Gapping / Gap filling

This is the filling of empty spaces where some seeds did not germinate. It is done by replanting fresh seeds in these gaps.

Digging around the plant

This is usually done for the following reasons:

To remove the weeds.

To loosen the soil so that underground stems can grow properly.

To encourage anchorage of the roots.

To cover the plant roots and tubers that are exposed to sunshine.

To improve the aeration around the plant roots.

To incorporate the fertilizers and manures into the soil.

To improve water infiltration around the plant.

Earthing up

This is the placement of a heap of soil around the base of the plant.

This helps to retain/ maintain enough moisture for plant growth.


Crops should be irrigated to supplement soil moisture especially during the dry season.


This helps to conserve moisture and modify soil temperature.

Weed control

Weeding should be done early to avoid competition with crops. Delayed weeding reduces crop growth and yields.


This is the removal of weak and unhealthy seedlings to allow enough space for the remaining plants.


  • To enable crops grow laterally.
  • To prevent over crowding and reduce competition.
  • Reduces the occurrence and spread of diseases.

Application of fertilizers

Artificial fertilizers e.g. phosphatic fertilizers, nitrogenous, potasic fertilizers should be applied to boost growth and production of crops.

When the artificial fertilizers are not there, natural/ organic manures can be used.


This is the removal of excess, diseased or injured branches or leaves or excess suckers from the plant.

Reasons/ importance

  • Facilitates easy spraying/ harvesting of crops.
  • Gives the plant a proper shape.
  • Gives a convenient height for workers to ease harvesting.
  • To control pests and diseases e.g. Antestia burgs in coffee.
  • It economizes chemical use e.g. pesticides.
  • It allows more air and light for photosynthesis thus encouraging healthy growth.
  •  Controls overbearing in coffee.
  • Regulates the quantity and quality of the fruits.

Pest and disease control

Pests and diseases should be controlled effectively because the lower the quality and the yield of the crop.

Timely harvesting

Crops should be harvested in time to reduce field losses caused by insect pests, birds, thieves, rain, rodents, shattering and germination of seeds.

 Too early harvesting may lead to the following:

  • Inadequate drying of produce due to high moisture content.
  • Difficulty in shelling and threshing.
  • Small sunken seeds of poor quality.
  • Susceptibility of seeds to pests and diseases.
  • Low germination capacity of the seeds.

Effects of delayed harvesting:

  • High loss due to shattering of crops, rotting of fruits and seeds in the garden
  • Increased number of volunteer plants which harbor pests and diseases.
  • Attraction of pests in the fields.

Drying crops

This practice is carried out especially on grains to obtain the correct moisture content for storage.

Reasons for drying grains/crops

  • To prevent the produce from rotting and decaying.
  • To reduce insect damage.
  • To prevent fungal growth.
  • To maintain seed quality and viability.
  • To prevent germination of seeds in the store.
  • To reduce bulkiness of crops for easy transportation.
  • To allow easy processing of the produce into other forms e.g. maize grains into flour.
  • To minimize wet heating problems.
  • To prolong the storage period of the grains/ produce.

Proper storage

This prevents spoilage of the seeds caused by storage pests. It also makes the produce available for future use.


This is the transformation of raw materials into final utilizable products. It includes activities like threshing, winnowing, sorting and grading/packaging.

Reasons for processing

  • To reduce the bulkiness and make transportation easy.
  • Reduces wastage due to spoilage.
  • Adds value to the product by improving its quality.
  • Converts the product to an easy and utilizable form.
  • Eases packaging.
  • It extends the availability of he product in the market and prevents shortage of he products.
  • It enables getting two (2) or more products from one crop e.g. maize bran and flour from maize grains.

Sorting and Grading

Crop products are sorted and graded to increase their value and price. Products are sorted and grades according to:




Degree of contamination.