The 50th edition of the

Kenya Students’ Science Congress.

Theme: Science and Technology for the realization of vision 2030

Category: Agriculture Exhibit

Title: Grain storage pesticide

Presenters: 1.Virginia Wanjiru Wangari

2. Ken Njunge Kibaki

School: Ruthimitu mixed secondary school.

Province: Nairobi

Venue:

Date: 19thMay 2012

Declaration -I-

The research as in this presentation was designed by us under the guidance of our teachers

1. Mr. Onyango Ngoye

and

2. Mr. Washington Mutahi

Signed: 1. Virginia Wanjiru Wangari………………………..

2. Ken Njunge Kibaki………………………………….

In this project we have analyzed a traditional cultural knowledge of pest control and have shown how to put it to better use in grain storage.

Declaration-2-

We supervised the research and writing of this paper and recommend it for presentation in the 50th edition of the students’ science congress 2012.

1 Onyango Ngoye ………………………………….

2 Washington Mutahi ………………………………….

School Stamp

AbstractWe noticed that communities in Kenya use ash from different sources to dress cereals for storage. We picked ash from cow dung burnt in plenty of air, which we noticed is most effective in controlling grain in weevils. We analyzed the chemical composition of the ash and proved presence of Potassium cations and Chloride anions. We also proved absence of carbonates, sulphates nitrates and sulphites. We used our home made pesticide to dress cereal seeds; maize, sorghum and beans. We have proved that it is an effective pesticide against beetles weevils and other grain storage insect pests.

AcknowledgementsWe would like to thank the following for their support in research and writing of this project;

1. Onyango Ngoye (Our Agriculture Teacher)

2. Washington Mutahi (Our Chemistry Teacher)

3. Mrs. Doreen Mirikau (H.O.D Science)

4. The Principal Ruthimitu Mixed Secondary School

They took their time to organize us and gave us to funds to fully facilitate this project;

1.Virginia wanjiru wangari ………………………………………………………..

And

2. Ken Njunge Kibaki …………………………………………………………………

Table of content Page

Prologue (a) Forum, Edition, Theme, Category, title and Name of presenters (i)

(b)Declaration (ii)

(c)Abstract (iii)

(d)Acknowledgements (iv)

(e)Table of Contents (v)

(f)List of appendices (vii)

Chapter 1 (a) Introduction 1

(b) Background information 2

(c) Statement of problem 3

(d) Objectives 4

( e) Relevance of project to theme 5

(f) Limitations 6

(g) Assumptions and Precautions 7

Chapter 2 Literature Review (i) Books 8

(ii) Scientific Journals 8

(iii) Internet 8

Chapter 3 Methodology (i) Procedure,& Diagrams 9

(ii) Observations 9

(iii)Data 9

Chapter 4 data analysis and interpretation 10

Chapter 5 conclusions and recommendations 14

List of appendices

Chapter 1

IntroductionBackground Information

I keenly watched my grandmother dress cereals with ash for storage. When the storage was long term, she would burn and use Cow dung ash. Curiosity led me to find out the active ingredients which help in grain preservation without being poisonous to the grain users.

I approached my Agriculture and Chemistry teachers to help me design foolproof experiments to investigate the phenomenon.

I did investigations on raw dung and burnt ash from the dung.

The results were amazing. I got to know the active ingredients which help to control insect pests in grain storage.

Statement of problem1. Kenyans depend on cereals as their staple foods.

Maize, Sorghum, Rice and Wheat.

2. According to statistics from the Ministry of Agriculture; 30-40% of all the cereals produced is destroyed by storage pests, the most notorious being the grain weevil.

3. Farmers are unable to control the weevils due to high costs of the pesticides.

Objectives

1. To provide an effective pesticide which can control weevils in stored cereal seeds to last at least twelve months.

2. To prove that the pesticide is medically safe for use by human beings.

3. To provide an area for further research for mass production of the chemical with multiple uses.

Relevance of project to theme

1. To achieve vision 2030, Kenya must have no food deficit, this requires saving the 30-40% of our grains which is lost to weevils.

2. Potassium Chloride can be processed for use as food preservative. Technologically advanced Kenya must produce and store food.

3. Potassium Chloride can be used in the manufacture of fire extinguishers for preparedness against arsonists and rogue accidental fires.

Limitations

1. There is possibility of other ingredients in the ash which we have not tested. That should be a research project for another day.

2. There are other uses of Potassium Chloride and other ingredients in the ash which can still be investigated.

Guarantee/assumptions and precautions1. Potassium Chloride is safe for use as a grain

preservative pesticide. Its LD-50 is 2.5 g/Kg body

weight. A person weighing 75Kg can take up to 190g a day before its toxicity-level reaches the lethal dose. This is as safe as common table salt.

2. Our home made herbicide can be prepared and used for mass storage of grains.

3. Industrialists can use our innovations for mass production and sale of the pesticide to farmers.

Chapter 2

Literature review1. Potassium Chloride is historically known as muriate of

potash.2. It is a metallic halide. 3. It is a white, odourless crystalline solid.4. It has a melting point of 77 0C.5. Boiling point 1500 0C.6. It is soluble in Water, glycerol and ethanol.7. Potassium Chloride is hygroscopic.8. As a source of Chloride ion, Chlorine can be

precipitated from it by a reaction with silver nitrate.

2KCl (aq) + Ag(NO3) (aq) AgCl2 (aq) + 2KNO3 (aq)

Other Uses of Potassium ChloridePotassium Chloride has other alternative uses as:

1. Fire extinguisher, more effective than sodium carbonate based Chemicals. Potassium Chloride is more compatible with protein foam than sodium carbonate.

2. Flux for gas welding of aluminum.

3. Medicine for treatment of;

(a) Hypocalcaemia(b) Anti-nausea(c) Anti-vomit(d) Anti-diarrhoea(e) High blood pressure

4. Water softener.5. Defrosting of frozen foods.6. Substitute of table salt.7. Food processing. It dries and stops fleshy food from rotting.

Chapter 3

Methodology Procedure

1. put cow dung into an evaporating glass2. heat the cow dung until it turns into ash3. After heating take a spatula of the cow dung ash and

put it in attest tube4. 4add distilled water into a test tube containing the

cow dung and shake5. 4after shaking, filter the solution using a filter paper

and a funnel into another test tube.6. 6take the nichrome wire and dip it into the fillate and

then heat the wire. Record your observations.7. 7take lime water and put it in a test tube and connect

it with the test tube containing the filtrate using delivery tube and corks. Heat the filtrate and record your observations.

8. 8 take the remaining filtrate and put it into four test tubes.

A. First test tube add dilute h2so4 (sulphuric acid) and test for presence of Co2 and ca(oh)2

B. Second test tube, add dilute nitric acid for the test of sulphate and record your observation

C. in the third test tube add barium chloride solution and a little hydrochloric acid for the test of sulphites and record your observations.

D. add silver nitrate to the fourth test tube then add dilute nitric acid for the test of chloride and record your observations.

Observations and results

1 when nichrome wire was dipped into the filtrate and then burnt using a Bunsen burner, it burnt with a lilac flame confirming the presence of k+ (potassium ions)

2 when test of carbonate was done it was not detected

3when the test of sulphate was done it was not detected.

4 when the test of sulphide was done it was not still detected

5when the chloride test was done using silver nityrate and nitric acid awhite precipate was formed confirming the presence of chloride(

Chapter 4

Data Analysis and Interpretation 1. Cow dung burnt in plenty of air contains Potassium

Chloride salt.2. This salt is hygroscopic and when used to dress cereals,

dehydrates the insect pests to death. 3. The salt is safe for use as a food additive and cannot

therefore poison grain users (man or livestock).

Chapter 5

Conclusions and Recommendations1. The grain storage pesticide which we have prepared is

Potassium Chloride.2. It is cheap, safe, long acting and effective pesticide.3. It should be produced in mass and used for grain

storage.

Appendix