40. Production Technology of Stevia

Stevia

 Introduction:

    Stevia is a plant species native to South America, particularly Paraguay and Brazil. It is a member of the sunflower family and has been used for centuries by the Guarani people of Paraguay as a natural sweetener for their tea and medicinal preparations.

    Stevia's sweet taste comes from a group of compounds called steviol glycosides, which are present in plant leaves. These compounds are 200-300 times sweeter than table sugar but have no calories or effect on blood sugar levels, making stevia an attractive alternative to artificial sweeteners.

    In the 20th century, stevia gained popularity as a sweetener in Japan, where it was approved for use in food and beverages in the 1970s. Since then, it has been approved as a sweetener in many countries around the world, including the United States and the European Union.

    Stevia is now commonly used as a sweetener in a variety of products, including soft drinks, baked goods, and other processed foods. It is also available in a granulated form for home use as a sugar substitute in cooking and baking.

Botanical Characteristics:

    Stevia, scientifically known as Stevia rebaudiana, is a perennial plant that can reach a height of 60-100 cm. The leaves of the plant grow opposite to each other and are sessile, ranging in size from 2 cm to 10 cm. Each plant can have up to 40-45 leaves.

    Stevia is typically grown in semi-humid subtropical regions with temperatures ranging from 20-30 degrees Celsius. It requires well-fertile soil that is rich in organic matter and has a pH level between 6.5-7.5. Sandy loam soil is preferred for cultivation, while soils with high salt or salinity are not suitable for growing stevia.

Production Technology

Land Preparation:

    Before planting stevia, it is crucial to properly prepare the field. This involves plowing the land 2-3 times to bring the soil to a fine tilth. During the plowing process, trichoderma should be mixed thoroughly with the soil. In the final plowing, farmyard manure (FYM) should be incorporated into the soil to provide additional nutrients.

Soil Type and climate:

    Stevia can be grown in a variety of soils, although it performs best in sandy loam to loamy soil with good drainage and high organic content. It is important to avoid cultivating stevia in saline soils, as these can be harmful to the plant's growth and yield. The ideal pH range for stevia cultivation is between 6 and 8.

Nursery Establishment:

    To start stevia cultivation, it is recommended to sow the seeds indoors in containers for 6-8 weeks. After sowing, it is important to cover the beds with peat moss and provide adequate watering to retain moisture in the soil.

    For bushier growth, it is recommended to pinch the tips of the plant before transplanting. This encourages the growth of lateral shoots and results in a fuller plant.

    When the seedlings are ready for transplantation, typically after 6-8 weeks, they should be transplanted onto raised beds that are 60cm wide and 15cm in height. It is important to water the seedling beds 24 hours before transplanting to ensure that the seedlings can be easily uprooted and are turgid at the time of transplantation.

Sowing

Time of sowing:

    The ideal time for sowing stevia is between February and March. This period provides optimal conditions for seed germination and early growth of the plant. It

Spacing:

    When transplanting stevia seedlings, they should be spaced approximately 18 inches apart to provide enough room for the plants to grow and spread out. The row spacing should be 20-24 inches apart, allowing for adequate airflow and room for maintenance between the rows.

Seed Rate:

    When transplanting stevia seedlings into the main fields, it is recommended to use a plant density of approximately 30,000 seedlings per acre. 

Raised Bed Preparation:

    Forming raised beds is considered the most effective and cost-efficient method for growing stevia. The recommended height for the raised bed is 15cm or half a foot, with a width of 15cm or half a foot as well. To ensure adequate spacing between the plants, a distance of 15cm is suggested between each plant, with a distance of 30cm or one foot between each row.

    By utilizing raised beds and following the recommended spacing, it is possible to establish approximately 50,000 stevia plants within one acre of land. 

Fertilizer:

    To achieve optimal production of stevia, it is recommended to apply a specific amount of fertilizers to the soil. Generally, two bags of urea, one bag of DAP, and one bag of potassium sulfate should be applied per acre of land.

Irrigation:

    Irrigation for stevia cultivation is typically performed using either sprinkler systems or drip irrigation. As the plant does not require excessive water, light irrigation is recommended at regular intervals. During the summer months, it is recommended to irrigate at intervals of every 8 days to prevent over-watering. It is important to avoid allowing water to stagnate in the field, as this can harm the stevia crop.

Weed control:

To control weeds in the field, hand weeding is typically performed. The first weeding is usually carried out approximately one month after planting, with subsequent weeding conducted every two weeks thereafter. Intercultural operations are also performed to remove weeds since the crop is grown on raised beds, which makes it easy for labor to access and maintain. By carefully managing weed growth, growers can help ensure that their stevia plants have the necessary resources to grow and produce a high-quality yield.

Plant Protection Measures

Pests and Their control:

    Aphids are soft-bodied sucking insects that are nearly transparent. When present in large numbers, they can cause leaves to yellow and die prematurely.

Control:

    To manage aphids, growers can use chrysoperla predators at a rate of 4-6 thousand per acre or use 50 grams of neem concentrate per liter. These methods are effective in reducing the population of aphids and preventing damage to stevia plants. 

Disease and their control:

    Stevia is vulnerable to root rot disease, which is caused by a fungus that is often present in the soil. The disease first appears as yellowing of the lower leaves, which then spreads to the upper parts of the plant and causes them to dry up. Root rot is most common in the early stages of growth and can cause the roots of affected plants to become weak and easily break.

Control:

    To control root rot disease, growers can mix 400 grams of Topsin-M with 100 liters of water and spray it around the roots of the affected plants. This method is effective in managing the spread of the fungus and helping to prevent further damage to the crop.

Harvesting:

    Harvesting of Stevia can be done when the plant attains a height of 40-60 cm. Flowering is induced by shorter days, which can impact the quality and quantity of the stevioside content.

Yield:

    Typically, three to four harvests are conducted annually, resulting in an average yield of 3-3.5 tons of dry green leaves per hectare. Stevia plants can be grown for up to five years after the initial planting, providing a sustainable source of leaves for production.

Drying and Threshing

    The drying time for Stevia depends on factors such as weather conditions and loading density, typically ranging from 24 to 48 hours at a temperature of 40°C to 50°C. Once the leaves are dried, a specialized thresher/separator is required to remove the dry leaves from the stems.:

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39. Agricultural Biotechnology and Its Pros and Cons

 Agricultural Biotechnology

Definition:

    Agricultural biotechnology involves the application of cutting-edge biological techniques, such as genetic manipulation, to alter agricultural practices and products.

Introduction:

    There are advocates and critics of utilizing biotechnology in agriculture. Advocates assert that biotechnology can enhance agricultural productivity by increasing crop yields and bolstering crops' immunity against pests and diseases. Additionally, they maintain that biotechnology has the potential to conserve resources by minimizing the requirement for pesticides and herbicides. On the other hand, detractors express concerns about the potential hazards associated with genetically modified organisms (GMOs), such as unanticipated ecological consequences and the risk of GMOs cross-pollinating with non-genetically modified crops.

    Agricultural biotechnology is a widely used method to propagate desirable traits and enhance productivity. This is accomplished through selective breeding, which involves manipulating the organism's genetic makeup. By utilizing biotechnology, crops, and animals can experience improved growth, decreased reliance on pesticides, and heightened nutritional quality. However, it is important to acknowledge that agricultural biotechnology may also have negative impacts on human health and the environment.

Pros of Agricultural biotechnology 

• Biotechnological Approaches to Enhance Nutritional Quality:

    Nutrient levels, including vitamins, are enhanced as a result of biotechnological approaches, resulting in improved dietary quality of food products. One example is golden rice, which has been genetically modified to contain three genes that enable humans to produce vitamin A. Similarly, the Banana 21 project has successfully enhanced the nutritional value of bananas by incorporating iron and vitamin A.

• Biotechnological Techniques for Enhancing Good Traits in Crops and Livestock:

    Agricultural biotechnology enables the propagation of desirable traits in plants and animals. This has been achieved through genetic modifications that result in animals with enhanced traits, such as rapid growth and heightened disease resistance. Additionally, biotechnology has been used to clone the growth hormone gene in cattle, resulting in increased milk production in dairy cows. Certain environmental conditions, such as low temperatures and high atmospheric pressure, can render some regions unsuitable for crop cultivation.

• Biotechnological Approaches for Reducing Pesticide Use:

    Agricultural biotechnology offers a solution for minimizing the use of pesticides by engineering crops with heightened resistance to pests and diseases. This increased resistance can lead to improved growth and higher food production. By reducing the need for excessive chemical application, the cost of production can be lowered and yields increased. Furthermore, minimizing chemical use in agriculture can reduce water and soil pollution, as chemical usage is one of the primary contributors to environmental contamination.

Cons of Agricultural biotechnology

• Antibiotic Resistance:

    In agricultural biotechnology, antibiotic resistance genes are commonly utilized as markers to identify the presence of newly introduced desirable traits in plants. While this technique has proven effective in verifying successful gene transfer, there is a potential risk associated with the use of these genes. Specifically, there is concern that the utilization of antibiotic-resistance genes may lead to the emergence of new antibiotic-resistant bacteria, which can be difficult to treat using conventional antibiotics.

• Health Risks and Concerns Associated with Agricultural Biotechnology:

    Agricultural biotechnology is a relatively new field, and the potential effects of its implementation on both the environment and human health remain uncertain. Opinions on this matter are divided, as experts are still investigating the potential health effects of genetically modified products on human beings. Genetic engineering, which is a common practice in agricultural biotechnology, involves the use of antibiotic-resistant genes as markers, which may have negative implications for health. Inserting these genes into a plant's genome could reduce the effectiveness of antibiotics and potentially transfer the resistance gene to pathogens, thus increasing their resistance to antibiotics.

• Negative Effects of Agricultural Biotechnology on the Environment:

    The effects of agricultural biotechnology on the environment are not yet well understood due to the relatively recent development of the field. However, research has indicated that the use of biotechnology in agriculture may lead to the proliferation of herbicide-resistant weeds, which can have negative consequences for the ecosystem. Genetic engineering involves the transfer of specific genes between organisms, which can result in the unintentional transfer of unwanted genes into weeds and pests, making them more difficult to eradicate. Furthermore, the transfer of genes that make microorganisms such as bacteria and viruses more virulent may result in the emergence of new, potentially harmful strains. In addition, genetically engineered plants may produce new proteins that could be toxic to wildlife, further impacting the environment.

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Food Safety Issues in Modern Agriculture

Modern Agriculture:

    Modern agriculture refers to the advanced farming practices and technologies that have been developed and adopted over the past century to increase agricultural productivity and efficiency. This includes the use of advanced machinery, genetically modified crops, synthetic fertilizers and pesticides, and precision agriculture techniques.

    One of the key features of modern agriculture is its focus on maximizing yields and profits through the use of technology and scientific knowledge. Farmers and agricultural companies use a variety of techniques and tools to monitor and manage crop growth, including sensors, drones, and satellite imaging. They also rely on genetic engineering and other biotechnology to develop crops that are more resistant to pests and diseases, have higher nutritional value, and can be grown in a wider range of environments.

    Overall, modern agriculture represents a significant transformation in the way we produce and consume food, and it will continue to shape our relationship with the natural world in the years to come. 

Food Safety Issues in Modern Agriculture:

    Modern agriculture has made great strides in increasing productivity and efficiency in food production, but it has also given rise to a number of food safety issues. From the use of pesticides and fertilizers to the risks of contamination during processing and transportation, there are a variety of potential hazards that can compromise the safety of our food supply. In this essay, we will explore some of the key food safety issues in modern agriculture and examine some of the steps that can be taken to mitigate these risks.

Use of Pesticides and Fertilizers:

    One of the most significant food safety issues in modern agriculture is the use of pesticides and fertilizers. These chemicals are essential to modern farming practices, as they help to control pests and increase crop yields, but they can also pose a risk to human health and the environment. Pesticides and fertilizers can contaminate soil and water, leading to health risks for farmers and nearby communities, as well as potential food safety risks if crops are contaminated. To mitigate these risks, it is important to follow strict regulations and best practices for the use of pesticides and fertilizers, as well as to develop new, more sustainable approaches to pest and weed management.

Risk of Contamination during Processing and Transportation:

    Another key food safety issue in modern agriculture is the risk of contamination during processing and transportation. As food products move through the supply chain, there are many opportunities for contamination to occur, from the use of contaminated water to improper handling and storage. This can lead to foodborne illness outbreaks and recalls, as well as economic losses for farmers and food companies. To address these risks, it is important to implement robust food safety management systems and supply chain traceability, as well as to promote education and awareness among farmers, processors, and consumers.

Animal agriculture:

    Animal agriculture is also a significant contributor to food safety issues, particularly with regard to the use of antibiotics and growth hormones in livestock. Antibiotics are commonly used to promote growth and prevent disease in livestock, but this practice can lead to the development of antibiotic-resistant bacteria, which can pose a significant risk to human health. Similarly, the use of growth hormones in livestock can lead to concerns about the safety of meat and dairy products, as well as potential health risks for humans who consume these products. To address these risks, it is important to promote the responsible use of antibiotics and growth hormones, as well as to develop new, more sustainable approaches to animal agriculture.

Sustainability and the Environmental Impact of Agriculture:

    Finally, food safety issues in modern agriculture are closely linked to broader concerns about sustainability and the environmental impact of agriculture. As the global population grows and the demand for food increases, it is important to develop more sustainable approaches to agriculture that balance the needs of food production with environmental protection and conservation. This might include the use of regenerative agriculture practices, such as cover cropping and crop rotation, as well as the promotion of sustainable livestock management practices, such as rotational grazing and manure management.

Conclusion:

    To summarize, food safety is an urgent concern in modern agriculture, and it is vital to implement measures to prevent contamination and minimize the possibility of food-related illnesses. This can be achieved by increasing regulations, embracing modern technologies, educating and training workers, and improving traceability. It is imperative that all stakeholders, including consumers, policymakers, agriculture professionals, and food safety experts collaborate to ensure the safety and security of our food supply.

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38. زراعت کی تاریخ

 زراعت کی تاریخ:

مصر میں 7000 ق میں زراعت پہلی بار اختیار کی گئی اور بھارتی ذیلی قارہ میں مہرگڑھ ، بلوچستان میں گندم اور جو کا کاشت کیا گیا تھا۔ 6000 ق میں، نیل کے کناروں پر قدیم زراعت شروع ہوگئی جہاں چاول کے ساتھ گندم ایک اہم فصل تصور کیا جاتا تھا۔ چین اور انڈونیشیا میں ، ٹارو ، مونگ اور ازوکی جیسی فصلیں تیار کی جاتیں تھیں۔ البتہ آبی نظم و بندی کے غلط استعمال کی وجہ سے، ان فصلوں کا کاشت صرف ندیوں اور کینالوں کے کناروں کے قریب کیا جاتا تھا۔ ان فصلوں کو پسند کیا جاتا تھا کیونکہ ان میں کاربوہائیڈریٹس اور ضروری پروٹین کی بڑی مقدار شامل ہوتی ہے۔ ان نئی کاشتکاری اور مچھلی پکڑنے کے طریقوں کے اختیار سے انسانی تہذیب میں اضافہ ہوا۔

    تاریخی ثبوت کے مطابق، زراعت کے پھیلاؤ کو بھی ہوا سہارا خطے سے لوگوں کے ماؤوجودہ کمیونٹیوں کی مہاجرت سے مدد ملی تھی، تقریباً 6500 سال پہلے۔ اس وقت تک، سمیریونز نے پہلے ہی بڑے پیمانے پر زمین کی کاشت، منو کراپنگ، تنظیم شدہ آبپاشی، اور متخصص کامگر قوتوں کے استعمال جیسی بنیادی زراعتی تکنیکوں کا ترقی دیا تھا۔ یہ تکنیکیں آج شاہراہ شط العرب کے نام سے جانی جاتی ہیں جو خلیج فارس ڈیلٹا سے ٹگرس اور یوفریٹیس دریاؤں کے ملانے کی جگہ تک پھیلتی ہے۔ پہلے زمانے میں، فصلوں کی کاشت عموماً شخصی استعمال کے لئے کی جاتی تھی، لیکن وقت کے ساتھ ساتھ، بہت سے ممالک تجارتی مقاصد کے لئے فصلوں کی کاشت شروع کردی اور تبادلہ کے لئے بارٹر سسٹم کا استعمال کرنے لگے۔

زراعت پودوں اور جانوروں کی کاشت کرنے کی عمل ہے جس سے غذائی اشیاء، جانوروں کا خوراک، ریشے، ایندھن اور مزید مختلف مہیا کرنے کے لئے اشیاء بنائی جاتی ہیں۔

زراعت کے ترقی کے پہلے لوگ عموماً شکاری اور جمع کرنے والے تھے، جو اپنی زندگی کے لئے قدرتی وسائل پر منحصر تھے۔ لیکن جب انسانوں کو مٹی کی حفاظت اور کاشت کے اہمیت سمجھ آئی، تب وہ قراردادی جماعتیں بنانے اور زراعت کو زندگی کا ایک طریقہ بنانے کے قابل بنے۔ اس سے قبائل اور کلان بننے لگے جو ایک جگہ میں رہ سکتے تھے اور آئندہ نسلوں کو زراعت کے علم کو ایک نسل سے دوسرے نسل کے درمیان منتقل کرسکتے تھے۔ زراعت کے اضافے کے ساتھ شہریں پیدا ہونا شروع ہوگئیں، اور ان کے درمیان تجارتی تعلقات مضبوط ہونے شروع ہوگئے۔ اس کے نتیجے میں انسانی معاشرے کے بناوٹ شروع ہوگئی، اور افراد اور گروہوں کے درمیان تعلقات پیچیدہ تر ہوگئے۔

کاشتکاروں نے دوران وسطی عصر، شمالی افریقہ اور قریب الشرق میں آبادی کے اصولوں پر بنیادوں پر بنے آبپاشی نظاموں کے ساتھ کھلی۔ ان میں ہائیڈرولک اور ہائیڈروسٹیٹک اصولوں پر مبنی آبپاشی نظاموں، پانی کی چکیوں یا نوریوں جیسی مشینوں کا استعمال اور پانی کی اونچائی کو بڑھانے والی مشینوں، بندوبستوں اور جنگلی علاقوں کا کشت پر زمین کا استعمال شامل ہے۔ اس دوران چینیوں کی مولڈبورڈ پلاؤ کی تشکیل ان کا اہم ترین کردار تھا۔

سن 1492 کے بعد، کروپس اور مویشی کا عالمی تبادلہ ہوا جس نے تمباکو، آلو، اور کافی جیسی نئی کروپ کی درآمد کی۔ یہ درآمد آبادی کی بڑھتی کی وجہ بنی۔ دو سو بیسویں صدی کی ابتدائی دہائی میں، منتخب نسلوں اور کشتکاروں کی مستقبل کے لئے درست انتخاب کی وجہ سے کروپس کی پیداوار تیزی سے بڑھ گئی۔ اس دوران، میکانیزڈ زراعت کا تعلق رکھتا ہوا ٹریکٹر کا ایجاد ہوا۔ اس ایجاد نے زراعت میں طلبہ کی مقدار کم کرنے میں مدد کی۔ بیسویں صدی کی ابتدائی دہائی میں، بہت سارے مزارع امریکہ، جرمنی، ارجنٹینا، اور دیگر ممالک میں قائم

برٹش زراعتی انقلاب:

بارہویں صدی سے آٹھارویں صدی تک، برطانیہ نے زراعتی پیداوار میں تیزی سے اضافہ کا سامنا کیا جس کو برٹش زراعتی انقلاب کہا جاتا ہے. یہ "انقلاب" کسی بھی زراعتی طریقے کی مختلف بہتریوں سے مشتمل تھا جو کہ کم اور زیادہ بالترتیب کئے جاتے تھے. کسانوں نے فصل کی ترتیب کے نئے طریقوں کو ترقی دی، جنمادے یا جنگلی زمین کا کاشت کرنا شروع کیا، اور شلجم جیسی نئی فصلیں بوائیں۔

اس میدان میں ایجادات:

خوراک کی پیداوار اور تقسیم میں ایجادات کا باعث آبادی کی مضافت کی خوراکی مانگوں کو پورا کرنے کے لئے اہم کردار ادا کرتے ہیں۔ مکسیکو، امریکہ کے شہریار ٹٹو، اور کسافا جیسے پودے جو امریکہ میں پائے جاتے تھے، دنیا بھر میں پھیل گئے اور ان کے اعلیٰ غذائی اجزاء نے کم تغذیہ پذیری کو روکا اور آبادی کی مضافت کی مدد کی۔ 18ویں صدی میں، نقل و حمل کے میدان میں اقدامات، جن میں بڑھتے ہوئے ریلوے، شپنگ کینال، اور نئی اناج کی ذخیرہ اور نقل و حمل مشینری شامل تھیں، نے امریکہ کو گندم اور مکئی کا اہم بیرونی فروخت کرنے والا بنا دیا، جس نے اروپا میں خوراک کی کمی کے دوران خوراک کی مانگ کو پورا کرنے میں مدد کی۔ ٹھنڈے نقل و حمل کے تیاری کے ترقیات نے بھی کسانوں کو ناقابل تحمل خوراک کی بھیجیاں بڑی فاصلوں تک بھیجنے کی اجازت دی، جس نے خوراک کی زیادہ بہترین اور وسیع پھیلاؤ کی اجازت دی۔

Wheat Production Technology in Pakistan

 Production Technology of Wheat in Pakistan

    Wheat is widely grown in various regions of Pakistan, with the typical planting time following cotton, rice, and sugarcane in irrigated areas. In both Pakistan and India, wheat yields tend to be higher in irrigated regions than in rainfed areas. To increase wheat production by up to 25%, farmers often employ crop rotation techniques.

    Compared to other cereal crops, wheat typically has a higher protein content. By utilizing a balanced approach to fertilizer use, we can effectively manage wheat production and ensure high-quality yields.

Growth stages of wheat:

    The wheat plant goes through several distinct stages of growth, including:

1. Pre-emergence stage
2. Emergence stage
3. Vegetative stage
4. Root growth stage
5. Tillering stage
6. Jointing stage
7. Reproductive stage
8. Maturity stage

    Each of these stages is critical to the plant's growth and development, from the initial germination of the seed to the maturation of the wheat grain. By understanding these stages and managing the crop accordingly, farmers can help ensure healthy growth and maximize yields.

1.  Pre-emerging stage:

    The germination of seeds gives rise to seminal roots and coleoptiles.

2. Emergence stage:

    When wheat seeds begin to germinate, the coleoptile emerges from the soil and becomes visible above the surface.

3. Vegetative stage:

As young wheat plants continue to grow, they establish a more extensive root system that allows them to absorb water and nutrients more efficiently from the soil.

5. Tillering stage:

    The tillering stage is a critical growth phase for wheat plants. During this stage, the plant begins to produce additional stems from the base of the main shoot. These additional stems, known as tillers, grow upward and develop their own leaves, which increases the overall leaf area of the plant.

    Tillering typically begins 2-3 weeks after emergence and continues for several weeks, with the number of tillers increasing as the plant develops. The extent of tillering can be influenced by several factors, including temperature, moisture, and soil fertility. With adequate moisture and nutrients, the plant can produce a greater number of tillers, which can ultimately lead to a higher grain yield.

6. Jointing stage:

    The jointing stage is an important growth phase in the development of wheat plants. It typically occurs around 6-7 weeks after emergence, depending on environmental conditions. During this stage, the stem of the wheat plant begins to elongate rapidly, and the first node appears at the base of the flag leaf.

7. Reproductive stage:

    At this stage, spikes become emerging from the leaf sheath.

8. Maturity stage:

    The maturity stage is the final growth phase in the development of the wheat plant. During this stage, the wheat plant has completed its reproductive phase, and the grain has reached its maximum size and weight. The plant's leaves and stems begin to turn yellow and die back, and the grain begins to dry and harden.

Wheat varieties growing in Irrigated Areas:

    There are several wheat varieties that are commonly grown in irrigated areas of Pakistan, including:

    Seher, Punjab-96, Kiran-95, NARC-2009, Inqilab-91

Verities of Rain-fed areas:

• The following are examples of wheat varieties commonly grown in Pakistan:
• Pakistan 2013, NARC 2009, Chakwal 50

In KPK Irrigated areas:

• Hashim 2008, Pirsabak 2008, NARC11, Pirsabak 2004

In KPK Rain-fed areas:

• Dharabi, Tatara, NIFA, Lalma 2013, Shahkar 2013

Preparation of soil before sowing:

• Use disease-resistant wheat seed varieties or use disease-free seeds for planting to mitigate the effects of the disease.
• Soak the seeds in water for 4-6 hours and then dry them under shade before sowing.
• Treat the seeds with fungicide at a rate of 2gm/kg to further prevent disease.
• Ensure that the soil surface is level for proper distribution of water and soil moisture.
• Prior to sowing, plow the soil surface with a chisel plow and uproot any weeds to prevent competition with the wheat.
• Use a rotavator to break up any soil clods and create a fine, even soil bed.
• Apply manure properly to the leveled field to increase the efficiency and productivity of the wheat crop.

Pre-harvest Management Practices

Planting Method:

• The drill sowing method is considered the optimal approach for wheat cultivation, as it facilitates uniform seed placement, appropriate seed depth, and improved crop yields.
• However, in many wheat-growing regions of Pakistan, the broadcast method is widely used due to its simplicity and lower cost. This method involves spreading wheat seeds over the soil surface and then using a light tillage method to incorporate the seeds into the soil.

Irrigation:

• The number of required irrigations for wheat may vary depending on the specific soil and region. Typically, wheat cultivation requires 4-7 irrigations throughout the growing season.
• Irrigation is particularly crucial 20-25 days after sowing, during the booting stage, and at the milking stage. These stages are critical for wheat growth and development and require sufficient water to ensure optimal yields.

Green Manuring:

• The addition of organic matter is a crucial factor in promoting optimal wheat growth and achieving high crop yields. Farmyard manure is an excellent source of organic matter and can be applied to the field at a rate of 8-10 tons per acre to improve soil quality.
• Adding farm yard manure to the soil can help to increase soil fertility, promote soil structure, and increase soil water-holding capacity. By improving the organic matter content of the soil, farmers can promote healthier crop growth, reduce the incidence of plant diseases, and achieve higher yields.

Fertilizer Usage:

• For average soil add 1-2 bags of DAP and 2-3 bags of urea before the sowing of wheat. 

Foliar Application:

    Mostly the soil of Pakistan is deficient in zinc. To tackle this problem zinc is applied at the interval of 15 days. 

Weeding: 

    Hoeing and Chemical applications are used to remove the weeds in the field. 

Disease-free seed:

    It is very important for the better production of wheat with the best quality grains using disease-free seeds.

Post Harvest care

Harvesting and threshing:

• For threshing use disease-free equipment for the proper and pure wheat seeds. Ask the thresher operator to clean their tools before entering the field.

Shattering:

• Avoid excessive shattering of wheat seeds in the field. Shattering can happen in the field through birds, tools, and also through dispersing wind.

Transportation: 

• It is the main reason in Pakistan for the loss of grains on a large scale. It is estimated that about 15.3% of losses occur due to transportation in Pakistan. But losses on an experimental basis in UAF are about 7.37%. 

Delayed Threshing in the field:

•  There is no delay in threshing if this happens then wind and rains cause severe losses. 

Reasons for threshing losses:

• Threshing tools should be properly cleaned before use to avoid contamination from previous harvests.
• It is important to have a skilled operator to handle the thresher to avoid any damage to the grain and ensure proper separation of wheat from the straw.
• Threshing should be done in the direction of wind velocity to prevent the spreading of wheat straws over a large area.

Losses during storage:

• Avoid using chemicals for long-term storage, as they may not be suitable for household use.
• Ensure that there is no entrance of air in the storage area to prevent mold and moisture buildup.
• Keep the storage area free from animals such as dogs, cats, rats, and other pests.
• Regularly inspect the storage area and the grain to check for any signs of insect or pathogen infestation.
• Use neem leaves to help prevent pathogen attacks in the storage area.
• Store wheat in an elevated area to prevent water damage and insect infestations.
• Maintain a moisture content level of 9-12% for proper storage.
• Use gunny bags, which are an effective option for wheat storage due to their breathable material and ability to prevent insect infestations.

Wheat diseases:

    There are some diseases and their control is given, these diseases included common bunt Tilletia caries, Kernal Bunt / Partial Bunt, Flag smut, Fusarium head blight, Fusarium wilt, etc.

To achieve better, pure, and healthier grains, it is crucial for farmers to adhere to the following instructions:

• For optimal crop growth, it is essential to cultivate the recommended varieties. 
• Weeds should be eliminated from the field to prevent competition for nutrients and resources. 
• To ensure consistency, it is recommended to grow the same variety in the same plot.
• Irrigation and fertilization should be applied on schedule to promote healthy growth and maximize yields. 
• If a pure variety of wheat is desired, it is important to use a cleaned thresher and its associated tools. 
• Additionally, the moisture content should be maintained below 10%.
• To further ensure the quality of the wheat, it is advisable to utilize seed graders to remove any contaminated wheat seeds. 
• Finally, to prevent pest infestations, fumigation can be carried out in the storage room.

References:

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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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36. Whip Smut of Sugarcane and Their Control

 Sugarcane

Introduction:

    Sugarcane is a valuable crop for growers as it serves as the primary source of white crystal sugar, and also provides alternative sources of sugar such as 'gur' and 'khandsari' (brown sugar). In addition, sugarcane tops can be used as cattle fodder, bagasse and leaf trash can be used as fuel, and the stubble and roots can serve as organic manure. Crop residues can also be utilized for mulch and compost. It is worth noting that sugarcane leaves are also used as a substrate for growing edible mushrooms.

    In Pakistan, sugarcane cultivation faces numerous challenges, including significant losses caused by various diseases. Over 50 diseases have been reported in sugarcane, with fungi, bacteria, viruses, and nematodes causing the most damage. The extent of losses varies depending on the crop variety and location, and cannot be ignored, neglected, or taken lightly as they can significantly impact the crop. These diseases can affect different plant parts, and their occurrence is influenced by a range of factors such as geography, weather, and time. Symptoms or signs of the diseases raise a concern about their potential effects on the quantity and quality of the sugarcane crop.

    Sugarcane, a crop grown in over 120 countries on around 26.27 million hectares, is the largest commercial crop globally. It yields approximately 1.90 billion tonnes worldwide, providing 80% of the world's sugar. The crop produces hundreds of tons of green matter per hectare annually, giving 75,000 million calories. However, sugarcane takes 12-14 months to mature and harvest, making it vulnerable to many biotic and abiotic factors, such as pathogens and insect pests that can reduce production by up to 20%. Fungal pathogens, in particular, pose a significant challenge, with over 100 fungi reported to cause sugarcane diseases.

Whip Smut of Sugarcane

Causal Organism:

    The fungal disease, known as smut, is attributed to Ustilago scitaminea. The fungus infects sugarcane plants via buds present on erect stems or sprouting buds in the ground. Once inside, the fungus establishes itself near the plant's growing points or meristems.

Symptoms:

• Sugarcane smut is identifiable by a black, whip-like structure that replaces the spindle leaf and grows from the sugarcane plant's growing point. Abnormal whips, sometimes containing flower parts, can also develop.
• The whips are produced in shoots arising from infected cane cuttings, contaminated soil, or side shoots from mature stalks. 
• The thin membrane of the whip eventually ruptures to release a mass of black spores, leaving behind a straw-colored core.
• Before whip formation, the youngest leaves undergo shortening and crinkling. 
• Infected plants tend to be stunted, and individual stalks appear thin and grass-like.

Disease Cycle:

    Sugarcane smut spreads through teliospores produced in the smut whip found in soil or on plants. Teliospores germinate in water and produce promycelium, which undergoes meiosis to form four haploid sporidia. The fungus is bipolar, producing two different spore types that must mate to create a dikaryon that infects sugarcane's meristematic tissue by penetrating bud scales. The fungus grows within the tissue, inducing flowering structures that it colonizes to produce teliospores. These structures transform into a whip-like sorus, covered by a silvery peridium that peels back to expose black-brown teliospores. These spores disperse via wind and repeat the cycle. Teliospores are reddish-brown, round or subovoid, smooth to moderately echinulate, and 6.5-8 um. Susceptibility to S. scitamineum populations in each area should be tested before distributing sugarcane cultivars.

Spread or Transmission:

    Sugarcane smut is mainly transmitted via wind-dispersed spores or by planting contaminated or infected cane cuttings. Typically, spores spread over short distances, up to 10-15 meters, but they can travel many kilometers during strong winds or cyclones. Spore transport on machinery and shoes is also feasible.

    Moist soil can support spore survival for only 2-3 months, whereas dry soil or other arid environments can sustain them for longer periods. The fungus remains viable within infected sugarcane plants as long as the host plant is alive, as it requires a living plant to produce spores.

Control:

1. It is advisable to avoid using sets from sugarcane plants affected by smut for planting.
2. Seed sets can be disinfected by immersing them in a solution of 0.1% mercuric chloride or formalin for 5 minutes, followed by covering them with a moist cloth for 2 hours. Other effective chemicals available in the market can also be used.
3. Internal infection can be eliminated by exposing sets to hot water treatment at 52°C for 18 minutes.
4. Sugarcane plants affected by smut should be uprooted and burned before the spores burst.
5. It is recommended to avoid ratooning of crops affected by the disease.
6. Practicing suitable crop rotations with non-host crops can help in controlling the disease.
7. Planting sugarcane in healthy soil is essential to avoid infection.
8. Where the disease is prevalent, it is advisable to use dry sowing for the crop.
9. Autumn planting of sugarcane should be avoided.
10. Encouraging the use of resistant varieties is recommended to help control the spread of the disease.

References:

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35. Mango Anthracnose and Its Impacts

 Mango 

Introduction:

    Mango, a stone fruit that is safe to eat, is derived from the tropical tree Mangifera indica. It is believed to have originated in the region encompassing northwestern Myanmar, northeastern India, and Bangladesh. M. indica has been grown in South and Southeast Asia since ancient times, resulting in two types of modern mango cultivars: the "Indian type" and the "Southeast Asian type". The majority of other species in the Mangifera genus that produce edible fruits are also referred to as "mangoes" and are found in the Malesian ecoregion.

    There are several hundred cultivars of mango worldwide, and the fruit varies in size, shape, sweetness, skin color, and flesh color, which can be pale yellow, gold, green, or orange, depending on the cultivar. Mango is the national fruit of India, Pakistan, and the Philippines, while the mango tree is the national tree of Bangladesh.

Mango Anthracnose

Causal Organism:

Colletotrichum gloeosporioides

Hosts:

    The fungus that causes anthracnose in mango can also infect several other crops, including avocado, capsicum, coffee, eggplant, papaya, tomato, and yam. Different strains of the fungus can infect various crops and weeds.

Symptoms:

• Anthracnose is a disease that affects various parts of the mango tree, including leaves, twigs, petioles, flower clusters (panicles), and fruits. 
• Symptoms of anthracnose on leaves appear as small, angular, brown to black spots that can expand and cause extensive dead areas. 
• During dry weather, the lesions may fall off the leaves. On panicles, the first signs of the disease are small black or dark-brown spots that can coalesce, enlarge, and kill the flowers before the fruits are produced, leading to a significant reduction in yield. 
• Petioles, twigs, and stems can also be affected, and they show the typical black, enlarging lesions found on fruits, leaves, and flowers. 
• Ripe fruits that are afflicted by anthracnose develop sunken, prominent, dark brown to black decay spots before or after harvesting. The fruits may fall from the trees prematurely.
• Anthracnose can cause extensive fruit rotting as the spots on the fruit coalesce and penetrate deep into it. 
• Infections in green fruits mostly remain latent and unnoticeable until ripening. Thus, fruits that seem healthy at harvest can quickly develop significant anthracnose symptoms when they ripen. 
• A second type of symptom on fruits is the "tear stain," where linear necrotic regions on the fruit, which may or may not be associated with superficial cracking of the epidermis, resulting in an "alligator skin" effect, and deep cracks in the epidermis that extend into the pulp.
• On stems and fruits, lesions can produce conspicuous pinkish-orange spore masses in wet conditions. 
• Anthracnose infections are favored by warm, humid weather conditions in the field. Post-harvest, warm and humid temperatures promote the development of anthracnose.

Disease Cycle:

      The pathogen responsible for anthracnose in mango is disseminated passively by splashing rain or irrigation water through its spores (conidia). These spores land on infection sites, such as leaves, panicles, or branch terminals, where they germinate and penetrate immature fruits and young tissues by ramifying through the tissues. In mature fruits, infections penetrate the cuticle but remain dormant until the onset of fruit ripening.

        Affected organs develop rapidly expanding, sunken, black lesions and symptomatic tissue produces sticky masses of conidia during moist conditions, especially rainy or humid weather. The fungus can undergo multiple disease cycles, multiplying during the season. It survives between seasons on infected and defoliated branch terminals and mature leaves.

Management

Cultural control:

    To reduce humidity and prevent the onset of anthracnose in mango trees, it is crucial to prune them and ensure that there is free airflow throughout the tree canopy. It is recommended to keep the trees below 4 meters in height to facilitate easy management and harvesting. Infected twigs should be removed and burned, and fallen leaves should be disposed of in the same manner.

Resistant Varieties:

    The Indo-Chinese and Philippine mango varieties are believed to possess some resistance to anthracnose, and their potential to resist the fungus should be evaluated in Pacific island nations. These varieties are known for their excellent flavor and low-fiber flesh.

Chemical control:

    To manage Glomerella leaf and flower blight, regular and timely use of fungicides is essential. Application of chemicals should commence when flowers first appear and continue at recommended intervals (such as 3 to 4 weeks) until the pre-harvest waiting period. In Australia, several fungicides, including mancozeb and copper, are registered for anthracnose control. Post-harvest treatment options for controlling fruit infections include dipping the fruits in fungicide (such as carbendazim) and hot water. Both treatments should last for 5 minutes at 52°C. When using carbendazim, it is important to use 3 liters of dip per kilogram of fruit.

Impacts:

1. Wet weather exacerbates the damage caused by the Stigmina fungus.
2. The fungus causes black spots on the leaves, which can expand to form large black areas.
3. In addition to the aesthetic damage, wet weather can cause early leaf fall due to the fungus.
4. The damage caused by Stigmina is primarily to the leaves of the plant and does not affect fruit or shoots.
5. Plant diseases have a significant impact on global food production and contribute to shortages of both food and fruit.
6. Ghana's tree and horticultural crops are particularly vulnerable to diseases, which have been well documented.
7. Mango production in Ghana is an important economic crop, but it is threatened by multiple diseases due to the crop's susceptibility to fungal pathogens.
8. Mango's high water-nutrient content makes it a perfect medium for fungal pathogen development, leading to a high susceptibility to diseases.
9. Anthracnose disease, caused by Colletotrichum gloeosporioides Penz. & Sacc, is a major limitation to mango production, with reported yield losses of up to 30% in the Yilo Kobo District of Ghana.
10. The impact of anthracnose disease on mango production is not limited to Ghana, as it has been reported to cause yield losses of 39% in India and render 60% of harvested avocado fruits unmarketable in Kenya.
11. Finding effective ways to prevent and control plant diseases, including anthracnose disease, is critical for sustainable food production and economic development in affected regions.

References:

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