Presentation on diseases of cotton plants

Embed Size (px)

Citation preview

Page 1: Presentation on diseases of cotton plants


Page 2: Presentation on diseases of cotton plants

An Assignment on Disease of

Cotton Plants

Submitted by: Santosh pathak

IAAS, Lamjung Campus (B.sc AG )

Page 3: Presentation on diseases of cotton plants

Introduction :Cotton is a soft, fluffy staple

fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium.

Cotton is the king of fibres, usually referred as white gold .

Current estimates for world production are about 25 million tones annually, accounting for 2.5% of the worldˋs arable land. China is the worldˋs largest producer of cotton, but most of this is used domestically

Page 4: Presentation on diseases of cotton plants

The United States has been the largest exporter for many years.

Cotton is grown mainly for its fibre used in manufacture of cloth for the mankind. It is also used for several other purposes like making threads, for mixing in other fibres and extraction of oil from the cotton seed.

Cotton seed after extraction of oil is a good manure and contains about 6% nitrogen, 3% phosphorous and 2% potash.

Cotton seed, cotton linter and pulp obtained during oil extraction and cotton meal are good concentrated feed for cattle.


Page 5: Presentation on diseases of cotton plants

cultivated cottons are annuals. Cultivated cotton is a herbaceous plant which attains a height of 60 to 200cm. The plant has a tap root with secondary roots that branch laterally from primary root.

The main stem is erect and much branched; the branches develop from buds located at the nodes of the main stem. The leaves are spirally arranged on the main stem.

Cotton belongs to the malvaceae family and the genus Gossypium. The genus Gossypium has been one of the most difficult to classify. Genus Gossypium includes 50 species in which 46 are wild and 4 are cultivated.

According to classification by Hutchison (1947) the following four cultivated species contain almost all the varieties of cotton in case of India.

Gossypium arboreum Gossypium herbaceum Gossypium hirsutum Gossypium barbadense

Page 6: Presentation on diseases of cotton plants

Objectives:To be familiar with the diseases found in the

cotton.To be able to know the sign and symptoms of

disease.To get maximum ideas regarding the control

measures and management of disease found in cotton.

To be familiar about the pesticides like fungicides, insecticides and their use in the crop at different times applying different methods

Page 7: Presentation on diseases of cotton plants

Review of literature Cotton crop is attacked by a number of diseases. Symptoms of

important diseases and their suitable control measures are given below.

Seedling diseases: Seedling diseases are presently causing great losses to cotton

producers in Tennessee. They comprise the number one disease problem. The estimated loss is an average of 9.72 percent annually based on a range of 5 to 18 percent since 1989.

Loss estimates do not include cost of replanting or losses due to lateness of replanted cotton.

  CAUSE . The organisms include both seed and soil-borne fungi and

bacteria. The soil-borne fungi, Rhizoctonia solani and Pythium spp., are the most important causes of seedling diseases in Tennessee.

Rhizoctonia solani is the fungus most commonly associated with seedling diseases; however, during cool, wet seasons Pythium spp. may become more prevalent.

Page 8: Presentation on diseases of cotton plants

SYMPTOMS The various phases of seedling diseases

include seed-rot, root-rot, pre emergence damping-off, and post emergence damping-off. Root-rot (or black-root) may occur anytime.

Pre emergence damping-off refers to the disease condition in which the seedling is killed between germination and emergence from the soil.

The death of seedlings resulting shortly after their emergence from the soil is termed post emergence damping-off. The latter is referred to as "sore shin" when only stem girdling occurs. Rhizoctonia is usually the cause of sore shin.

  CONTROL Fungicides seed treatment helps control

seed rot and some pre emergence damping off.

Some of the practices include use of correct planting equipments and date of planting, good seed bed preparation, correct use of herbicides and insecticides and use of high germination seed.


Page 9: Presentation on diseases of cotton plants
Page 10: Presentation on diseases of cotton plants

Root rot This disease is caused by soil-borne fungi

Rhizoctonia bataticola and Rhizoctonia solani . The diseased plants occur in more or less

circular areas and this is very characteristics of the disease.

The affected plants can be easily pulled out of the ground. The roots of the affected plants decay and a yellowish brown discoloration sets in. In badly affected plants the wood becomes brown or thick. Due to this disease perfectly healthy plants may wilt within 24 hrs with leaves dropping without showing any discolouration.

  Control measures: Irrigate frequently to keep down soil

temperature. Follow a wheat-jowar-paddy-cotton rotation. Treat the seed with Brassicol(75w.p.) 200g/50

kg of seed of acid delinted seed and 300g/ 50 kg of machine delinted seed.

In areas where the soil is heavily infested with the disease causing fungus it should be treated with Brassicol 20 dust/20-50 kg/acre

Page 11: Presentation on diseases of cotton plants
Page 12: Presentation on diseases of cotton plants

Fusarium wilt

This disease is caused by a soil-borne fungus Fusarium moniliform, Fusarium vasifectum.

Plants can be affected this disease in any stage. Disease incidence in seedlings can be high in cold soils, but mean temperatures about 230c favors the disease

. In young as well as old plants the initial symptoms are stunting followed by yellowing, wilting and dropping of most of the leaves.

The cut stems of wilted plants shows brown or black vascular tissues inside.

In old plants, lower leaves towards the base are affected first followed by younger ones towards tips.

Leaf discoloration appears around the edges and progresses towards the midrib and leaves gradually drop.

Page 13: Presentation on diseases of cotton plants

Control measures: .Grow tolerant varieties like LD-

694.Application of potash and

organic matter in sufficient amount is helpful in reducing disease.

Soak 4 kg seed(non-delinted) in 8 litres of water containing 8 g of Bavistin/Derosal for 6-8 hrs and 2-3 hrs in case of delinted.

Avoiding over irrigation and over application of nitrogen..

Crop rotationField inspection for early

detection and containment of isolated outbreaks.

Farm hygiene.

Page 14: Presentation on diseases of cotton plants

Verticillium wilt: . Verticillium wilt is caused by the soil-borne

fungus, Verticillium albo-atrum. This fungus can survive in the soil for many

years even in the absence of cotton. Cotton seedlings infected with Verticillium

usually turn yellow, dry out, and die. Plants which become infected later in the season

are stunted and exhibit a yellow condition along the leaf margins and between the major veins.

This yellow imparts a mottled appearance to the plant. Severely affected plants will shed their leaves.

Sprouts or new shoots may develop near the base of infected plants.

The discoloration associated with Verticillium wilt is usually more evenly distributed across the stem than that associated with Fusarium wilt.

The browning of the stem tissues are also usually less intense where the wilt is caused by Verticillium.

Control by using Deltpine and crop rotation.

Page 15: Presentation on diseases of cotton plants
Page 16: Presentation on diseases of cotton plants

Boll rot: Boll rots have caused heavy losses to cotton producers during wet

growing seasons. Rain and high humidity during late summer and fall are optimum

conditions for boll-rot development and increase the incidence of the disease.

A number of fungi and bacteria have been associated with boll rots. Some of these organisms invade the cotton bolls directly, whereas others enter through insect wounds or as secondary invaders.

Infected seed will result in seedling blights the following season. Boll rots usually first appear as water-soaked spots.

Later, as the infection spreads, the bolls turn black and may be covered with a moldy fungus growth. Badly infected bolls may drop from the plant.

  Control measures:

To prevent boll rots, cotton growers should avoid excessive applications of nitrogen which promotes rank growth of cotton.

It has been found that skip-row cotton provides better air drainage, resulting in less boll rot. Defoliation will also help reduce boll rots.

Page 17: Presentation on diseases of cotton plants
Page 18: Presentation on diseases of cotton plants

Angular leaf Spot (Xantomonas malvacearum):

It is also known as Bacterial blight. This disease is usually least severe in or absent in hot dry condition, but it can be severe during warm wet weather.

It is quite sever in the irrigation cotton growing area of the country. • Symptoms will be most severe on leaves when the humidity is high with

air temperature average 86-95 degrees F and when rain, heavy dew, fog or sprinkle irrigation are frequent.

Small round spot occur in the cotyledon during the early seedling stage of growth and angular lesions on the older plants.

The disease on the leaves appears first as water soaked spot that enlarge to angular brown to black lesion.

The spot occurs on the leaves from the seedling to the mature plants stage during of high temperature.

The spot are light-green spots that are visible on the upper and lower surface of the leaves. These spots quickly turn dark brown to black

. The margin of this spots has sharp angles. The round, light green lesions on bolls may develop into boll rot. Black elongation lesion occurs on the young stem.


Page 19: Presentation on diseases of cotton plants

Control measure:

The acid delinted seed should be treated with 0.1% Streptocycline solution, by keeping it emmersed for 2hrs (Two grams of streptocycline dissolved in 20 liters of water is enough to treat seed required for one acre).It should be dried on the shade and the seed should be treated with Ceresin wet or Agrosan. G.N@25- 10 kg of the seed .If seed is not acid delinted it should be treated with Streptocycline as described and after coating it with slurry of ash and dung it should be treated with Ceresan or Agrosan G.N.

The crop should be sprayed from the time of the first appreance of the disease with Blitox 50, flytolan, Blue copper 50 or Cupramer in a concentration of 0.3 to 0.5 % considering the severity of the disease.

Resistance variety should be used. Rotating cotton with soybean or corn planting for once or more years

will help reduce the severity of bacterial blight on next cotton crop. Plant only acid-delinted seed produced in fields free from this disease.


Page 20: Presentation on diseases of cotton plants
Page 21: Presentation on diseases of cotton plants

Anthracnose (Colletorichum indicum):

. This disease is caused by two species of colletotrichum which are seed born in nature. The disease is chiefly attacks seedling, bract and bolls.

Affected seedling have reddish or dark brown lesion on the stems below the soil surface and on roots.

Symptoms on bracts appear on the form of circular water soaked spot which enlarge and may spread to the bolls. When the disease area extend to the base of the bolls, the bolls shed away.


Control measures:

Seed treated with 5 g of ceresan wet and 8 g of agrimycin-100 in 5 liters of water per 6-8 kg seed for 6-8hrs is effective in eliminating seed-born infection.

Spray seedling copper fungicides such as Bliotx or Fytolan at the rate of 2 kg per hectare in 1000 liters of the water once or twice checks seedling blight. Spraying during boll formation reduces damage from boll rot.

Spray the seedling with Bordeaux mixture help in checking the disease in seedling stage.

One year rotation and ploughing under the disease debris after harvesting the crop are quite effective in eliminating the source of primary inoculum.

Defoliation of the crop by dusting with calcium cyanmide @15 ks/acre reduces humidity round the boll and results in rapid drying of the bolls and lint after the rain, thereby reducing the boll rot phase of the disease

Page 22: Presentation on diseases of cotton plants
Page 23: Presentation on diseases of cotton plants

Alternaria leaf spot (Altenaria termis, Alternaria macrospore; A. gossypium and A. gossypina)

The disease is common of occurance in the cotton growing area of our country. It makes it appearance in the form of pale to brown round or irregular spot on the affected leaves of the plants.

Sometimes the leaf veins may also get infected. Ultimately the affected leaves become dry and fall of. In the rare case the disease may cause canker on the stems.

The infection spread to the bolls only when the attack is very severe and they may finally fell off.

  Control measures: Destruction of disease plant debris along with all other

practices included under clean the cultivation are essential for reducing disease appearance.

Spray the cop with Zineb or Ziram in the concentration of 0.2 to 0.25 and 0.15 to 0.2% respectively keeping an interval of 7 to 10 days can effectively control the disease

Page 24: Presentation on diseases of cotton plants
Page 25: Presentation on diseases of cotton plants

Root-knot nematode: Missouri scientist recently surveyed for cotton parasitic nematodes in

Dunklin, New Madrid, and Pemiscot counties,. Root-knot nematodes are so named because the galls they produce on roots look like knots in a rope. The most common species are Meloidogyne incognita, Meloidogyne arenaria etc.

Root-knot nematodes will be a greater problem when cotton is planted year after year and when planted in sandy soil. Root-knot nematodes are best adapted to coarse-textured, sandy soils rather than fine-texture silty or clay based soils.

 Symptoms: Root-knot nematodes are not uniformly distributed in soil; they occur in irregular

patches. These patches may be small and limited in number, or they may be large and widely distributed.

Depending on the nematodes population, plants in these patches may be damaged and show symptoms ranging from mild severe stunting. Leaves on infected plants may wilt at mild day more readily than healthy plants.

In addition, root-knot nematodes cause visible galls or knots on roots. Swellings of the infected root tissues can be found on the cotton taproots and the lateral roots from about six weeks after emergence until harvest.

The galls are easier to detect if cotton plants are carefully dug from the soil. For a positive diagnosis, send root and plant testing laboratory. The soil and roots should be kept cool from the time they are collected until shipment. Store the material in a plastic bag in a cooler bag in a cooler and ship it by overnight express it to the lab.

  Management:  Rotate cotton with resistant soybean varieties. Use a nematicide.  

Page 26: Presentation on diseases of cotton plants
Page 27: Presentation on diseases of cotton plants

Bronze wilt: During the late summer of 1995, cotton plants in several southeast Missouri fields

began to discolor. The leaves turned from green to bronze, and the leaves wilted at mid day. This

malady was refered to as bronze wilt.   Symptoms: The first visible symptom of bronze wilt is the red and bronze

discoloration of leaves. The discolored leaves will feel warmer to the touch than leaves of

normal plants. The stems and petioles of affected plants turn red soon after the

leaf color changes. The leaves of affected plants will drop during the hottest part of the day and may recover partially or completely by early morning.

These plants may occur next to plants that appear normal. The leaf discoloration may disappear soon after a rain or irrigation but will develop soon after the soil dries.

All squares and small bolls will shed from affected plants within a week of when symptoms begin to develop. However , squares that develop on these plants after soil moisture becomes abundant may remain attached and mature bolls may develop.

  Management: Plant varieties that have exhibited few if any symptom

Page 28: Presentation on diseases of cotton plants
Page 29: Presentation on diseases of cotton plants

Summary of general cotton disease control measures:

Plant high- quality seed. Plant on a high bed and enhance drainage of field. Plant when the soil temperature 4 inches deep at 8:00

am is 60 degree F and when five days of warm weather are predicted.

Plant only in fertile soil. Use an in furrow fungicide when planting cotton early

in the season(mid April in Missouri), in clay soils and in poorly drained fields.

Rotate cotton with wheat, soybean or corn crops. Plant varieties that have high yield potential and resistance to disease.

Page 30: Presentation on diseases of cotton plants

Pesticides used in cotton:

Page 31: Presentation on diseases of cotton plants


Page 32: Presentation on diseases of cotton plants
Page 33: Presentation on diseases of cotton plants

Conclusion: Cotton is a cash or commercial crops which has its high values in the market.

Cotton has not only importance in making cloth but also used in different purposes. In case of Nepal, there is not enough research in the field of cotton. Cotton development board which was established in 1986 and could not completed its task due to various reasons. It was established at Khajura, Nepalgunj which is the western part of Nepal. The western part of Nepal like Banke, Bardiya, kailali, kanchanpur etc is the famous for cotton production before some decade ago. Nowadays, there is not any research program but only cultivation practices are done. There are not so good facilities of laboratory and the storage houses.

Disease is also important aspect that reduces the yield which causes lots of loses, so farmers are not interested to cultivate this crop. Diseases like Verticillium wilt, Fusarium wilt, Root rot, Bacterial disease are common in case of Nepal. We have different ideas about the diseases symptoms and control measures by the assignment given by our respected sir. We are able to know the disease symptoms found in cotton plants. We have deal a lot of farmers and scientist related to this crop. We had got a lot of experience in the field and the laboratory. Disease is very fatal to crops. We had learnt controls methods of diseases which is very useful. We had collected different problems of farmers like disease, insect pest management etc.


Page 34: Presentation on diseases of cotton plants

References: Thakur. C, Scientific Crop Production, New Delhi,

Metropolitant Book Co. Pvt. Ltd.Martin, John.H et.al, Principles of Field Crop Production,

3rd Edition, New York, Macmillan Publishing Co. Inc.Singh et.al, Modern Techniques Of Raising Field Crops,

2nd edition, New Delhi, Oxford & IBH Publishing Co.Pvt.Ltd,2009.

IPM, Cotton Pests Scouting and Management, Boyd M.L et al, retrieved from http://www.ipm.missouri.edu/ipm_cotton.pdf


Page 35: Presentation on diseases of cotton plants

Thank you