A Study on the Plant Genetic Resources Diversity and Seed Supply System of
Bohol Island, Philippines
CBDC Bohol Project, SEARICE, Philippines
Year: 2001
A PGR survey was conducted in 1994 to assess
the extent of genetic diversity of seven crops, namely: rice (Oryza
sativa), corn (Zea mays), yam (Dioscorea alata), cassava (Manihot
esculenta), sweet potati (Ipomoea batatas), taro (Colocasia
esculenta), and banana (Musa spp). Furthermore, the survey was
carried out to understand and assess the existing seed supply
system (SSS) in both formal and informal sectors of the focus
crops except banana.
The survey showed that Bohol is diverse in all focus crops. Sweet
potato has the most number of varieties (88), followed by rice
(63), yam (38), corn (32), cassava (29), banana (25) and taro has
the least number with 20 varieties. The diversity of these crops
was largely influenced by the nature of the crop (whether self or
cross-pollinated), farmers' management practices and selection
pressures (man-made and natural).
Majority of these crops were either traditional
or farmers' varieties which only shows that farmers were able to
maintain diversity in their fields.
|
Statement of the Problem
The erosion of plant genetic resources is occurring
at an alarming rate today. The irreversible loss of thousands of crops
and crop varieties from farmers’ fields due to the introduction of
"modern high-yielding" varieties is one of the adverse
impacts of the Green Revolution which started in the 1960’s. In the
Philippines for example, 3,500 rice cultivars were known to be in
cultivation before the government introduced the Masagana 99 rice
program in the early 1970’s. With the introduction of genetically
uniform high-yielding varieties, farmers are now planting fewer rice
varieties in their fields (Salazar, 1993). The same dire situation is
happening in many other crops where diversity has given way to
uniformity.
Considering that much of the conservation efforts
today are concentrated on ex situ approaches, there is clearly a need
to balance these efforts by giving due recognition and support to
community-based in situ researches and activities in relation to PGR
diversity conservation and development.
Rationale of the Research
The objective of this research is to study the
local community innovation systems (CIS) in relation to PGR diversity
and the seed supply system. The research focused on the hypothesis
that farmers conserve and develop plant genetic resources in an
innovative system that maintains a diversity of varieties/landraces
and secures local seed supply. It recognizes farmers’ knowledge as
the main source of information and farmers’ fields as the main
source of genetic material and indigenous technology for conserving
PGR diversity and maintaining the local seed supply. The results of
this research shall be used as baseline data to guide the project’s
succeeding work in participatory on-farm conservation and development
Scope and Limitations
The survey on PGR diversity and seed supply system
focused on four root crops - yam (ubi), cassava, sweet potato and
taro, two cereals- rice and corn, and a fruit crop - banana. Both the
upland and rainfed lowland rices were included in the research. The
study was conducted from October 1994 to May 1995.
General Objectives:
1. To assess the extent of plant genetic diversity of
the subject crops in the province of Bohol;
2. To determine and assess the seed supply system of
these crops in both the formal and informal sectors.
Collection of Secondary Data
Prior to the survey, relevant secondary data were
gathered from the Department of Agriculture/Bureau of Plant Industry
(DA/BPI), Visayas State College of Agriculture (VISCA), Bohol
Agricultural College (BAC) and the Bohol Agricultural Promotion Center (APC). The data were used to draw a picture of the overall agricultural
situation in Bohol, especially on PGR diversity.
Information on the seed supply system was obtained
from formal institutions. For root crops, the sources of data were VISCA,
BAC and DA/BPI; and for cereals, sources were the private seed industry,
APC, DA/BPI and the University of the Philippines at Los Banos/Institute
of Plant Breeding (UPLB/IPB). The Central Visayas Integrated
Agricultural Research Center (CENVIARC) in Ubay, Bohol provided
information on how it produces and supplies seeds and planting material
for the different crops.
Survey
Different Bohol towns were visited before the survey
proper to initially assess their extent of PGR diversity. Target sites
were selected on the basis of the diversity of the area and the
ecosystems they represented. Forty-two barangays in 13 municipalities
were covered by the survey. The ecosystems represented in the selected
sites were coastal hilly, coastal grassland, interior mountainous,
interior grassland and interior hilly.
Using purposive sampling methods, three farmers per
barangay were identified as key informants upon consultation with
village heads and local contacts. The respondents were selected
according to the following criteria: they should be planting all if not
most of the subject crops, and they should have a reputation in their
communities as expert or innovative farmers.
The survey questionnaire first sought to establish
the socio-economic profile of the respondent, and then for each focus
crop, the questions dealt on items associated with PGR diversity and
seed supply system. The data were analyzed using simple frequency
distribution method.
Community Workshops
After completing the individual interviews, the
respondents were convened in community workshops. All three respondents
in each barangay were invited to these workshops to validate the
information gathered from the individual interviews and to obtain
further information about their communities on:
- rainfall pattern
- cropping pattern/calendar (seasonality diagram)
- land use (distribution mapping)
- varieties previously planted / genetic erosion (historical transect)
Actual Field Observation
When standing crops were available, the crop
varieties cultivated by the respondents were characterized using a
descriptor lists. This was intended to prevent duplication in the
counting of each crop variety.
Respondents’ Profile
One hundred twenty four respondents were interviewed.
Majority were more than 40 years old and have been farming for 26 - 45
years. Most came from farming families and are themselves dependent on
farming for their livelihood. The respondents may be considered as
seasoned farmers who are experts in their own field considering their
age, farming experience and family background.
The area of land cultivated by each respondent varied
with the crop. Sweet potato and yam are usually planted in small areas
measuring less than 1000 m2 . Farm size for cassava is more than 1000
m2. Rice are usually planted in less than 2 hectares and corn in less
than 1 hectare. Bananas are planted in small patches of land. Most of
the respondents maximize the use of their land by also planting vegetables, fruits and other plants.
Status of PGR diversity
The results of the survey indicate the existence of
diversity for the seven subject crops in Bohol. Sweet potato has the
most number of varieties followed by rice, yam, banana, corn, cassava
and taro.
Sweet Potato(Ipomoea batatas)
The high number of varieties in sweet potato may be
attributed to a combination of natural factors and farmers’ practices.
Sweet potato is an open-pollinated crop and most farmers plant more than
one variety in a single patch of land (Figures 1a to 1c). The mixing of
varieties in a single field allows crosses between varieties to take
place. The new genotypes created in the field may then be selected and
propagated by farmers to eventually become new varieties.
Number of varieties of each crop per ecosystem.
|
|
Ecosystem |
|
Crop |
Total no. |
CH (a) |
CG (b) |
IM (c) |
IG (d) |
IH (e) |
|
Yam |
38 |
23 |
13 |
11 |
11 |
18 |
|
Sweet Potato |
88 |
23 |
14 |
38 |
26 |
31 |
|
Cassava |
29 |
9 |
11 |
11 |
14 |
10 |
|
Taro |
20 |
1 |
1 |
7 |
11 |
8 |
|
Rice |
63 |
14 |
7 |
18 |
36 |
23 |
|
Corn |
32 |
10 |
7 |
6 |
17 |
13 |
|
Banana |
25 |
8 |
11 |
13 |
12 |
16 |
|
TOTAL |
|
88 |
64 |
104 |
127 |
119 |
(a) coastal hilly
(b) coastal grassland
(c) interior mountainous
(d) interior grassland
(e) interior hilly
Although erosion appears relatively high, this actually indicates the
dynamic selection process of genetic materials by farmers for this crop.
The rate of displacement of varieties in sweet potato is high because
farmers continuously practice selection of new genotypes from their own
fields.
Nearly all the cultivated varieties in sweet potato
are considered farmers’ varieties, i.e., varieties originating from
farmers’ fields and maintained by them through selection and
propagation. The high diversity in this crop can be attributed to
farmers’ selection. Formal sector breeding has created little impact
in sweet potato cultivation.
Although the Philippine Root crop Research and
Training Center (PRCRTC) has developed several lines of sweet potato
using traditional farmers’ varieties as parent materials, these hybrid
varieties have not displaced farmers’ cultivars.
Rice (Oryza sativa)
Filipino farmers traditionally plant an array of rice
cultivars. However, this diversity has been gradually displaced by the
introduction of genetically uniform varieties. Although survey results
show that rice ranks second to sweet potato in diversity, most of
these varieties are formal releases representing genetically-uniform
introductions that have displaced many of the traditional varieties.
Genetic erosion has been very pronounced in rice considering that the
development and introduction of new varieties has been rapid in this
crop.
Origins of varieties for cereals.
|
Crops |
Formal |
Traditional |
Farmers |
|
f
|
Releases (a) |
Varieties |
Selections (b) |
|
Rice |
22 |
25 |
16 |
|
Corn |
10 |
22 |
f
|
|
TOTAL |
32 |
47 |
16 |
(a) Refers to varieties bred/developed by
breeding institutions.
(b) Refers to varieties believed to be
selected/developed by farmers from formal releases through
selection.
Nevertheless, farmers are still maintaining a
significant number of traditional varieties. In addition, there are also
farmers’ selection consisting of varieties believed to be derived by
farmers from both modern and traditional cultivars. A common
characteristic of these selections is red grain color. This trait is
preferred by Boholanos because it is associated with superior eating
quality and gives higher market value. A survey in the neighboring
province of Cebu showed that most red rice sold there comes from Bohol (APC, 1989).
Yam (Dioscorea alata)
Yam ranks third in terms of diversity with 38
varieties. Contrary to Martin's claim (US Department of Agriculture,
1976) that only a few varieties of yams are to be found in the
Philippines, the survey results indicate that yam is quite diverse in
Bohol. Yam diversity in Bohol consists mainly of farmers' varieties.
Respondents indicated that most of these varieties have been with their
communities from the time of their grandparents. Erosion in yam is also
very minimal with only one variety lost. Yam is usually cultivated with
at least two varieties in a single patch providing genetic diversity
even at the farm level.
Corn (Zea mays)
The survey respondents cultivated 34 varieties of
corn.Most of the respondents maintained only one variety. The dominant
variety is tiniguib, a traditional variety. The dominance of tiniguib,
can be attributed to its superior agronomic and gastronomic traits.
Tiniguib is resistant to corn borer, corn weevil, and earworm whereas
the hybrid varieties are highly susceptible to these pests (APC, 1988).
Corn has had the highest number of new introductions
by the formal sector after rice. However, Genetic erosion in corn is not
serious. Only two varieties are no longer in cultivation and one of them
is a formal released variety of sweet corn.
Cassava (Manihot esculenta)
The diversity in cassava consists of 29 varieties.
Half of the respondents plant only one variety. The dominant variety is
Yellow, a traditional variety. Yellow cassava is favored by farmers
because of good yield and eating quality. Although several cassava
varieties are no longer in cultivation, many traditional varieties have
still persisted. Farmers have maintained their traditional varieties as
cassava is still mainly a consumption crop.
Taro (Colocasia esculenta)
Compared to the rest of the food crops, taro is the
least diverse. The islands' relatively dry climate does not favor the
growing of taro which is mainly a wetland crop. Taro is not an important
food source in Bohol compared to other crops. As such, there is no major
motivation for farmers to diversify. Furthermore, taro is considered a
shy-flowering plant (Pardales, 1982) and some cultivars have never been
known to flower. This characteristic restricts the development of new
genotypes. Normally, taro is grown in the backyard or in areas around
the main crops with farmers maintaining only a few plants. There are no
formal releases among the taro varieties cultivated by the respondents.
Banana (Musa sp.)
The survey results show that banana is diverse in Bohol, even more than corn and cassava. The Philippines being part of
the Southeast Asian center of origin and diversity for this crop
(Cooper, et. al.), banana's diversity in Bohol may be considered as
endemic to the area. Furthermore, banana is considered an important
fruit and food source for Boholanos while requiring little management
practices. Except for one variety, namely Cavendish, a formal
introduction, all the banana varieties in Bohol are farmers'varieties.
Ecosystem diversity
In general, the diversity of the seven crops in Bohol
spans across the different ecosystems. However, certain ecosystems are
either more diverse or less diverse in crop varieties than others.
Overall, the interior grassland areas contain the most varietal
diversity for all seven crops while the coastal grassland areas are the
least diverse.
A major factor for the diversity in the interior
ecosystems is socio-economic. Farming is the main source of income in
the interior areas while in the coastal areas, farming is usually
combined with fishing and other occupation. Thus, farmers in the
interior areas would tend to maintain greater crop diversity for their
food source. Differences in topography and climatic conditions between
the interior and coastal ecosystems that may have also contributed to
variations in diversity. Most of Bohol's coasts are rocky and the
climate is generally drier.
Yam is most diverse in the coastal hilly areas
including parts of Panglao town where the most number of yam varieties
were identified. Panglao is the major producer of yam in Bohol and is
particularly famous for the kinampay, an aromatic yam with purple flesh,
that is said to grow best on the island. In contrast, the interior
mountainous and interior grassland areas had the least varieties of yam.
In the coastal grassland areas, fewer sweet potato
varieties were found compared to the interior mountainous areas which
include Anda where the highest number of sweet potato varieties were
identified. The diversity of sweet potato in Anda may be attributed to
the area's steep terrain that makes it less suitable to growing rice.
Sweet potato is thus used to substitute for rice as staple food.
Diversity in cassava is distributed quite evenly
across ecosystems although it is in the interior grassland areas where
it is most diverse and in the coastal hilly areas where it is least
diverse. The even diversity of cassava across ecosystems is probably
accounted for by the crops ability to easily adapt to different
agro-ecological conditions even with little management. Cassava is also
known as a drought-tolerant crop (Pardales, 1982).
Rice is very diverse in interior grassland areas
where the relatively flat terrain and normally good supply of water
favors rice-growing. Grassland and hilly areas along the coast are least
diverse probably because of their more rocky soil conditions and drier
climate compared to the interior ecosystems.
Corn is also more diverse in interior grassland areas
while being least diverse in the interior mountainous areas where the
rugged terrain make them less suitable to corn cultivation. For banana,
its diversity is more or less evenly distributed across ecosystems
underlying its versatility and importance as a food source throughout
Bohol.
In general, we find that crop diversity exists and is
maintained by farmers in Bohol. This diversity results from the
interplay of both natural and human factors. Varieties may have
developed through natural crosses between cultivated varieties,
introgression from wild to cultivated varieties, and genetic mutation
due to environmental stresses. Farmers contribute to the natural
processes of genetic diversity by their own methods of mass selection
and adoption of varieties.
Socio-Cultural Factors
Farmers' preferences
Preferences of farmers affect their choices of
varieties for each crop. For root crops in general, good cooking and
eating quality and fine flesh texture, are the most common
considerations in the choice of varieties. Root crops are consumed in
different ways, i.e., mixed with vegetables or meat, eaten as snack, or
substitute for rice. Thus, cooking, eating quality and flesh texture are
highly important characteristics.
The main agronomic reason in choosing root crop
varieties is good yield followed by early maturity and resistance to
pests and drought. These traits directly affect farm productivity which
farmers need to optimize given their often-marginal conditions. Concern
for good agronomic performance acquires even greater priority in
cereals. Although to a lesser extent compared to root crops, good
cooking and eating quality also figure significantly in cereals as a
reason for choosing varieties.
Just as farmers have specific reasons for planting
certain varieties so do they have reasons for discarding other
varieties. The process of discarding and replacing varieties is a normal
routine for farmers as they seek varieties that would suit their needs
and preferences as well as adapt to the specific agro-ecological
conditions of their farms. The major reasons why farmers changed their
varieties are low yield, late maturity, and susceptibility to pests.
Another important reason is access to new varieties, which are either
formal releases or new selection from their own field or from other
places. Farmers are generally interested and willing to try new
varieties for their own evaluation.
In yam, farmers normally do not like varieties whose
tubers grow deep into the soil since this makes harvesting difficult. At
the same time, unsuitability to the soil is a reason for changing
varieties in yam.
For rice, a variety's susceptibility to lodging is an
important concern because this can cause tremendous yield losses.
Typhoons and monsoons periodically hit Bohol. Strong winds can destroy
rice fields planted to varieties that are highly susceptible to lodging.
Susceptibility to lodging normally affects the taller varieties, thus,
plant height is a major consideration for farmers when evaluating
varieties.
Another reason cited for changing rice varieties is
the need for varietal rotation. Farmer have observed that continuous
planting of one variety in the same area may cause yield to drop and the
plants to become susceptible to pests. To prevent this, varieties are
replaced after a certain number of seasons.
Genetic erosion
By conscious choice of farmers or due to certain
external factors, varieties become eroded or no longer cultivated in a
particular area. Rice has the highest number of lost varieties followed
by sweet potato and cassava. Erosion in other crops is almost
negligible.
The major cause of genetic erosion in rice is the
introduction of new varieties. To a lesser degree, erosion in cassava
was also affected by new introductions. Unavailability of planting
material is the major cause of erosion in sweet potato.
Causes of erosion of varieties for each crop.
|
Causes |
Yam |
Sweet Potato |
Cassava |
Totals for |
Rice |
Corn |
Totals for |
|
f
|
f
|
f
|
f
|
Rootcrops |
f
|
f
|
Cereals |
|
1. Agronomic |
f
|
f
|
f
|
f
|
f
|
f
|
f
|
|
a. low yield |
0 |
0 |
0 |
0 |
11 |
0 |
11 |
|
b. susceptibility to disease |
0 |
0 |
0 |
0 |
5 |
1 |
6 |
|
c. susceptibility to heat/drought |
0 |
9 |
0 |
9 |
0 |
0 |
0 |
|
c. poor post-harvest/processing quality |
0 |
0 |
0 |
0 |
3 |
1 |
4 |
|
d. late maturity |
0 |
0 |
0 |
0 |
11 |
0 |
11 |
|
2. Gastronomic |
f
|
f
|
f
|
f
|
f
|
f
|
f
|
|
a. poor cooking/eating quality |
0 |
0 |
3 |
3 |
3 |
0 |
3 |
|
3. Socio-economic |
f
|
f
|
f
|
f
|
f
|
f
|
f
|
|
a. poor market value |
0 |
0 |
0 |
0 |
1 |
0 |
1 |
|
b. inavailability/loss of planting material |
1 |
22 |
2 |
25 |
0 |
0 |
0 |
|
c. introduction of new varieties |
0 |
0 |
3 |
3 |
28 |
0 |
28 |
Erosion may actually reflect a dynamic process in
which farmers periodically change their varieties and try out new ones.
Farmers consciously replace varieties that exhibited traits they did not
desire such as low yield, disease susceptibility, heat intolerance, and
late maturity. Farmers, for example, have replaced many traditional rice
varieties which did not yield as much as the HYVs and which were late
maturing. Many cassava growers replaced their old varieties in favor of
new varieties preferred by the starch processing plant in the island. In
the case of sweet potato, the loss of planting material may have
actually resulted from replacement by farmers of old varieties with new
ones that developed in their fields.
Crop management practices
In general, the use of inorganic or chemical inputs
for fertilization and pest control is more common in cereals than in
root crops. Majority of respondents use inorganic fertilizers for rice
and corn. For root crops in general, most farmers do not fertilize
although some use organic fertilizer, specifically for yam.
For insect and disease control, the rate of chemical
use is quite low for both root crops and cereals. Instead, some farmers
employed botanical/biological, manual, mechanical and cultural methods
of insect and disease control. A significant number of farmers did not
use any form of conscious control against insects and diseases. However,
even without employing actual control methods, farmers secure their
crops against insects and diseases by their seed selection methods and
timing the season of planting. By selecting healthy seeds, farmers help
ensure good plant growth and better resistance to diseases.
Herbicide is applied only in rice and corn to a
minimal degree. For farmers, the most economical and effective method of
controlling weeds was by simple hand weeding. This method not only helps
clean the field but the decomposed weeds could also serve as fertilizer.
Cropping system
Many farmers plant medium maturing varieties for
sweet potato, rice and corn. In yam, most varieties are early maturing
while in cassava they are mostly late maturing. With different maturity
ranges and cropping seasons per crop, diversity in the field enhances
food sufficiency for the farmers as different crops are harvested and
made available for consumption or for market throughout the year.
Utilization patterns
Generally, the respondents use most of their crops
for consumption although a few crop varieties are planted primarily for
the market. This pattern of use favors crop diversification because
diversity can ensure more food sources for the farmers. Since the
respondents plant mainly for consumption, they are free from market
forces which normally exert pressure towards monocropping.
Seed Supply System
Sources of Planting Material
Most respondents obtain their planting material from
informal sources such as parents, relatives, neighbors and other
communities. Few respondents obtain their planting material from formal
sources like government institutions and private companies. Usually,
farmers get their planting material from formal sources for varieties
being planted for the first time. During succeeding planting of a
variety however, respondents either use their own seeds or get their
planting material from within their community.
Selection Process
The male respondent is usually the one involved in
selecting the planting material for each crop although it should be
noted that most respondents in the survey were males. There are more
females involved in the selection process for root crops than for in
cereals. An interesting area of further study would be the impact of
gender roles in the selection process of planting material. There is
possibly a difference in the selection criteria and methods between men
and women based on the type of crop.
Healthy seed is the most important selection trait
for both root crops and cereals. Healthy planting material ensures good
germination and growth of crops as reasoned out by a significant number
of respondents. In cereals, the absence of off types is another
important criterion, whereas for root crops, morphology is also a major
consideration, e.g. size of tubers (yam) node position (cassava) and
others.
Reasons for selection criteria per crop.
|
Reasons |
Yam |
S. Potato |
Cassava |
Totals for |
Rice |
Corn |
Totals for |
|
|
|
|
|
Rootcrops |
|
|
Cereals |
|
Uniform growth/maturity |
0 |
0 |
0 |
0 |
7 |
8 |
15 |
|
Healthy growth |
25 |
29 |
28 |
82 |
3 |
14 |
17 |
Planting materials for root crops are usually
selected right before planting and never before harvest. Sometimes
selection is done at harvest (yam and sweet potato) or after harvest
(yam and cassava). In the case of cereals, planting material for corn
may be selected at any time while that of rice can be done anytime
except immediately before planting. Selection time is an important
factor in ensuring that the best planting material are selected. As we
shall also see in the succeeding discussion on storage system, the time
of selection is also related to the storability of each crop's planting
material.
Time for selection of planting material per crop.
|
Crop |
Before/at |
Before |
At |
After |
|
|
Planting |
Harvest |
Harvest |
Harvest |
|
Yam |
27 |
0 |
14 |
21 |
|
Sweet Potato |
54 |
0 |
4 |
0 |
|
Cassava |
68 |
0 |
0 |
6 |
|
Rice |
0 |
32 |
14 |
17 |
|
Corn |
37 |
5 |
16 |
31 |
|
TOTAL |
186 |
37 |
48 |
75 |
Planting materials for sweet potato (vines) and
cassava (stems) are highly perishable and cannot be stored for a long
time. They are stored alive in the field until the next planting.
Planting materials are planted within a few days after they are
collected. They are kept in the protective shade of trees in the
interim.
Storage system of planting material per crop.
|
Crop |
Left in the |
Inside the |
Buried |
No Storage |
|
|
field |
house |
in soil (c) |
|
|
Yam |
4 |
40 |
5 |
0 |
|
Sweet Potato |
45 (a) |
0 |
0 |
0 |
|
Cassava |
43 (b) |
1 |
0 |
21 |
|
Rice |
0 |
89 |
0 |
0 |
|
Corn |
0 |
88 |
0 |
0 |
|
(a) planting material highly perishable (2-3 days).
(b) planting material highly perishable (5 days).
(c) presprouting. |
Yam tubers can be stored during its dormancy period
for up to six months inside the house or hut. A few respondents leave
tubers in the field until before planting time while others bury the
tubers in the soil for storage and also to enhance pre-sprouting. With
cereals, which have orthodox seeds, storage can be done for a longer
period.
Among the crops stored inside the house or hut,
various storage containers and areas are utilized. Rice seeds are
usually placed inside closed containers like sacks, bamboo crates and
cans in order to keep out moisture. Corn cobs are either put in closed
containers or hung above stove area where the occasional smoke prevents
weevil infestation (APC, undated). Yam tubers need adequate aeration to
keep them dry so they are placed on bamboo beds during storage or in
bamboo crates where holes allow air to circulate well. For farmers,
these storage methods are inexpensive and generally serve the purpose of
maintaining the quality of the planting materials.
Sharing System
Farmers willingly share their planting materials with
others. Planting materials for root crops are usually shared free. Very
few respondents would sell their planting material or exchange them with
another variety, another commodity or with labor. Rice is hardly given
free but corn seeds are sometimes shared for free.
|
Crop |
Given free |
Sold |
Exchanged (a) |
|
Yam |
36 |
5 |
15 |
|
Sweet potato |
71 |
0 |
0 |
|
Cassava |
79 |
0 |
2 |
|
Rice |
1 |
3 |
68 |
|
Corn |
23 |
8 |
52 |
|
TOTAL |
24 |
11 |
120 |
|
(a)Exchanged with other varieties, commodities, labor. |
|
Seed distribution and exchange takes place very
extensively within and outside the community. It is a system that has
been in existence for many years and which ensures that quality planting
material are maintained by a great number of farmers under varying
agroecological and socioeconomic conditions.
The survey shows the existence of genetic diversity
in the seven focus crops in Bohol. Sweet potato is the most diverse with
88 varieties followed by rice (63), yam (38), corn (32), cassava (29),
banana (25) and taro (20). Crop diversity is distributed across a wide
range of ecosystems, i.e. coastal hilly, coastal grassland, interior
mountainous, interior grassland, and interior hilly. The interior areas
contain much greater diversity for the seven crops since farming is
normally the main source of income in these areas.
The existence of genetic diversity indicates that
Boholano farmers have been conserving and developing plant genetic
resources. Many of the varieties presently cultivated are traditional
and farmers’ varieties.
This represents in situ conservation of valuable
genetic variation that can form the material for further crop
improvement and diversification at the farm level.
In farmer’s fields, crops are not only conserved
but are subjected to various selection pressures, both natural and
man-made, that result to the emergence of varieties highly adapt to
specific ecosystems and cropping patterns. Highly adapted varieties
exhibit stable yield and resistance to many pests which are perhaps the
reason why many traditional varieties have persisted with farmers
despite introductions of new varieties. In root crops for example, there
are 10 formal releases compared to 202 traditional or farmer’s
varieties. In cereals where introductions have been pronounced, formal
release (32) are still less than the traditional varieties (47).
Preferences of farmers affect their choices of
varieties. In root crops, gastronomic traits are more important than
agronomic reasons in choosing varieties. In cereals, however, agronomic
reasons prevail over gastronomic traits.
Farmers conservation of plant genetic resources is
closely related to the use-value of crops and their varieties. Farmers
conserve and develop PGR by utilizing them to meet their needs,
preferences and conditions. Outside the context of use-value, farmers
would find little reason to conserve and develop PGR.
The informal seed supply system is also a critical
factor in the conservation of PGR diversity in farmers’ fields. The
informal system has been the main source of planting material for
farmers. Within this
system, seed quality is maintained using appropriate
selection criteria, techniques, and indigenous storage methods. The
practice of farmers in sharing their planting material for free or under
some exchange scheme served as an effective and efficient channel for
distributing germplasm across wide areas.
The survey has generated valuable information to
support subsequent efforts towards PGR conservation and development.
These efforts or areas of intervention may include: (1) formulation and
implementation of strategies that will conserve and enhance the genetic
diversity in farmer’s field (2) further studies and more detailed
documentation of specific cases of farmers involvement in genetic
diversity conservation
and improvement revealed in this survey, and (3)
advocacy work on programs and policies believed to have deep implication
in crop diversity conservation.
In the formulation of strategies for the conservation
and enhancement of genetic diversity, the active involvement of farmers,
and adequate scientific advise from experts must be sought to ensure
that said strategies will be both technically feasible and adaptable
under real farm situation.
In addition to technical feasibility and
adaptability, the bottom line in any course of action to be taken is
farmer participation. Conservation efforts should start with what the
farmers have, in terms of PGR diversity, and in what they know, in terms
of local knowledge of how this diversity has been maintained. From
there, farmers capability should be build up so that they can
effectively perform the core activities in genetic conservation and
improvement. These activities can include collection, documentation and
storage of germplasm; formulation of breeding objectives, and actual
process of breeding and selection. A participatory project like this can be initially
carried out in certain communities where we have active farmer-partners.
Finally, PGR conservation and development must be undertaken in the context of sustainable agriculture. The technology and
methods to be used in community PGR conservation must be environmentally
and economically sustainable. In the end, PGR
conservation must adequately provide for the food needs of farmers while
conserving genetic diversity.
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