৪৯তম বিসিএস ⎯ কৃষিবিজ্ঞান [৮০১]

Urea becomes available within 3 days and remains about one week.
✓ Urea is lost through leaching and volatilization.

volatilization: When urea fertilizer is applied to the floodwater, it quickly converts to ammonium (NH4+​). If the pH of the floodwater is high (alkaline) and the temperatures are warm, this ammonium can transform into ammonia gas, which then escapes into the atmosphere.

মাঠ ফসলের (Field crops)  বৈশিষ্ট্যঃ 
    প্রতিটি গাছের পৃথক পৃথক যত্ন লাগে না, সমষ্টিগত ভাবে যত্ন নেওয়া যায়
     জমিতে বেড়া দেওয়ার প্রয়োজন হয় না
     বীজ সাধারনত ছিটিয়ে বপন করা হয়
     সমস্ত ফসল একসাথে পরিপক্বতা লাভ করে
     ফসলের উৎপাদন খরচ এবং উৎপাদন ঝুকি বেশী থাকে
     সাধারণত ফসল শুকিয়ে মাড়াই করা হয়
     সাধারনত একবর্ষজীবী হয়

Trench method                                               STP method
Each sett has 3 nodes.                       Each sett has 1or 2 nodes.
Setts are planted directly                   Seedlings transplanted from seed bed or poly
Germination percentage lower          Germination percentage higher
Yield is low                                         Yield is high
Early planting isn’t possible                Early planting is possible

সিম এবং ডাল জাতীয় উদ্ভিদের মূলে নডিউল থাকে। নডিউলের মধ্যে  Rhizobium bacteria  বসবাস করে।এই ব্যাকটেরিয়া বাতাস থেকে সরাসরি নাইট্রোজেন সংবন্ধন করে সিম বা ডাল জাতীয় উদ্ভিদের মূলে সঞ্চয় করে। উদ্ভিদের মূল সেখান থেকে নাইট্রোজেন গ্রহণ করতে পারে। এজন্য ইউরিয়া সারএর প্রয়োগের প্রয়োজন হয় না।

Trashing: Removal of old dried leaves to provide maximum sunlight
Wrapping/ Tying: When sugarcane becomes 5 months old , 3-4 clumps are wrapped together to prevents lodging.
Propping: The areas where storm occurs with high speed sugarcane may lodge. So the canes are to be propped with the help of bamboo.

জিংক সমৃদ্ধ  ধার: BR 62, BR 64, BR 74
BRRI dhan 62 বা BR 62 এই দুইভাবে লেখা সঠিক। 

ভুট্টা: বর্নালী, শুভ্রা, প্যাসিফিক
চীনাবাদম: বারাক ৫-৯, ডিজি-২, ঝিঙ্গা বাদাম
মসুর: বারি মসুর (৩-৮) , বিনা মসুর (১-১২)

Irrigation
✓ Yield of wheat can be doubled giving irrigation
✓ 2-3 times irrigation is required
✓ 1st irrigation when the seedlings become 17-21 days old (3
leaves stage / CRI stage)
✓ 2nd irrigation during the flowering stage and
✓ 3rd irrigation during grain formation stage

For wheat cultivation, the most suitable climatic conditions are cool and moist weather during the vegetative growth period, followed by warm, dry weather during grain ripening and harvesting.
Optimum temperature for seed germination is 20 - 25 °C
During the heading and flowering stage high and low temperature are harmful for grain development. (Best tem. 16°C to 23°C)

Gossypium hirsutum - Cotton
Helianthus annus - Sunflower
Arachus indica - Grpondnut 
Glycine max - Soybean 

Ploughing is the process of tilling or turning over the soil, typically with a tool called a plough, before sowing seeds. 

Winnowing is the process of separating grains from the chaff 

Threshing is a process where the edible part of a cereal crop, such as the grain, is separated from the inedible stalk and husks.

Harvesting is the process of gathering a ripened crop from the fields. 

যে পদ্ধতিতে ধান ক্ষেতে সর্বনিম্ন পরিমাণ পানি প্রদান করে, স্বাভাবিকের থেকে অধিক পরিমান ধান উৎপাদনের জন্য ধানের চারা বর্গাকারে এককভাবে রোপন করা তাকে SRI পদ্ধতি বলে।

• In the textile industry, a yarn made by blending jute and cotton fibers is sometimes informally called "jutton." This blend combines the strength and low cost of jute with the softness and comfort of cotton.

   

The world's most expensive tea is Da Hong Pao. It is a type of oolong tea, which is found on the Wuyi Mountains in the Fujian province of China.

According to the processing 4 types of tea i) black ii) Green ii)Oolong iv) Brick/ white tea

Dapog method is a versatile and efficient way to raise rice seedlings, making it especially useful in areas with water management challenges (Flooding area), limited land, or where mechanized farming is practiced.

Gluten is a type of protein found in certain cereal grains like wheat, Barley, Rye etc.

আউশ (Aus) ধানের স্থানীয় জাত: ধারিয়াল (Dharial), দুলার (Dular), কুমারী (Kumari), কটকতারা (Kataktara), মুখশাইল (Mukhshail)

আমন (Aman) ধানের স্থানীয় জাত: নাজিরশাইল (Nazirshail), ইন্দ্রশাইল (Indrashail), কাজলশাইল (Kajalshail), বিনাশাইল (Binashail)

বোরো (Boro) ধানের স্থানীয় জাত: কালি বোরো (Kali Boro), লতাই বালাম (Latai Balam), নয়নমনি (Nayonmoni), জাগলি বোরো (Jagli Boro), পশুশাইল (Poshushail)

Urea should be applied in three installments
1. 1/3rd at 20 DAT as top dressing
2. 1/3rd during early tillering stage (30-35 DAT)
3. last 1/3rd at panicle initiation stage (50-55 DAT)

In jute cultivation, it is generally best to harvest the crop when about 50% of the flowers have bloomed. 
At this stage, the fibre quality is optimal—soft, strong, and fine. 
If harvested earlier, yield decreases; if harvested later, fibre becomes coarse and woody.

Tillering Stage: Tillering is the process where a rice plant produces
new, secondary shoots or stems from the basal nodes of the main
stem. These new shoots, called tillers, are genetically identical to the
main plant and will eventually grow their own leaves and roots.

Milk stage
✓ This stage occurs a week or two after flowering.
✓ The developing grain (caryopsis) contains a white, milky and
sugary liquid.
✓ The endosperm is soft and filled with a fluid that has a milky
consistency

Dough Stage
✓ The liquid inside the grain begins to solidify.
✓ The contents thicken and become soft, like dough.
✓ This stage is further divided into soft dough and hard dough.

Booting stage:
✓ The developing panicle causes the flag leaf
sheath to swell or bulge, giving the stage its
name "booting".

Acceleration of retting speed may be applying urea in the
water or bucket full of rotting effluent for increasing the
micro-organism

Corchorus capsularis (white jute or Deshi jute) is known for its tolerance to waterlogging.

Corchorus capsularis: The fiber is coarser, stronger, and more lustrous
The fiber is whitish-yellow to grayish-white.
It is more tolerant of waterlogging and can be grown on lower, poorly drained lands.

Skiffing is a light form of pruning in tea cultivation. Its main purpose is to maintain a manageable plucking surface and encourage new, vigorous growth, thereby sustaining the tea bush's productivity.

Four types of pruning of tea
i) Collar pruning: 
ii) Medium pruning: 
iii) Top pruning: 
iv) Skiffing: 

Nicotiana tabacum.-Tobacco
Gossypium hirsutum - Cotton
Thea sinensis -Tea
Arachis hypogaea. - Groundnut

A Leaf Color Chart (LCC) is a simple tool used to assess the nitrogen status of a crop, particularly rice , by matching the color of a plant's leaf to a color chart. It is a visual and qualitative way to determine if a crop needs additional nitrogen fertilizer.
The LCC typically consists of a plastic ruler-like strip with four to six color shades ranging from yellowish-green to dark green. The colors correspond to different levels of nitrogen in the plant.