05% Endosulfan ( 150 ml Thiodon or endocil 35 EC in 100 L water)15-20 days before flowering or when caterpillars apple

2.Diseases:-

Diseases also cause great damage to the apple trees. Apple scab, powdery mildew, premature leaf fall, canker and root rot are major diseases of apple plantation.

1. Apple scab :-

∆This is caused by venturia inequality..

∆Light brown or olive green spots which soon turn musty black appear on either or both sides of the young leaves in spring.

∆ Young lesions are velvety brown to olive green becoming more distant with age, leading to curling of leaves.

∆ On the fruits, small lesions develop and slowly increase leading to mishappening and cracking of fruits

Control:

1.Follow the spray schedule of dodine (0.1%) or mancozeb (0.3%) at silver tip to green tip, mancozeb (0.3%) + carbendazim (0.05%) at pink bud, benomyl/ carbendazim (0.05%) at petal fall, zineb (0.3%) or dodine (0.075%) at pea size fruit, mancozeb + carbendazim in June-July and urea 5% spray after fruit harvest to control the disease.

Powdery mildew:-This disease is caused by fungus Podosphaera leucotricha,which survive as mycelium on dormant buds.

 

∆ The young leaves show white mildew growth on its surface and also on twigs and look silvery white.

Control:- 

1.Prune off affected twigs .

2.Spray during dormancy, green tip, petal fall and two weeks after petal fall with fungicides like wettable sulfur (200-300 g/100 L) or contaf (50 g / 100 L) or Baycor (50 g/ 100 L).

Canker :-Many fungi have been reported to be involved in the canker complex.

∆ Symptoms appear on the trunk and branches, resulting in the production of wounds which develop length wise more rapidly.

∆ These are normally elliptical and the wound may increase up to a meter in length.

∆ The bark beneath the rough exterior becomes hard, dry and tough.

Control:- 

1.Cut and burn the badly cankered portion of the tree.

2.Scarify the cankered portions up to healthy portions and paint with Chaubatia paint.

3.Immediately after pruning, apply chaubattia paste or copper oxychloride paint on cut portions of the shoot.

4.Spray copper oxychloride (300 g) or captan (200 g) in 100 L of water after fruit harvest.

White root rot:-

∆ This is caused by Dematophora necatrix fungi.

∆ Affected trees show sparse foliage, slow growth, bronzing or yellowing of leaves. Such trees ultimately die

∆. Root turns brown and remain covered with white cottony mycelium of fungi in rainy season

Control:- 

1.Improve the drainage of an orchard.

2.After leaf fall, remove the infected roots and apply Chaubattia paste ( Red lead, copper carbonate and linseed oil (1:1:1.25) or copper oxychloride (300 g/100L) in Nov- December on cut ends of the roots.

3.Give at least four drenchings of Carbendazim (100 g) along with mancozeb (300 g) in 100 L of water during April, June, July and September in infected trees.