Field Guide of Discovery-based Exercises for - Aseanipm ...

Section 7 • Participatory Plant Breeding, Seed Production, Harvest, and Post-Harvest Management
Exercise No. 7.02
PARTICIPATORY PLANT BREEDING BY FARMERS
FOR ORGANICALLY-GROWN SELF-POLLINATED
(STRING BEAN AND EGGPLANT) VEGETABLE CROPS
BaCKGroUND aND raTIoNalE 245
Native to Southeast Asia, string bean, yard long bean or
pole sitao is a mostly climbing plant, and a close relative
of cowpea. It comes in different varieties, from a more
common pale green pod variety or a more slender darker
green one to a deep brownish red variety. The vegetable
is popular among farmers and usually grown on poles,
although free-growing varieties are also available. Young
pods of string bean are used as cooked vegetable, mostly
combined with rice as main dish. In Indonesia, fresh young
pods are consumed as salad. Sometimes, shoots and young
leaves are also consumed. Like other fruiting vegetables,
growth stages of string bean overlaps. After germination,
growth is very fast. Flowering usually starts on 5 th week
after sowing and harvest of young pods starts 2 weeks later.
Depending on crop health and intensity of harvesting,
senescence starts 1½-2 months after sowing and plant dies
after 3-4 months. Pods can reach a length of one yard (90 cm); hence it is also called yard-long bean.
String bean is a naturally self-pollinating crop, although some degree of cross-pollination by insects
occurs. Flowers are large and easy to manipulate, keel is straight, beaked, and not twisted. Flowers
have few floral nodes per raceme.
Eggplant, on the other hand, originates from India and is now generally grown as a vegetable throughout
the tropical, sub-tropical, and warm temperate areas of the world. Eggplant varieties display a wide
range of fruit shapes and colors, ranging from oval or egg-shaped to long club-shaped, and from white,
yellow, green through degrees of purple pigmentation to almost black. An increasing number of F1
hybrid varieties are available in the market. However, many farmers still prefer to keep or exchange
their own seed. Fruits are popular in the market as they are used in many dishes, either as boiled,
fried, or stuffed. Unripe fruits are sometimes used as curries. Although semi-perennial, eggplant is
usually grown as an annual with cropping season duration of 5-6 months. Seeds are small and need a
245 Smolders, H. and Caballeda, E. 2006. Field Guide for Participatory Plant Breeding in Farmer Field Schools: With Emphasis on Rice and Vegetables.
Participatory Enhancement of Diversity of Genetic Resources in Asia (PEDIGREA) Publication. Center for Genetic Resources, the Netherlands. 136p.
355
when is this exercise most
appropriate?
ɶ In FFS, TOT, and VST
sessions, when some selfpollinated
vegetables
(e.g., string bean and
eggplant) are organicallygrown
as parent materials
for studies of plants’
biological processes (e.g.,
planting to harvest) and
for participatory plant
breeding exercises (e.g.,
flowering stages) in
learning field; and
ɶ When farmers want to learn
from other farmers and do
hands-on of proper selfing
and hybridization of selfpollinated
vegetables (e.g.,
string bean and eggplant)
in their own farms.