Sodium Chlorate and Sulphuric Acid—total, with a wide effect on all plants. Used at
10-15 kg/ha in dry conditions. Often mixed with selective herbicides such as 2,4-D and
MCPA. It is inflammable when it is dry.
)Safety Precautions
water sources.
- Herbicides must be applied at the correct growth stage of both the weed and the
crop, and at exactly the recommended dosage. It is imperative to read the label on
the container very carefully and also to follow all the instructions very carefully. - Storage of herbicides, and all other chemicals, must be in a place protected from
both the elements and thieves. - Some herbicides are persistent, both in the soil and in the produce of the crop. For
example, a herbicide which is used on a cereal crop may persist in the cereal straw,
which can be dangerous if it is fed to animals, or if it is used as a mulch on a
sensitive crop. - In windy weather nearby crops can be damaged by spray drift, which can also affect
people and animals.
M Tools
In vast areas around the globe the land and crops are still mainly cultivated with hand
tools. These tools have been slowly evolved, developed and improved over generations
of use so as to be the most suitable for the local conditions of soils and crops, and they
are often made only from locally available raw materials.
Ideally hand tools should be easy to make, and easy to maintain and to repair, and
they should be made from locally available materials. Local blacksmiths are often
responsible for these functions, though the shortage of raw materials, especially metal,
can often be a problem. In some countries blacksmiths have a low social status, though
this situation is slowly changing as local people increasingly appreciate the value of
these valuable artisans in their community.
HDRA (the Henry Doubleday Research Association based in Coventry, UK)
conducts research on locally made tools and equipment using local materials and skills.
Rate of Work: The human power unit is limited to about 0.1 HP (0.075kW), so farmers
who have to rely on hand tools are often limited by them as to the amount of land they
can cultivate and hence the amount of food they can grow.
Distribution or Sale of Hand Tools
Many farmers tend to be rather conservative and traditional people who are reluctant to
adopt new ideas. Their choice of tools is no exception. In agricultural development or
rehabilitation programmes it is essential that any tools which are provided are the same,
or very similar, as the tools which are normally used by the recipients. It is well worth
92 TONY WINCH
Particular care should be taken to prevent herbicides from reaching rivers or other
Herbicides are toxic chemicals that are potentially dangerous to all life forms.