SCSCS News letter, Issue 2


SCSCA Newsletter 2

An experience with farmers


Students interacting with farmers

The students were given an assignment to collect plant disease samples and prepare a disease album with photos and samples of plants. To collect them, five of us went to Sastapara village to collect plant samples. It was really a nice experience to be there and to face farmers in real life situations and to know the problems. The interesting fact was that they were really cooperative, helpful and polite.

A woman in the ahu rice field with her little son

A funny situation arose as the farmers thought us as peoples of government and requested us to supply some pesticides to them. We all laughed among ourselves. Over all it was a very nice evening with handful of experiences.


Diseases caused by spiroplasma –

  1. Citrus stubborn – Spiroplasma citri
  2. Corn stund – Spiroplasma sp.

Protozoal disease :-

  1. Phloem necrosis of coffee – Phytomonas leptovasorum
  2. Heart rot of Coconut palm – Phytomonas sp.
  3. Empty rot of cassava – Phytomonas sp.

Green algae :

  1. Red rust of tea – Cephaleuros mycoides
  2. Red rust of coffee – Cephaleuros coffeae
  3. Red rust of mango – Cephaleuros parasiticum

    Red rust of tea (1)
    Red rust disease
  4. Red rust of cocoa – Capheleuros minimum

Viral disease –

  1. Non persistant –
    1. Cucumber necrosis – Olpidium cucurbitacerum
    2. Tobacco necrosis, Tobacco stunt, Lettuce big vein – Olpidium bassicae
    3. Beat necrotic yellow vein virus, potato mop top – Spongospora subteranea
    4. Barley yellow mosaic, wheat mosaic – Polymyxa graminis
    5. PVX – Synchytrium endobactum
Bridge ove champawati



Sustainable agriculture its components and advantages

Sustainable agriculture
Diagram showing sustainable agriculture principle

Sustainable agriculture mainly has three goals

  • Environmental health
  • Economic profitability
  • Social and economic equity

As a definition it can be stated as-

The production of food, fiber, grains or other plant or animal product using the farming techniques that emphasis on full utilization of available resources with dual aim of protecting the environment, public health, human communities and animal welfare and saving the resources for the future generation.

Components of sustainable agriculture –

Environmental preservation – Sustainable farms produce crops and raise animals without relying on chemical pesticides, genetically modified seeds, synthesized fertilizers or practices that degrade soil quality, water or other natural resources. By using techniques like crop rotation, conservation tillage, pesteur based livestock husbandry sustainable farm protects biodiversity.

Protection of public health: The aim of SA is that food never in expanse of human health. Sustainable agriculture farms exclude the use of chemically hazardous pesticides and other harmful chemicals in production of food and thus they are able to grow foods that are safe for the consumers, workers and surrounding communities.

Sustaining vibrant communities: A critical component of SA is that it is economically viable, providing the farmers, workers or employees a livable wage and safe, fair working conditions. It also builds the local and regional economies creating good jobs and building strong communities.

Benefits of sustainable agriculture:

Human health benefit :

Crops grown by sustainable agriculture are safe for people health as it contain no chemical pesticide

Environmental benefit :

It uses 30% less energy per unit of crop yield as compared to industrial agriculture.

It’s independency over fossil fuel reduce pollutants.

It maintains soil quality.

It increases biodiversity of an area by healthy variety of organisms.

Life struggle



Crop rotation

Definition: It is the practice of growing of different crops in the same area in sequential seasons with an aim to get maximum products with minimum cost and to increase soil fertility.

Crop rotation
Diagram showing crop rotation


Ex- A traditional element of crop rotation is the replenishment of nitrogen with green manuring crops in sequence with cereals or other crops.

Characteristics of crop rotation:

  1. It should adaptable to the existing land, economy and climate.
  2. It should be maintained in such a way that we can get maximum products and the soil erosion leads to minimum.
  • It should be arranged to check the growth of pathogen, disease, weeds etc.
  1. Rotation should include most profitable cash crop in that particular area.
  2. The rotation should provide Pasteur and fodder for the livestock kept on farm.
  3. An ideal crop rotation is one that provide maximum employment for and also give economic support for labour.
  • Crops of the same family should not be grown in sequence.

Benefits of crop rotation:

  1. It helps to replenish the nitrogen in soil through use of green manure.
  2. It also checks the /growth of various pathogens and pest which often occurs in soil due to continuous cultivation of the same crop in an area.

Since plants of the same family generally face the same pathogen attack and by rotating the crop the life cycle of the pathogen is stopped. Thus they cannot grow on the land.

  1. It can also improve the soil structure by alternating deep root system and swallow root system.
  2. It can prevent soil erosion as crop rotation does not allow the land to become barren, the surface runoff is reduced resulting less runoff.
  3. One can use the land for full period of time instead of letting them fellow after harvesting of one kind of crop.
  4. The amount of artificial fertilizer is reduced resulting less cost of production.
  5. Overall financial risks are less.

Disadvantages –

  1. Some crops are picky in a type of soil they need for maximum profitability but crop rotation is centered on the needs of the soil not the crop.
A moment from Inter college Dance competition



FBV (Fastidious vascular bacteria) (RLO)

Discovered by Windson and Black (1972) in club leaf of elover disease – phloem limited

  1. These are obligate bacteria.
  2. These cannot be grown of artificial media.
  3. Confined in either phloem or xylem but never both.
  4. Transmitted by leaf hopper.
  5. They are rod shaped.
  6. Aflagellate, outer wall is mostly undulating.
  7. Gram negative (Xylella), few gram negative gram positive (clavibacter)
  8. More than 20 plant diseases are reported.
  9. Marginal necrosis of leaf, general declination and reduced health are symptom of xylem inhabiting FVB.

Phloem inhabiting bacteria-leaf stunting, shoot proliferation, witches broom.

They are of two types –

1. Xylem limited:

They may be gram positive or gram negative.

Pierce disease of grape vine –Xylella fastisiosa

Pierce disease of grape vine caused by Xyllela fastidiosa
Pierce disease of grape vine caused by Xyllela fastidiosa

2. Phloem limited:

Clover club leaf

Citrus greening


Moments —





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