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Discoveries in Agriculture and Food Sciences - Vol. 12, No. 3
Publication Date: June 25, 2024
DOI:10.14738/dafs.123.16901.
Okelola, F. S., Lawal, I. T., & Adebisi, M. A. (2024). Assessment of Seed Storability Attributes of Selected Nigerian Rice Varieties Under
Ambient Conditions in Guinea Savannah Ecology. Discoveries in Agriculture and Food Sciences, 12(3). 29-40.
Services for Science and Education – United Kingdom
Assessment of Seed Storability Attributes of Selected Nigerian
Rice Varieties Under Ambient Conditions in Guinea Savannah
Ecology
Okelola, F. S.
National Agricultural Seeds Council,
Lokoja – Abuja Highway, Sheda, FCT, Abuja
Lawal, I. T.
Department of Crop and Animal Science,
Ajayi Crowther University, Oyo, P.M.B. 1066, Oyo State, Nigeria
Adebisi, M. A.
Department of Plant Breeding and Seed Technology,
Federal University of Agriculture, Abeokuta, P.M.B. 2240, Ogun State, Nigeria
ABSTRACT
Temperature and seed moisture content are the two most important factors which
influence longevity of seeds in storage. Freshly harvested seeds of the 22 varieties
of Nigerian cultivated rice varieties grown during 2017 cropping year at the
National Agricultural Seeds Council, Abuja, a guinea savannah environment of
Nigeria. Seed lot of each variety were stored under ambient humid conditions of the
Seed Processing and Storage complex in NASC, Abuja Nigeria. Two factors were
evaluated i.e. 22 cultivars and six storage durations (0, 60,120,180,240 and 300
days). Harvested and cleaned seeds were stored under ambient storage conditions
(28 - 31oC ± 1; 70 – 72% RH) for 300 days using CRD in three replicates. The stored
seeds were drawn every 60 days and tested for seed quality and longevity
attributes. Data obtained were subjected to Analysis of Variance and means were
separated using Tukey’s HSD at 5% probability level. Pearson’s correlation
coefficient and principal component analyses were also used. PROBIT analysis was
done on seed longevity. PROBIT modeling showed that seeds retained its viability,
irrespective of storage time, and had very low varietal deterioration. PROBIT
modeling predicted that FARO 22 and FARO 57 can be stored with good seed storage
conditions for an average of 51 and 45 months, respectively, before they start
deteriorating.
Keywords: seed deterioration, storage, probit, rice seed, seed quality.
INTRODUCTION
Seed storage is the preservation of seed under controlled environmental condition that
maintains seed viability for long period (Kameswara, 2006). High temperature, ambient
relative humidity and seed moisture content are main factors influencing seed storage capacity
(Abdul-Baki, 1980).
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Discoveries in Agriculture and Food Sciences (DAFS) Vol 12, Issue 3, June- 2024
Services for Science and Education – United Kingdom
Temperature and seed moisture content are the two most important factors which influence
longevity of seeds in storage. The two factors are, however, inter-related, the higher the value
of either the faster the rate of deterioration and consequently loss of seed viability. The two
rules based on temperature and moisture applies independently. Seed deterioration is also
described as an unavoidable process, though it is possible to retard the process of ageing
through optimum seed storage (Delouche, 1973). High quality seeds should be stored since
seed storage does not improve seed quality but maintains it. When seeds deteriorate, they tend
to lose vigour and become more sensitive to stress upon germination and eventually lose the
ability to germinate.
Storability of seeds is mainly a genetically regulated character and is influenced by quality of
the seed at the time of storage, pre-storage history of seed (environmental factors during pre- and post-harvest stages), moisture content of seed or ambient relative humidity, temperature
of storage environment, duration of storage and biotic agents (Khatun et al., 2009; Biabani et
al., 2011). Damage of seed during storage is inevitable (Balesevic-Tubic et al., 2005). These
environmental conditions are very difficult to maintain during storage. The seed storage
environment highly influences the period of seed survival. After planting of deteriorated seeds,
seedling emergence may be poor and transmission of pathogens to the new crop may occur.
Lower temperature and humidity result in delayed seed deteriorative process and thereby
leads to prolonged viability period (Mohammadi et al., 2011). Hence this study was conducted:
1) to investigate the storability potential of these rice varieties under ambient humid condition
of guinea savannah ecology, and 2). to estimate seed storage life of these rice varieties stored
under ambient humid conditions after 300 days of storage using PROBIT modeling.
MATERIALS AND METHODS
Seed Materials and Sources
Freshly harvested seeds of the 22 varieties of Nigerian cultivated rice varieties grown during
2017 cropping year at the National Agricultural Seeds Council, Abuja, a guinea savannah
environment of Nigeria.
Seed Preparation Before Storage
Clean seeds of these varieties were tested for moisture content and moisture content was
regulated to 10.5 -11% using halogen moisture tester (model). Seed of the 22 varieties were
tested for the following attributes as initial quality attributes; Seed germination, Seedling
Length (shoot + root), Seedling Vigour Index Each trait was determined following the
procedures outlined by ISTA (1995).
Experimental Site and Storage Conditions
Seed lot of each variety were stored under ambient humid conditions of the Seed Processing
and Storage complex in National Agricultural Seeds Council, Abuja Nigeria. The temperature
and relative humidity of the storage conditions were monitored during the storage period.
Experimental Design and Treatments
The study was arranged in a completely randomized design with three replicates. Two factors
were evaluated i.e. 22 cultivars and six storage durations (0, 60,120,180,240 and 300 days).
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Okelola, F. S., Lawal, I. T., & Adebisi, M. A. (2024). Assessment of Seed Storability Attributes of Selected Nigerian Rice Varieties Under Ambient
Conditions in Guinea Savannah Ecology. Discoveries in Agriculture and Food Sciences, 12(3). 29-40.
URL: http://dx.doi.org/10.14738/dafs.123.16901
Seed Packaging, Storage and Duration
A 200 gramme seed of each variety was placed inside moisture proof polyethylene bags of 20
by15 cm dimension and then sealed and arranged on a pallet in the seed store with protective
wire net against store rodents. Packaged seed lots were stored for 360 days and seed samples
were taken every 60 days for physiological quality determination.
Seed Quality Determination
Seed samples were drawn at 60days interval (0, 60,120,180,240 and 300days) for a period of
300 days and were subjected to the following quality tests:
Seed Viability (%):
Germination test was used to determine this trait according to ISTA (1995) procedure. Fifty
seeds of each cultivar in three replicates were placed in a Petri dish moistened with filter paper
and then arranged in an incubator regulated to 20-25oC. Germinated (viable seeds) count was
determined at 3 and 8 days after sowing. Percentage of viable seeds was computed thus;
Seed Viability (%) = Number of Viable Seeds
Number of Seeds Sown
x 100
Seedling Shoot Length (cm):
Ten normal seedlings were randomly selected and their root length were measured in
centimeter.
Coleoptile Length (cm):
Length of ten randomly selected seedlings were used to determine the coleoptiles length.
Number of Roots Per Seedling:
Average number of roots from ten randomly selected seedling were counted and recorded.
Seed Storage Life (longevity):
Mean percentage values derived from seed viability test was used to estimate seed storage life
according to the procedure of Roberts (1973) as reported by Adebisi et al. 2008).
Statistical Analysis
Data obtained for each character were subjected to 2-way Analysis of Variance and significant
treatments means were separated at 5% probability level using SPSS Statistical package
(version 25). Seed storage life (Seed longevity estimation) was carried out using PROBIT
modeling as outlined by Roberts using SASTM PROC. PROBIT parameters sorted the data by
cultivars and storage time (month). Seed longevity parameters were estimated from the
procedure based on seed viability test data. PROBIT estimates of rate of extermination (δ) and
time taken for seed ageing to decline to 50% (P50) was estimated by the PROBIT Procedure for
each seed lot. Seed storage life was estimated as half-life (P50) value multiplied by 2 then divided
by 30 days of a month (Robert, 1973).
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Discoveries in Agriculture and Food Sciences (DAFS) Vol 12, Issue 3, June- 2024
Services for Science and Education – United Kingdom
RESULTS
The mean square values for the effect of storage time on seed quality parameters of 22 Nigerian
cultivated rice varieties under ambient conditions in guinea savannah ecology is presented in
Table 1. From the Table, variety effect was highly significant (p< 0.01) for 100 seed weight,
seedling shoot length and number of roots but significant (p< 0.05) for seed viability. Storage
time effect also showed highly significant effect for all the seed storability attributes evaluated.
However, the interaction of variety × storage time was highly significant (p<0.01) on 100 seed
weight, seedling shoot length and number of root but significant (p<0.05) on seed viability.
Table 1: Mean square values for seed quality parameters of Nigerian cultivated rice
varieties stored under ambient conditions guinea savanna ecology
Source of
variation
Df 100 seed
weight
Seed
viability
Seedling root
Length
Seedling
shoot length
Coleoptile
length
Number of
roots
Replicate 2 0.02ns 54.93ns 1.03ns 1.13ns 0.07ns 0.02ns
Variety 21 0.59** 448.83* 4.42ns 7.78** 0.15ns 0.37**
Storage time 5 1.54** 4594.25** 476.48** 180.45** 18.75** 60.62**
Variety ×
storage time
105 0.36** 454.11* 2.29ns 13.00ns 0.10ns 1.87**
Error 262 0.12 250.9 3.86 3.28 0.11 0.15
** Significant at 1% probability level. *significant at 5% probability level, ns not significant.
In Table 2, the data reveal that variability existed amongst the 22 cultivated varieties for seed
quality parameters across the storage period. A careful look of the data shows that there were
significant differences amongst the varieties during the storage period for 100 seed weight. The
highest 100 seed weight of 2.85 – 2.99g was observed in FARO 60, FARO 80, FARO 63 and FARO
59, while the lowest 100 seed weight (2.25g) was observed in FARO 61. Seed viability showed
statistical differences among varieties with the highest value (85.44%) in PAC 832 and FARO
21 (80.52%), but this was not significantly different from the 80.32% observed in FARO 61,
WAB 189 and FARO 47 with values of 79.85 to 80.52%. Other varieties recorded viability values
of between 78.64% in FARO 45 and 69.40% in FARO 27. The lowest viability values were
observed in FARO 44, FARO 64, FARO 22, FARO 61 and FARO 52 with values of between 64.37
and 69.40%. With regards to seedling root length, the highest value was noticed in FARO 27
(11.33 cm) as well as the values recorded in FARO 60, FARO 41, FARO 64, FARO 48, and FARO
31 while FARO 58 with a seedling root length of 9.99 cm had the lowest value over the storage
periods. In the case of seedling shoot length, the highest seedling shoot length was noticed in
PAC 832 (15.64 mm) as well as in FARO 47, FARO 48, FARO 57, FARO 21, WAB 189, FARO 22,
FARO 52 and FARO 62 with statistically similar values. The varieties with lower seedling shoot
length over the storage period included FARO 27 (13.33 cm), FARO 63 (13.43 cm), FARO 41
(13.70cm) and FARO 21 (13.69 cm). Coleoptile length was highest in FARO 62, FARO 52, FARO
58, FARO 21, FARO 61, FARO 64, FARO 50 and FARO 47(1.66 to 1.50 cm). Lowest coleoptile
length values were recorded in FARO 31, FARO 27, FARO 41, FARO 60, FARO 57, FARO 27, FARO
45 and FARO 63 with statistically similar values ranging from 1.35 to 1.41 cm. The number of
roots was highest in WAB 189 (3.17) though statistically similar values were obtained in other
varieties except FARO 64 with lowest value of 2.40. Other varieties had similar number of roots
with values ranging from 2.64 in FARO 44 to 2.96 in FARO 41.
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Okelola, F. S., Lawal, I. T., & Adebisi, M. A. (2024). Assessment of Seed Storability Attributes of Selected Nigerian Rice Varieties Under Ambient
Conditions in Guinea Savannah Ecology. Discoveries in Agriculture and Food Sciences, 12(3). 29-40.
URL: http://dx.doi.org/10.14738/dafs.123.16901
Table 2: Mean performance of Nigerian cultivated rice varieties for seed quality
attributes across storage periods under ambient conditions guinea savannah
environment
Genotype 100 seed
weight (g)
Seed
viability (cm)
Seedling root
length (cm)
Seedling shoot
length(cm)
Coleoptile
length (cm)
Number of
roots
FARO 62 2.85a 79.85ab 10.18ab 14.67a 1.66a 2.68ab
FARO 60 2.99a 74.65bc 11.24a 14.35ab 1.41b 2.77ab
FARO 52 2.58c 66.27c 9.75ab 14.81a 1.64a 2.70ab
FARO 61 2.25d 69.90c 9.64ab 13.69b 1.55a 2.89ab
FARO 41 2.77b 72.54bc 11.04a 13.69b 1.36b 2.96ab
FARO 22 2.63c 66.65c 10.30ab 15.53a 1.48ab 2.94ab
WAB 189 2.59c 78.79ab 10.13ab 14.87a 1.46ab 3.17a
FARO 21 2.69b 80.52a 10.03ab 14.73a 1.58a 2.81ab
FARO 63 2.97a 73.79b 10.75ab 13.43b 1.41b 2.73ab
FARO 64 2.69b 64.37c 11.13a 13.79ab 1.536a 2.41b
FARO 50 2.49c 74.43b 10.43ab 13.95ab 1.51a 2.72ab
FARO 27 2.49c 69.40bc 11.33a 13.33b 1.35b 2.69ab
FARO 57 2.64b 70.54b 10.73ab 14.99a 1.38b 2.74ab
FARO 48 2.69b 71.96b 11.19a 15.29a 1.40b 2.71ab
FARO 47 2.66b 80.32ab 10.73ab 14.96a 1.49a 2.81ab
FARO 59 2.97a 77.19b 10.58ab 14.25ab 1.55a 2.73ab
FARO 44 2.73b 67.84c 10.76ab 14.26ab 1.47ab 2.64ab
FARO 58 2.49c 72.81bc 9.99b 14.15ab 1.59a 2.65ab
FARO 65 2.46c 70.27bc 10.33ab 13.96ab 1.45ab 2.82ab
FARO31 2.80ab 74.10b 11.22a 14.71ab 1.35b 2.84ab
PAC 832 2.65b 85.44a 10.48ab 15.64a 1.46ab 2.86ab
FARO 45 2.59c 78.64b 10.81ab 14.97ab 1.39b 2.99ab
Means followed by the same alphabet along the column are not different from another at 5% probability level.
In Table 3, the storage period effect shows that 100 seed weight values were highest at 0 and
60 days after storage (DAS) with 2.86g each and thereafter declined significant from 120 to 300
days with values of between 2.61 to 2.56g. For seed viability, values were statistically highest
and similar at 0, 60 and 120 DAS with values of 81.21 to 82. 82% and thereafter steadily
declined to 74.14% at 180 DAS which was greater than values obtained at 240 and 300 days.
Also, seedling root length values were highest at 0 and 120 DAS with values of 13.91 and 13.92
cm and thereafter declined to 9.55cm and further statistically declined to 8.22 and 7.86 cm at
240 and 300 DAS, respectively. For seedling shoot length, there was significant increase in the
values with advance in storage time and highest value was obtained at 180 DAS with 17.39cm,
followed by 15.25cm recorded at 240days and further declined to 14.12cm at 300 DAS while
the least values were obtained at 0 DAS. Coleoptile length varied within the storage periods
with highest value of 2.34cm at 180 DAS, followed by 1.94cm at 240 DAS while the values
recorded in other storage periods were statistically similar. In respect of the number of roots,
highest values were obtained at early storage period 0 and 60 DAS and thereafter recorded
statistically similar values of between 2.11 to 2.18 during the remaining storage period.
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Discoveries in Agriculture and Food Sciences (DAFS) Vol 12, Issue 3, June- 2024
Services for Science and Education – United Kingdom
Table 3: Effect of storage period on seed quality attributes of Nigerian rice across
varieties under ambient conditions of guinea savanna environment
Storage
Time
(days)
100 seed
weight (g)
Seed
viability
(%)
Seedling root
length (cm)
Seedling shoot
length(cm)
Coleoptile
length (cm)
Number of
roots
0 2.86a 82.82a 13.91a 12.88e 1.21c 4.03a
60 2.86a 81.48a 13.92a 13.31d 1.21c 4.03a
120 2.61b 81.21a 10.02b 13.78d 1.34c 2.11b
180 2.61b 74.14b 9.55c 17.39a 2.34a 2.17b
240 2.56b 66.15c 8.22c 15.25b 1.74b 2.18b
300 2.56b 61.59c 7.86c 14.12c 1.04c 2.17b
Means followed by the same alphabet along the column are not different from another at 5% probability level.
The effect of storage time on 100 seed weight of the 22 Nigerian cultivated rice varieties stored
under ambient conditions in guinea savannah environment for 300 days. Table 4 reveals that
at 0 month of storage, FARO 63 had the highest 100 seed weight of 3.28g and the value was
statistically similar to the weights observed in FARO 59, FARO 60, FARO 62 and FARO 41. Other
varieties exhibited seed weight values that were statistically similar ranging from 2.41 to 2.97g.
At 60 days of storage, the varieties exhibited a similar trend with FARO 63 still with the highest
weight of 100 seed of 3.20g, followed by FARO 60, FARO 59, FARO 31 FARO 41, FARO 62, FARO
44 and FARO 57 with 100 seed weight values of 3.17, 3.16, 3.03, 3.02, 3.00, 2.99 and 2.98g,
respectively while other varieties exhibited similar 100 seed weight values of between 2.52 in
FARO 61 and 2.96g in PAC 832. After 120days of storage, 100 seed weight was highest in FARO
60 with 2.86g but this was not statistically different from the weights recorded in FARO64,
FARO 59, FARO 44, FARO 31, FARO 63, FARO 62, FARO 52, FARO 41, FARO 22, WAB 189, FARO
21, FARO 57, FARO 47, FARO 48 and PAC 832 with values ranging from 2.45 to 2.82g. The 100
seed weights at 120 DAS was lowest in FARO 61 with a value of 1.96g which was statistically
similar to the one in the other remaining varieties. At 180 DAS of storage, weights of 100 seeds
were statistically highest and similar in FARO 63, FARO 59, FARO 60, FARO 62, FARO 48, FARO
31, FARO 64, FARO 41, FARO 47, FARO 50, FARO 21, WAB 189, FARO 44, FARO 58 and FARO
45, with values ranging from 3.13 to 2.50g. Lowest seed weight of 2.27g was observed in FARO
27 but this weight was not significantly different from the values in the remaining varieties.
After 240 DAS, the 100 seed weight values were not statistically different among the 22
varieties but with values of 2.36 to 2.79g. Also, 300 days of storage, the seed weight differed
among the varieties with FARO 62 (2.93g) and FARO 60 (2.96g) showing highest values, though
not different from 2.88g recorded in FARO 59 while FARO 61 and FARO 65 had lowest values
of 1.94 – 2.35g. The effect of storage time on seed viability of the 22 cultivated rice varieties is
presented in Table 5. At 0 month of storage, WAB 189 had the highest value of 89.16% and the
value was statistically similar to the values observed in FARO 50, FARO 44, FARO 58 and FARO
45 (above 86.00%). The lowest seed viability values were noticeable in FARO 62, FARO 63 and
FARO 59 with 61.49, 63.25 and 62.93%, respectively. After 60 DAS, the highest viability of
76.92% was obtained in FARO 62, followed by FARO 21, FARO 59, FARO 47, FARO 45, WAB 189
and FARO 60 with values ranging from 70.26% to 74.26%, which was not statistically different
from the value recorded for FARO 62. Seed viability was however, lowest in FARO 41 and FARO
52 with 46.59 and 44.26% respectively.
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Okelola, F. S., Lawal, I. T., & Adebisi, M. A. (2024). Assessment of Seed Storability Attributes of Selected Nigerian Rice Varieties Under Ambient
Conditions in Guinea Savannah Ecology. Discoveries in Agriculture and Food Sciences, 12(3). 29-40.
URL: http://dx.doi.org/10.14738/dafs.123.16901
seed physical characteristics of their seeds. These other genotypes (FARO 44, FARO 64, FARO
22, FARO 61 and FARO 52 were the least storable in seed viability but with moderate to high
seedling growth characteristics which could be attributable to their genetic weakness and weak
physical characteristics (coat and size) of their seeds.
The highest seed viability percentages were recorded at the earlier storage period 0 to 60days
of storage while a great fall in seed viability was after 120days of storage while seed stored for
300 days of storage had the lowest seed viability and other seedling vigour attributes. This
decline in seed quality aspects could be due to deterioration process which occur in all
biological organisms. The ageing gradually set in and advanced with length of storage and as
further aggravated by high temperature (27oC) and high relative humidity (65%) of the
ambient conditions of the guinea savanna environment which enhanced higher respiration and
led to higher degradation of the assimilates leading to the death of many of the stored seeds.
Earlier reports by Adebisi et al. (2008), Esuruoso (2016), Abdul Rafiu (2015); Adebisi et al.
(2012), Kehinde (2018), Adebisi et al. (2019) have utilized PROBIT modelling to predict seed
storage life of sesame, eggplant, cayenne pepper, watermelon, kenaf and pigeon pea,
respectively under ambient humid storage conditions. In this study, the observations of PROBIT
modelling result showed that the seeds maintained its viability, irrespective of the storage time
for a period of 300days. The seeds had very low rate of deterioration in all the 22 rice varieties
used in this study, implying that seed longevity was prolonged and FARO 22 and FARO 50 had
the highest days of 766 and 672 of seed half-life (P50), implying high storability potential of such
seeds while FARO 27 (90 days) and FARO 64 (92days) had the lowest values in days to seed
half-life, implying that these varieties were least storable under ambient humid conditions of
guinea savanna environment.
Nevertheless, the PROBIT modelling predicted that FARO 22 and FARO 50 can be stored for an
average of 51 and 45 months, respectively before they start deteriorating, if the seeds are put
under good storage conditions. This finding corroborates the observations of Jyati and Malik
(2013) that the rate of deterioration fluctuates critically from one species to another and also
among varieties of the same species. The decline in seed quality parameters could be due to the
intrinsic factors in the seeds, irrespective of genotype, as well as other factors such as
endosperm size, seed coat, the normal profile of the seed, the type of assimilate (minerals,
vitamins and other seed chemicals) that is predominant in the seed among others. The study
therefore concluded that storage periods under ambient humid tropical conditions should be
given due consideration when storing seeds of cultivated Nigeria rice, irrespective of genotypes
available for storage.
References
Abdul-Baki, A. A. 1980. Biochemical aspects of seed vigour. Hort Sci 15: 765-71.
Abdul-Rafiu, A. M. 2015. Effect of plant population, processing method and storage duration on seed yield,
quality and longevity characters in pepper (Capsicum frutescenes L.) genotypes. Unpublished PhD Thesis,
submitted to the post graduate School, University of Agriculture, Abeokuta. Ogun state Nigeria.
Adebisi, M.A., Ola, J.A., Akintobi, D.C.A, and Daniel, I.O. 2008. Storage life of sesame (Sesamumindicum L.) Seed
under humid tropical conditions. Seed science and Technology 36:379-387.