International Journal of Horticulture, 2017, Vol.7, No.14, 115-123
120
situation is worsened by the fact that over 90% of the farmers plant seeds they save from previous harvests, or
they acquire from markets or neighbours (Khurana and Garg, 2003; FAO, 2013). Farmers can improve their seeds
from informal sources through positive selection.
To assure high quality seed, the process of producing basic
seeds should be rapid and should minimize the number of times the pre-basic seeds are multiplied in the field;
frequent exposure of seeds to the soil leads to rapid build-up of soil-borne pathogens such as bacteria as well as
viruses. Production of large number of minitubers through rapid multiplication techniques (RMT) such as
aeroponics and hydroponics allows for rapid bulking of basic seeds in only two field generations rather than the
conventional four to six. This not only reduces the cost of producing basic seeds but also prevents the build-up of
diseases in the field.
Potatoes are largely propagated through tubers; there is a great risk of introducing alien
pathogens or pests into the region through seed tubers movement.
Measures to prevent/avoid introduction of pests
and diseases include zoning or quarantining seed production areas as well as strict observation and enforcement
of importation regulations.
6.3 Postharvest
Unlike many vegetables and fruits, potatoes can be stored for several months without serious loss of quality.
Improved crop storage can help reduce market supply and price volatility by allowing the harvest to be more
evenly distributed throughout the year. Ware potato should be stored in a suitable environment to prevent weight
loss, rot, shrinkage, sweetening, dis-colouring and sprouting (Gottschalk and Christenbury, 1998). Additionally,
seed potatoes need to be stored to maintain their dormancy pending planting in the next season. An ideal method
for seed storage particularly among small scale farmers is use of the diffuse light store (DLS). In Kenya,
KARI-Tigoni in collaboration with other development agencies such as USAID and the Deutsche Gessellschaft
f¨ur Technische Zusammenarbeit (GTZ) have been promoting use of DLS, which allow for better potato seed
storage and uniform sprouting.
6.4 Agronomic interventions
Agronomic practices such as planting time, irrigation, minimum tillage, mulching and intercropping are
recommended to increase water percolation into the soil, reduce surface runoff, reduce evaporative loss and
increase water use efficiency.
Planting date
: Planting date results in the greatest differences in growth and yield of potato crop; the situation is
compounded by the low and erratic rainfall occasioned by climate change. Although potato has a narrow planting
window, planting early in the season helps the crop to grow and mature before drought times set in (Mendoza and
Estranda, 1979; Robert, 2003; David, 2007). One strategy that farmers can use to maintain or increase crop yields
in the face of a changing climate is to adjust planting dates (Lauer et al., 1999). According to Kucharik (2006)
planting dates can change over time due to changes in climate as well as changes in technological and
socio-economic factors. Effective use of planting date as an intervention strategy depends on reliable weather
forecasts.
Irrigation
: Climate change will most likely lead to increased need of water harvesting and improved water use
efficiency. Rainwater harvesting will primarily involve the collection, storage and subsequent use of captured
rainwater as either the principal or as a supplementary source of water. Over eighty percent of Kenya’s landmass
is hot and dry and therefore unsuitable for arable farming, However, Kenya has two major fresh-water rivers,
Tana and Athi River, which have traditionally been used mainly for production of paddy rice in irrigation
schemes. The Kenyan government having realized the huge potential the country has in improving food
sufficiency through prudent use of irrigation water is putting a lot of emphasis into expanding the irrigation
schemes in the country (GoK, 2007). In addition, there is need to increase productivity of these irrigation
schemes through crop diversification. In most of these irrigation schemes, paddy rice is the main food crop; it is
rotated with maize. The irrigation board has been seeking alternative crop with which to rotate with rice because
maize takes a long time to mature; a short-duration crop such as potatoes could fill in the gap. Introduction of
potatoes as one of the rotational crops to replace maize may play an important role in increasing productivity of
