International Journal of Horticulture 2015, Vol.5, No.13, 1
-
4
1
A Letter Open Access
Prolonging the shelf-life of seed potato tubers at farm level: Cold storage or
Diffused Light Store?
Muthoni J.
1
,
, Kabira J.N.
1
, Kipkoech D.
1
, Abong G.O.
2
, Nderitu J.H
3
1.KARI-National Potato Research Centre-Tigoni. P. O. Box 338 00217 Limuru. Email:kari.tigoni@yahoo.com
2.Department of Food Science, Nutrition and Technology, University of Nairobi. Email:georkoyo@yahoo.com
3.Mount Kenya University.
Corresponding author email
International Journal of Horticulture, 2015, Vol.5, No.13 doi: 10.5376/ijh.2015.05.0013
Received: 03 Jun., 2015
Accepted: 05 Aug., 2015
Published: 18 Sep., 2015
Copyright
© 2015 Muthoni et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Muthoni J., Kabira J.N., Kipkoech D., Abong G.O., and Nderitu J.H., 2015, Prolonging the shelf-life of seed potato tubers at farm level: Cold storage or Diffused
Light Store? International Journal of Horticulture, 2015, Vol.5, No.13 1-4 (doi
Abstract
Planting well sprouted potato tubers is key to achieving high yields. In the face of climate change, it is even more
important to have well sprouted tubers to ensure a crop matures even when rains are low and erratic. A study was conducted in
2011-2012 at KARI-Tigoni to evaluate the behavior of common Kenyan potato varieties after cold storage (at 40C) and diffused light
storage (DLS) for a period of up to eight months. Eight potato varieties commonly grown in Kenya and of different maturity periods
were used. Five kilograms of each potato variety was put in the cold store or DLS store for a period of 8 months in 2011. These were
replicated three times. After 8 months, data was collected on weight loss and general acceptability of seed tubers. During the long
rains season (March-June) 2012, the tubers from the store were planted out at KARI-Tigoni. Data was collected on plant emergence
and yields at harvest. All the cold-stored tubers were acceptable after eight months storage; the opposite was true for DLS-stored
materials. However, the DLS stored tubers gave high yields than the cold-stored ones.
Keywords
Cold store; Diffuse light storage; Seed potato tubers
Introduction
In order to improve the quality of farm-saved seed,
farmers are usually encouraged by extension staff and
researchers to conduct positive seed selection to
improve quality of the seeds. If such “clean seeds” are
well-sprouted before planting, the on-farm yields can
be improved substantially above the national yields of
less than 10 t/ha particularly when complemented with
adequate fertilizer and crop protection practices.
Seed potatoes previously distributed by the Agricultural
Development Corporation (ADC) to farmers used to
be sold following 7-9 months of cold storage (at 4
0
C
and high relative humidity). However, this ceased
when ADC collapsed in the late 1980’s. Since then,
a regular supply of well sprouted seed potatoes ceased
and farmers had to sprout their own seeds. Additionally,
the commonly used pre-sprouting chemical “rindite”
was withdrawn from the market in the 1990’s; since
then, most farmers use freshly harvested tubers for
planting leading to low yields. The diffuse light
storage (DLS) technique developed by the International
Potato Centre (CIP) can be used for seed storage for
up to five or six months (Demo, 2002). DLS uses
natural indirect light and good ventilation or air flow
instead of low temperature to control excessive sprout
growth and associated storage losses. Storage in DLS
has been shown to delay physiological ageing of the
tubers and to reduce apical dominance resulting in
many, short and firm sprouts per tuber (CIP, 1985a).
This translates into more stems and hence more yields
since potato is a stem tuber. In addition, there are less
storage losses from pests and diseases because the
crop can be easily monitored. Generally, DLS is a low
cost on-farm technique meant to store limited quantities
of seed potatoes for a period: of 5-7 months. On the
other had, cold storage is a high cost technique suitable
for certified seed production; it can store seeds for a
period of 9-10 months (Demo, 2002).
Research work funded by the former National Council
for Science and Technology (NCST) (currently NAC
-OSTI). was conducted to evaluate sprouting behaviour
of commonly grown potato varieties after storage in
cold store (
4
0
C and 95% RH) and in naturally ventilated
diffuse light store (DLS) for aperiod of upto 8 months.
Materials and Methods
Eight potato varieties (Table 1) were grown at
KARI-Tigoni during March-June long rains season of
2011. The trial was a randomized complete design
