Field management in cassava field banks

Contributors to this page: IITA, Nigeria (Dominique Dumet), Bioversity International/ILRI, Ethiopia (Alexandra Jorge); INIA, Peru (Llerme Rios); independent consultant (Clair Hershey).

Information management


Choice of environment

Field preparation

Traditional field methods

Innovative method developed at CIAT

Field planting

Plot size and spacing will depend on the size and purpose of the collection, land availability and demand for planting material.



Back to top

 Maintenance and management

 Weed management




One of the problems of longer-term maintenance in the field can be excessive growth of some accessions.


Common pests and diseases

The Americas have the greatest diversity of cassava pests, followed by Africa and then Asia.

Under natural conditions, pests and pathogens are often kept under control by a combination of natural enemies, host plant resistance, and management practices.

In genebanks, these controls are often absent or reduced and pest and disease management can become a major challenge.

  • Damage in Africa is often high due to the lack of natural predators of pests.
  • Damage tends to be seasonal. Often insect and mite pests are more damaging in the dry season and diseases more damaging in the wet season.
  • Consult the cassava health diagnosis menu for detailed list of pests and diseases and procedures.

Pest and disease control

  • Weekly or bi-weekly (maximum) surveying of the collection is essential, to be aware of any problems that arise and need to be corrected.
  • Select healthy planting material. Do not take cuttings from plants that had leaf chlorosis, shoot tip die-back, cankers, fungus patches or streaks on the stems.
  • Treat cuttings with pesticides and fungicides before planting, and the plants during the growth stage when necessary.
  • Rogue and burn diseased plants regularly during the growth season (if it does not compromise the survival of a specific accession).
  • After harvest, destroy discarded stems and roots that have disease symptoms or pest contamination.
  • Use natural enemies against cassava pests as much as possible. Complement by applying appropriate pesticides as necessary.
  • Weed the field regularly.
  • In the worst situation, cuttings can be replaced with the backup stems.

Insecticide treatment

  • Insecticide or miticide treatments may be required to prevent widespread invasion of white flies, green mites, mealy bugs, termites, grasshoppers and other pests.
  • To be effective, treatments need to be applied at an early stage of insect development (visible eggs or larvae).
  • Pesticides should always be used according to label instructions.
  • When working with pesticides, worker safety is always of utmost importance. Gloves, mask, (to cover the nose and mouth), safety goggles and rain boots are needed to give the sprayers full protection.

Herbicide treatment

  • Herbicides are applied both pre-emergence immediately after planting and post-emergence at three, six, and nine months after planting.
  • For pre-emergence weed control, it is advisable to spray on a moist soil and prior to a forecast rain if possible, to facilitate diffusion of the chemical into the soil, in contact with weed seeds.
  • At the earlier development stages (up to three months), plants are short and tender. Extreme caution is advised during spraying to avoid chemical contact with young plants by using a guard fitted to the nozzle of the spraying equipment.
  • This precaution is not as important when the plant matures, but efforts should always be made to spray only on weeds.
  • Herbicides should always be used according to label instructions.
  • When working with herbcides, worker safety is always of utmost importance. Gloves, mask, (to cover the nose and mouth), safety goggles and rain boots are needed to give the sprayers full protection. 


  • Harvest the stakes at the end of the growing season (this guide does not refer to any root or seed harvesting, dealing only with the vegetative propagules), usually 12–18 months after planting, depending on the cultivars and environment. In some environments most of the leaves will have dropped, but in others, a leaf canopy remains at maturity.
  • Be careful to identify the stem cuttings from each plot.

Post-harvest management

  • Store the stakes in a well-ventilated and shaded cool place until planting or in case they need to be replanted (keep extra planting material for a while until the collection is established).
  • Take care during the harvesting and subsequent handling of the stakes not to bruise them.
  • Extend storage time (not recommended for collections) with longer uncut stakes tied in bundles pre-treated in pesticide, at 70–80% RH and 20–23°C.
  • Stakes can also be stored (also not recommended for collections) buried in the ground for several months, with the basal side down, or laid horizontally; regular watering is required to avoid excessive dehydration.
  • Stakes or cuttings also store well for weeks in polythene bags in drier areas and/or during the dry season.

Back to top

Information management

System for tracking material/inventory system during field bank storage

  • Use pegs, tags or barcodes for labelling.
  • Use impermeable ink and write clearly.
  • Plots must be well labelled to avoid errors.
  • Barcodes help avoid errors in recording.

Recording information during field bank storage

The following information should be recorded for each step:

  • Site name and map/GPS reference.
  • Name of collaborator.
  • Field genebank site name (a code to identify the site location).
  • Plot reference (the plot number at the field site).
  • Accession number; population identification.
  • Name of staff (name of staff recording the data).
  • Method of planting, date and spacing.
  • Field layout used.
  • Field management details (watering, fertilizer, weeding, pest and disease control, stresses recorded, others).
  • Environmental conditions (altitude, precipitation, temperature, soil type and others).
  • Number of plants established.
  • Days from planting to flowering (note: this will only be important if seed collection is anticipated).
  • Harvest date and method.
  • Number of plants harvested.
  • Quantity of cuttings harvested.
  • Comparisons with reference materials (record any identification numbers or references of any samples taken from the plots).
  • Any evaluation undertaken during the growing period or at harvest.
  • Post harvest (describe any relevant procedures).
  • Others.

References and further reading

Fukuda WMG. 1996. Banco de germoplasma de mandioca: manejo, conservação e caracterização. Cruz das Almas, BA: EMBRAPA-CNPMF. 103 p. (EMBRAPA-CNPMF, Documento, 68).

Frison EA, Feliu E, editors. 1991. FAO/IBPGR Technical Guidelines for the Safe Movement of Cassava Germplasm. Food and Agriculture Organization of the United Nations, Rome/International Board for Plant Genetic Resources, Rome.

IITA Genebank Manual Series, Cassava field bank operations at the International Institute of Tropical Agriculture (IITA). International Institute of Tropical Agriculture, Ibadan, Nigeria.

Mohd SS, Rao VR, editors. 2001. Establishment and Management of Field Genebank, a Training Manual. IPGRI-APO, Serdang. 121 p. Available here.

Back to top

The Genebanks

The 11 CGIAR genebanks currently conserve 730,000 of cereals and grain legumes, forage crops, tree species, root and tuber crops, bananas and crop wild relatives.