Q.1. Define Agronomy & write scope and importance of Agronomy.
Agronomy- ‘It is the branch of agricultural science which deals with the principles and practices of field management for crop production.’
Scope - scope means at which things or places we can apply the knowledge of Agronomy. We can get all possible things (production, yield) which the basic farmers or producers need. We can study of the following contents.....
- Crop production - by maximizing our yield.
- Soil management - by improving soil fertility & productivity.
- Proper method of tillage - by using modern concept of tillage (Minimum tillage, Zero tillage).
- Suitable time of sowing - most important for seed germination & stability of plants.
- Proper method of sowing - (Drilling, Dibbling etc) for maintaining plant population.
- Maintaining farm implements & machineries in proper shape.
- Management of livestock including their feeding, management & disposal of farm and animal products like milk and eggs etc.
Importance- For getting higher yield,
1) Organic farming
2) Sustainable agriculture
3) Forestry
4) Mixed farming
5) Poultry production
6) Sheep & Goat rearing
7) Mixed & Inter Cropping etc.
Tillage:- ‘The manipulation of soil with tools & implements for loosening the surface crust and bringing conditions favorable for the seed germination & crop growth.’
Objectives :-
1) To make the soil loose and porous (friable).
2) To remove weeds.
3) To mix manures and fertilizers.
4) To destroy insects and their eggs
5) To aerate the soil
6) To increase the soil temperature
7) To remove stubble
8) To break hard pan (big stones).
Factors affecting tillage –
i) Previous crops: New and fallow lands cannot be brought in satisfactory condition without Ploughing. If the land is under crops like sugarcane, sorghum, maize etc.
ii) Crops to grown: The crops like turmeric, ginger, potato and gr-nut require loose and fine seedbed for proper development of underground commercial parts. So deep ploughing with sub-sequent tillage operations is necessary.
iii) Weeds: The deep ploughing is necessary in the fields infested with perennial weeds like Hariali (Cynodon dactylon), Nut grass Or lavala (Cyperus rotundus) and kans (Saccharum spotaneum) which Grows and difficult to eradicate.
iv) Soil: The fine textured soil such as clay soils with poor drainage need deep ploughing for improving aeration and drainage. While coarse sandy soils or loamy soils may not need ploughing every year and these soils can be prepared by 2 to 3 harrowing.
for conservation of soil moisture.
vi) Type of farming: The frequency of tillage operations is more in irrigated farming due to adoption of multiple cropping or growing more than two crops on the same land in year.
vii) System of culture or type of crop cultivation: The land preparation of upland rice (drilled rice) differs from low land rice (transplanted rice)
Q. 3. Define Seed and write the qualities/characteristics of good seed.
Seed - ‘Any material used for sowing or planting or propagation of a crop is called as seed. It may be in the form of seed or seedlings or tubers or bulb or rhizome or root or cuttings or graft or any other vegetatively propagated material.’
Characteristics/Qualities of good seed :
1) It should be genetically pure
2) It should have high germination Percentage
3) It should be free from any insect pests.
4) It should be free from disease bearing organisms.
5) It should be free from any admixture, dirt & inert material.
6) It should be free from noxious, objectionable & satellite weed seeds.
7) It should be clean, dry, bold, uniform in size & shape etc
Objectives of seed treatment -
1. Control of disease
2. Convenience in sowing
3. Quicker germination
4. Nitrogen Fixation.
5. Protection against insects and pests
6. Inducing earliness
7. Inducing variation
8. Breaking seed dormancy
9. Increasing the yield.
Sowing of crop is done by following methods...
1) Broadcasting
2) Drilling or line sowing
3) Dibbling
4) Transplanting
5) Planting
6) Putting the seeds in plough furrow.
Drilling or Line sowing: To overcome the problems of broadcasting, drilling the seeds in line has come into practice. In this method the indigenous seed drill, two bowl seed drill or mechanical seed drill is used for placing seeds into the soil and then seeds are covered with the help of wooden plank or blade harrow. Direct drilling of seeds is the usual method of seeding in dry land agriculture. This method is adopted for sowing crops like sorghum, pearl millet, upland rice, wheat, oat, soybean, chickpea, black gram, green gram, safflower etc
Advantages:
1) Line sowing facilitates uniform depth of sowing resulting in uniform crop stand.
2) Less seed rate is required as compared to broadcasting method.
3) Spacing between crop lines is maintained uniformly.
4) Weeds can be controlled economically by inter cultivation in line sown crops.
5) Sowing is done at correct soil moisture level.
Disadvantages:
1) The seed drill can be used only when soil moisture is optimum or at Vapasa condition.
2) Plant to plant spacing within a line is not maintained (i.e. Intra row spacing is not maintained).
Methods of fertilizer application are...
1) Broadcasting
2) Drilling
3) Band placement
4) Point placement
5) Injection into soil
6) Fertigation
7) Root dipping
8) Foliar application
I) Application of fertilizers in solid form:
A) Broadcasting: Spreading of manures and fertilizers evenly and uniformly all over the field and then mixed with soil by tillage implements is called broadcasting. To apply larger quantities this method is useful.
B) Localized placement: Application of fertilizers in the soil by taking into account the position of seed, seedlings or growing plants. In other words, application of fertilizers in the soil close to the seed or plant. This method is useful, when relatively small quantities of fertilizers are to be applied.
i) Contact placement: Drilling of fertilizer and seed together while sowing i.e. placing of seed and fertilizers in the same row. The greatest hazard of this method is that the seed germination may sometimes be affected.
ii) Band placement: Fertilizer is placed either continuous or discontinuous bands. Application of fertilizer in discontinuous bands is known as ‘hill placement’. It is most useful for widely spaced crops e.g. fruit crops, vegetables etc.
iii) Pellet application: In this method, the nitrogenous fertilizer is applied in the form of pellets 3 to 5 cm. deep between two rows of the paddy crop. For this purpose fertilizer is mixed with soil in 1:10 ratio and made into dough.
iv)Side dressing: In this method the fertilizers are spread in between the rows or around the plants.
1. Application of nitrogenous fertilizers in between the rows by hand.
2. Wide spaced crops like Maize, Sugarcane, Tobacco etc.
3.Application of mixed or straight fertilizers around the base of fruit trees like Banana, Grape, and Mango. It is also known as hill application or ring method.
II) Application of Fertilizers in Liquid form: -
A) Starter solution: Solutions of fertilizers consisting N, P2O5 and K2O in the ratio of 1:2:1 or 1:1:1 are applied to young vegetables plants at the time of transplanting. This solution is known as starter solution. The starter solution helps in rapid establishment and quick early growth of the seedlings.
B) Foliar application: Spraying the leaves of a growing crop with a fertilizer solution of one or more nutrients. The most common materials used are urea and some micronutrients. It is well known fact the plant nutrients are also absorbed through the leaves of plant in limited quantities.
C) Direct application of liquid fertilizer to the soil: With the help of special equipment anhydrous ammonia and nitrogen solutions are directly applied to the soil. By this method, liquid fertilizers containing two or more of the major nutrients can also applied to the soil.
D) Application of fertilizers through irrigation water: Fertilizers are allowed to dissolve into irrigation stream. The nutrients are thus carried into the soil in solution. Nitrogenous fertilizers are most commonly applied through the irrigation water.
Q. 6 Define Crop Rotation. Write Principles & Advantages of crop rotation and enlist factors affecting crop production.
Crop rotation - ‘Crop rotation is the recurrent succession of crops on the same piece of land either in a year or over a longer period of time.’
Principles of crop rotation-
1. The crop rotation should be adaptable to the existing soil, climatic & economic factors.
2. It should be cover all type of crops viz. cereals, pulses, fodder etc.
3. It should be helpful to the land by adding OM into it.
4. It should be arranged in a specific manner for controlling weeds, diseases & insect-pests.
5. It should give maximum yield and minimum soil erosion.
6. It should provide maximum employment to the family as well as labors. Etc
Advantages of crop rotation-
1. There is an overall increase in the yield of crops.
2. It adds organic matter (OM) content into the soil.
3. There is regular flow of income throughout the year.
4. It supply various needs of farmers & their cattle.
5. It supply the more nutrients into the soil.
Example of crop rotation-
1. Cotton – Jowar/Bajra – Groundnut
2.Sugarcane – Rice – Gram
3. Soybean –Jowar/Safflower/Gram
4. Sunflower – Jower
Q. 7. Define growth & development. Explain Growth Curve. Write the factors affecting growth & development.
➢ Growth- may be defined as an irreversible permanent increase in size, volume or mass of a cell or organ or whole organism accompanied by an increase in dry weight.
Development- Plant development is an overall term which refers to the various changes that occur in a plant during its life cycle.
Growth Curve - It is an ‘S’ shaped curve obtained when we plot growth against time. It is also called ‘sigmoid curve’. This curve mainly shows four phases of growth-
1. Lag phase - Initial slow growth occurs
2. log phase/grand period of growth/exponential phase - The rapid period of growth where maximum growth is seen in a short period.
3. Diminishing phase - where growth is seen slow.
4. Stationary/steady phase - where finally growth stops.
Factors affecting growth & development Includes –
A) Genetic factors - (Internal factors) :
1) Genes
2) Chromosomes
3) Genomes etc.
B) Environmental factors – (External factors) :
1) Temperature
2) Moisture supply
3) Radiant energy
4) Composition of the atmosphere
5) Soil aeration
6) Soil reaction
7) Biotic factors
8) Plant nutrients.
Q. 8. Define plant ideotype. Write in short types of ideotype.
➢ The term Ideotype was introduced by Donald (1968). Acc. to him ideotype- is a biological model which is expected to perform or behave in a predictable manner within a defined environment.
This term has a following synonyms viz. Model plant type, Ideal plant type.
Types of ideotype -
1) Isolation ideotype - The model which perform best when the plants are space-planted. Isolation means planting distance
2) Competition ideotype - The model which perform well in genetically heterogeneous (different) population. The crops in this model are able to compete with its less aggressive neighbors. Such ideotype’s crops have following features viz. annual habit, tallness, leafy canopy, tillering or branching, seed size, speed of germination & oot characters.
3) Crop ideotype - This ideotype performs best at commercial crop densities because it is a poor competitor. In the case of cereals a crop ideotype is erect, sparsely-tillered plant with small erect leaves.
Q. 9. How will you Classify herbicides.
Classification of Herbicides:
1) Based on Method of application:
a) Soil applied herbicides: Herbicides act through root and other underground parts of weeds. e.g. Fluchloralin
b) Foliage applied herbicides: Herbicide primarily active on the plant foliage e.g. Glyphosate, Paraquat
2) Based on Mode of action: Herbicides are grouped into selective and non-selective herbicides depending on their selectivity
a) Selective herbicide: A herbicide is considered as selective when in a mixed growth of plant species, it kills some species without injuring the others. e.g. Atrazine or Selective herbicides kill only targeted plants or weeds while crops are nor affected; e.g., simazine, atrazine, 2, 4-D, MCPA, butachlor, alachlor.
b) Non-selective herbicide: It destroys majority of treated vegetation e.g. Paraquat or Non-selective herbicides kill all vegetation that they come in contact with irrespective of whether it is a crop or weed; e. g., paraquat and diqua
3) Based on mobility
a) Contact herbicide: A contact herbicide kills those plant parts with which it comes in direct contact e.g. Paraquat.
b) Translocated herbicide: Herbicide which tends to move from treated part to untreated areas through xylem/ phloem depending on the nature of its molecule. e.g. 2,4-D, clodinafop.
4) Based on Time of application – i) Pre-plant application (PPI) ii) Pre-emergence iii) Post-emergence
5) Based on molecular structure - i) Inorganic compounds ii) organic compounds.
Q.10. Give Principles of weed control.
Principles of weed control are:
a) Prevention
b) Eradication
c) Control
d) Management
a) Preventive weed control: It encompasses all measures taken to prevent the introduction and/or establishment and spread of weeds in a new area.
b) Eradication (Ideal weed control rarely achieved): Eradication means complete removal of weed species, its seed and vegetative part and that weed will not reappear unless reintroduced to the area. Because of its difficulty and high cost, eradication is usually attempted only in smaller area
c) Control: It encompasses those processes where by weed infestations are reduced but not necessarily eliminated. Weed control does not mean cent precent control of weeds but due to this method weed population lowered to such a level that economic yields are ensured.
d) Weed management: Weed control aims at only putting down the weeds present by some kind of physical or chemical means while weed management is a system approach whereby whole land use planning is done in advance to minimize.
