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The papaya, papaw or pawpaw is the fruit of the plant Carica papaya, commonly known as ‘melon tree’ in the genus Carica. It is native to the tropics of the America. This highly loved tropical fruit was reputably called “The Fruit of the Angels” by Christopher Columbus. Papaya is considered powerhouse of nutrients as it is rich in anti-oxidants, vitamins viz. A, B, C, minerals like potassium and magnesium and fiber. Together, these nutrients needed for function of a healthy immune system, promote the health of the cardiovascular system and also provide protection against colon cancer. In addition, papaya contains the digestive enzyme, papain, which helps in digestion and is widely used in industry for various purposes. 

The purple passion fruit (Passiflora edulis) is a native of the rainforest margins in the Amazon region of Brazil. Passion fruit acquired its name from Spanish missionaries who thought that parts of the plant’s flower resembled different religious symbols such as the crown of thorns. Passion fruit grows on a vine in tropical regions. It has a tough, smooth, waxy rind that can be either yellow or purple. The flavour is like a cross between melon and guava. Passion fruits get sweeter as they shrivel. The fruit will quickly turn from green to deep purple (or yellow) when ripe and then fall to the ground within a few days. They can either be picked when they change colour or gathered from the ground each day.

A plum or gage is a stone fruit tree in the genus Prunus. The European plum is thought to have been discovered around two thousand years ago, originating in the area near the Caspian Sea, while Japanese plums actually originated in China. However, they derived their name from the country where much of their cultivation and development have occurred. Mature plum fruit may have a dusty-white coating that gives them a glaucous appearance and is easily rubbed off. This is an epicuticular wax coating and is known as “wax bloom”. Plum fruit tastes sweet and/or tart; the skin may be particularly tart. It is juicy and can be eaten fresh or used in jam-making or other recipes. Plum juice can be fermented into plum wine; when distilled, this produces a brandy known as Slivovitz or Rakia in Eastern Europe. Dried plums (or prunes) are also sweet and juicy and contain several antioxidants. 

Raspberries are grown for the fresh fruit market and for commercial processing. There are many species of raspberry but the name originally referred with the red fruit to the European species Rubus idaeus. The English name comes from an old English term “raspis”, which refers to the slightly hairy or “rasping” surface of the fruit. The raspberry can be of any colour from orange, pink, red, purple to black. Rubus albescens also known as Mysore raspberry is native to India. It is also called Snowpeaks, Ceylon or Hill raspberry. 

The English walnut (Juglans regia) is a native of Western and Central Asia. The nut was the food of the royalty and was introduced by the Greeks in Rome, where it became Juglans, a name derived from Jovis and glans, meaning Jupiter’s Acorn or the ‘Nut of the Gods’. The English walnut tree, also known as the Common, Persian or Royal walnut tree, is an ancient tree with many uses, most notably for its use as timber and for the walnut fruit. The common walnut tree has been used as a food, beauty aid, medicine and natural health supplement. In China the tree is used horticulturally in classical garden design.

This crop is gaining importance as a main ingredient in Indian diet due to its medicinal properties. Large areas are under its cultivation and the larger fruited varieties have become very popular. It is one of the prime constituents in ayurvedic preparations
Bark-eating caterpillars - Indarbela quadrinotata, I. tertraonis: Metarbelidae
The larvae of this species make zigzag galleries and feed on the bark under silken ribbon- shaped webs. They are stout and dirty brown in colour.
Fruit- borer : Deudorix Isocrates : Lycaenidae: The larvae of this beautiful butterfly cause considerable damage (up to 42%) to fruits.  They start feeding while the fruit is tender, and growing. During severe infestations, chemical control may be warranted. This can be done by spraying contact insecticides like malathion, or dichlorvos or  fenvalerate or other synthetic pyrethroids.

Mealy bugs: Ferrisia virgata, Planococcous lilacinus, P. pacificus, Maconellicoccus hirsutus, Perisopneumon ferox: Pseudococcidae

The fruit is seen covered with a mealy coating due to colonies of small reddish-white mealy bugs. They also infest leaves, shoots and buds. Due to sucking of sap by nymphs and adult female mealy bugs, fruits remain small in size and become shrivelled. Large number of mealy bugs is seen in the tip of the petiole abd also on the grooves of fruits epicarp. The fruit also becomes blackish due to the development of sooty mould.

Stem-borer: Batocera rufomaculata, B. rubus, Olenecamptus bilobus:Cerambycidae

These are large dark brown adult beetles that lay eggs in loose bark.  Grubs bore into the trunk and make tunnels in branches and main trunks.  This causes drying and wilting of the branches. Adults of O. bilobus are pale whitish with long serrate antenna.
 
When bark is suspected to have the grubs, try mechanical removal of them. Paste the tree trunk with mud paste containing insecticides like chlorpyriphos or carbaryl. In endemic areas, spray the bark with Carbaryl 4gm /l, Malathion one ml/l, or Chlorpyriphos 2.5ml/l

Shoot and fruit borer : Diaphania (Margaronia) caesalis :  Pyraustidae

The shoot-and fruit-borer D.caesalis is a major pest of jackfruit in India. The larvae are reddish brown with pale brown head and thin hairs from black warts. The caterpillars bore into the shoots, buds and fruits.  Affected shoots wilt or dry up and the fruits rot and drop. The adult is brown with grey elliptical patterns on the wings.

Fruit borers : Criptophlebia illepida, Rapala varuna, Deudorix epijarbas, D. Isocrates : Lycaenidae

Of the four species, C.illepida is more damaging to litchi fruits. The larvae bore into developing fruits and seeds, filling the bore-holes with excreta and the infested fruits start rotting.

Fruit –fly : Bactrocera dorsalis :Tephritidae

The process of egg laying and ovipunctures makes the fruits deformed. Feeding of maggots in the pulp induces rotting and fruit drop.

Bark-eating caterpillar : Indarbela quadrinotata

Severe damage on loquat due to I. quadrinotata was observed during October- November in Uttar Pradesh. There are some cultivars like  Thames Pride which are less susceptible.

Olive-scale: Metacernema japonica: Black scale: Saissetia oleae: Coccidae

Olive scales are tiny pale-greyish insects which settle on branches, leaves and fruits and are active during April-November. S. oleae are round greenish brown scales. Nymphs and adults of both the species suck the sap from the tender shoots, and leaf petioles. Sooty-mould appears on leaves and branches of infested plants as a consequence of honeydew secre-tion. Shoots get dried up and fruits remain undersized.

Green peach aphid/peach leaf curl aphid : Brachycaudus helichrysi Aphididae

These are green aphids that suck the sap from growing buds. Leaf buds become weak and result in poor setting and premature fruit fall.
 
Blossom thrips : Thrips rhopalantennalis, T. flavus, T. florum, Haplothrips tenuipennis, Frankliniella dampfi : Thripidae

These are tiny, yellow, pale-brown and black slender insects seen within the flowers and flower buds. Adults and nymphs lacerate floral parts and suck sap resulting in brown spots. Infested flowers give sickly and faded look. Lesions cause flower fall, inferior fruits and loss in yield. Attack on tender leaves causes necrotic silvering, curling, deformation and withering.

Mealy bug: Dysmicoccus brevipus: Pseudococcidae

Mealy bugs are major pests of pineapple in India. They can attack roots and aerial parts. Colonies of reddish –white mealy bugs infest roots, crown, and fruits and suck sap. The leaves change in colour from green to red or pink and the margins reflect inwards and leaf tip starts drying. Severely infested plants become stunted and bear only small fruits. The attacked plants should be drenched with an insecticide solution of contact insecticides like Quinalphos or Dichlorvos or Chlorpyriphos@ 0.05% concentration, in between the fronds and allowed to drip down to reach the roots. Addition of liquid soap @4 ml per litre or 4 g of soap powder per litre is a must to get the best results.

STRAWBERRY

White grubs and cut worms

These insects cut the roots and stems of young plants.
 
Hairy caterpillars

Defoliate plants during June-July

Lace wing bug: Monantha globulifera : Tingidae

Eggs are inserted slantingly into leaves and other tender foliage.  Black spiny nymphs and lace winged adults suck the sap from leaves. Attacked leaves develop yellow patches become brown, shrivel and dry up in severe cases.

Leaf feeder : Helicoverpa armigera : Noctuidae

The female moth lays eggs on tender foliage. Young larva feeds on tender foliage and starts infesting the older ones in later instars. A single caterpillar can destroy many leaves

Semilooper: Thysanoplusia(Plusia) orichalcea : Noctuidae

Bluish green or grey coloured eggs are laid singly on lower surface of leaves.The larvae are semi loopers and feed voraciously on leaves and cause defoliation of the plants.

Thrips : Thrips flavus : Thripidae

Infestation of thrips is generally during hot months with high night humidity.  The attack by thrips leads to discolouration, bronzing and drying of affected leaves.

Semilooper : Thysanoplusia orichalcea  : Noctuidae

Bluish green or grey coloured eggs are laid singly on lower surface of leaves.  Larvae feed voraciously on leaves and defoliate plants.

The cotton aphid :Aphis gossypii: Aphididae

Both nymphs and adults cause the damage by sucking the plant sap from shoot tips, flowers and leaves.  Severe infestation may result in complete drying of affected parts.  Attacked leaves curl up, wither and fall. These are yellowish green or brown coloured aphids.  The total life cycle from first instar nymph to adult occupies an average of 8-10days.  It reproduces parthenogenetically and viviparously.  The female may produce 10-30 young ones in a life span of 10-12 days.  The nymphs transform into adult in 5-8 days after passing through four moults.

The cotton aphid: Aphis gossypii: Aphididae

Symptoms of Damage

Both nymphs and adults cause the damage by sucking the plant sap from shoot tips, pods and leaves. Severe infestation may result in complete drying of affected parts. Attacked leaves curl up, wither and fall. These are yellowish green or brown coloured aphids. The total life cycle from first instar nymph to adult occupies an average of 8-10days. It reproduces parthenogenetically and viviparously. The female may produce 10-30 young ones in a life span of 10-12 days. The nymphs transform into adult in 5-8 days after passing through four moults. 

Shoot borer: Chilo infuscatellus : Pyralidae

This pyralid is more commonly known as a pest of sugarcane. Eggs are laid in batches on lower side of leaves.  The emerging larvae move down and cut a hole at the ground level and enters the stem.  Due to feeding of larva, the central shoot begins to wilt and dry causing dead heart. The yield of the crop is affected.New tillers may develop but will not have the physiological maturity and oil content at the time of harvest.

Cabbage semilooper: Thysanoplusia orichalcea :Noctuidae

Eggs are laid singly on lower surface of leaves.  The emerging larvae feed as a scraper initially and then feed voraciously on the leaves. The larva is greenish and hence not easily noticed initially. But when patches of damage occur in the crop, examine for the larvae and remove and destroy all the larvae. Chemical control is not advisable, and spraying extracts of other aromatic plants can deter egg laying very well.

Cut worms: Agrotis suffusa: Noctuidae

Adult moth lays eggs in moist soil or on lower side of leaves.  Dark brown larvae cut young plants at ground level and shoot of grown up plants. Damage results in growth retardation of plants and reduced yield.

Leaf webber: Syngamia abruptalis :Pyralidae
 
Caterpillars feed extensively on tender foliage leaving veins alone and the growth of the plants are affected.

Leaf roller: Psara stullalis: Pyralidae

Larvae of these small moths are also leaf Webbers and rollers, and rolls the leaves and feed inside causing browning and drying of affected leaves. Inspect the crop for the pest incidence and remove the initial attacks systematically.

Sphingid larva: Dilephila nerii :Sphingidae

The large larvae cause severe damage to plants by feeding extensively on leaves, buds and flowers.They are very big and can easily be hand picked and killed or fed to poultry.

Scale: Saissetia coffeae: Coccidae

Scale insects

Brownish black scale infests lower surface of leaves along with mid ribs and mid veins.They also cover petioles and tender shoots.  Due to draining of sap, leaves turn yellow and drop, plants become stunted.

Aphids: Myzus persicae : Aleyrodidae

Aphids are considered as the most serious pest of carnation. Both adults and nymphs suck sap from the leaves and debilitate the plants. They transmit carnation ring spot and carnation mosaic virus disease. They are thus more important as vectors. Regular monitoring for the incidence of the aphid and spot spray-ings of contact insecticides on the shoot tips can easily manage the pest.

Chrysomelid beetle : Aulacophora foveicollis : Chrysomelidae

Adults cut tender shoots and feed on leaves resulting in holes and loss of leaf. Grubs feed on roots and underground stems leading to yellowing,wilting and drying of attacked plants.

Spikeborer : Helicoverpa armigera : Noctuidae

Larvae of this polyphagous moth feed on the spikelets, flowers and developing seeds. The young larvae bite holes into the spikelets and the grown up ones attack the mature spikes

Thrips : Taeniothrips simplex : Thripidae

Yellow coloured nymphs and black adults damage leaves and spikes by rasping tissues and sucking the sap.  Affected leaves and spikes develop silver streaks, turn brown, get deformed and dry when attack is severe.  Corms in storage are also attacked. Infested corms are sticky, get shriveled and produce weak plants.

Bud-worm : Hendecasis duplifascialis : Pyraustidae

This pest is serious on J.sambac. The larvae are dark green with black head which bores into immature buds.  They make a hole on the buds, and feed inside, leaving behind faecal pellets entangled in few silk strands. Webbing is seen in severe infestation and pupation takes place in soil.

Bud caterpillars : Helicoverpa armigera : Noctuidae

Eggs are laid singly on young buds.  Larvae feed on developing flowers by damaging florets. They can also eat the leaves.

Leaf webber : Phycita sp. : Phycitidae

Larvae of Phycita sp. feed on heads of buds and flowers.

Biosduval Scale/Orchid scale : Diaspis boisduvalii : Diaspididae

These scales are round flat and yellow in colour. Only the first instar crawlers move. The others are sedentary. The young and mature scales suck the juice from the leaves, petioles and shoots and also inject toxins into the plant. Affected plants turn yellow in patches, lose vigour and get stunted.

Thrips: Thrips tabaci : Tuberose thrips Franklinella schultzei: Thripidae

These minute insects, preferring hot humid weather, rasp and suck the cell sap, causing bronzing, withering and drying up of leaves and flowers. This is the most serious pest on tuberose. Damage to young plants results in stunted growth.

Spindle bug: Carvalhoia arecae :Miridae

Nymphs and adult bugs suck the plant sap from spindle leaf and tender leaves.  Feeding marks are seen as necrotic lesions in the spindle and fully opened leaves.  The pest is seen in the nursery plants round the year but incidence is high during rainy season.

Scale insect: Lepidosaphes sp.: Diaspididae

The mature scale is elongated and oval in shape and dark grey in colour. They infest the stems, leaves and petioles, causing shriveled leaves due to sucking of the sap. The affected parts wither and dry up. In severe infestation leaves dry up and give sticky look and gradually the vine wilts.

Stem-borer: Sahyadrassus malabaricus: Hepialidae

Presence of the pest is understood when chewed tissue is seen at at the col­lar region. The mouth of the tunnel in which the borer feeds show pieces of bark, wood and frass particles held together by silk. The saplings break off at the point of injury. When the main stem is attacked, there is mat-like frass at basal region of stem. Larvae girdle main stem and bores downward killing the tree.

Adult moth is peculiar and hangs vertically down by the support of two pairs of legs. Egg period is for 7-10 days, and larvae live for about 10 months inside the larval tunnels. They pupate for 3-5 weeks.

Coriander aphid: Hyadaphis coriandri: Aphididae

Coriander aphids are yellow-green in color, dusted with grayish wax. They have short, dusky, slightly swollen, siphunculi (or cornicles). The Aphids form dense, damaging colonies on leaves, heads, and stems of their host plants.

In its native land, Florida, USA, the life cycle of the coriander aphid is similar to that of other host-alternating aphids. Overwintering eggs occur on other hosts.  A fundatrix (or stem mother) hatches from the egg in the spring. Her offspring are parthenogenetic, and the winged-females are spring migrants. They colonize summer host plants in the family Umbelliferae.

Scale insects:Pseudaulacaspis cockerelli, Parasaisettia nigra:Coccidae

Attack Adults and nymphs feed on plant sap and cause wilting and drying of seedlings and young plants.
 
Brown soft scale: Lecanium sp. (=Coccus) hesperidum : Coccidae

Thrips: Thrips tabaci: Thripidae

The nymphs and adults of the thrips desap from the narrow spaces between the inner leaf axils. Leaves are faded, with curled tips and shining silver streaks or brown spots.  Many minute yellow or white insects are seen moving, generally near the base or middle of leaves and they suck the sap from the plants.  Plants are faded and the yield is reduced.

Leaf-and shoot folders: Hymenia recurvalis : Pyraustidae

Pycnarmon cribrata;Phostria piasusalis

Sciarid(mushroom flies): Bradysia paupera, Lycoriella auripila: Sciaridae

The larvae feed on the mycelial attachments and restrict the growth of the spawn. The maggots also feed on the developing mushrooms or pinheads and thus cause loss in yield. They also bore the developing mushrooms and render them hollow.

Reducing insecticide application to the lowest level is the motto of IPM in vegetables. Monitoring for the initial build up and timely mechanical removal of the first population is a must in vegetables. Always remove the first affected plants, by diseases like mosaic, and destroy them by burying or burning. Remove insect eggs, insect affected plant parts and adults and immature stages of insects, and destroy them every day. Do not throw them in the field. They will either come back, or pupate and attack later. During nursery stage, use wood ash, cow dung solution, and plant extracts to deter all pests. Use only low residual insecticides like Dichlorvos 1ml/l, Malathion 2ml/l, Endosulfan 2ml/l or Quinalphos 2ml/l, in spots, at the beginning of attack itself.

Paper chromatography (P.C.) is the easiest to perform and requires simple and ordinary apparatus. It easily provides qualitative information since components of a mixture can be separated based on their mobilities or molecular weights. It also can provide quantitative information if some special attention and calculation procedures are followed. Paper chromatography is a technique that involves placing a small dot or line of sample solution on to a strip of chromatography paper. The paper is placed in a jar containing a shallow layer of solvent and sealed. As the solvent rises through the paper, it meets the sample mixture, which starts to travel up the paper with the solvent. This paper is made of cellulose, a polar substance, and the compounds within the mixture travel farther if they are non-polar. More polar substances bond with the cellulose paper more quickly, and therefore do not travel as far.

This technique is used in the separation of ionised and ionisable compounds.It consists of an insoluble matrix to which charged groups are covalently bound. The charged groups are associated with mobile counter ions. These counter ions can be reversibly exchanged with other ions of the same charge without altering the structure of the matrix.

The ion exchanger is complex and polymeric. The polymer carries an electric charge that is exactly neutralized by the charges on the counter ions. These active ions are cations in a cation exchanger and anions in an anion exchanger. A cation exchanger consists of polymeric anions and active cations whereas anion exchanger consists of polymeric cations and active anions. Amberlite IR 120 and Dowex 50 WX are cation exchangers while Amberlite IRA 400 and Dowex 1X are anion exchangers. Ion exchangers should be insoluble in water and hydrophilic to allow the ions to pass through. It should be chemically stable and should be denser than water when swollen.

Atomic-absorption (AA) spectroscopy uses the absorption of light to measure the concentration of gas-phase atoms. Since samples are usually liquids or solids, the analyte atoms or ions must be vaporized in a flame or graphite furnace. The atoms absorb ultraviolet or visible light and make transitions to higher electronic energy levels. The analyte concentration is determined from the amount of absorption. Applying the Beer-Lambert law directly in AA spectroscopy is difficult due to variations in the atomization efficiency from the sample matrix, and non-uniformity of concentration and path length of analyte atoms (in graphite furnace of AA). Concentration measurements are usually determined from a working curve after calibrating the instrument with standards of known concentration.

Atomic-absorption (AA) spectroscopy uses the absorption of light to measure the concentration of gas-phase atoms. Since samples are usually liquids or solids, the analyte atoms or ions must be vaporized in a flame or graphite furnace. The atoms absorb ultraviolet or visible light and make transitions to higher electronic energy levels. The analyte concentration is determined from the amount of absorption. Applying the Beer-Lambert law directly in AA spectroscopy is difficult due to variations in the atomization efficiency from the sample matrix, and non-uniformity of concentration and path length of analyte atoms (in graphite furnace of AA). Concentration measurements are usually determined from a working curve after calibrating the instrument with standards of known concentration.

When a fixed voltage is applied to two electrodes dipping into a solution,a current will flow, depending on the conductivity of the solution. Conductivity measurements do not give information about the nature of the ions in solution. However, they are useful in the quantitative measurement of the ions.

Organic material especially, seeds, grains, leaves, fruits and nuts contain prominently three groups of compounds. They are carbohydrates, proteins and fats/oils, mostly in that order. They also contain 3-5% minerals and smaller quantities of vitamins and other minor constituents. Cereal grains contain more of carbohydrates while oilseeds and nuts contain more oil. Tree nuts and even oilseeds may contain 30-50% protein while cereal grains contain 5-8% protein only. The starch and sugar contents of oilseeds may be less than 10% while the oil content of cereal grains ranges around 5%. The actual content and the composition of these groups of compounds really account for their quality as well as commercial value.

Fig. 25: ICPH 2671 in field