37. Impacts of Cotton Leaf Curl Virus on the Yield of Cotton In Pakistan

 Cotton Leaf Curl Virus

Cotton Introduction:

    Cotton is a type of natural fiber that grows in a protective case called a boll, around the seeds of plants belonging to the Gossypium genus in the Malvaceae family. The fiber is composed mainly of cellulose, with small amounts of waxes, fats, pectins, and water. In the wild, the cotton bolls help to spread the seeds.

    This versatile fiber is typically spun into yarn or thread and used to create textiles that are soft, breathable, and long-lasting.

History of CLCuV:

    Cotton leaf curl disease was initially discovered in Multan in 1967 and was not considered a significant threat until 1987. In 1988, however, the disease caused damage to the cotton crop on 60 hectares in the Multan district, leading to concerns about its potential impact. The following year, the disease affected 200 hectares, and by 1990, it had spread to 800 hectares. The situation worsened in 1991, when the disease appeared in epidemic proportions, affecting an area of 14,000 hectares in the Multan, Khanewal, and Vehari districts. 

        The disease continued to spread, with over 485,000 hectares affected in 1992, resulting in a decrease in production and significant financial losses for the country. In 1993, the disease spread throughout the entire Cotton Belt of Punjab, causing varying levels of damage on 889,000 hectares. The disease was also reported in D.G. Khan and Sindh.

Symptoms:

• The primary symptom of Cotton leaf curl disease is the thickening of the veins in affected plants. 
• Additionally, infected plants may display the yellowing of small veins on the underside of the leaves, as well as leaf curling. 
• In more severe cases, a cup-shaped leaf-like outgrowth may appear on the underside of curled leaves. 

• Early infection can lead to stunted plant growth and significant reductions in crop yield.

Spread or Transmission:

    The Cotton leaf curl disease is transmitted between plants through its carrier, the whitefly. This virus has the ability to thrive not only on cotton, but also on several other weeds and hosts, including ladyfingers (okra), eggplant, chilies, tomato, cucumber, tobacco, and melon during the off-season. The disease has the capacity to multiply on weeds and other hosts, as well as on plant debris from previous crops that are present during the season.

Control or Management:

• Planting multiple varieties of cotton.
• Growing tall varieties of cotton to minimize whitefly infestations.
• Clearing fields and the surrounding areas of weeds to reduce the availability of hosts for whiteflies and the virus.
• Regularly removing any CLCuV-infected plants to prevent the further spread of the disease.
• Applying nitrogen during sowing to promote initial plant growth.
• Ensuring adequate irrigation, especially during the hot months of May, June, and July, to prevent water stress and maintain growth rates.
• Irrigating each field separately to avoid the spread of the disease.
• Practicing crop rotation with non-host crops to reduce the buildup of the virus in the soil.
• After harvesting, plow all plant debris into the soil or burn them if possible.
• Apply a seed treatment with Imidacloprid 600 FS at a rate of 5 ml/kg and Thiamethoxam 250 g/kg at 25% w/w to effectively control the virus.
• To combat whitefly attacks (the vector of CLCV), use effective insecticides such as diafenthiuron 500 g/L at 47.2% w/w, imidacloprid 200SL at 250 ml/acre, or acetamiprid 20SP (e.g. Mospilan) at 125 gm/acre during May, June, and July to control the whitefly. Buprofezin has been proven effective against nymphs, while acetamiprid, diafenthiuron, and imidacloprid have been effective against whitefly adults.

Impacts of CLCuV on the Yield of Cotton:

• In 1991-92, the highest-ever production of cotton was achieved, with 12.8 million bales being produced. 
• However, in the following years, there was a downward trend in production, with only 8.04 million bales being produced in 1993-94 due to a severe outbreak of cotton leaf curl disease (CLCuV), which caused significant damage to the cotton crop. 
• Unfortunately, since then, a decline in yield due to CLCuV has been a regular occurrence every year, resulting in the loss of approximately 6.5 million bales over the last decade.
• Fortunately, due to an increase in the cultivation of relatively tolerant or resistant cotton cultivars, along with other remedial measures taken against CLCuV, the declining trend in cotton production has been checked and even reversed. 
• For example, in 1995-96, the country was able to produce 10.06 million bales of cotton. However, during 1996-97, production declined again to 9.35 million bales due to severe attacks from whitefly and leaf curl virus, as well as continuous hot and dry weather.
• With the increasing prevalence of CLCV in Punjab and its transmission by the whitefly (Bemisia tabaci), a monitoring program was launched in Sindh in 1996, with a focus on geminiviruses including CLCV. The disease was first detected near Ubavro, an area close to the Punjab-Sindh border. 
• Since then, the incidence of CLCV has been on the rise, spreading from Ubavro to other areas. The disease has now traveled as far as Sakrand, which is located about 450 kilometers away from the original site of its detection in Ubavro. 
• The spread of the disease over the past three years has been a cause of concern for farmers and agricultural authorities in the region.

References:

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21. Cotton Production Technology

 Cotton

Scientific Name:

Gossypium herbaceum

Botany of Cotton:

It belongs to the circle of the family "Malvaceae".

Kinds: 

1. Gossypium hirsutum (American cotton) – used for fiber
2. Gossypium arboretum (Desi cotton) – used for cotton
3. Gossypium barbadense (Egyptian cotton)

• Root: It has a tap-root solid gadget up to two hundred cm deep in the soil.
• Stem: Erect, circular and woody stem (1-five toes excessive) with several lateral branches. The most crucial step includes branches and leaves but no flowers. Units are of two types i.e. Monopodial branches (2-4 in number) do now not endure flower and fruit, and sympodial branches that directly undergo flower and fruit. 
• Leaves: Leaves are hairy with 5-7 lobes.
• Flower: The flower bud is referred to as rectangular (Gudi). Self-pollination happens in cotton.
• Fruit: Fruit is known as a boll or pill. Immature segments of the boll upon its beginning are known as locules which can be 2-6 in variety. While the boll opens at adulthood, it yields a fluffy mass of fibers called lint with seeds Lint + seed is called seed cotton at the same time as seeds are known as cotton seeds. It contains 15% protein and 25% oil.

Economic Importance of Cotton:

• In Pakistan function of cotton in GDP is 1% and in value, the addition is 5.1% location below cotton cultivation is two.917 million hectares, production in step 12 months is 10.074 million tones and yield in line with hectare is 587kg. 
• Pakistan is in 4th wide variety in cotton production. 
• China is the first maximum cotton generating us within international India and U.S.A. They are on 2nd and third range. 
• The middle area of cotton production in Pakistan is Multan, Khanewal, Vehari, Lodhran, Bahawalpur, Bahawalnagar, D.G. Khan, Rajanpur, Muzaffargarh, Layyah, and Rahimyar Khan.

Climate and Locality:

• Grow in Tropical and sub-tropical regions.
• Soil temperature must be 15-20 degree Celsius. 
• Harvesting app. 150-200 days.

Properties of soil for cotton growth:

• It grows well in fertile soil.
• It ranges from sandy to very heavy clays.
• The best cotton lands are the mixtures of clay and sandy loam.

Production Technology of Cotton:

Seed-bed preparation:

    Deep plowing should be carried out to break a hard pan because its root penetrates deep into the soil. The steps for land preparation are 1 rotavator, 3 cultivations, and a pair of plankings.

Sowing time and varieties:

A) Early sowing: 15 March - 15 May additionally

Early sowing varieties: Ali Akbar-703, Sitara-008, Neelum-121, Tarzan-1, MNH- 886, VH- 259, BH-178, CIM-599, CIM-602, FH-118, FH-142, IR NIAB- 824, IUB-222, Sitara 11M, A -555, K2-181, Sayban-201, Tarzan-2

B) Late sowing: 15th April - 15th May can also be done.

Late sowing varieties: IR-3701, MG-6, Ali Akbar-802, GN Hybrid-2085

    Recommended sowing time for higher Punjab is April, for critical Punjab, it can also and for South Punjab is May and June

Seed Rate:

• 6-10 kg/acre for bed sowing
• 8-12 kg/acre for drill sowing.

Sowing methods:

1. Bed Sowing
2. Drill Sowing

1. Bed Sowing:

• Ridge to Ridge distance = 60-75 cm
• Plant to Plant distance = 9-12 inches
• After the seed mattress, beds are made through ridge-bed shaper which makes 75 cm huge bed furrows. Furrow intensity is 7 inches. On both margins of beds, sowing can be accomplished manually by using labor, or a mattress planter may be used.
• In the case of manual sowing, irrigation is implemented in furrows and just after irrigation, 2-four seeds are sown manually 2.5 cm above the water stage.
• In the planter sowing, sowing is executed on both the beds' margins using a bed planter. After sowing, irrigation is applied in furrows 5 cm beneath the seed.

2. Drill Sowing:

• Row to Row distance = 75 cm
• P to P distance = 6-9 inches (through thinning at 20-25 DAS)
• Seed intensity 2-2.5 inches
• After first irrigation, it is earthing up that needs to be executed in alternate rows to make beds. Its miles managed to keep irrigation water up to twenty-30% and excess water will be tired out.

Fertilizer Application:

• For early sowing apply 161 N, 46-70 P2O5, and 50 kg/acre K2O
• For late sowing use 80 N, 35-58 P2O5, and 38 kg/acre K2O
• P and K use whole at first and N applies in 3 terms
• 1/3 at sowing
• 1/3 at first irrigation
• 1/3 at flowering
• If deficiency signs and symptoms of B and Zn seem, those ought to be carried out through foliar utility at forty-five, 60, and 90 days after sowing. Boric acid (17%) @ 300g per100L water (five kg) and ZnSO4 (33%) @ 250 g per a hundred L water (6 kg)

Irrigation:

    6-8 irrigations are required for cotton in both methods.

Measures for Plant Protection:

Weeds:

• These can reason up to 20-30% loss in cotton yield due to weeds.
• Essential weeds of cotton are Itsit, deela, tandla, lehli, chulai, kulfa, madhana, lumb ghaas, hazardani, chibber, parthinam, makro, hulhul etc.

Physical Control:

• Hoeing through khurpa or kasula

Chemical Control:

A) Pre-emergence herbicides: those are carried out earlier than crop emergence within 24 hrs of crop sowing

1. Pendimethalin @ 1L/A both for large-leaved weeds and grasses

2. S-metolachlor @ 800ml/A each for enormous leaved weeds and grasses

3. Pendimethalin + S-metolachlor (dual gold) @ 800ml/A

4. Acetochlor+ Pendimethalin @1L/A

B) Post-emergency herbicides:

1. Haloxyfop @350 ml/A for grasses

2. Quizilafop-p-ethyl 15EC @ one hundred-a hundred and twenty ml/A for all weeds

3. Quizilafop-p-ethyl 5EC @ four hundred-500 ml/A for all weeds

Insect Pests:

1. Sucking bugs:

• Aphid, jassid, whitefly, thrips, mites, mealy insects, dusky cotton malicious program
• A spray of Confidor, Imdacloprid, Buperofezin, Acetamiprid, Talstar, and many others.

2. Borers:

• I noticed bollworms, red bollworms, American bollworms, military worm
• A spray of Karate, Cypermethrin, Spinosad, Chlorpyrifos

Diseases and their Symptoms:

Verticillium wilt: A fungal disorder that reasons yellowing and wilting of leaves and stems.

Fusarium wilt: A fungal disease that influences the roots and stem of the plant, inflicting yellowing, wilting, and eventual death.

Bacterial blight: A bacterial disorder that reasons yellowing and wilting of leaves and might additionally cause plant death.

Cotton leafroll dwarf virus: A viral ailment that reasons stunting and yellowing of the plant.

Target spot is a fungal disease that reasons circular spots at the leaves, mainly defoliation, and decreased yield.

Alternaria leaf spot: A fungal sickness that reasons round or irregularly fashioned darkish spots at the leaves, which can cause defoliation and decreased yield.

Harvesting:

    The primary steps in the cotton harvesting manner are:

• Maturity assessment: The cotton flowers are monitored for adulthood and boll beginning to determine the most useful time for harvesting.
• Cutting: The cotton flowers are cut with the use of either a mechanical cotton picker or a guide cotton stripper. The mechanical picker makes use of a rotating drum to cast off the cotton bolls from the plant, while the manual stripper involves manually doing away with the bolls by hand.
• Gathering: The harvested cotton bolls are amassed into massive piles or into cotton modules, which are large cylindrical bales of cotton.
• Transport: The harvested cotton is transported to a gin (short for "engine"), which is processed to separate the cotton fibers from the seeds and different plant debris.
• Ginning: The gin uses a mixture of mechanical and manual methods to separate the cotton fibers from the seeds and other plant particles.
• Baling: The wiped-clean cotton fibers are then compressed into bales, which are packaged and saved for later use within the manufacturing of cotton products.

    The timing and methods used for cotton harvesting can affect the first class and amount of cotton produced, so it's far critical to control the manner to maximize yields and limit waste cautiously.

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