eChapters

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

SUGARCANE (Saccharum officinarum)
Fungal diseases
1) Red rot
Symptoms: It is one of the most destructive disease of sugarcane. Dark reddish spot with brown margin appear along the mid rib. When the diseased canes are split open red blotches with transversely elongated white centres are seen. Under humid conditions numerous black dot like acervuli develop in the central discoloured portions. The diseased tissues emit a typical alcoholic odour. The juice of the affected stalks gives a sour alcoholic smell.
Causal organism: Colletotrichum falcatum
Management
i) Select healthy and disease free setts.
ii) Dip the setts on Carbendazim 50% WP or Thiophanate Methyl 70% WP @0.15% solution for 30 minutes before planting.
iii) Avoid rationing of infested crops.
iv) Growing resistant/tolerant varieties, i.e. Co6907, Co 7219, Co838,
 

Red Rot

Colletotrichum falcatum (Perfect stage: Physalospora tucumanensis)

Economic Importance

• The disease is so devastating in nature that it has been referred to as cancer of sugarcane.
• Red rot occurs in all sugarcane growing tracts of India and several epiphytotics have been recorded in the past from states like U.P., Bihar, Haryana, Punjab, Andhra Pradesh and Kerala.
• In U.P and Bihar, the two popular varieties, namely, CO 213 and CO 312 were badly hit by the epidemics of 1938-40 and 1946-47.
• There have been reports of red rot epidemics in many other countries viz., USA, Mauritius, Australia, Hawaii and Myanmar.
• Red rot also causes appreciable damage to canes in Bangladesh, Taiwan and Pakistan.
• The loss in cane yield has been estimated 12 to 44.5% and 35 to 86 % in cane yield of ratoon over preceding plant crops have different levels of disease.

Diagnostic Symptoms

• Practically all above ground parts are affected, but stalks are the main targets of stack.

• Spindle leaves (third or fourth) starts drying.

• Further stalks becomes discolored and hollow.

Sulphur (S) is a vital mineral for livestock and poultry, playing a key role in the synthesis of amino acids (methionine, cysteine), vitamins (biotin, thiamine), and other critical metabolites. While sulphur deficiencies or excesses are less common than imbalances in other minerals, they can lead to significant health and production challenges. Effective nutritional management is crucial to prevent and address sulphur-related disorders.
Importance of sulfur in livestock and poultry
Sulfur is essential for:
1. Protein synthesis: It is a component of sulfur-containing amino acids like methionine and cysteine, which are critical for growth and tissue repair.
2. Structural integrity: Sulfur contributes to the structure of keratin, essential for wool, feathers, and hooves.
3. Metabolic functions: It is involved in the synthesis of vitamins (biotin and thiamine), enzymes, and coenzymes.
4. Detoxification: Sulfates aid in detoxifying harmful substances in the liver.
Sulphur deficiency (hypo-sulfurosis)
Causes
1. Low dietary sulphur: Diets low in sulfur-containing ingredients, such as grains or poor-quality forages.
2. Imbalanced nitrogen-sulphur ratio: Excessive non-protein nitrogen (e.g., urea) in ruminants’ diets without adequate sulfur supplementation.
3. Poor feed quality: Grazing on sulfur-deficient soils or consuming sulfurdepleted feeds.

Root Rot or Charcoal Rot

Rhizoctonia bataticola

(Pycnidial stage: Macrophomina phaseolina)

Economic Importance

• Charcoal rot is of great economic importance in the World and has been found to reduce head weight and diameter, stem height and weight and in particular, the stem girth and root weight of sunflower plants.
• The first report of the occurrence of charcoal rot on sunflower was from Sri Lanka by Small (1927).
• Under favourable condition, losses can reach 60-90%.
• Infected plants generally die before seed set is finished.

Diagnostic Symptom

• Circular to oval, dark brown to black spots appear on the leaves.The spots enlarge into round to irregular spots with concentric rings and coalesce causing blighting and withering of leaves.

• These are surrounded by chlorotic zone with grey white necrotic center.

Damping Off

Pythium aphanidermatum

Economic Importance

• The disease is reported from China, Indonesia, South Africa and the USA.
• It causes extensive damage in the tobacco tracts of Andhra Pradesh, Maharashtra and Gujarat in India.
• The damage in some areas can be hundred percent, in the absence of protective sprays.

Tomato (Lycopersicon esculentum Mill.) is one of the most important vegetable crop and is known as protective food due to its wide spread production and special nutritive value. Tomato is referred to be native of tropical America. In the 16^th century, it got spread from America to other parts of the world and became popular in India within the last six decades. It is known as world’s largest vegetable crop after potato and sweet potato. The overall world production of tomato is 1,180,000 tons with a productivity of 65 t/ha. Contribution of USA in tomato production is 13.2 million metric tons to the total world production (FAOSTAT). USA ranks third in position in the total world production of tomato after China and India (FAOSTAT). India produces 22,337MT of tomato from 801ha area.

Fungal Diseases

Fusarium Wilt

Economic Importance

Fusarium wilt caused by Fusarium oxysporum being so widespread, turns out to be a significant problem in many crops. It is one of the most widespread and damaging diseases of tomato wherever tomatoes are grown intensively. The pathogen also causes damage to many other crops likepotato, and pepper of the family Solanaceae. Yield losses of effected crops can goup to 45% in tomato in India.

Introduction

Tomato scientifically known as Solanum lycopersicum L. is a widely cultivated and consumed fruit that is often mistaken for a vegetable due to its culinary uses. Belonging to the Solanaceae family, tomatoes are native to western South America with their domestication dating back to ancient civilizations in Mesoamerica. Tomatoes are prized for their vibrant red colour, juicy flesh, and rich, slightly sweet f lavour. They are a versatile ingredient used in a wide range of culinary dishes, from salads and sauces to soups and sandwiches. Tomatoes are a significant source of essential nutrients, including vitamin C, vitamin K, potassium, and folate. Additionally, they contain the antioxidant lycopene, which is believed to have various health benefits.

Leaf Spot

Colletotrichum capsici

Economic Importance

• The disease is common in many parts of South India, and in recent years has become very severe, causing much damage to the crop.
• The yield losses occur due to leaf spot infection is through the loss of photosynthetic green surface.
• During the period of heavy infestation, yield loss could be as much as 50%.

Leaf spot

Colletotrichum capsici

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 .

Diseases of bladder and urethra are most commonly reported in farm animals than diseases of kidney. Knowledge of the physiology of the urinary secretion
and excretion is required to understand the urinary tract diseases. The functions of kidneys are to excrete the end products of tissue metabolism except CO2
and to maintain homeostasis with respect to fluid and solutes including acid base balance by selective excretion of these substances. The kidney maintains
homeostasis by varying volume of water and the concentration of solutes in the urine.

MANIFESTATIONS OF URINARY SYSTEM DISEASES Urinary tract diseases in farm animals  are generally clinically characterized by        pain    and        difficult    urination    (dysuria);    alterations    in    urine    volume    and    its composition; rupture of the renal pelvis, bladder and urethra; and inadequacy of nervous control of urination. Clinical Signs • Dysuria and abdominal pain are common expression of discomfort owing to urinary tract diseases. Acute abdominal pain is rarely seen in cattle due to sudden distension of renal pelvis (pyelonephritis), ureter or renal infarction. Abdominal pain from urethral obstruction leading to distension of urinary bladder is clinically manifested by tail switching, kicking at belly, straining at urination and grunting. Horses with acute tubular nephrosis may show signs of renal colic (arching back, rubbing perineum and tail head). Dysuria (frequent passage of small amounts of urine with pain) is associated with cystitis, vesicle calculus and urethritis • Uremia is commonly seen in cases of acute renal failure and is manifested

1 Homeostasis in kidney is generally maintained by

a) Glomerulus b) Renal tubules

c) Both (a) and (b) d) None of the above

Important diseases of vegetable crops

1. Damping off: (Phytophthora parasitica, Pythium sp. Rhizoctomia solani):This is a disease of the seedlings at the nursery stage. Due to the attack of this fungus seedlings rot at the ground level and collaps.

Rust

The rust of wheat has been studied more than any other disease in the world. In India, K.C Mehta and his associates studied this disease with exemplary zeal. Three rusts of wheat are known. These are Black stem rust, caused by Puccinia graminis tritici, Brown rust (leaf rust), caused by Puccinia recondita, and Yellow rust, caused by P? striiformis. Brown and yellow rusts cause more damage thant the black rust, because of early appearance in the season.

Loose Smut

Ustilago nuda tritici (Ustilago tritici)

Economic Importance

• Loose smut has been observed and recorded on cultivated wheat from all over the wheat growing regions of the world.
• In India, it is prevalent in areas having cool, humid and semi humid climate during flowering period.
• Loose smut has recently became a more serious problem in the Ladakh region in the Himalayan mountains of India.
• If uncontrolled, loose smut can wipe out entire crops, since it replaces the grain.
• In areas where people depend on their grain crops for survival and don’t have the money or technology resources to control it, the disease can be devastating.
• Not only does it wipe out the crop, growers cannot even try again next year since any seeds they were able to harvest will be infected and will not produce seed the following season.

PREVENTION

This section will discuss ailments that affect the fish kept in our aquariums. We will simply not call them diseases because most are not true diseases but a response to some sort of stimuli such as poor tank water management or the presence of actual parasites. A list of the most common ailments, the reasons behind them and the appropriate action needed to “fix” the problem is given in this Chapter.

If you maintain good water quality, keep the right kind of fish together, feed good quality food and monitor all your water properties you will rarely have any problems. A few common sense precautions when you purchase new fish can save you a lot of trouble.

A disease is any process which disrupts an animals’s normal function. Occurrence of diseases causes heavy economic loss in terms of livestock health and production. Presence and accumulation of infectious agents in the environment lead to reduction in quality and quantity of animal products. Strategic control and eradication of economically important diseases will result in enhancing goat production in the country. Goat suffer from many diseases although the susceptibility of goats to diseases is less as compared to sheep or cattle. Goat diseases can be bacterial, viral or parasitic. Viral diseases are more common in herds and are responsible for large scale mortality at one time. With a good hygiene in the barn and if the goats are kept in a way appropriate to their species, most of the diseases can be avoided.

Much attention has not been paid for prevention and control of goat diseases since most of the goats are reared by poor people and prevention and control is generally considered uneconomical. However, this is not true, as small investment in disease prevention and control can bring enormous gains in goat productivity. Simple preventive measures like deworming and vaccination alone can save the herds from heavy mortality and can increase production considerably. Serious and early efforts on diagnosis and prevention of goat diseases are essential in order to improve the health and production. A wide range of bacterial, viral, parasitic infections, causing heavy mortality and morbidity result in huge economic loss to different goat farming systems. Metabolic and nutritional disorders in goats also affect their production performance. Metabolic disorders are of great importance in pregnant goats, especially those carrying multiple foetuses. Deficiencies of essential minerals, metabolites and amino acids below the critical level also adversely affect the production. Therefore, it is necessary to avert these imbalances (calcium, magnesium, Co, Cu, Zinc, Iodine) in the ration. Provision for extra energy and protein in late pregnancy are necessary to avoid parturient paresis due to low blood sugar and high ketones and hepatic insufficiency of glycogen. Soil- plant- animal interactions in relation to the incidence of chronic deficiency diseases of goats are often being observed.