eChapters

Description

Bucket elevator is one of the equipments used in the material handling to convey the material vertically. The lab model bucket elevator (Fig.34.1) consists of number of buckets/cups arranged to an endless flat belt. The belt with cups run vertically and cups are placed at a particular interval in the belt. The belt is wrapped over two pulleys, one at the top is called head pulley which receives power from an electrical motor 0.5 hp through suitable power concentration and rotates at required rpm. The belts, cups and pulleys are mounted on a steel frame. The grain from the hopper is reaches to the bottom pulley. The bucket is filled with grains during upward movement and is discharged at the top due to the centrifugal force. An outlet is provided at the top to collect the discharge grain. The capacity depends on the bucket size and seed of operation. For proper discharge of the material, the weight of the material in each cup should be equal to the centrifugal force created due to rotation.

Aim

To determine cost of operation of processing machineries with available data.

Total operation cost

For calculation of cost of operation of processing machineries, two types of cost viz., fixed cost and variable cost to be estimated.

Greenhouse selection

Selection of greenhouse to be constructed is important as each type has its own merits and demerits. There are two common types of commercial greenhouses namely; (i) Freestanding (single span) and (ii) Ridge and furrow (gutter connected or multi-span). Multi-span structure permits economy in construction, heating and cooling but the single span gives flexibility as far as microclimate inside the greenhouse in concerned. The freestanding Quonset type is usually accommodates many growing situations but there height restrictions near the side walls. Another freestanding type is single gable greenhouse and its many variations. The ridge and furrow or gutter connected greenhouse are joined at the eave by a common gutter.

Theory

Heat required for heating greenhouses is based on the quantity of heat lost through different structural components of greenhouses per unit time. Shapes of greenhouse (A-frame and quonset) and structural components (roof, wall, gable, curtain wall, curved covering and end) are mainly influencing the calculation of heat requirement. The amount of heat lost from a greenhouse depends on glazing materials, exposed surface area of the house, inside desired temperature, outside existing temperature, wind speed, and condition of house (old, new, tight or loose). The outside temperature should be based on the lowest average expected temperature during the heating season.

Aim

To design of greenhouse cooling system

To determine the rate of air exchange in an active summer and winter cooling system.

Theory

Elevation factor (F_elev)

Elevation factor is directly proportional to the elevation. The values of elevation factors, used to correct the rate of air removal for a particular elevation. The rate of air removal from the greenhouse increase as the elevation of the greenhouse site increases.

Aim

To study the different materials used for chain survey

Theory

Chain surveying is the method of land surveying in which only linear measurements are made. This method of surveying quit simple and it requires only a chain, a tape, few ranging rods and few arrows. It is used for securing data for exact description, marking the boundaries of land and preparing the maps of the area to show various details. The term details mean a natural or man-made feature at the ground surface.

Aim

To measure horizontal distance on the level ground using chain

Materials required

Chain

Ranging rods

Chain pins

Field note book

Aim

To determine the area of given field by triangulation method of chain survey

Materials required

Metric chain

Measuring tape

Ranging rods

Chain pins

Aim

To find out the area of given field by cross-staff survey method

Materials required

Cross-staff

Metric chain

Measuring tape

Ranging rods

Chain pins

Theory

Area computation is an important part of surveying. The term ‘Area’ is meant the projected area on a horizontal plane. The area is computed from the following methods: (i) Graphical method (ii) Instrumental method and (iii) Use of formulae. In graphical method, the area can be computed by dividing the whole area either into triangles or squares. The area of individual triangle is computed from base and the altitude and summation of individual area gives the total area. A tracing paper is divided into number of small squares is placed over the plan. The number of complete squares within the boundary is counted. The squares more than half are counted as full squares and those less than half are neglected. The total number of squares multiplied by the area of each square gives the total area of the field. In instrumental method, the planimeter is used to measure the area of a plotted plan. In use of formulae, computation of area by formulae depends on the shape of the field.

Aim

To identify different parts of prismatic compass and to know their functions.

To practice of taking the angular measurement.

Compass survey principle

Compass surveying is a branch of surveying in which directions of survey lines are determined with a compass and the lengths of the lines are measured with a chain or tape. In practice, the compass is generally used to run a traverse. In compass surveying, a traverse consists of a series of straight lines connected together to form an open or closed polygon as shown in Fig.44.1. The points A, B, C, D and E defining the ends of the traverse lines are called traverse station or traverse points. The lengths of the traverse lines are measured with a chain or tape. At each traverse station, where the traverse lines meet, the angle is measured with a compass.

Aim

To determine the area of the given field by radiation method using a prismatic compass.

Materials required

Prismatic Compass

Tripod

Measuring tape

Arrows

Ranging Rods

Aim

To determine the area of the field by intersection method using a prismatic compass.

To determine the included angle of the closed polygon.

Materials required

Prismatic Compass

Tripod

Measuring tape

Arrows

Ranging Rods

Aim

Studies on plane table survey instruments

To determine the area of given open field by radiation method of plane table survey.

Plane table survey

Plane table surveying is a simple method of surveying for determination of area of field. The plane table survey is quite suitable for plotting small-scale and medium scale mappings directly in the field where great accuracy is not required. It is also used for plotting the topographical maps in the field. The plane table survey is generally more rapid and less costly than other types of survey.

In this survey, a plane table is used for taking the measurements and for plotting the plan in the field. Plane table surveying is a method in which the field observations and plotting of the plan proceed simultaneously. The plotted map can be compared with the actual features in the field. Errors in measurements and plotting can be easily detected in the field by taking suitable check lines.

Aim

To determine the area of given field by intersection method of plane table survey.

Materials required

Tripod

Plane table

Plumbing fork

Level tube

Magnetic compass

Alidade

Measuring tape

Ranging rods

Drawing sheet

Pins, pencil and eraser

Aim

To determine the area of given field by intersection method of plane table survey.

Materials required

Tripod

Plane table

Plumbing fork

Level tube

Magnetic compass

Alidade

Measuring tape

Ranging rods

Drawing sheet

Pins, pencil and eraser

Aim

To study the levelling instruments

To practice the simple leveling

Leveling

Leveling is a method of surveying used for determination of the difference of elevations or levels of various points on the surface of the earth. The elevation of a point is its vertical distance above or below a reference level, called datum. Most commonly used datum is the mean sea level (M.S.L). Leveling is required to determine the undulations of the earth’s surface for topographic mapping. Leveling is needed for the design of highways, railways, canals, sewers, etc. Leveling is essential for the layout of construction projects, locating the excavation levels and for the control of various elevations in buildings, bridges, dams etc. The results of the leveling can be used to determine the catchment area, volume of the reservoir and the area submerged by a reservoir.

Aim

To determine the reduced level of various points

To find out difference of elevations of two points

Materials required

Dumpy level

Levelling staff

Aim

To determine the reduced levels on various points on the road

To plot the profile of the road

Materials required

Dumpy level

Levelling staff

Theory

Profile leveling is the process of leveling along a fixed line to determine the elevations of the ground surface along that line. The fixed line is generally the centre line of a highway, railway, canal, sewer, etc. The profile leveling is done to determine the undulations of the ground surface. Cross-sectioning is required to determine the levels across the line along which profile leveling is done. Profile leveling should be commenced from a bench mark and should end at a bench mark, as far as possible. When the ground surface does not have many undulations, the intermediate points are fixed at a uniform interval. If the ground surface is irregular and there are abrupt changes in the ground surface, the interval may be non-uniform.

Aim

To prepare a contour map by direct method using dumpy level.

Materials required

Dumpy level

Leveling staff

Measuring tape

Wooden pegs/chain pins

Field book

Theory

For locating a point on the ground on a contour, its position and elevation in a horizontal plane should be known. In direct method, the contours to be plotted are located on the ground with a level by making various points on each contour, and these points are surveyed and plotted on plan. This method is more accurate but slow and tedious, and is suitable for contouring small areas where great accuracy is required. For locating the points of the same elevation, the instrument is set in such a commanding position from where maximum number of points can be covered. The bench mark is established near the site of survey. The height of the instrument (H.I) is determined after taking a back sight (B.S) on the established bench mark.

Aim

To determine the contours by grid method using dumpy level.

Materials required

Dumpy level

Leveling staff

Measuring tape

Wooden pegs/chain pins

Field book

Aim

To determine the contours by cross-section method using dumpy level.

Materials required

Dumpy level

Leveling staff

Measuring tape

Wooden pegs/chain pins

Field book

Aim

To determine the contours by radial line method using dumpy level.

Materials required

Dumpy level
Leveling staff
Measuring tape
Wooden pegs/chain pins
Field book

Aim

To measure irrigation water by volumetric method

Apparatus required

Siphon tube

Stop watch

Measuring bucket

Aim

To measure irrigation water by area-velocity method by using (i) float and (ii) current meter

Apparatus required

Float

Current meter

Theory

The rate of flow of water in open channel can be determined by multiplying the cross sectional area of the flow section at right angles to the direction of flow by the average velocity of water. In area-velocity method, the water can be measured at motion. The water is measured in motion by means of rate of flow or discharge and is expressed in litre per second (lps), litre per minute (lpm), cubic metre per second (m³/s), etc. Litre per second: A continuous flow amounting to 1 litre passing through a point each second. Cubic metre per second: A flow of water equivalent to a stream of 1 m long, 1 m wide and 1 m deep flowing at a velocity of 1 metre per second. In area-velocity method, the velocity of water is measured either by float or current-meter

Aim

To measure the irrigation water by using weirs

a) Weirs

A weir is a notch or opening of some definite shape installed on a channel or a stream through which waterfalls (Fig.59.1). Materials like wood, concrete, mild steel, rigid PVC etc. can be used for construction of a weir. Mainly a cut on a sheet metal is used for fabrication of weirs, to be installed at various locations in a channel. Advantages of weirs are (i) capable of accurately measuring a wide range of flows (ii) easy to construct, portable and adjustable (iii) tends to provide more accurate discharge rating than flumes and orifices.

Aim

To measure the irrigation water by using orifice

Orifices

An orifice is an opening in a bulk head with closed perimeter usually circular or rectangular cross-section through which water flows. For measurement of water, orifices are fabricated by making an accurate cut of proper size and shape in a mild steel sheet, aluminum plate etc. Proper machining is done to have a sharp edge through which water flows (Fig.60.1).

Free discharge

If the downstream water level is lower than the bottom of the orifice opening, the water jet discharges freely into the air and then it is said to be free discharge. The depth of water on the upstream side of the orifice that causes the flow is called the head. The orifice flow formulae can be applied only when the orifice flows fully.

Aim

To measure the irrigation water by using parshall flume

Construction of Parshall flume

Parshall flume is a water measuring device that can be used to measure water flowing in an open channel and intended primarily for use in irrigation. The flume consists of a converging inlet section, a throat section with straight parallel sides, and a diverging outlet section (Fig.61.1). The floor of the converging section is level with walls which converge in the direction of flow, towards the throat. The throat section constitutes the middle portion of the Parshall flume. The floor of the throat section is dips downward in the direction of flow, but the walls are parallel. The throat width specifies the dimensions of the parshall flume. The diverging outlet section of the flume has a floor which rises in the direction of flow. The walls become further separated in the direction of flow (diverge).The parshall flume can be constructed by G.I. sheet, aluminum sheet, M.S. sheet, brick masonry, reinforced concrete or timber. Flumes made of G.I. or aluminum sheets are easily portable. Brick masonry and concrete flumes are permanently constructed in the channels. Stilling wells should be constructed at the side to take measurements.

Aim

To measure the irrigation water flowing through a pipe by using Venturimeter

Theory

A venturimeter is a device used to measure the rate of flow of a fluid through a pipe and is often fixed permanently at different sections of the pipeline to know the discharge there. Venturimeter consists of three parts: (i) a short converging part (ii) a throat (iii) a diverging part (Fig.62.1). In the venturimeter, the fluid is accelerated through a converging cone of angle 15-20° and the pressure difference between the upstream side of the cone and the throat is measured, and provides the signal for the rate of flow. Due to the constriction there is an increase in the flow velocity and hence an increase in the kinetic energy. The fluid slows down in a cone with smaller angle (5-7°) where most of the kinetic energy is converted back to pressure energy. Because of the cone and the gradual reduction in the area there is no “vena contracta”. The flow area is at minimum at the throat.

Aim

To design the grassed water ways or open channel

Geometric characteristics of different waterways

The shape of open channel is dependent upon the field conditions and types of the construction equipments used.

The common shapes of open channels generally used are (i) Parabolic or semi circular (ii) Triangular (iii) Rectangular and (iv) Trapezoidal section.

The parabolic shape approximates a natural channel. The reason is that in natural course of channel flow, the trapezoidal and triangular sections tend to become in parabolic shape due to deposition of sediments and bank erosion.

Aim

• To design the contour bunds

Design parameters

The design of contour bund includes determination of following parameters:

• Choice of bund
• Spacing of bunds
• Size of bund
• Alignment of bund

1. Choice of bund

The choice of bund should be selected weather the contour bund or graded bund depends on the annual rainfall, soil condition and types of outlets used.

Aim

To design a graded bunds

The procedure in design of contour bund is followed while design a graded bund. A stability of 10-25%, should be given to contour bund. This is called graded bund.

Example: Design a graded bund length of 500 m with an average land slope of 3.5% in a sandy loam soil. Vertical distance between consecutive bund is 2.5 m. Rainfall intensity for the time of concentration and for the recurrence interval is 18.5 cm/hr. The runoff coefficient is 0.3. For stability, the grade provided for first 100 m is 0.1%, for next 200 m is 0.15% and for last 200 m is 0.18%. For the sandy loam soil, side slope of the bund and slope of seepage line are 1.5:1 and 5:1 respectively is assumed.

Aim

To design bench terrace

1. Components of bench terrace

The bench terrace essentially consists of the four components namely: riser, outlet channel, platform and shoulder bund

Aim

To estimate the soil loss using universal soil loss equation

Universal soil loss equation

Wischmeir and Smith (1962) has been developed a predictive equation for estimating the soil loss taking into account following factors: Climatic characteristics, soil characteristics, crop management and conservation practices. It is called Universal soil-loss equation (USLE).

Pomegranate (Punicagranatum L.) an extraordinary fruit crop that is cultivated worldwide with dominancy in Mediterranean countries like Morocco, Spain, Egypt, Iran, Afghanistan and Baluchistan since primordial times. Tropical and sub-tropical regions of the Indian sub-continent are the prominent areas under cultivation of this fruit crop. India plays a leading role in pomegranate production with contribution of nearly 50% of global production. The total area under pomegranate is 132 thousand hectare with annual production of 1357 thousand MT in 2014-2015.

Pomegranate (Punica granatum) a deciduous shrub in the family Lythraceae, subfamily Punicoideaeis one of the most adaptive sub-tropical fruit crop. It was introduced in the Indian subcontinent during 15^th century from the Mediterranean region of the globe. India holds the first rank as producer and exporter of pomegranate since last decade. Among the states, Maharashtra is the largest producer of Pomegranate (Punica granatum) in India. Pomegranate have an impressive nutrition profile it contains 7 grams fiber, 3 grams protein, 30% Vitamin C, 36% Vitamin K, 16% Folate and 12% Potassium. It also contains 24 grams of sugar and 144 calories. It contains two important compounds namely Punicalagins and Puninic acid. Along with the above nutritional advantages, it also has immense health benefits right from curing a fatal disease like cancer to remedying arthritis and joint pain. India stands first in the list of Pomegranate producer countries with respect to cultivation area. The states leading in pomegranate production in India are Maharashtra (70.2%), Karnataka (10%), Gujarat (7.4%), Andhra Pradesh (6.7%), Telangana (1.9%), Madhya Pradesh (1.9%), Tamil Nadu (1.0%) and Rajasthan (0.4%) (Source: Horticultural Statistics at Glance, 2015).

Introduction

Citrus (Citrus spp, Fam: Rutaceace, sub-family Aurantioidae) is considered as one of the most remunerative fruit crops in India occupying 953.4 thousand ha with an annual productivity of 11655 thousand tonnes fruit , thereby ranking 4^th at global level (Meena et al., 2018). Citrus is the third most important fruit crop in the world after apple and banana accounting for the production of about 135.76 million tonnes with massive area of cultivation spreading over 9.68 million hectares worldwide (Meena et al., 2018). It is believed that most species under the genus Citrus are originated from tropical and sub-tropical regions of Southeast Asia particularly India, South China, Indonesia and Peninsular Malaysia. The North-eastern states of India is recognized as one of the primary gene centre or natural home and reservoir of 17 Citrus species of which 8 species are indigenous to the region (Bhattacharya and Dutta, 1949).

The crop is commercially cultivated in all the four geographical zones viz. northwest, central, south and northeast, producing different kinds of mandarins (Citrus reticulata), sweet orange (C. sinensis), acid lime (C. aurantifolia), sweet lemon (C. limettoides) and lemon (C. lemon) (Biswas, 2010). They are universally propagated by budding onto seedling rootstocks, seed and propagating materials influencing the chances of pathogen infection, thereby, affecting citrus production nationally and internationally. Citrus production is subjected to variety of diseases caused by various microorganisms’ viz. fungi, bacteria, virus, viroids and nematodes. The present review gives a brief highlight about most important citrus diseases viz. canker, greening, quick decline, gummosis, exocortis, slow decline etc along with their characteristic symptoms, causal organisms, disease cycle, epidemiology as well as integrated management approaches.

Citrus Canker- Xanthomonas citri subsp. citri

Banana (Musa spp.) is one of the most important fruit crops grown in tropical and subtropical regions in the world. The word ‘banana’ is a general term embracing a number of species or hybrids between Musa acuminata and M. balbisiana in the genus Musa and family Musaceae (Perrier et al., 2011). India is known to be one of the origins for bananas and it was grown even before the Vedic period (c.1500 - c.500 BCE). It is referred as “Kalpatharu” (Plant of virtues) due to its multifaceted uses (Mishra et al., 2012). It has been estimated that one medium-sized banana contains about 105 calories (Bjarnadottir, 2017). Raw bananas contain 75% water, 23% carbohydrates, 1% protein, and negligible amount of fat (USDA, 2018). However, carbohydrate, protein and moisture content of banana depend upon the variety, genotype and climatic conditions (Mohapatra et al., 2010). Banana fruits are rich source of antioxidants and vitamins such as vitamin A, B, C, E and P-carotene (Paul and Southgate, 1978; Kanazawa and Sakakibara, 2000; Waller,2005), minerals like potassium and calcium (Mohapatra et al., 2010) and contains a fair amount of fibre (Bjarnadottir, 2017).

Banana is the major staple food crop for millions of people in Central, East and West Africa, Latin America and the Caribbean. In 2016, world production of bananas and plantains was 148 million tonnes, led by India and China with a combined total (only for bananas) of 28% of global production with the adoption of advanced technologies like drip irrigation, use of quality tissue culture plants, fertigation and integrated plant protection technologies lead the country to be number one in area and production. Other major producers were the Philippines, Ecuador, Indonesia, and Brazil, together accounting for 20 per cent of the world total of bananas and plantains. In India, banana ranks first in production followed by mango and third in area among fruit crops after mango and citrus. Banana production accounts about 30.4 M tonnes from an area of 0.86 M ha with an average productivity of 35.4 tonnes/ha (Anon, 2017). Banana crop is a year round food security crop and source of income to a large group of farmers and has tremendous potential as cash and export commodity for most banana growing countries. However diseases and pests constitute major limiting factor for increasing its production and productivity. Banana cultivation is almost evenly spread out across the world and there is a remarkable low genetic variation among plantations, owing to the popularity of a select few cultivars. This exposes monocultures to increasing damage caused by pests and diseases (Ghag et al., 2015).

Introduction

The mango (Mangifera indica L.) is regarded as king of fruits. It is a key fruit crop in the subtropical regions of world including India. Prakash and Srivastava, 1987 reported that mango is attacked by more than 140 fungi (70 diseases), about 12 nematodes and a dozen of phanerogamic parasites and epiphytes. Among these diseases some major diseases of mango having economic important in India are briefly described in this chapter.

Anthracnose

Anthracnose is a severe disease of mango. High disease severity results to heavy loss including post-harvest losses during transit and marketing of produce. Mango anthracnose has been reported to spoil about 29 per cent of Alphanso fruits at Bangalore. Young plantations of Bombay green variety are completely wiped out in Tarai region of Uttar Pradesh as a result of severe wither tip Bose et al., 1973. At Lucknow, 24 per cent loss of fruits of Dashehari variety has been reported by Raoof and Prakash, 1984.

Jackfruit (Artocarpus heterophyllus Lam.) is the largest edible fruit in the world (Naik, 1949; Sturrock, 1977), known as “poor man’s food” belongs to the family Moraceae (Bose, 1985; Haque, 2010). It is an important tree crop in tropical and sub-tropical regions, usually grown in home gardens and commercially in orchards (Elevitch and Manner, 2006; Sangchote et al., 2003). The primary economic product is the fruit, but the tree is also used for timber, fodder, dyes and traditional medicines (Haque, 2006). Jackfruit originally native to Indian subcontinent, is now widely cultivated in the tropics of both hemispheres (Ochas et al., 1981). Incidence of different kinds of diseases of biotic and abiotic origin at different growth stages of Jackfruit have been reported (Haque, 2006; Sangchote et al., 2003). Some of the commonly occurring diseases of jackfruit with symptomatology, causal organism, perpetuation and management approaches have been elucidated below.

LeafSpot

Incidence of leaf spot at different growth stages of jackfruit caused by Chaetopyrena hesperidum (Srivastava, 1974), Cercospora mehra (Rao and Subhendar, 1979) Botryodiplodia theobromae (Rao and Deshmuk, 1986), Corynespora cassiicola (Sangchote et al., 2003), Colletotrichum gloeosporioides (Sirayoi, 1993; Srivastava and Mehra, 2004), Phyllosticta- artocarpi (Annon, 2003) has been reported by various workers from different parts of the world. Some of the common leaf spot diseases have been discussed below.

Economic Importance

Apple (Malus domestica, M. communis, M. pumila and M. sylvestris), the generic name Malus is derived from the Latin word belong to the rose family and include literally hundreds of cultivated varieties. In the apple, the original ancestral species is obscured by so many cultivated variations throughout the centuries that some authors lump them all into one species, Malus domestica. They all originated in western Asia (or Eurasia) and are characterized by fleshy fruits called pomes. In the pome a thick, fleshy hypanthium layer (also called the floral cup or calyx tube) surrounds (and is fused with) the seed bearing ovary or core. The edible part of most fruits is the actual ovary, but in apples and pears only the outer hypanthium layer is eaten (unless you enjoy eating the core). Apple is commercially the most important temperate fruit and is fourth among the most widely produced fruits in the world after banana, orange and grape. China is the largest apple producing country in the world. It is premier table fruit of the world and excels other fruits in having prolonged keeping quality and wide variety of flavour and taste (Sharma, 2000). Apple is a highly remunerative crop and is grown in all temperate regions of the world. In India apple is grown in Jammu and Kashmir, Himachal Pradesh, Uttarakhand and some parts of Arunachal Pradesh. Jammu and Kashmir account for sixty per cent apple in total apple produced in India and is the most important fruit among all the cultivated fruits in the state. The state annually produces 1.31 lakh metric tons apple fruit from an area of 1.28 lakh hectares (Anonymous, 2008). It forms the backbone of the state’s economy and is main cash crop for the small and marginal farmers. However, the production and quality of apple is poor as compared to that of the developed countries because of several factors including diseases and insect-pests (Thakur, 2000). Although a large number of insect pests attacks to apple crops but some of them are very serious and need attention for their control. Besides the insect pests, mites are also associated with apple production and cause significance economic losses to commercial fruit growers (Kerik, 2012).

Aegle marmelos (L.) Corr. is one of the sacred trees of Hindus and is highly popular for its medicinal properties. This tree is commonly known as “Bael” in India and the leaves are used for worshipping Lord Shiva. It has the potential for curing a number of ailments and has been in use since time immemorial. At present bael has become an important source of medicine for curing various human diseases such asdiabetes, liver toxicity, fungal infection, microbial infection, inflammation, pyrexia and to relieve pain. The raw fruits are used to prepare sugar impregnated sweets called murraba and jelly where as juices and shakes are prepared after ripening.

Bael is native to India and found throughout Southeast Asia. In India this fruit is grown in Indo-Gangetic plains and Sub-Himalayan tracts up to a height of 500 m, in North-East India and dry and deciduous forest of central and southern India.

Aegle marmelos is a subtropical plant and grows up to an altitude of 1,200 m altitude from sea level. It grows well in the dry forests on hilly and plain areas. Aegle marmelos is a widely distributed plant and found in India, Ceylon, China, Nepal, Sri Lanka, Myanmar, Pakistan, Bangladesh, Nepal, Vietnam, Laos, Cambodia, Thailand, Indonesia, Malaysia, Tibet, Sri Lanka, Java, Philippines and Fiji. In India it found in Sub-Himalayan tracts from Jhelum eastwards to West Bengal, in central & south India. It found almost in all the states of India.

Bael is a hardy crop and is quite resistant to diseases. However, there are certain fungal and bacterial diseases that have been reported to cause yield reduction in bael. In this chapter, important diseases of beal with causal organism, disease cycle, epidemiology and management practices are described.

Plant diseases comprise a major factor in the culture of papaya. Adequate control measures are necessary to intensify the production of papaya. There are over 17 diseases caused by fungi, viruses, mycoplasma and nematodes, which affect papaya plant all over the world. Of these about 5-6 diseases like collar rot, damping off, anthracnose, mosaic and leaf curl are serious problems in many papaya growing areas of the world. They can reduce yield greatly and impair marketability of fruits. They must be checked and losses due to them must be minimized in order to increase the economics of papaya production.

Anthracnose

Economic Importance

Anthracnose is considered as one of the principle postharvest disease of papaya occurring worldwide and has been noted to cause huge losses in countries like Brazil, Hawaii (USA) and Mexico. It is one ofthe most ubiquitous and destructive disease of papaya, mainly during storage. The fungus infects various parts of the plant but mainly occurs in fruits, which later becomes unfit for commercialization. It is a major limitation to papaya production of about 90% along with the exportation of the fruit to bigger overseas market. The disease can have serious effect on refrigerated fruit for export. The use of inappropriate postharvest methods can result in production of up to 100% diseased fruits from some orchards.

Guava, Psidium guajava L. (Family: Myrtaceae), is native to South America and the West Indies but it is also grown other parts of the tropics and subtropics including India. It is considered to be important hardy crop grown in neglected soil. It is commonly known as ‘Amrood’ or Safed Safari’ in Hindi, which is an important fruit plant of India. It is grown all over the country for its fruits which are nutritive, rich in vitamin C, highly flavoured and delicious. Leading producers are Brazil, India and Mexico. The cultivated varieties of guava are attacked by several pathogens which cause considerable loss in yield and reduce market value.

Wilt

Wilt is one of the most destructive disease of guava in India and there is a significant yield loss. In India, guava wilt was first reported in 1935 from Babakkarpur (Allahabad). Das Gupta and Rai (1947) reported the disease in a severe form in orchards of Lucknow, while Dey (1948) reported it from Allahabad, Kanpur and Lucknow. The work so far done on wilt disease has been reviewed by Prakash and Misra (1993), Misra (1995), Misra and Pandey (1996), Misra (2001) and Negi et al. (2001). Chattopadhyay and Bhattachaijya (1968a) reported up to 80% yield losses due to serious wilt in the commercially grown guava orchards in West Bengal. About 150 and 300 acres of guava orchards in the Punjab and Haryana was forced uprooting during 1979-81 (Jhooty et al., 1984). Wilt infection of 15 to 30% trees in Allahabad, Farrukhabad and Unnao, 5-15% in Kanpur and Jaunpur and less than 5% in Gorakhpur, Balia, Hardoi and Varanasi districts (Mathur, 1956).

Introduction

Mulberry (Morus spp.) is a most important crop which is used as food for silkworm (Bombyx mori L.) belonging to the genus Morus and family Moraceae. In tropical and temperate countries, mulberry is cultivated as shrubs and tree respectively. The total area under cultivation of mulberry in India is around 2,82,244 ha. The largest mulberry producing state is Karnataka (1,66,000 ha) followed by Andra Pradesh (38,084 ha). All over the world there are almost 68 species of Morus genus among 1000 varieties were commercially cultivated (Central silk board, Mysore). The nutritive values of mulberry leaves are affected by many diseases like leaf spot, powdery mildew, rust, root rot and bacterial blight which are causing severe yield loss up to 10-30%. In addition it also affects the growth, development of silkworm and cocoon yield due to feeding ofthose diseased leaves. (Sastry, 1984; Sundareswaran et al. 1998). Occurrence of these diseases based on some factors such as season, temperature, humidity and variety of mulberry (Sukumar, 1996). This chapter will be discussed about the disease causing organism, epidemiology and their management practices.

Cercospora leaf spot

Economic Importance

Cercospora leaf spot is an economically important disease causing abundant damage by reducing the leaf quality of mulberry (Siddaramaiah and Krishnaprasad, 1978). During July-December it causes yield loss of 10-15% and the disease present till January-February.

Introduction

Strawberry (Fragaria vesca) belonging to family Rosaceae is an important fruit crop in India and is commercially produced in temperate and sub- tropical areas of the country. In India, it is mainly cultivated in the states of Himachal Pradesh, Uttar Pradesh, Maharashtra, West Bengal, Delhi, Haryana, Punjab and Rajasthan. Nainital and Dehradun districts of Uttarakhand, Mahabaleshwar (Maharashtra), Kashmir valley, Kalimpong (West Bengal) are the core centers of strawberry cultivation in India. Sub-tropical areas in Jammu also possess tremendous potential to grow the crop in irrigated condition. Strawberry cultivation can boost the income potential of small scale and marginal farmers because its high value creates potential for significant profit. It yields quickest return in shortest time than any other profit. The leaves of strawberry are rich in essential oil. India exports strawberries to countries like Austria, Bangladesh, Germany and Jordan.

Strawberry also possess many health benefits such as flavonoids content lowers the risk of heart diseases. Potassium, Vitamin K and magnesium content of fruit are important for healthy and strong bone. Strawberries are rich in antioxidant ellagic acid, which protects the elastic fibres of skin to prevent sagging. Strawberries lowers blood levels of C- reactive proteins, a signal of inflammation in the body.

The optimum day and night temperature for better growth, development and fruiting of the plant is 22-25°C and 7-13°C respectively. Also, it thrives best on a well drained medium loam and slightly acidic soil with high organic matter content.

Although the strawberry crop is highly remunerative however, its management is intensive and encounters a number of setbacks in form of diseases and pests. A large number of fungal, bacterial and viral diseases are known to infect different parts of plant such as foliage, fruit and root.

Some major diseases of strawberry includes leaf spot, powdery mildew, anthracnose, grey mould, fusarium wilt, crown rot, rhizobus rot, red stele, nematode diseases etc. Few other diseases caused by abiotic factors includes sunburn, frogmouth, albinism.

Introduction

Pineapple is one of the most important commercial fruit crop in India. It occupied an importance in the horticultural wealth and economy of the country. India ranked seventh among the pineapple producing country in the world during 2013-14 (GoI, 2014). It grows well in practically all type of soils with slightly acidic in nature, both in plain and hills. It is affected by several different pathogens wherever it grown and result in substantial crop losses. Some important diseases cause complete loss of the fruit marketableimportance. The major problems faced by pineapple growers in India are discussed below.

Introduction

Pear (Pyrus communis L.) is a temperate fruit that mainly grows in hilly areas at a elevation ranging from 1,500 to 2,500 metres. This temperate fruit is commonly eaten fresh or is canned. It is used to produce an alcoholic beverages and perry. The production of pear is 17 million tons per year in worldwide and the cultivation is expanding throughout the worldwide.

Pear cultivation is affected by many bacterial, fungal and viral diseases due to which it reduces the plant strength and decreases the quality of yield. Besides,pear can be also affected by many disorders and nematodes.

Bacterial Diseases

Fire blight

Fire blight disease is a serious concern to pear producers. It can destroy an entire orchard under optimal conditions in a single growing season.

Introduction

Ber (Zizyphus mauritiana L.) is one of the important fruit crops of arid and semi arid zones of the world. It is known by various other names such as ber, bor, bogori, boroior, kool and ruguin Hindi, Punjabi, Marathi, Assamese, Bengali and Telegu respectively. In America, it is called jujube or Chinese date. Ber is popularly called “poor man’s fruit crop” but now its status in tropical fruit culture has improved considerably. The fruit is palatable and delicious and is known for its high nutritive value. The crop is considered as minor fruit in this country on the basis of its production in restricted area; popularity and awareness but recently itbecame an important cash crop in some areas and its acreage and production have increased. The plant is usually a piny, evergreen shrub or small tree up to 15 m high, with trunk diameter around 40 cm or even more; spreading crown; stipular spines and many drooping branches. The ripe fruits are mostly consumed raw (Bal and Uppal, 1992). In India it is extensively grown in Madhya Pradesh, Bihar, Punjab, Uttar Pradesh, Assam, Gujrat and Maharashtra. The fruits are quite nutritious, rich in vitamin C, second only to aonla and guava and much higher than citrus and apple. The ripe fruits have high nutritive value, having 13-24 per cent total soluble solids and up to 160 mg/100g vitamin C. The dehydrated fruits are kept for a long time and are consumed in the off season.

Due to rapid spread of commercial cultivation, the crop has become a target of different biotic and abiotic factors causing serious losses. So far, little attention to the diseases of ber has been given as the importance of the crop generally continues in a locality or a particular state. So, it overlooked the national importance particularly crop protection measures, leading to limited knowledge for management of different diseases both in pre-harvest as well as post-harvest stage. Ber is affected by many serious diseases like powdery mildew, leaf spots (Alternaria, Cercospora, Septoria, Cladosporium, Pestalotiopsis etc.), sooty mold, anthracnose, fruit rot etc.

Grape is an important fruit crop grown mainly under tropical climatic conditions in India. It has spread on an area of 137 thousand ha with a production of 2951 thousand MTduring 2018-19. Famous Indian medicine scholars, Sasruta and Charaka in their medical treatises entitled ‘Sasruta Samhita’ and ’Charaka Samhita’, respectively, written during 1356-1220 BC, mentioned the medicinal properties of grapes. Native spp. resembling Vitis lanata and Vitis palmata grow wild in the northwestern Himalayan foothills. Indigenous varieties known as ‘Rangspay’, ‘Shonltu White’ and ‘Shonltu Red’ are grown in Himachal Pradesh even today. Cultivated grapes are believed to have been introduced into the north of India by the Persian invaders in 1300 AD, from where they were introduced into the south (Daulatabad in Aurangabad district of Maharashtra) during the historic event of changing the capital from Delhi to Daulatabad by King Mohammed-bin-Tughlak. Currently Mahrashtra, Karnataka, Andhra Pradesh and Tamil Nadu are the major grapes growing states of India.

However, the higher production of grapes is constrained by the incidence of several diseases and pests. The important diseases of grapes causing economic losses have been listed below and discussed in detail in the chapter.

Avocado fruit has become one of the most sought after food sources worldwide. It is a nutritious source of food and is part of the staple diet of many people in third world countries where it is cultivated and where it is native. Production costs are very high owing to the cultural requirements of the avocado tree and the presence of diseases, which can be major limiting factors to production. Phytophthora root rot, caused by Phytophthora cinnamomi, is such a disease. During the developmental stages of hefruit in the orchard and at harvesting, the fruit is also exposed to diseases such as scab (Sphacelomapersea), anthracnose (Colletotrichum gloeosporioides) and Cercospora spot (Pseudocercospora purpurea) Marias (2006).

Major Fungal Diseases of Avocado

Phytophthora root rot

Economic Importance

The causal fungus Phytophthora cinnamomi Rands was first isolated from cinnamon trees in Sumatra in 1922 and has since been reported from over 70 countries. It has an extremely wide host range including 1000 varieties and species of plants. In California alone it has been estimated to affect between 60-75% of the orchards and causes a loss in excess of $40 million annually (Coffey 1992).