1. রোগের কারক (Causal organism):

এই রোগের কারণ একটি ভাইরাস যার নাম Potato Leaf Roll Virus (PLRV)।

এটি উদ্ভিদের খাদ্য পরিবহন ব্যবস্থাকে (phloem) আক্রমণ করে, ফলে গাছের বৃদ্ধি কমে যায় এবং কন্দের আকার ছোট হয়ে যায়।

2. বাহক পোকা (Vector):

• এই ভাইরাস প্রধানত ছড়ায় জাব পোকা (Aphid)।    সবচেয়ে গুরুত্বপূর্ণ বাহক হলো Green peach aphid (Myzus persicae)।
• এই পোকা আক্রান্ত গাছ থেকে সুস্থ গাছে ভাইরাস ছড়িয়ে দেয়।

3. রোগের লক্ষণ (Symptoms):

     পাতায় লক্ষণ-

• পাতার কিনারা উপরের দিকে মুড়িয়ে যায়।
• পাতা শক্ত ও মোটা হয়ে যায়।
• পাতার রং হালকা সবুজ বা হলদেটে হয়।
• নিচের পুরোনো পাতায় আগে লক্ষণ দেখা যায়।

     গাছে লক্ষণ-

• গাছ খাটো ও দুর্বল হয়ে যায়।
• বৃদ্ধি ধীর হয়ে যায়।
• ডালপালা কম বের হয়।

     কন্দে লক্ষণ-

• কন্দ ছোট হয়।
• কন্দের ভিতরে বাদামি জালের মতো দাগ (Net necrosis) দেখা যেতে পারে।
• সংরক্ষণ ক্ষমতা কমে যায়।

4. রোগ হওয়ার কারণ (Reasons / Favorable conditions):

      এই রোগ বেশি দেখা যায় যখন-

• আক্রান্ত বীজ আলু ব্যবহার করা হয়।
• জমিতে জাব পোকার আক্রমণ বেশি থাকে।
• শীতের শেষে তাপমাত্রা কিছুটা বাড়লে aphid দ্রুত বৃদ্ধি পায়।
• জমিতে আগাছা বেশি থাকলে ভাইরাসের উৎস তৈরি হয়।

5. রোগের বিস্তার (Mode of spread):

• জাব পোকার মাধ্যমে।
• আক্রান্ত বীজ আলুর মাধ্যমে।
• জমিতে স্বেচ্ছায় জন্মানো আলু গাছ (volunteer plants) থেকেও ছড়াতে পারে।

6. ব্যবস্থাপনা (Management):

      প্রতিরোধমূলক ব্যবস্থা-

• সবসময় রোগমুক্ত ও প্রত্যয়িত বীজ আলু ব্যবহার করতে হবে।
• জমিতে আগাছা নিয়মিত পরিষ্কার করতে হবে।
• আক্রান্ত গাছ শুরুতেই তুলে নষ্ট করতে হবে।
• হলুদ স্টিকি ট্র্যাপ ব্যবহার করলে aphid পর্যবেক্ষণ সহজ হয়।

7. রাসায়নিক নিয়ন্ত্রণ (Chemical Control – Aphid control):

ভাইরাস সরাসরি মারা যায় না, তাই বাহক পোকা দমন করাই প্রধান উপায়।

কার্যকর কীটনাশক সমূহ-

I. Imidacloprid 17.1% SL গ্রুপের কীটনাশক

ডোজ: 0.5-1 ml প্রতি লিটার জলে

বাণিজ্যিক নাম: Confidor

II. Thiamethoxam 25% WG গ্রুপের কীটনাশক

ডোজ: 0.25 gm প্রতি লিটার জলে

বাণিজ্যিক নাম:: Actara

III. Acetamiprid 20% SP গ্রুপের কীটনাশক

ডোজ: 0.5 gm প্রতি লিটার জলে

বাণিজ্যিক নাম: : TATA MANIK

অত্যধিক আক্রমণ হলে-

I. Dinotifuran 40% + Spinetoram 5% SC গ্রুপের কীটনাশক

ডোজ: 1-1.5 ml প্রতি লিটার জলে।

বাণিজ্যিক নাম: : Trassid

II. Spinetoram 11.7% SC গ্রুপের কীটনাশক

ডোজ: 1 ml প্রতি লিটার জলে

বাণিজ্যিক নাম: : Delegate

III. Abamectin 1.9% EC গ্রুপের কীটনাশক

ডোজ: 1 ml প্রতি লিটার জলে

বাণিজ্যিক নাম: : Abacin

স্প্রে করার সময় পাতার নিচের দিকে ভালোভাবে স্প্রে করতে হবে, কারণ এফিড সাধারণত পাতার নিচে থাকে।

8. গুরুত্বপূর্ণ পরামর্শ (Farmer Tips):

• বীজ আলু নির্বাচনই এই রোগ প্রতিরোধের সবচেয়ে গুরুত্বপূর্ণ ধাপ।
• নিয়মিত জমি পরিদর্শন করলে শুরুতেই রোগ ধরা যায়।
• প্রথম এফিড দেখা গেলেই স্প্রে শুরু করা উচিত।

1. Disease Name: Black Scurf of Potato

2. Causal Organism:

Rhizoctonia solani (fungus)

3. Affecting Stage:

• Affects the crop during the sprouting, vegetative, and tuberization stages.
• Primarily seen on tubers at harvest and during storage.

4. Symptoms:

Stem and Leaf Symptoms: 

• Poor emergence or irregular growth of plants due to damage to emerging sprouts.
• Dark brown lesions or cankers on the stem near the soil line, causing plant stunting.
• Severe infections may cause wilting, yellowing of lower leaves, and plant death.

 Tuber Symptoms: 

• Presence of black, hard, crust-like structures (sclerotia) on the tuber surface, giving it a rough appearance.
• Tuber infections may not penetrate deeply but can affect the marketability.
• In storage, infected tubers may develop dry rot or shriveling over time.

5. Favourable Conditions:

• Cool and moist soil conditions during sprouting and tuber formation.
•  
• Poor soil drainage or waterlogging.
• Use of disease infected seed tubers or planting in infested fields.
• Dense planting and poor crop rotation practices.

6. Cultural Control:

• Use certified, disease-free seed potatoes to prevent initial infections.
• Rotate crops with nonhost crops like cereals or legumes to break the disease cycle.
• Avoid planting in fields with a history of Rhizoctonia infection for 2-3 years.
• Practice proper soil drainage and avoid overwatering during the crop cycle.
• Ensure early planting in warmer soils to reduce disease severity.
• Harvest tubers at the right maturity to minimize sclerotia formation.

7. Organic Controls:

• Treat seed tubers with Trichoderma viride or Pseudomonas fluorescens to suppress the pathogen.
• Apply well decomposed organic manure or compost to improve soil health.
• Use neem cake or other biofertilizers as a soil amendment to reduce fungal inoculum.

8. Chemical Control:

• Treat seed tubers with Carbendazim 50% WP @ 2-3g/kg seed before planting.
• Use Fluopyram 17.7% + Tebuconazole 17.7% SC @ 1 ml/liter of water as a foliar spray to manage soilborne infections.
• Azoxystrobin 23% SC @ 1 ml/liter of water as a soil drench to reduce fungal inoculum.
• Validamycin 3% L @ 2 ml/liter of water for preventive soil treatment.

9. Trade Names of Chemicals:

• Bavistin (Carbendazim 50% WP) – BASF.
• Luna Experience (Fluopyram 17.7% + Tebuconazole 17.7% SC) – Bayer.
• Amistar (Azoxystrobin 23% SC) – Syngenta.
• Validacin (Validamycin 3% L) – Tata Rallis.

By implementing these management practices, Black Scurf of potato can be effectively controlled, improving crop health, yield, and marketability of tubers.

Black Scurf of potato:

1. Disease Name: Black Scurf of Potato

2. Causal Organism:

Rhizoctonia solani (fungus)

3. Affecting Stage:

• Affects the crop during the sprouting, vegetative, and tuberization stages.
• Primarily seen on tubers at harvest and during storage.

4. Symptoms:

Stem and Leaf Symptoms: 

• Poor emergence or irregular growth of plants due to damage to emerging sprouts.
• Dark brown lesions or cankers on the stem near the soil line, causing plant stunting.
• Severe infections may cause wilting, yellowing of lower leaves, and plant death.

 Tuber Symptoms: 

• Presence of black, hard, crust-like structures (sclerotia) on the tuber surface, giving it a rough appearance.
• Tuber infections may not penetrate deeply but can affect the marketability.
• In storage, infected tubers may develop dry rot or shriveling over time.

5. Favourable Conditions:

• Cool and moist soil conditions during sprouting and tuber formation.
• Poor soil drainage or waterlogging.
• Use of disease infected seed tubers or planting in infested fields.
• Dense planting and poor crop rotation practices.

6. Cultural Control:

• Use certified, disease-free seed potatoes to prevent initial infections.
• Rotate crops with nonhost crops like cereals or legumes to break the disease cycle.
• Avoid planting in fields with a history of Rhizoctonia infection for 2-3 years.
• Practice proper soil drainage and avoid overwatering during the crop cycle.
• Ensure early planting in warmer soils to reduce disease severity.
• Harvest tubers at the right maturity to minimize sclerotia formation.

7. Organic Controls:

• Treat seed tubers with Trichoderma viride or Pseudomonas fluorescens to suppress the pathogen.
• Apply well decomposed organic manure or compost to improve soil health.
• Use neem cake or other biofertilizers as a soil amendment to reduce fungal inoculum.

8. Chemical Control:

• Treat seed tubers with Carbendazim 50% WP @ 2-3g/kg seed before planting.
• Use Fluopyram 17.7% + Tebuconazole 17.7% SC @ 1 ml/liter of water as a foliar spray to manage soilborne infections.
• Azoxystrobin 23% SC @ 1 ml/liter of water as a soil drench to reduce fungal inoculum.
• Validamycin 3% L @ 2 ml/liter of water for preventive soil treatment.

9. Trade Names of Chemicals:

• Bavistin (Carbendazim 50% WP) – BASF.
• Luna Experience (Fluopyram 17.7% + Tebuconazole 17.7% SC) – Bayer.
• Amistar (Azoxystrobin 23% SC) – Syngenta.
• Validacin (Validamycin 3% L) – Tata Rallis.

By implementing these management practices, Black Scurf of potato can be effectively controlled, improving crop health, yield, and marketability of tubers.

2. Causal Organism:

Phytophthora infestans (fungus like oomycete)

3. Affecting Stage:

Can affect potato plants at any growth stage, but most severe during the vegetative and tuber formation stages.

4. Symptoms:

 Leaf Symptoms: 

• Initially, small, water-soaked spots appear on leaf tips or edges, often surrounded by light green halos.
• Spots enlarge, becoming brown to purplish black, and cause blighting of the leaf.
• During humid conditions, a whitish fungal growth can be seen on the underside of leaves near the lesion edges.
• Severely infected plants exhibit rapid wilting and drying of foliage.

 Stem Symptoms: 

Dark brown or black lesions develop on stems and petioles, leading to tissue collapse.

 Tuber Symptoms: 

• Tubers show brownish to purplish sunken lesions on the surface.
• On cutting, infected tubers reveal brown, granular, or corky rot extending into the flesh.
• Secondary infections by bacteria can lead to tuber soft rot.

5. Favourable Conditions:

• Cool and humid weather with temperatures between 10-25°C and high humidity (90% or more).
• Frequent rainfall, dew, or irrigation during susceptible growth stages.
• Dense planting and poor airflow in the crop canopy.

6. Cultural Control:

• Plant resistant varieties such as Kufri Jyoti, Kufri Himalini, or Kufri Bahar.
• Use certified disease-free seed potatoes to prevent initial inoculum.
• Avoid excessive irrigation and ensure proper field drainage to prevent waterlogging.
• Practice crop rotation with nonhost crops (e.g., cereals or legumes) to break the disease cycle.
• Remove and destroy infected plant debris and volunteers from previous crops.
• Apply mulches to reduce soil moisture fluctuations and protect tubers from infection.

7. Organic Control:

• Spray with neem oil or garlic based biopesticides as a preventive measure.
• Use of Trichoderma viride as a soil application or foliar spray to suppress the pathogen.
• Application of compost tea to boost plant immunity against infections.

8. Chemical Control:

• Mancozeb 75% WP @ 2.5g/liter of water (protective fungicide).
• Chlorothalonil 75% WP @ 2g/liter of water (contact fungicide with protective action).
• Metalaxyl 8% + Mancozeb 64% WP @ 2g/liter of water (systemic + contact action).
• Cymoxanil 8% + Mancozeb 64% WP @ 2g/liter of water (curative and protective fungicide).
• Propamocarb hydrochloride 722 SL @ 2.5 ml/liter of water (systemic fungicide).

9. Trade Names of Chemicals:

• Dithane M-45 (Mancozeb 75% WP) – Indofil.
• Kavach (Chlorothalonil 75% WP) – Indofil.
• Ridomil Gold (Metalaxyl 8% + Mancozeb 64% WP) – Syngenta.
• Curzate (Cymoxanil 8% + Mancozeb 64% WP) – DuPont.
• Previcur Energy (Propamocarb hydrochloride 722 SL) – Bayer.

By adopting these integrated management strategies, Late Blight in potato can be effectively controlled, ensuring higher yields and quality tubers.

Disease Overview :

• Disease Name: Early Blight of Potato
• Causal Organism: Alternaria solani (fungus)
• Affecting Stage: Can affect plants at any stage, but symptoms are more severe on older leaves during the vegetative to tuber formation stages.

Symptoms :

Leaf Symptoms:

Small, dark brown to black spots on older leaves, forming concentric rings (target-like appearance), surrounded by yellow halos.

Stem Symptoms:

Dark brown to black lesions on stems and petioles, causing partial wilting.

Tuber Symptoms:

Sunken, irregularly shaped brown to black lesions on the surface, with dry, dark brown corky rot extending into the tuber flesh.

Favorable Conditions :

1. Warm and Humid Weather: Temperatures between 20-30°C.
2. Leaf Wetness: Periods of leaf wetness from dew, rainfall, or irrigation.
3. Plant Stress: Plants stressed by nutrient deficiency, water stress, or excessive nitrogen application.
4. Poor Airflow: Dense planting, reducing air circulation.

Management Strategies :

1. Cultural Control:

Use resistant varieties, rotate crops, plant certified disease-free seed potatoes, maintain proper plant spacing, avoid over watering, and remove crop debris.

2. Organic Control:

Spray neem oil or garlic-based biopesticides, apply Trichoderma harzianum, and use compost tea.

3. Chemical Control:

Apply Mancozeb, Chlorothalonil, Azoxystrobin, Cymoxanil + Mancozeb, and Difenoconazole.

Trade Names of Chemicals :

1. Dithane M-45: Mancozeb 75% WP (Indofil)
2. Kavach: Chlorothalonil 75% WP (Indofil)
3. Amistar: Azoxystrobin 23% SC (Syngenta)
4. Curzate: Cymoxanil 8% + Mancozeb 64% WP (DuPont)
5. Score: Difenoconazole 25% EC (Syngenta)

Effective Management :

By adopting these control measures, False Smut can be effectively managed, protecting rice crops from yield and quality losses.

Potato (Solanum tuberosum) is a staple food in many European countries and has been proven to be valuable in providing food during emergencies. It is an important source of starch. It could be a wealthy source of body-building substances such as carbohydrates, vitamins (B1, B2, B6, and C), minerals (Ca, P, and Fe), and protein.

• Ideal conditions for better growing potatoes :

Soil: 

Almost all types of soil are are reasonable for the development of potato. The well drained clay loam soil with pH between 5.0 and 7.5 is considered as ideal for its cultivation. On sandy loam soil, crop can be effectively developed given manuring is done intensely and the crop is irrigated properly and timely.

Climate :

It could be a cool season crop and can endure moderate frost. It requires a soil temperature of 20°C for better germination. Young plant growth is good at 24°C but later growth is favoured by a temperature of 18°C. No tuberization takes place when the night temperature exceeds 23°C. Maximum tuberization occurs at 20°C. Tuber formation stops completely at about 29°-30°C.

Planting Season :

Planting time varies by region. In northern India, it’s from October to November, while in southern India, it’s from June to July.

Soil Preparation :

Deep ploughing helps in breaking hardpans and enhancing soil aeration. The fields are ploughed to a depth of 20-35 cm first with soil turning plough and afterwards by 4 to 5 ploughing with country plough/disc harrow.

Seed Selection, Varieties & Seed Rate :

1. Seed Selection: Use certified, disease-free seeds from reliable sources.
2. Varieties: Choose varieties suitable for the region and resistant to local pests and diseases.
3. Seed Rate: 25-35 q/ha.

Seed Treatment :

1. Fungicide Treatment: Treat seeds with fungicides to prevent fungal diseases.
2. Sprouting: Pre-sprout seeds by exposing them to light for 10-14 days.

Planting Season :

Planting time varies by region. In northern India, it’s from October to November, while in southern India, it’s from June to July.

Spacing :

Maintain a spacing of 45-60 cm between rows and 20-25 cm between the tubers within the rows to ensure adequate growth.

Breaking of Dormancy:

Hill tubers can not be used for autumn crop immediately because of dormancy period of 2-3 months in tubers. This dormancy can be broken by utilizing a few chemicals –

1. Thiourea (Sodium Potassium thiocynate) @ 1-2% solution which is used as a treatment to cut tubers for 1-1.5 hours and about 1 kg of thiourea is sufficient for 10 quintals of seed tuber. (Or)
2. Tubers are kept in 5 ppm solution of GA3 for 10 seconds.

Manures and fertilizers :

Apply FYM (farmyard manure) @100q/ha at the time of field preparation. Fertilizer dose varies depending upon the fertility of the soil. However, fertilizers are applied @ 120:80:60 kg N: P2O5: K2O /ha, respectively. Full dose of farmyard manure, phosphorus and potassium and half of N should be applied at the time of planting. Remaining part of N should be top dressed at the time of earthing up for effective utilization by the crop.

Irrigation :

Pre-planting irrigation is advantageous for uniform germination. Second irrigation is given after about a week and ensuing as and when required. Light and frequent irrigations are way better than heavy and less frequent irrigations. Water is applied effectively and economically at critical stages in crop development i.e. stolon formation, tuber initiation and tuber development stages of the crop. Irrigation is stopped about 10 days before harvesting of crop to allow firming of tuber skin.

Common Diseases and Their Management :

Early Blight (Alternaria solani)

1. Symptoms:

• Spots with concentric rings of brown to black colour are formed on the leaves.
• Heavily infected leaves fall off after drying.
• Spots also appear on stems.

2. Management:

• Destroy crop debris by burning.
• Spray mancozeb or zineb @ 2g/l or 0.3% copper oxychloride at fortnight intervals 3-4 times. 
• Grow resistant varieties, e.g. Kufri Naveen and Kufri Jeevan.
• Control with fungicides like Chlorothalonil.

Late Blight (Phytophthora infestans)

1. Symptoms:

• Lower leaves are infected generally from margin or apex and having cottony growth on the lower side.
• Water soaked lesions appear on the margins.
• Tubers decay under severe infection.

2. Management:

• Use disease free certified seed.
• Follow crop sanitation.
• Spray Ridomil MZ 72  (2g per litre of water)
• Grow resistant varieties like – Kufri Griraj and Kufri Himsona.

Black Scurf and Rhizoctonia Canker

(Rhizoctonia solani) 

1. Symptoms:

• Sprouts are killed before emergence.
• Cankers cause wilting of plants.
• Black crust on tubers gives ugly appearance.

2. Management:

• Plant disease-free, certified seed tubers and avoid planting in cold, wet soils.
• Seed tubers should be treated with recommended fungicides like thiophanate methyl.
• Follow crop rotation.

Common Scab (Streptomyces scabies) 

1. Symptoms:

• Tubers with common scab can have shallow, deep, or a combination of the two scabs.
• A shallow or surface scab is a shallow, roughened region on the tuber.
• Rough, corky lesions on tuber surfaces.

2. Management:

• Maintain soil pH between 5.0 and 5.5 and avoid alkaline conditions.
• Use resistant varieties and avoid using fresh manure.

Common Pests and Their Management :

Effective pest management is crucial for successful potato cultivation.

Aphids (Myzus persicae) 

1. Symptoms:

• Aphids feed on plant sap, causing yellowing, curling of leaves, and stunted growth.
• They also transmit viral diseases.

2. Management:

• Remove and destroy infested plant debris.
• Introduce natural predators like lady beetles and parasitic wasps.
• Use insecticides such as imidacloprid or neem -based products.

Potato Tuber Moth (Phthorimaea operculella)

1. Symptoms:

Larvae bore into tubers, creating tunnels and leading to secondary infections.

2. Management:

• Use healthy, certified seed tubers and practice crop rotation.
• Use pheromone traps to monitor and reduce moth populations.
• Apply insecticides like Bacillus thuringiensis and spinosad.

White Grubs (Holotrichia consanguinea)

1. Symptoms:

Grubs feed on roots and tubers, causing wilting and reduced tuber quality.

2. Management:

• Deep plowing to expose and kill larvae.
• Use entomopathogenic nematodes like Heterorhabditis bacteriophora.
• Apply soil insecticides like chlorpyrifos.

Integrated Pest Management (IPM) :

To manage pests and diseases effectively, farmers should adopt an Integrated Pest Management (IPM) approach. Key components of IPM include- 

a) Regular Monitoring: Scout fields regularly to detect early signs of pest and disease infestations.

b) Crop Rotation: Rotate potato crops with non-host crops to break pest and disease cycles.

c) Sanitation: Remove and destroy infected plant material to reduce sources of infection.

d) Resistant Varieties: Plant potato varieties that are resistant to common pests and diseases.

e) Judicious Use of Chemicals: Apply pesticides and fungicides based on economic thresholds and only when necessary, to avoid resistance buildup.

Weed Management :

a) Mechanical Control – Manual Hand weeding at 20-30 days after planting. And also Regular hoeing to keep the field weed free.

b) Chemical Control – Use pre-emergence herbicides like Metribuzin for effective weed control.

Harvesting and Its Methods :

a) Harvest when 70-80% of the foliage has yellowed.

b) Use mechanical or manual methods, ensuring minimal damage to tubers.

Post-Harvest Management :

a) Cure tubers at 15-20°C and 85-90% humidity for 10-15 days to heal wounds.

b) Store in cool, dark, and well-ventilated conditions at 4-7°C.

Conclusion :

Implementing Good Agricultural Practices in potato cultivation ensures better yields, higher quality produce, and sustainable farming practices. By focusing on site selection, seed treatment, nutrient management, irrigation, pest control, and proper harvesting techniques, Indian farmers can significantly improve their potato production. Embracing these practices will not only benefit the farmers economically but also contribute to the overall agricultural sustainability in the region.