Development, Fabrication And Performance Evaluation Of A Single Wheel Driven Boom Sprayer

CHAPTER TWO
2.0    Literature Review
2.1    Spraying Operations
Spraying is a way of covering crops with chemical in order to kill harmful insects and diseases. It involves the application of herbicide to reduce the competition from weeds, protective fungicide to minimize the efforts of fungus diseases, insecticides to control various kinds of insect, pest and hormones to regulate crop growth.  In addition, spraying is employed for the application of micro-nutrients such as manganese or boron for burning off excessive flag on cereal crops in order to reduce the danger of lodging.
While much of modern agriculture is based on mass mechanized production, advance in sensing and manipulation technologies may facilitate precision autonomous operations that could improve the crop yield and quality while saving energy, reducing man power, and being environmentally friendly. Agriculture is the backbone of human civilization. It evolve with human history whereas in the righteous book.; Al-quran, there are verses of agriculture significance invariably in many societies, agriculture integrates into various socio religious practices.  Refer to Imam Nawawi on Kitab Sahih, the best work or effort for the human being is agriculture.  In Malaysia, agriculture was and is always an important government agenda to ensure the country’s food security for all the people.
Site specific targeted spraying can lead to reduced pesticide application there by, improving sustainability and overcoming environmental concerns, reducing material cost and human labor and diminishing medical hazards.  Correcting spraying in vineyards is conducted homogenously along the rows, without considering areas with low foliage density or gaps between the grapevines. Estimates indicated that 10 – 30% of the pesticide agents can be reduced by using smart sprayers targeted towards foliage only.
Typically, foliage spraying is done by using boom that covers the entire height. The spraying boom is dragged along the row and sprays the entire foliages.  While spraying is done non-selectively, spraying the grape clusters in the row of two ways.  Often, a human carries a portable sprayer and sprays the plants individually.  This operation is very time consuming and labor intensive.
Typically, agrochemicals are applied to over trees uniformly within a whole orchard without regard to the partial variability of the target crop profile.  By reducing the spray losses, treatment efficiency can be improved by associating with deposition on the ground and off target drift.  The manually control system selectively activate individual sections of the spray boom in real time based upon the prescribe demand. (Alam, 2000)
2.1.1    Spray Materials
Friedrich (1997) Defined sprays as the atomized liquid that comes out in the form of solution.  Many spray materials can easily be dissolved in water to give solutions or may be mixed with water to form stable emulsions.
According to  Friedrich (1997) Spray materials can be in the form of
i)    Solution:  This is a homogenous mixture of two or more dissimilar molecular structure.  Water is a common solvent, also oil is used.
ii)    Suspension:  This is a two phase system consisting of very small solid particles distributed in liquid dispersion medium.  The active materials are present in solid particles dispersed in water or oil.  Suspension concentrate is prepared by steering in dispersible water e.g. powder in water and oil.
iii)    Emulsion: These are Solid particles solved in organic solvent capable of further dilution in water.  Requirements of emulsions are :
•    Sufficient stability after dilution
•    High oil content and suitable for measuring and modeling
•    Not corrosive to storage container
2.1.2    Classification of Sprayers
Willam, R (1997) Classify sprayers according to the following
i)    Method of droplet production
    Hydraulic energy sprayers:  In hydraulic sprayers, the spray fluid is pressurized either directly by using a positive displacement pump or by using an air pump to build the air pressure above the spray fluid in the air tight container. The pressure fluid is then forced through the spray lance, which controls the spray quantity and pattern.