Agricultural CET important topics with explanation
List of topics
- Legume effect
- Sink source ratio
- Ideotypes of wheat
- Vertical mulching
- Cash crops
- Silage crops
- Hulling percentage of rice
- Pre and post-emergence herbicides
- Other topics
What is allelopathy?
The interactions between the crops may also occur through other means, i. e., competitive and non-competitive. The competitive interaction between the crop species in intercropping and sequential cropping through the release of chemical substances or toxins is known as allelopathy. It results into benefiting the subsequent crop in two ways:
- Subsequent crop escapes from the allelopathy effect.
- The rapid decomposition of sunflower residues causes mineralisation of soil nitrogen.
Types of allelopathy:
- True allelopathy.
- Functional allelopathy
What is legume effect?
It is the beneficial effect of the legumes in any crop rotation and intensive cropping system. The inclusion of legumes in any cropping system is beneficial in many ways.
Also read: Legume, sorghum and cotton effect
What is sink source ratio?
Sink: It is the place where photosynthesis accumulate. Examples of sink are grain, stem (potato), root (sugarbeet), leaf (palak)
Source: It is the part of plant where photosynthesis occurs.
How should the ideotypes of wheat be?
According to Donald (1968), the ideotype for wheat or the similar crop has following features:
- To avoid lodging, there should be short strong stem.
- Few small erect leaves to allow the sunshine into its canopy.
- A large erect ear.
- The number of fertile florets per unit area should be more so that HI is more.
- There should be awns to increase the photosynthetic area.
- A single culm to avoid waste vegetative growth.
- Resistant to insect pests and diseases.
- There must be proper partitioning and translocation of assimilates.
Explain vertical mulching
Vertical mulching is a method of subsoiling. Subsoiling is the most effective method of breaking hardpans. It improves root penetration, aeration and water percolation. Vertical mulching is very effective in black soil, to improve infiltration and storage of rain water. It consists of digging narrow trenches across the slope at intervals and placing the straw or crop residues in these trenches. This method is very useful in coffee garden.
Other types of mulching
- Soil mulch or dust mulch.
- Stubble mulch.
- Straw mulch.
- Plastic mulch.
What are some examples of cash crops?
Some examples of cash crops are as follows:
Jute, cotton, tobacco, and sugarcane.
What are some easily available silage crops?
Some easily available silage crops are as follows:
What is the hulling percentage of rice?
The hulling percentage of rice is 70-75.
What are the different seasons for paddy or rice cultivation?
The different seasons for paddy or rice cultivation are as follows:
- Aus or autumn: Sowing time is pre-monsoon and harvesting season is August-September.
- Aman/Kharif: Harvesting time is winter.
- Boro/summer: Sowing time is January to February and harvesting time is April to May.
What are pre-emergence herbicides?
- Application of herbicides before weeds have emerged.
- In case of annual crops application is done after the sowing of the crop.
- Application is done before the emergence of weeds and it is known as pre-emergence herbicides.
- Soil application by spraying of atrazine on 3rd day after transplanting in a sugarcane field is pre-emergence application of herbicide.
- Examples: Atrazine, Pendimethalin, Butachlor, Thiobencarb, Pretilachlor.
What are post-emergence herbicides?
- Post-emergence herbicide application is Herbicide is the emergence of crop or weed as post-emergence application. Here weeds grow before the plants in case of early post-emergence.
- Example of early post-emergence herbicide is 2,4-D.
- Some post emergence herbicides are as follows: Paraquat, glyphosate, 2,4-D, sodium Salt.
What is solid planting?
Solid planting is opposite of inter cropping. It is defined as the cultivation of one crop variety in pure stands at normal density in a certain time and place.
What is annidation?
The complimentary interaction between intercrops in the intercropping system is known as annidation. It occurs both in time and space.
Types of annidation?
- Spatial annidation.
- Temporal annotation.
What is the CI of mono cropping?
The CI or the cropping intensity of mono cropping is 100%.