eChapters

Introduction

Chili peppers, also spelled chile or chilli, are varieties of the berry-fruit of plants from the genus Capsicum, which are members of the nightshade family Solanaceae, cultivated for their pungency. Chili peppers are widely used in many cuisines as a spice to add "heat" to dishes.

Botanical Name : Capsicum annum

Family : Solanaceae

Chromosome Number (2n) : 24

Diseases of Chilli

 1. Powdery Mildew

The disease was first reported from Morocco in 1937.

Anthracnose or Fruit Rot and Die Back

Colletotrichum capsici

Diagnostic Symptoms

Dieback symptoms

• Small, circular to irregular, brownish black scattered spots appear on leaves .

1. Introduction

Chirata (Swertia chirayita) belongs to the family Gentiniaceae, a potential medicinal plant used as bitter tonic in treatment of fever and for curing various skin diseases, is a perennial herb and distributed throughout the eastern Himalayan region of India. The plant is a native of temperate Himalayas, found at an altitude of 1200-3000 m (4000-10000 ft), from Kashmir to Bhutan and in the Khasi hills at 1200-1500 m (4000 to 5000 ft). It can be grown in sub-temperate regions between 1500 and 2100 m altitudes. It is used in traditional medicine to treat numerous ailments such as liver disorders, malaria, and diabetes and are reported to have a wide spectrum of pharmacological properties. Its medicinal usage is well-documented in Indian pharmaceutical codex, the British, and the American pharmacopeia’s and in different traditional medicine such as the Ayurveda, Unani, Siddha, Horopathy and other conventional medical systems. This ethno medicinal herb is known mostly for its bitter taste caused by the presence of different bioactive compounds that are directly associated with welfare of human health. The increasing high usage of Swertia chirayita, mostly whole plant, as well as the illegal overharvesting combined with habitat destruction resulted in a drastic reduction of its populations and has brought this plant to the verge of extinction. The increasing national and international demand for Swertia chirayita has led to unscrupulous collection from the wild and adulteration of supplies. The bitterness, antihelmintic, hypoglycemic and antipyretic properties are attributed to amarogentin (most bitter compound isolated till date) 1, swerchirin, swertiamarin and other active principles of the herb. Due to the high demand, this plant is being cultivated in many places of Darjeeling district both for domestic use within India and for exporting purpose. During our roving survey (2011-2014), it was observed that this high value medicinal plant facing a number of diseases (like seedling blight, leaf spot, Leaf blight etc.), ultimately, cultivation of Swertia chirayita is getting hampered. The quality of plant is affected due to the occurrences of diseases as whole plants part being used as medicinal purpose and also affects the marketing scenario; the demand of good quality chirata is increasing at a rate of 10% annually. To harvest the benefit of megabiodiversity zone of eastern Himalaya needs urgent attention to combat the upcoming epidemic of diseases of chirata. Here, we are trying to throw some light related to present status of diseases of chirata and standard management practices.

Introduction

Chrysanthemum, commonly known as “mums” or “chrysanths,” is a genus of plants that bloom and belong to the Asteraceae family. These plants are native to Asia and northeastern Europe, with China being the primary centre of diversity for the genus. Chrysanthemums are well-known for their attractive and colorful f lowers, and they are popular ornamental plants in gardens, floral arrangements, and as cut flowers.

Chrysanthemum morifolium is a herbaceous perennial flowering crop. It is the second most popular cut flower worldwide, right behind roses, and a significant decorative plant for commerce (Silva et. al., 2013). Certain species’ flowers, such as those of Chrysanthemum morifolium and Chrysanthemum indicum, are rich in nutrients and biologically active substances and are used to make medicinal tea and cosmetics, respectively (Lin et. al., 2010).

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

Gummosis

Phytophthora spp

Diagnostic Symptoms

• Dark water soaked large patches appear on the basal portions of the stem near the ground level.

Introduction

The innermost layer of the pericarp is the endocarp. The segments are also called “liths”, and the space inside each lith is a locule filled with juice vesicles, or “pulp”. From the endocarp, stringlike “hairs” extend into the locules, which provide nourishment to the fruit as it develops. Citrus fruits are notable for their fragrance, partly due to flavonoids and limonoids (which in turn are terpenes) contained in the rind, and most are juice-laden. The juice contains a high quantity of citric acid giving them their characteristic sharp flavour. The genus is commercially important as many species are cultivated for their fruit which is eaten fresh, pressed for juiceor preserved in marmalades and pickles.

Coconut

 Kingdom: Plantae

 Phylum: Magnoliophyta

 Class: Liliopsida

 Subclass: Arecidae

 Order: Arecales

 Family: Arecaceae

 Genus: Cocos

 Species: Cocos nucifera Linnaeus

 1. Bud Rot

The fungus Phytophthora palmivora is responsible for the ailment known as “bud rot.” Butler first mentioned bud rot in India in 1906. Due to a number of factors, the disease has recently spread to practically every region of the state in a very serious manner.

Cauliflower, Cabbage and Knol khol
1. Leaf spot
Pathogen
Alternaria brassicae (Berk.) Sacc.
Symptoms
Alternaria leaf spot usually appear in early stage in cauliflower while at later stage symptoms in cabbage appear as circular light brown spot in leaves. Concentric rings are clearly visible on the spots. In older plants on leaves, petioles and stem, brown to black circular to slightly elongated spots appear.

Common salt, or sodium chloride (NaCl), is an essential mineral that plays a critical role in the health and productivity of livestock and poultry. It is a major source of sodium (Na) and chloride (Cl), both of which are vital for maintaining osmotic balance, acid-base regulation, nerve conduction, and muscle function. However, deficiencies or excesses of common salt can lead to severe health issues, reduced productivity, and even mortality in animals. This chapter discusses common salt disorders, their causes, symptoms, and the nutritional management strategies necessary to prevent and mitigate these
problems.
Importance of common salt in animal health
1. Electrolyte balance: Sodium and chloride maintain osmotic pressure and fluid balance within the body.
2. Acid-base regulation: Sodium and chloride are crucial for maintaining acid-base homeostasis in the blood.
3. Nerve and muscle function: Sodium is essential for nerve impulse transmission and muscle contractions.
4. Digestive health: Chloride is a major component of gastric acid (hydrochloric acid), which aids in digestion.
5. Milk and egg Pproduction: Adequate salt levels are required for optimal production in dairy animals and laying poultry.

1 Condition characterised by bran - like scales on skin surfaces is called

a) Pustule b) Parakeratosis

c) Erythema d) Pityriasis

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.

Wilt

Fusarium oxysporum f.sp. vasinfectum

Economic Importance

• Wilt is one of the major diseases of cotton, found wherever this crop is grown like Mexico, African countries, France, Italy, Yugoslavia, India and West Indies.
• In India, the disease was first reported from Nagpur by Evans in 1908.
• It appears in almost every cotton tract of the country. However, it is more or less absent in the loamy soils of Indo Gangetic plains and sandy loams of Maharashtra, Tamil Nadu, Karnataka and other States.
• In affected susceptible varieties yield losses exceed 45-50%.

Wilt

Fusarium oxysporum f.sp. vasinfectum

Diagnostic Symptoms

• Disease affects the crop at all stages.

Introduction

Cowpea (Vigna unguiculata subsp unguiculata) is widely grown in Africa, Asia and Brazil. The crop is grown on about 7 million ha in warm to hot regions of the world (Rachie, 1985). It acts as a major source of protein (20-30%) for Indian vegetarians. Besides, it contains high carbohydrate. Cowpea is generally rich in lysine and limiting in sulphur amino acids and important for human food and animal feed. The crop is also valuable source of dietary fibre as well as vitamins and minerals including folate, thiamin and riboflavin. Besides this, it can fix about 240 kg ha^-1of atmospheric nitrogen and make available about 6070 kg ha^-1nitrogen for succeeding crops grown in rotation with it (Aikins and Afuakwa, 2008).

The crop is prone to several diseases induced by species of pathogens belonging to various pathogenic groups viz., fungi, bacteria, viruses, nematodes, and parasitic flowering plants, and it constitute one of the most important constraints to the profitable Cowpea production in all agroecological zones. Different diseases like anthracnose, fusarium wilt, bacterial blight, Cowpea mosaic virus (and several other less prominent viruses), cercospora leaf spot, rust and powdery mildew etc are reported to be important disease of the crop. In this chapter detail of these diseases and their integrated management approaches are mentioned.

Anthracnose

Colletotrichum lindemuthianum, Glomerella lindemuthiana Shear [teleomorph]

Economic Importance

• Anthracnose is an important disease in Kenya, Uganda, Brazil, Argentina, Mexico, Guatemala, Costa Rica, Nicaragua, India, Peru, Ecuador, and Colombia .
• The disease causes huge losses in temperate and subtropical zones.
• Yield losses of 95% have been recorded in Colombia and over 92% in Malawi.
• Anthracnose also affects seed quality and marketability of the crop.

Introduction

Members of the family Brassicaceae, sometimes known as Cruciferae, include cruciferous vegetables, such as cauliflower, cabbage, kale, garden cress, bok choy, broccoli, brussels sprouts, mustard plant, and other related green leafy vegetables. This family comprises several genera, species, and cultivars that are cultivated for food production. While some are shrubs, herbaceous plants make up the great bulk. The leaves are simple (though sometimes deeply incised), without stipules, and grouped in rosettes or alternately on stems. The terminal inflorescences are devoid of bracts. Four longer free stamens and two shorter free stamens are present on. blossoms, as well as four free petals and sepals that alternate.

1. Damping off
Pathogen
Pythium spp
Phytophthora spp
Fusarium spp
Sclerotium spp
Symptoms
It is a term used to describe the damage caused by various fungi to the seed and emerging seedling in the reduced plant stand and sometimes it is so serious that  resowing becomes inevitable. Major symptoms are the failure of the seedlings decay or sudden death of the emerged seedlings roots and lower stems of emerged seedlings become soft and watery and may be reddish brown in colour.

Cucurbits are major crops of countries having a wide variety of vegetables. Cucurbits include bottle gourd, bitter gourd, pumpkins, squashes, ridge gourd, sponge gourd, and cucumbers. Cucurbits are a large, diverse crop group that are susceptible to over 200 diseases (Zitter et al., 1996). A wide range of pathogens affect the productivity of cucurbits. The diseases may be caused by fungi, bacteria, Cucurbits crops are warm-season large group of crops that are cultivated and harvested over different seasons like spring, summer, and winter. These crops as a group are an important part of a diverse and nutritious diet. Melons are eaten as fruits, whereas summer and winter squashes, cucumber, and pumpkin are eaten as vegetables. In addition, cucurbits are used for fiber, utensils, decoration, ceremonial and medicinal purposes.

A wide range of pathogens affect the productivity of cucurbits, which constitute over 200 diseases (Zitter et al., 1996). The diseases may be caused by fungi, bacteria, viruses, or mycoplasma- like organisms. The disease may be soilborne, seedborne (carried by seed), spread by wind, or transmitted by insect vectors. The moisture content of the seed, storage period, prevailing temperature, and degree of invasion influence the development of seedborne fungi (Anjorin and Mohammed 2009). The pathogen may cause seed abortion and rot, necrosis, reduction, or elimination of germination capacity as well as seedling damage at later stages of plant growth, resulting in the develop- ment of the disease as systemic or local infection (Khanzada et al., 2001). The diseases cause heavy loss in terms of yield and quality. The diseases caused by pathogen are controlled by fungicides against fungal diseases, antibiotics for bacterial diseases, or insecticide in case of viruses transmitted by insect vectors. The diseases of cucurbetaceous crops can be managed by adopting different cultural, biological, and chemical methods of disease management. The following management practices are required to be taken into consideration for raising disease-free cucurbitaceous crops:

Introduction

Cucurbits, a versatile and economically significant group of plants within the Cucurbitaceae family, encompass a wide array of popular vegetables such as cucumbers, pumpkins, squash, zucchinis, and melons. These cucurbit crops are not only vital components of global diets but also key players in agriculture. Also, cucurbits are used as fibre source and for utensil preparations, decorations, and ceremonial and medicinal purposes (McGrath 2004). However, their productivity and quality are frequently compromised by a range of diseases. In this chapter, we embark on a comprehensive exploration of the diseases that afflict cucurbits, including their names, symptoms, causative agents, etiology, disease cycles, favourable conditions, and strategies for effective management.