eChapters

Introduction
Mango (Mangiferaindica L) known as “the king of fruits” and “Apple of the Tropics” is most popular fruit in the tropics and sub-tropics. It moved from India to different countries and has gained popularity around the world. It has long been associated with the Indian culture and religious functions. Among different states, Uttar Pradesh and Andhra Pradesh constitute 23.64 per cent and 22.99 per cent share in the total mango, respectively, in the country. In 2023, Mango production had a total export volume of 78.56 billion MT. India is the biggest mango producer with a total production volume of 25 million MT of mangoes during the year. The top 10 mango producers in 2023 include India (25 million MT), China (3.8 million MT), Indonesia (3.6 million MT), Pakistan (2.7 million MT), Mexico (2.4 million MT), Brazil (2.1 million tons), Malawi (1.7 million MT), Thailand (1.6 million MT), Bangladesh (1.5 million MT) and Vietnam (1.4 million MT). As regards world-wide mango exports, Mexico is the biggest mango exporter with total exports worth $576.36 million in 2023. It was noted that Mexico’s mango exports increased by 5.09% from the previous year. The top 10 mango exporting countries in 2023 include the following:

Introduction
World population is increasing and currently stands at 8.2 Billion as on 2025. Food security of population of any country is becoming a challenging task and the entire population depends on the available national resources. The importance of scientific community in securing foods for everybody was felt necessary and it was expressed that there is a huge herculean task to ensure food for everybody. Farming community and fruit growers across the globe were engaged in serious efforts to produce fruits of good quality. The necessity to develop advanced technologies for nutritious foods was thus given national importance not only for food security but also of nutritional security. The sincere scientific efforts to develop recent innovative technologies to support fruit production even at harsh soils and environmental conditions are praiseworthy. Farmers, stakeholders, policy planners and technology developers have been devoted to achieve the target of Sustainable Developmental Goals. The target of United Nation’s 2030 to eradicate poverty and eradication of malnutrition should be achieved sustainably. People across nations are working devotedly to achieve the target. However, climatic changes have been significantlyaffecting the food production to food security across nations. Decadal information suggested the adverse impact of climates on the fruit production. Recent changes in weather extremisms had also affect harshly on the food production to supply chain. Thus, the role of scientific community to coup up the environmental hazards and to sustain fruit production becomes a reality. In this context, agroadvisory services plays significant role to support farming community and fruit growers to adopt time bound managemental practices. The ultimate aim of these services is to improve the orchard soil and tree health condition, enhance factor productivity vis-à-vis profitability and precise use of available natural resources. Quantification of variability in environmental indicators, soil and tree interactions were felt necessary for formulating effective policy plan (Malhotra, 2017). Adak et al. (2022) advocated for foliage spraying of 1 per cent zinc sulphate on mango cv. Dashehari to enhance yield and nutrient richness in fruit pulp.

Introduction
Crop production is weather dependent and almost every crop has been affected by the changing climate. The favourable weather may result bumper production sometimes or even complete destruction of crop may take place under severe weather aberrations. The number of events of sudden aberrations is increasing in a cropping period with the gradual climate change in the recent past. It has been recorded too severe in case of perennial crops. Ready to harvest crops have several times been completely destroyed due to thunderstorm or cyclone in coastal regions or even in main land. Thus, Indian agriculture is being impacted by the climatic changes, and its affect is very much visible now (Aggarwal, 2008). Horticulture sector is not escaped from its’ ill affect and new challenges are coming for production (Singh et al., 2021). The role of adaptation strategy has now been felt crucial (Babu et al., 2021; Banerjee et al., 2022) and importance of agro advisory not only protects the crops from such types of risks but also provide guidance to farmers about the right time for activities in crop husbandry (Adak et al., 2018). Issuance for improving water productivity in water limited areas (Adak and Babu, 2024), micronutrient management for nutrient richness and enhanced yield (Adak et al., 2023; Shukla et al., 2020), rejuvenating unproductive orchards (Shukla et al., 2021; Mishra et al., 2007), disease (Misra et al., 2013; Shukla et al., 2015, 2019, 2020, 2021a,b; 2022; Kumari et al., 2021) and insect pest (Gundappa et al., 2016; 2018) management are becoming very crucial and essential for the benefit of growers.

1) Powdery mildew
Diagnostic Symptoms
• A white, powdery fungal growth on the upper, lower or both leaves and shoots.
• There may be discolouration of the affected parts of the leaf, and heavily infected young leaves can be curled and distorted.
• Mildew growth may also be found on the stems, flower stalks, calyces and petals.
• Heavily infected flower buds frequently fail to open properly.
• Mildew growth on stems and flower stalks is usually thicker and more mat-like than that on the leaves.
• Mildew growth on all parts may turn browner as it ages (Fig-1).

1) Botrytis Gray Mould
Diagnostic Symptoms
• Appearance of a gray, fuzzy mold leaves, stems and on flowers of or plants. Also called, “gray mold”.
• Spotting or blight on leaf and flower stem lesions, and dieback.
• Flower parts become necrotic and die(Fig-1).
Etiology
Domain : Eukaryota
Kingdom : Fungi
Division : Ascomycota
Class : Leotiomycetes
Order : Helotiales
Family : Sclerotiniaceae
 

1). Stem Gall
Diagnostic Symptoms
• Symptom appears in the form of tumor-like swellings of leaf veins, leaf stalks, peduncles, stems as well as fruits.
• Infected veins show a swollen hanging appearance to the leaves.
• Initially the tumors are glossy which rupture later on and become rough. They are about 3 mm broad and up to 12.5 mm long.
• Badly affected plants may be killed.
• In the presence of excessive soil moisture, especially under shaded conditions, when the stem fails to harden and remain succulent, the tumors are numerous (Fig-1).
Etiology
Scientific Classification
Kingdom : Fungi
Division : Ascomycota
Class : Taphrinomycetes
Order : Taphrinales

1) Leaf Spot
Diagnostic Symptoms
• Initially oblong brown spots having about 4-5 cm in length and 2-3 cm in width with grey centres surrounded with yellow hallo are found on the leaves.
• Large number of spots may be found on a single leaf and as the disease advances, spots enlarge and cover a major portion of leaf blade.
• Severly affected plants dry and wilt.
• Black dots acervuli formed in concentric rings on spot.The grey centres become thin and get teared(Fig-1).
Etiology
Scientific Classification
Kingdom : Fungi
Division : Eumycota
Sub- division : Deuteromycotina

1. Vein-Clearing/Yellow Vein Mosaic
Bhendi yellow vein mosaic virus
Diagnostic Symptoms
• Yellowing of the entire network of veins in the leaf blade is the characteristic symptom.
• In severe infections, the younger leaves turn yellow, become reduced in size and the plant is highly stunted.
• The veins of the leaves will be cleared by the virus and intervenal area becomes completely yellow or white.
• In a field, most of the plants may be diseased and the infection may start at any stage of plant growth.
• Infection restricts flowering and fruits, if formed, may be smaller and harder.
• The affected plants produce fruits with yellow or white colour and they are not fit for marketing (Fig.1).
• The virus is spread by whitefly.

1) Anthracnose
Diagnostic Symptoms
• All the above ground parts are affected. However, the characteristic symptoms appear on pods.
• On cotyledons, spots are sunken dark brown or black with pink spore mass.
• Seedling infection results in collapse of seedling.
• Spots on leaves appear on lower side and are black. Later these may also appear on upper surface. When the infection is severe, the affected plants wither off.
• Black, sunken, circular spots of varying sizes appear on pods with bright red, yellow or orange margins. The centre of these spots later turns grey or pink due to sporulation of the pathogen. The border of these spots appear raised (Fig.1).

1. Alternaria leaf spot
Diagnostic Symptoms
• Spots are small, dark coloured.
• They enlarge, soon become circular & 1mm. in diameter.
• Under humid conditions groups of conidiophores will be formed in the spot.
• Spots develop concentric rings.
• Finally the spots coalesce leading to blighting of leaves.
• Pathogen is seed borne and cause shriveling of seeds and poor germination.
• Linear spots also appear on petioles, stems, pods & seeds (Fig.1).

1) Downy Mildew
Diagnostic Symptoms
• Yellow, angular spots restricted by veins resembling mosaic mottling appear on upper surface of leaves .
• Corresponding lower surface of these spots shows a purplish downy xgrowth in moist weather.
• Spots turn necrotic with age.
• Diseased leaves become yellow and fall down .
• Diseased plants get stunted and die .
• Fruits produced may not mature and have a poor taste (Fig.-1).
Etiology
Scientific Classification
Kingdom : Fungi
Division : Eumycota

1. Anthracnose or Fruit Rot and Die Back
Diagnostic Symptoms
The disease occurs in two forms: the die back and the ripe -rot Die back symptoms
• Small, circular to irregular, brownish black scattered spots appear on leaves.
• Severely infected leaves defoliate.
• Infection of growing tips leads to necrosis of branches from tip backwards.
• Necrotic tissues appear grayish white with black dot like acervuli in the center.
• Shedding of flowers due to the infection at pedicel and tips of branches.
Fruit symptoms
• Ripe fruits are more liable for attack than the green ones.
• Small, circular, yellowish to pinkish sunken spots appear on fruits.

1) Phomopsis fruit rot or Blight
Diagnostic Symptoms
• Plants are attacked at all stages of growth.
• On leaves, circular to irregular, clearly defined grayish brown spots having light centers appear. The diseased leaves become yellowish in colour and may drop off.
• Several black pycnidiacan be seen on older spots.
• Lesions on stem are dark brown, round to oval and have grayish centers where pycnidia develop.
• At the base of the stem, the fungus causes characteristic constrictions leading to canker development and toppling of plants.
• On fruits, small pale sunken spots appear which on enlargement cover entire fruit surface. These spots become watery leading to soft rot phase of the disease. A large number of dot like pycnidia also develop on such spots.
• Infection of fruit through calyx leads to development of dry rot and fruits appear black and mummified (Fig.1).

1. Damping off
Diagnostic Symptoms
• Disease occurs in two stages, i.e. the pre-emergence and the postemergence phase.
• In the pre-emergence phase, the seedlings are killed just before they reach the soil surface.
• The young radical and the plumule are killed and there is complete rotting of the seedlings.
• The post-emergence phase is characterized by the infection of the young, juvenile tissues of the collar at the ground level.
• The infected tissues become soft and water soaked. The seedlings topple over or collapse (Fig.1)
Etiology
• Pathogen; Pythium aphanidermatum.
• The fungus has a characteristic mycelium, which coenocytic, hyaline, freely branching and thick hyphae.
• It reproduces both asexually and sexually.

1. Early Blight
Diagnostic Symptoms
• Brown-black necrotic spot-angular, oval shape characterized by concentric rings .
• The concentric ring produce a target board effect, the most characteristic symptom of the disease.
• Several spot coalesce & spread all over the leaf.
• In severe attacks leaves shrivel and fall down.
• Infection and rotting of tubers has also been reported (Fig.1).
Etiology
Scientific Classification
Kingdom : Fungi
Phylum : Ascomycota

1. Anthracnose
Colletotrichum gloeosporioides (Glomerella cingulata)
Diagnostic Symptoms
• Disease produces symptoms like leaf spot, blossom blight, withertip, twig blight and fruit rot .
• Symptoms on leaves show as gray to brown spots with dark margins and a yellow halo. The spots later enlarge and coaleasce to form sizable necrotic areas.
• Tender shoots and foliage are easily affected which ultimately cause die back young branches.
• Blossom blight may vary in severity from slight to a heavy infection of the panicles .
• Black spots develop on panicles as well as on fruits. Severe infection destroys the entire inflorescence resulting in no setting of fruits.
• Young infected fruits develop black spots, shrivel and drop off.
• Fruits infected at mature stage carry the pathogen into storage and cause considerable loss during storage, transit and marketing (Figure -1).

1) Rust
Diagnostic Symptoms
• The disease is restricted to leaves although sometimes it can seen on tender shoots and berries.
• The rust pustules appear as small spots, 1-2 mm in diameter.
• In early stages these spots are yellowish becoming orange in color with increase in size.
• On the upper surface, opposite the spots on the lower surface , the color is often brownish.
• In severe attack leaves may dry and wither.
• The berries remain small and fail to ripen.
• Extensive defoliation weakens the trees and results in poor yield, severe die back of twigs, and death of trees (Fig.1).

1) Blister Blight
Diagnostic Symptoms
• Initially oily, yellowish, translucent spots appear on the tender leaf and turn to deep red shiny blisters.
• The circular spot gradually enlarges to 3 to 13mm diameter, bulged on the under surface of the leaf with a concave trough like depression on the upper surface.
• Leaves become curled and distorted.
• First flush of 2-3 young leaves are attacked and the young shoots and buds are killed.
• Mature leaf is not affected.
• In nursery infection, seedlings are stunted with many thin stems instead of a single stalk.
• Repeated attacks cause death of seedlings.
• Badly affected nurseries will have to be abandoned.
• Succulent leaves and green shoots of newly pruned tea are most susceptible (Fig.1).
• Basidiospores cause secondary infection.

1) Bud Rot
Diagnostic Symptoms
• Severe on young palms.
• Yellowish green discoloration of the heart leaf or crown leaf.
• The basal tissues of the leaf rot quickly and can be easily separated from the crown.
• Spindle withers and droop down.
• Older leaves develop irregular, water soaked spots which are sunken in nature.
• The leaves and sheath in the central spindle fall off leaving an outer whorl of green leaves.
• The withered central shoot can be pulled out very easily from the crown.
• The central crown may rot and in few months the tree may wilt.
• Young nuts fail to mature and fall (Fig.1).

1) Leaf Spot
(Mycosphaerella fragariae teleomorph, Ramularia brunnea Peck anamorph). Disease Symptoms
• Older leaves usually show purple spots (3-6 mm in diameter) on the upper surface, sometimes with a slightly darker halo.
• As the spots mature, they become white to gray and surrounded by a brownish halo.
• A typical lesions, uniformly brown without darker border or lighter centers, may form on young leaves.
• Later on, the whole leaf is covered by numerous lesions and become chlorotic, withered and die.
• Fruits are generally not directly infected, but the loss of foliage can reduce their quality and yield (Fig-1).
Etiology
Scientific Classification
Kingdom : Fungi
Division : Ascomycota
Class : Dothideomycetes