PLANT PROTECTION PROBLEM OF DIFFERENT FRUIT CROPS AND CONTROL MEASURE TAKEN IN NEPAL

PLANT PROTECTION PROBLEM OF DIFFERENT FRUIT CROPS AND CONTROL MEASURE TAKEN IN NEPAL

Shankar Paudel

M.Sc.Ag. (Horticulture)

shankarpaudel23@gmail.com

Abstract

Fruits contribute important role in Nepalese horticulture/agriculture and production of fruits offer opportunity of high income per unit area of acute land scarcity with favorable income generation. Fruits of Nepal can be classified in to 3 categories based on the climatic requirement. Tropical fruits include Mango, Banana, Jackfruit, Pineapple, Papaya etc. Subtropical fruits includes citrus, Guava, Pomegranate, Litchi, Grapes etc. Similarly temperate fruits are Apple, Pear, Peach, Plum, and Walnut etc. Production and productivity of fruits sector is not satisfactory. This sector has many constraints. Generally, most fruit crops take long gestation period before trees start giving economic yield and this is one of the demotivational factor. Disease and pest cause huge loss in fruits industries. Plant protection problems of fruit include insect pest, disease and disorder of fruits. Very few researches are conducted in Nepal in fruit sectors to solve the prevalent problem of fruit production. Various insect pests have been reported in fruits in various locations. Among these, wooly aphid, scale, oriental fruit fly, green stinkbug, mango stem borer, mango stone weevil, banana stem weevil and banana rhizome weevils are considered to be key insect pests in Nepal. Among the diseases prevalent in country citrus greening disease and tristeza virus consider the major threats of citrus production of Nepal. Similarly, Guava wilting of Guva; Rhizopus rot of Jack fruit; Panama wilt, Bunchy top, Sigatoka disease of Banana; powdery mildew, anthracnose of mango; Root rot, collar rot, papaya mosaic, Papaya ring spot virus of Papaya; powdery mildew of apple are some important disease of fruits. In Nepal research is focused in citrus. Government of Nepal has given priority to solve the problem of citrus like citrus greening that cause citrus decline in western part of Nepal. Wooly aphid is major problem in apple and researchers are focused to reduce this problem. Similar focused should given to other problem of plant. New technique and method indeed need to farmer level which can solve the protection. Plant clinic may be one method to identify the disease and pest found in farmer’s level. Researchers are needed to focus on the protection issues.

Key word: fruit, insect pest, disease, management

1. Introduction

1.1 Background

Nepal has a great agro-ecological diversity and numbers of fruits are grown in various region of country.  Fruits contribute important role in Nepalese horticulture/agriculture and production of fruits offer opportunity of high income per unit area of acute land scarcity with favorable income generation. Fruits have important nutritional value which required about 67 g along with other in daily balance diet (Ranjit and Pun, 1990 as reviewed by Shrestha, 2010). Fruits and spice contributes about 13% in AGDP. According to the statistical data of 2011/12 the production of fruits is 10,29,754 mt from 1,01,233 ha and productivity is 10.17 mt/ha (Krishi Diary, 2070). Fruits can be classified in to 3 groups based on their climatic requirement they are Tropical, Sub-tropical and Temperate fruits. Tropical fruits include Mango, Banana, Jackfruit, Pineapple, Papaya etc. Subtropical fruits includes citrus, Guava, Pomegranate, Litchi, Grapes etc. Similarly temperate fruits are Apple, Pear, Peach, Plum, and Walnut etc. Among these, apple and pear are major temperate fruits grown in high mountains. Among citrus, mandarin orange is one of the most important income generating crops for farmer of middle hill of Nepal. Mango and banana are major tropical fruits grown in Terai and inner Terai region of country.

Production and productivity of fruits sector is not satisfactory. This sector has many constraints. Generally, most fruit crops take long gestation period before trees start giving economic yield and this is one of the demotivational factor. Other factors are plant protection problem, irrigation and infrastructure problem, lack of proper marketing facilities, lack of post harvest management practice etc. Fruit species grown in our country have many problems like insect pest infestation, disease infestation and improper management practices which cause considerable loss in fruit production (Shrestha, 2010). Plant protection problems of fruit include insect pest, disease and disorder of fruits. Very few researches are conducted in Nepal in fruit sectors to solve the prevalent problem of fruit production. Various insect pests have been reported in fruits in various locations. Among these, wooly aphid, scale, oriental fruit fly, green stinkbug, mango stem borer, mango stone weevil, banana stem weevil and banana rhizome weevils are considered to be key insect pests in Nepal (Paneru and Giri, 2011). Among the diseases prevalent in country citrus greening disease and tristeza virus consider the major threats of citrus production of Nepal. Similarly, Guava wilting of Guva; Rhizopus rot of Jack fruit; Panama wilt, Bunchy top, Sigatoka disease of Banana; powdery mildew, anthracnose of mango; Root rot, collar rot, papaya mosaic, Papaya ring spot virus of Papaya; powdery mildew of apple are some important disease of fruits.

1.2 Objectives

v  To identify the major insect pest of fruit grown in Nepal

v  To identify the major disease of fruits

v  To access with the control measure taken to manage disease and pest

2. Methodology

 For the review of plant protection problem of fruit crop and control measure taken in Nepal information were collected from different literature available. Journal, Articles, Thesis, leaflet, booklet, proceeding available in library of NARC, Annual Report of different fiscal year published in NARC and Fruit Development Directorate (FDD) were mostly studied. Similarly, available materials in different web/internet were consulted. Literatures available were thoroughly read and important points were noted.

3. Disease and Insects Problems of different Fruits

Tropical fruits

Important tropical fruits are mango; banana, jackfruit, papaya, pineapple etc. are important tropical fruits. Mango is the most important tropical fruit grown in Nepal. Major insect pests and disease found in Nepal are given in table.

Table: insects of mango with major symptoms and general management

S.N.	INSECTS	SYMPTOMS	MANAGEMENT
1.	Mango hopper Idioscopus niveosparsus	Suck the sap and secrets honeydew and due to which sooty mold is develops and in sever condition wilting of leaves takes place	Cultural method: Use the light trap @ 1 trap/ha. Biological method: Use the entomopathogenic fungi: Metarhizium. Chemical method: Use of systematic fungicide every evening time.
2.	Mango mealy bug Drosicha mangifera	Both nymph and adult suck the sap from tender parts and secrets honey dew and which inturn develop sooty mold in infected part	Cultural method: Use the greasy band of about 10-15 cm wide in the tree trunk to prevent the migration of the female into the soil. Chemical method: Use systemic type of pesticide. Use 250 gm per tree of methyl parathion dust- 2%.
3.	Mango fruit fly Bactrocera dorsalis	The maggots consume the internal tissue from where decaying takes place from which fruit drop takes place	-Complete field sanitation. -Collection of the fallen fruit and destroying it. -install the pheromone trap with methyl eugenol bottle trap along with malathion to attract and kill male fruit flies( 10 traps/ha). Replace methyl eugenol and malathion inside trap in 2 week interval. -apply the protein bait sprays on the few spots @50 ml/plant in a field to kill the flies attracted to these spots. -use of neem fruits to repel female flies, use of tobacco extracts and ginger extracts to kill fruit fly. (Paneru and Giri., 2011)
4.	Mango stem borer Batocerarufomaculata	Saw dust is seen just at the mouth of hole made by borer	Chemical method: Use kerosene oil in the hole. Use Dursban 20% EC @2.5 ml/lt water to main trunk, branches and expose roots host trees. Cultural method: Jerking the hole with the help of long stem. The larva is infected by a kind of entomopathogenic fungi which is Metarrhizium anisopliae.
5.	Mango stone weevil Sternochetus mangiferae	Young grub feed on pulp and stone and later cotyledon. No external symptoms of grub attack appear on the fruits, while fruits are already damaged inside. The infested fruits usually fall down.	-collect destroy all fallen fruits and weevil damaged mangoes at weel;y intervals and destroy all leftover in the orchard after harvest(Neupane, 2009) -spray chemical insecticides such as Dursban 20% EC @2.5 ml/lt on main trunk, primary branches and junction of branches prior to flowering to manage beetles hiding in the bark(Paneru and Giri, 2011)
5.	Mango shoot gall maker Apysylla cistellata	It attack of new twigs, and formed cone shaped galls which cause to stop leaf and flower in new twigs	-destroy the infected plant part -use resistant varieties like Alphanso, Himsagar, gulabkhas etc. (Neupane, 2009)

Table: some disease of mango with their major symptoms and general management practices

S.N.	Disease	Symptoms	Management
1.	Powdery mildew of mango Oidium mangiferae (fungal disease)	The powder like substances is seen in the upper part of the leaves at the region of around mid-rib which in sever condition shows the sporangial growth in the lower portion of the leaf. Such leaves curl and are distorted.	Chemical method: Dusting the tree with sulfur can be done. A Karathane (0.05%) spray is found effective against this disease.
2.	Leaf blight Macrophoma mangifera	Spots gradually enlarge discoloring the surrounded tissue, which 1st become biscuit colored, then brown and dark brown with slightly raised and broad dark purplish margin.	Chemical method: Dithane m-45 can be used to control this disease
3.	Die back Botryodiplodia theobromae	It is characterized by dying back of twigs from top downwards particularly of the older trees followed by complete defoliation which gives an appearance as it has been scorched by fire.	Chemical method: This can be controlled by spraying the trees by copper oxychloride sulphate and applying the copperoxychloride paste at the cut ends. Use of Bordeaux mixture(5:5:50) is found most effective to control this disease
4.	Anthracnose of mango Gloeosporium raciborskii Glomerella cingulated	Numerous oval or irregular vinaccous brown or dark brownish spots of variable sizes roundish or angular scattered over the leaf surface are the characteristics symptoms. The spot may begin from the apex of the leaf or any other portion of leaf.	Cultural method: Diseased twigs and leaves which fall on the ground are a potential source of infection. Such diseased material should be collected and all infected twigs from the tree should be pruned away and such refuse should be brunt. Chemical method: Spraying of Zineb, captan and Bordeaux mixture on panicles results good control of anthracnose
5.	Pink disease Pellicularias almonicolor	Pinkish powdery coating on twigs and branches is seen as first symptoms. Fungus invades inside tissue and girdle the stem. It infers the transfer of nutrients, so leaf becomes yellow and dry, shoot and branches of tree will wilt and ultimately dry up.	Cultural method: The disease can be controlled by cutting and burning the infected branches. Chemical method: Bordeaux mixture should be sprays and Bordeaux paste should be applied to cut the ends.
6.	Alternaria leaf spot Alternaria alternate	Symptoms appear as small, brownish circular spots on the surface of leaves and fruits and as black patches on the twigs. Initially it becomes apparent on lower surface of the leaf where it shows light brown coloration. After a few days the infection is visible on the upper surface of the leaf also.	Chemical method: Application of Bordeaux mixture is found to be more effective for this disease. Mercurised Copper oxychloride also can be used.
7.	Mango mal formation Fusarium moniliformae	-the apical end of shoot forms a crown of small leaves with greatly reduced internodes between leaves(vegetative malformation) -the diseased inflorescence becomes clustered and rounded the flowers lack essential organs and donot set fruits hanging on tree for month (floral malformation)	-affected plant part should removed and exposed plant part should be posted with Bordeaux -spraying 100 ppm NAA in October -deblossoming at bud brust stage

Banana

Table : insects pest of banana and their management

S.N.	INSECTS	SYMPTOMS	MANAGEMENT
1.	Banana pseudo-stem weevil Odoiporus longicollis	Tunnel is seen from outside and even in small wind flow the pseudo-stem will fall	Cultural method: Use resistant variety: Robusta, William Hybrid. - remove water sucker regularly -Cut down the spent -pseudo-stem close to the ground as soon as the bunch harvested. Chop it into small pieces up to 60 cm lengths and split each of them in the field. These cut pieces act as egg laying traps, shelter and feeding stuff to the weevils. When the eggs hatch, the newly emerged grub die from desiccation as the cut pieces dry out(Neupane, 2009). Chemical method: Use of aluminum phosphide @1 tab/ stem. -wash sucker and dip in a solution of Dursban 20%EC (chlorophyriphos) @2.5 ml/liter before planting(Paneru and Giri, 2011).
2.	Banana rhizome weevil Cosmopolites sordidus	Grub makes the tunnel inside the rhizome  and rhizome starts to rot	Cultural method: Crop rotation, clean cultivation, uproot and burn all plants in the case of sever infestation. Grow healthy and vigorous plant in good husbandry practices. Chemical method: Use Umet granules pesticide @ 1-2 per pit. Spray Dursban 20% EC @ 2.5 ml/liter water (Paneru and Giri, 2011)
3.	Leaf beetle Nodostomasubcostatum	They chew the fruit and the leaves seriously from August to September	Cultural method: It can be controlled by clean cultivation Chemical method: spraying of BHC @ 0.1%.

Table: some disease of banana with their major symptoms with general management practices

S.N.	DISEASE	SYMPTOMS	MANAGEMENT
1.	Panama Wilt Fusarium oxysporium f. cubensis	Fungi remain in soil and attack the roots of plant and plug the vascular bundles and wilting occurs. In initial stage yellow spots are seen to bottom of old leaf later on whole plant start to wilt.	-removing and destroying effected plant -do not grow banana in effected area upto 3 years -spray Bavistin 2  ml/l water -spray 1 part lime and 3 part soil around the pit.
2.	Bunchy top Banana virus 1 or Musa virus 1 (banana aphid is a vector)	-leaves of affected plant are yellow and stunted growth occurs, leaves are crowded.	- destroy the affected plant and plant’s part -use virus free tissue cultured plantlet. -control banana aphids
3.	Sigatoka disease Mycosphaerella musicola	This fungal disease enter the plant from stomata and attack the lower surface of leaves. Yellow spots are seen in	-destroy the affected plant and plant’s part -good provision of drainage as prone increase in water logged condition -maintain some distance between two plants(Ghimire and Aryal, 2010)
4.	Anthracnose Cercospora musae  (fungal disease)	Dark blotchy areas appear on the skin of the ripening fruit and enlarge rapidly	Chemical method: Spraying with Bordeaux mixture 1%(10g lime, 10 g CuSO4 in 1 lt water)(FDD, 2013), Dithane Z-78 or Difolaton (0.2%) gives good control
5.	Moko disease Pseudomonas solanacearum (bacterial disease)	Development of the yellowish discoloration of the inner leaf lamina close to the petiole	-    Destroy all unnecessary pant in banana orchard -    Remove inflorescence just after the fruiting(Ghimire and Aryal, 2010).

Papaya: papaya is one important nutritional fruits grown in Terai and inner Terai region of Nepal. No such serious damage is caused by insects found in Nepal but birds damage the fruit in ripening stage. Some insects found are scale insects (Aspidiotus detructer), Root knot nematode (Melodogyne incognita), Renifarm nematode (Patylenchulus  reniformis), red spider mites(Tetranchus spp.) etc. But viral and fungal diseases are the serious problem of papaya. Which are given below in table.

S.N.	DISEASE	SYMPTOMS	MANAGEMETN
1.	Collar rot disease Pythiun aphanidematum (soil dwelling fungal disease)	Water soaked patches are seen on the stem which gradually enlarge and girdle the base of the stem, the depleted area turn into black	-uprooting of affected plant -prevention of water stagnation -spray 1% Bordeaux mixture or copper oxychloride at the rate of 2g/lt
2.	Root rot Phytophthora palmivora Rhizoctonia solani Fungal disease	Rotting of root occurs	-seed treatment with captan and caresan -sterilization of nursery by burning dry leaves -spray formaldehyde 2 week before sowing in nursery
3.	Papaya mosaic Papaya mosaic virus (virus disease)	Stunted growth of plant, yellow motling, bending down of petiole, blister like patches on leaves followed by death plant	-roughing of infected plant -controlling insect vector by insecticide
4.	Papaya ring spot virus (PRS) Potyvirus Transmitted by aphid Myzus persicae	Yellowing , distortion and severe mosac. Oily or water soaked spots and streak appear on the trunk and petioles, tisse necrosis	-use of resistant varieties -provision of quarantine -control of aphids -rouging of infected plant and destroy them -use of healthy seedling

Rhizopus rot caused by fungi Rhizopus artocarpi is the most destructive disease of Jackfruit (Shrestha, 2010). At first, soft water soaked brown spots develop on the flowers and fruit subsequently which later formed powdery, fuzzy looking mass of black spores and white fungal mycelia covers the Jackfruit surface and make unsuitable for consumption. Some of the control measures are given below,

·         Prune the tree to encourage good ventilation and to reduce relative humidity in canopy

·         Remove and destroy diseased fruit from trees and the ground

·         Field sanitation around the tree

·         Avoid water logging

·         Control of weed

·         Avoid wounding of fruit

·         Spray copper fungicide

(Agritech, 2011)

Sub-tropical fruits

Citrus, litchi, guava, pomegranate, and grapes are commercially important sub-tropical fruits species of inner Terai to mid hills of Nepal. The citrus species occupy largest area among all fruit crops in Nepal.

Protection problems and control measures of citrus

Citrus is the highly profitable fruit in mid hills than other traditional crops. Mandarin, sweet orange, limes and lemon dominate in area and production. Among these mandarin and sweet orange are grown most commercially. The production of this important fruit has been decline by problem of disease, pest and disorders. Study of Dhakal et al., 2002, found that blossom and fruit drops due to a long spell of drought and strong hailstorms during flowering and fruiting season as well as citrus green stink bug, shoot borer, leaf miner, lemon butter fly and citrus aphid are major problems. Similarly same study found that die back, citrus canker, gummosis and tristeza virus are known as serious disease in country. From the inspection of 17 commercial orchard for disease prevalence and lab test of samples Shrestha, 2010 found that powdery mildew was major disease followed by anthracnose, sooty mould and greasy spot. The frequency of citrus tristeza virus was 7.7 %.  All citrus orchards are affected by various disease (powdery mildew, sooty mold, greening disease, gummosis, canker) and pests (scale, citrus psylla, lemon butterfly, green stink bug and borer) (Acharya et al., 2007).

Table 1: farmer’s perception on presence of important disease and pest in survey conducted in Dailekh

Problem	Presence (%)	Absence (%)
Tip drying (citrus greening)	85	15
Powdery mildew	65	35
Sooty mold	65	35
Parasitic plant (Toranthes sps)	45	55
Green stink bugs	100	0

(Source: survey, 2008)

Main problems of citrus are fruit drop, granulation and citrus decline/die back/frenching/chlorosis/neglectosis. Due to the lack of pollination and fertilization, imbalance C:N ratio, hormonal imbalance, extreme weather and disease and pest cause fruit drop. With the proper orchard management, irrigation, disease pest management, application of PGR can reduces this fruit drop problem.

Granulation is the physiological disorder of the juice sacs of citrus fruits where in they become comparatively hard, assume a greyish color and become somewhat enlarged. It is the serious problem affecting the marketability of citrus and thus reducing the profits to grower. Several factors such as high relative humidity, high temperature during spring, age and vigour of plant, tree aspect, varieties are related with granulation problem. Spray of lime @18-20 kg in 450 lt water, spraying of 2,4-D 12 ppm and micro nutrients like Zn and Cu can minimize the granulation problem. Cracking and splitting of fruits is also another common physiological disorder in lime and lemons. This is also associated with the sudden changes in weather conditions, heavy irrigation or rainfall after a prolonged drought and infection of bacteria, hot winds. It can be minimize with the application of light and frequent irrigation.

Citrus decline is not a specific disease but is a symptomatic expression of many disorders in the plant. Two or more cause contributed to the decline. Some of the insect pests and disease are tabulated below.

Important insects pest found in Nepal are sever: Citrus Psylla(Diaphorina citri), Black aphid(Toxoptera citricida), Purple Scale(Lepidosaphes backii), Citrus leaf miner(Phylllocnistis citrella), Citrus Green Stink bug(Rhynchocoris hymalera), moderate: Black Scale(Coccos herperidum), Soft scale (Icery spp.),Brown scale()  , Citrus White fly(Alaurocanthus citrifolii), Citrus red mite(Paratetranchus citri), and citrus fruit fly(Dacus spp. ) and   mild  Citrus mealy bug(Pseudococcus citricidus), citrus lemon caterpillar(Papiolio demoleus), citrus black fly (Alaurocanthys woglumi), Red scale (Aonidiella auranti) etc. (Ghos and Singh, ?)

Table: insects of citrus with major symptoms and management.

S.N. 1.	INSECTS’ NAME Citrus sting bug Rhynchocoris humeralis	MAJOR SYMPTOMS Suck the juice from fruits so juice less fruit is observed, brown ring can be found at the site of infection	MANAGEMENT Cultural method: Hanging the carrion in citrus orchard attract the citrus stink bug. Collect nymph and adult in insets sweep net in the morning or evening hours and destroy them(Neupane, 2000) Biologicalmethod Big head ant, Pheidole megacephala  and spiders are known to feed upon the young nymphs of bugs. (Paneru, 2009)
2.	Citrus scale Aonidiellaaurantii	Suck the sap, Show die back symptoms at severity	Chemical method:sulphur and lime sulphur are also used against citrus snow (white louse) scale. Use of Agro-servo oil @500 ml/15 plants Biological method: lady bird beetle can be used as a predators. Cultural method: Over-fertilising with nitrogen should be avoided as it is known to encourage higher levels of reproduction in some citrus scales.
3.	Citrus aphid Troxoptera citricida (this transmit citrus tristeza virus)	Feed on plant part using their sucking mouthparts, yellowing of leaves, sooty mold develops	-spray roger 30% EC(dimethoate) @ 2ml/lt of water -incorporate Disiston 5% G(disulfoton) or Thimet 10% G(phorate) or Temik 10 %G(aldicarb) @ 10 g, 40-50 g and 50-100 g per plant in trench around the root zone of small, middle and big sized tree respectively and cover the soil with soil and then irrigate immediately. (Neupane, 2009) -plant disease free plant -remove or replace stunted plant
4.	Citrus stem borer Stromatiumbarbatum	Releasing the saw dust excreta outside the hole	Chemical method: Use of kerosene oil inside the hole. Physical method: Plugging the hole.
5.	Citrus mealy bug          Planococcu  citri	Suck sap, secrete honey dew which inturn develop sooty mold	Biological method: Use lady bird beetle and wasp as natural predators. Chemical method: Use Agro-servo oil @ 5 ml/lit of water.
6.	Lemon butter fly Papilo domeleus	Caterpillar attack leaf and foliage and consume the plant part and make bare.	Chemical method: spray deltra methrin 2 ml/liter
7.	Citrus psylla Diaphorina citri ( vector of citrus greening)	Suck the saps of plant. Sooty mould fungus develop on excreta.	-apply neem oil or petroleum oil @ 5ml per liter of water -dip roots of sapling in 0.1% solution of fenitrothion or dischlorvos just before planting(Paneru et al., 2011) - use the method as in citrus aphids
8.	Oriental Fruit fly Bactocera dorsalis	As in mango fruit fly	As in mango fruit fly given above

In Nepal to control the insects pest IPM method is given priority in recent year.

Some important disease of citrus are listed below in tabulated form

Different virus, bacteria and fungi causes disease in citrus in Nepal. According to T. K. Lama, 1999a, virus disease found in Nepal are citrus greening disease, tristeza virus, exocortis, xyloporus wooly gall and bud scion crease. Among these disease citrus greening disease and tristeza virus are most cause of citrus decline in Nepal.

Citrus greening disease (Huanglonbing-HLB): this disease first seen in china in 1870 in Huang Long Bing region and it is a phloem limiting negative bacterium (Liberibacter asiaticum)which was consider as virus in initial stage. It is the most destructive disease and in Nepal it was entered with the infected sweet orange planting material from Sharanpur, India reported in Pokhara. Later it was believed to be spread to other part of country specially in western part with planting material produce in Pokhara Station. Based on the visual observation of 302 citrus orchard in Lamjung district, 232(72 %) were found suspected to be HLB. Some of the control measure are given below,

v  Established citrus orchard and nursery above 700 m elevation and if possible surrounded the nursery by thick forest trees(Lama, 2001)

v  Raise orchard under insect pest free condition and protect the orchard with dimethoat, especially during spring flush when vtor is inactive.

v  Biological control by rearing and releasing natural enemies of Diaphorina citri

v  Use of quality sapling

v  Rehabilitation program should be initiated (for the rehabilitation program of HLB affected area 1.5 years old seedling should use in3×3 m) planting distances

v  Internal and internal quarantine

 (Annual report 2067-68 of NARC)

Citrus tristeza virus: it is reported for the first time in Pokhara valley in 1971. The virus is naturally transmitted by aphid  Toxoptera citricidus. This cause lime tree decline in orchard. It is found severe in pokhara and dhading. The control measures are

·         Establish disease free citrus nursery for distribution

·         Control vector with chemical spray and with natural enemies.

·         This virus resistant root stock

Some fungal disease of citrus reported by Lama, 2001 in Pokhara are given below,

Phytophthora sp. (blight or gummosis), Elsinue fawcettii (scab dissease), Colletotrichum gloesporioides (antracnose), Capodium citri (sooty mold), Nectaria sp. (Pinkish disease), Olidium citri(powdery mildew), Penicilliun italicum and P. digitarium (blue and green mold on fruit), Mycosphacrella karli(greay spot on leaves and small twigs), Pesthaletia sp(orange leaf spot),  Alternaria citri(fruit rot of citrus) etc..

Table: some other important disease of citrus

S.N.	DISEASE	SYMPTOMS	MANAGEMENT
1.	Citrus canker Xanthomonas axonopodis Transmitted by citrus leaf miner	Characteristics lesion on leaf, fruit, and stem with raised, brown, water soaked margins, usually with yellow halo or ring effect around the lesion.	-prune and burn the affected plant part -spray bordeaux mixture or blitox 1% -control leaf minor by spraying metasystox  @ 0.1 % at regular interval
2.	Gummosis Phytophthora spp.	Gum formation on the trunk. Sapoozing from small crack, giving the tree a bleeding appearance	-preventive method should be follow to control this method -disease free planting material should be use.
3.	Pink disease	Pathogen attack the branches causing wilting and premature drying during the post monsoon	-remove all the affected plant part -apply Bordeaux paste on cut ends. -spray Bordeaux mixture in January, February, June and September(Subedi et al., 1996 )
4.	Powdery mildew Oidium citri	-white powdery spots appear on upper leaf surface -young leaves turn a pale whitish green	-use disease free plant -use karathane 0.01 % (Mishra, 1985) -corrective pruning and use Bordeaux paste

Guava

Guava is another important sub-tropical fruits of Nepal. Guava whitefly, guava moth and carobbean fruit fly are the major problems in guava in different agro-ecological zones. Mealy bugs, scale, common white flies and thrips are the minor problems. Use of systematic insecticide can control the major insects. In some country the fruit is covered when small with paper sacks to protect it and assure prime quality fruits for markets.

Foliage disease, such as anthracnose, can be a problem in humid climates. They can be controlled with regular fungicide application. Where present root-knot nematode will reduces plant vigor. Disease attacking to the guava are guava wilt, anthracnose, stem canker, seedling blight, and scab disease. Among them guava wilt is the most important disease of guava destroying the whole guava orchard.

Guava wilt is most serious disease causing decline of guava orchard spread out throughout the country and especially in Terai region of Nepal. This wilting is cause by the fungus Fusarium oxysporium f. psidi Sources of infection are soil. The symptoms are yellowing of leaves followed by drying of leaves and twig from the tip and complete wilting of trees within 10-15 days. This disease spread rapidly during the rainy season and occurs severally in acid soils. Cultural practices includes removing the infected plant, avoiding water stagnate, use of certified saplings, use of resistant varieties, use of Chinese guava as a root stock etc. and chemical control include use of lime along with irrigation water, around the infected tree, soil drenching around the tree with 0.8% Bordeaux mixture (4:4:50) at the early stage, soil drenching with brassicol and , soil drenching around the tree with 0.8% Bordeaux mixture (4:4:50) at the early stage at the early stages of infection etc. are the control measure of guava wilt.

Litchi

Litchi has the high value in markets so its commercializing is taking up in sub-tropical region of Nepal. But the production of this fruit is decline due to various problems. Some problems like fruit cracking, fruit drop, seediness, low pulp etc. Shrestha, 1981 indicated that ethephon was effective in reducing the problem.

Table: insects of litchi

S.N.	INSECTS	SYMPTOMS	MANAGEMENT
1.	Litchi bug Tessaratoma papillosa	Suck the fluid from the tender parts and in sever condition premature fruiting and fruit drop take place	Chemical method: Use chloropyrivus @ 2ml/lit of water. Biological method: Protection of hymenopteron parasitoids in nature because the bug is easily parasitoids by it.
2.	Lichi leaf curl mite Aceria litchi or Erisone mite	Attack the young leaves causing hairy blister like gall on the upper side of the leaves: the leaves become thickened, wrinkled and distorted	Chemical method: Spray with sulphur or kerathane 0.12@ of 1-2 ml/lit of water. Spray malathion 50% 20 ml/ 10 lt water. Spray monocrotophos @ 1.25 lit/1250 liter water/ha. Cultural method: practice field sanitation; collect and burn all the infected leaves and maintain optimum planting density.

Disease of litchi are given below

S.N.	DISESASE	SYMPTOMS	MANAGEMENT
1.	Litchi leaf spots Colletotrichum gloeosporioides (fungal disease)	The symptoms of the disease start from the tip of the lamina and extend towards the base. These spots are irregular in outline and are brown in color with prominent brown margin encircling them.	Cultural method: Destruction of infected leaves is recommended for the control of these leaf spot as economic control. Chemical method: Zineb and maneb also provide effective control of the leaf spots under laboratory as well as field conditions.
2.	Red rust/Algal leaf spots Cephaleuros virescens (algal disease)	The disease is characterized by red round misty spots mostly on the leaves and sometimes also on the tender stems. Orange yellow to pink velvety coating is formed on the spots which are sporangia of the alga.	Chemical method: Spray copperoxychloride @ 0.3% . The fungicide captafol (0.2%) and ziram (0.25%) were also effective.
3.	Fruit rots Aspergillus variecolor (Fungal disease)	Diseased portions on the fruits are somewhat in circular patches but subsequently they coalesce and become irregular. Gradually the diseased surface turns velvety and finally brownish green color.	Chemical method: Pre-treatment of fruits with 500 ppm of aureofungin is effective against fruit rots.

In Nepal red rust of litchi is a serious problem among these diseases.

Grapes

Though the grapes is not commercially in Nepal it has some problems

Table: Insect pest of grapes

S.N.	INSECTS	SYMPTOMS	CONTROL MEASURES
1.	Grape vine flea beetle Sceledonta strigicollis	The adult consumes the fresh leaves after pruning.	Chemical method: Spray with parathion 0.025 %
2.	Ground beetle Gonocephalum depressum	They suck the fruit juice from the grape fruit	Chemical method: spray with 0.25 % BHC is recommended to control
3.	Leaf roller Syleptatunalis	They feed on green tissue in the early stage and eat up a large portion of leaf as they grow	Chemical method: Spray of endrin 0.02% /parathion 0.025%/ monocrotophos 0.04%

Table : disease of grapes with major symptoms and general management practices

S.N	DISEASE	SYMPTOMS	MANAGEMENT
1.	Downy mildew of grape Plasmopara viticola	Disease appears on any succulent parts of the vines on leaves; small-greenish yellow spots develop on the upper surface and downy growth consisting of conidia and conidiophore appear on lower leaf surface.	Chemical method: Use Bordeaux mixture. Spray blitox-50 (0.3%), zineb, maneb, mancozeb (0.2%), captan (0.2-0.5%)
2.	Powdery mildew of grape-vine Uncinula necator	It infects the plants at any stage of the growth, attacking all the aerial parts, especially the young leaves and fruits. Leaves show white patches on both the surfaces. Diseased vines give a sickly look and show restricted growth.	Cultural practices is important. Chemical method: Spraying vine with sulfex (0.2%) or bavistin (0.1%) gives effective control.
3.	Anthracnose Gloeosporium ampelophagum	Leaves produce dark brown spots during July-August and November-December. Depressed canker are produced at the stem and twigs. On the berries, circular brown sunken spots with dark-brown margins develop leading to their shriveling and drying.	Cultural method: Removal of diseased twigs. Destruction of pruned materials. Chemical method: Spraying with Bordeaux mixture (5:5:50)
4.	Rust of grapes Phakospora ampelophagum	The symptoms are numerous orange colored sori mostly on the lower surface of the leaves. Severely infected older leaves show upward curling, distortion and drying up.	Chemical method: Spraying with sulfex (0.2%) or sulphur dusting during morning hours is helpful in controlling it.
5.	Black rot Phyllosticta ampelicida	On leaves, red-brown irregularly shaped spots develop in which black fruiting structures of the fungus are produced in concentric rings. Small dark elliptical cankers are produced on shoots, tendrils, cluster stems and petioles. First symptoms on berries are light brown soft  circular spots, as these enlarge the entire berries become discolored.	Cultural method: Destruction of the infected vine material by burning or by deep burial helps to reduce inoculum levels. Chemical method: Pre-bloom and post-bloom treatments are done with fungicides like Bordeaux mixture.

Temperate fruits

Temperate fruits are Apple, pear, peach, plum, walnut etc. Although there are lots of potentiality of different temperate fruits species in Nepal the apple is the most important species in the country. Apple has many problems like fruit drop, biennial bearing, physiological problem includes bitter pit, cork spot, scald, jonathan spot, water core etc.and insects pest and diseases.

S.N.	INSECTS	SYMPTOMS	MANAGEMENT
1	Wooly aphid Eriosoma lanigerum	They are fruit sucker. Produce honey dew like substances where sooty mold develops. In severe infestation, the affected branches show knots like structure.	Chemical method: Agroservo oil can be used @ 10-15ml/lit of water as a foliar spray. Spray Biomite or Ramban @ 0.66ml/lt foliar spray 3 times in 7day duration. (GC et al., 2011) Biological method: Aphilinus mali- a hymenopteron parasite also can be used to control. (ARS, Jumla, 2011) -use of wooly aphid resistant rootstocks MM series Physical method: Banding with the help of greasy substance above 50 cm from the ground level restrict the nymph to climb the tree.
2	San jose scale Quadraspidiotus perniciosus	Suck the sap from new succulent plant parts and plant shows yellowing coloration. Develop honey dew and sooty mold in turn.	Cultural method:Use healthy saplings. Cutting the affected branches. Chemical method: Use of Agro-servo oil @10-15 ml/lit in May- April. Apply ATSO@ 10 ml/lt(ARS, Jumla, 2011) Biological method: encourage building of ladybird beetle.(Paneru, et al.,2011)
3	Apple stem borer Zeuzera spp	Bore the stem of apple by larva. Release of saw dust where it has affected.	Chemical method: Use of 1-2 drops of the kerosene oil in each hole. Cultural method: Plugging the hole. Cutting the affected branches and pasting with Bordeaux mixture(Neupane, 2009).
4.	Tent caterpillar Malacoxoma indica	Makes tent like webby structure in twig and leaves. Defoliation of leaves take place.	Chemical method: Use neem based pesticide. Use Sumicidin 20% 1 ml/lt. (Neupane, 2009) Cultural method: Pruning and removing of small twigs that hold egg masses, before egg hatch. Biological method: Bacillus thuringiensis var. kurstaki (Bt) is effective in controlling early instar caterpillars
5.	Slug caterpillar Caina spp.	It eats the tender leaves voraciously and remain only the vein structure and appear like the net.	Chemical method: Use contact poison @2 ml per lit. Cultural method: Collection of larva and pupa  and destroy them.()

According to Paudel, 1986, of the four insecticides such as, Metasystox, Dimecron, Rogor and Sumithion, the last one controlled wooly aphid as much as 100 %. Various other insects namely, San Jose  scale, tent caterpillar, apple leaf roller are also controlled by Meatacid, Metasystox, sevin, Thidoan alone or combination in Marpha (Gurung, 1985)

Table: disease of apple prevalent in Nepal

S.N.	DISEASE	SYMPTOMS	MANAGEMENT
1.	Scab Venturia inequalis (fungal disease)	Olive green irregular spots are seen underside of  the leaves. Later these spots become metallic black in color and appear on both side of the leaf surface giving rise to “sheet scab”. These symptoms appear in both foliage and leaf and rearly in twigs.	Chemical method: Spray the mancozeb  or captan @300 gm/100 lit of water or bavistin 0.2% Cultural method: Physical removal and burning of infected leaves also can be done in small garden.
2.	Powdery mildew Podosphaera leucotricha (fungal disease)	Powdery growth of fungus appears on young leaves, shoots, bloosm and fruits of the commercial cultivars. Greyish or white patches of mycelium develop on the under surface of the affected leaves then after leaves become crinkled, curled, hard and brittle and soon dry up.	Chemical method: Powdery mildews are best controlled with the application of sulphur fungicide. Spray carbendazim (0.05%). Cultural method: Removal of affected twigs, branches and leaves.
3.	Crown gall Agrobacterium radiobacter pv tumefaciens and A. rhizogenes (bacterial disease)	Globular, elongated or irregular galls are produced at or near the graft union. First evidence of the disease is a convoluted tumour production composed of light colored frostly masses of tissues. The roots are thick which gives woody appearance, characteristics of this disease.	Chemical method: Entire roots system of healthy grafted plants should be dipped in 1 % copper sulphate soln. for 1.5 hrs.prior to transplanting. Physical method: Destruction of infected plant material by uprooting and burning.
4.	Pink disease Pellicularia salmonicolor	In initial stage water soaked area formed which is change into pink color	Cultural method: removal of infected plant Chemical methods: use of blitox 50. Paint the cutting surface with the bordo paste.

Some previous research in Nepal shows that bavistin (0.2%) is more effective than 80W 0.2%. similarly Bordeaux mixture and Dithane M-45(0.2%) are effective to reduce the intensity of the apple scab disease. The spray of urea (5g/l) before leaf fall and then with bavistin (0.2%) to reduce the intensity of apple scab disease in Marpha condition. (Gurung, 1985). Powdery mildew of apple in Marpha is control by spray Karathane 0.5ml/l and Bavistin (2ml/l) at 15 days intervals when its symptoms appear on leaves and flower. For the control of papery bark in apple, Bordeaux mixture (6:6:50) at 20 days intervals were good in Marpha condition.

Anthracnose (Gnomonia leptostla) a fungal disease and bacterial disease (Xanthomonas camestris pv.  juglandis) are important disease of walnut. Application of benomyl, chlorothalonil, cubric hydroxide, dodine and maneb to control anthracnose and spray streptocyclin 250 PPM + 0.3 cupper oxychloride for bacterial blight are used to control. Walnut caterpillar is the major insects of walnut. In plum Shot Hole (Stigmina earpophila) and rust(Tranzschelia discolor) are important fungal disease. Bordeaux mixture is used to control these diseases. Peach leaf curl aphid is the important of insect peach which is green in color and both nymph and adult suck the plant saps from twigs and leaves. This cause curling of leaves. Similarly, peach leaf curl( Taprina deformans) is important fungal disease of peach which is control/manage by spraying captan 0.2% and benlate 0.075 %.

4. Conclusion

Fruits are important part of horticulture contribute important role in AGDP. Most of the fruits found in world are found in Nepal due to its high agro-ecological diversity. The production and productivity is not satisfactory due to various problems. Very few researches are conducted in Nepal to solve the fruit related problem. Plant protection is most important issue of in production, processing and marketing of fruit. In Nepal there are much devastative diseases and insect pests like Citrus greening, Tristeza virus, wooly aphid, guava wilting, banana bunchy top, panama wilt, Rhizopus rot, fruit fly etc are found. These cause huge loss of fruit production.  Integrated disease and pest management should follow to minimize the loss from the disease and pest. Research related fruit crops and plant protection problem are not satisfactory. New technique and method indeed need to farmer level which can solve the protection. Plant clinic may be one method to identify the disease and pest found in farmer’s level. Researcher are need to focus on the protection issues.

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