Lettuce is included in the group leafy vegetable crops is known in the
society. These vegetables contain nutrients, especially vitamins and minerals
that are complete to qualify the nutritional needs of the society. Lettuce as
food vegetables can be consumed in their raw form as fresh vegetables together
with other food ingredients. Besides useful for groceries, lettuce is also
useful for the treatment (therapy) of various diseases. Thus, lettuce has a
very important role in supporting public health.
In Indonesia lettuce plants cultivated by people in areas of vegetable
centers in lowland and upland with various varieties grown.
The lettuce has a name that is different in every country, for example,
lettuce (Indonesia), mustard (Taiwan), and lettuce or head lettuce
(International).
According to various published sources, lettuce plant (lactuca sativa)
is native to Europe and Asia. The new plant to be cultivated to get attention
after it has benefits as a food ingredient vegetable contains good nutrition.
In addition, the lettuce plants known to also have benefits for the treatment
(therapy) various diseases. Lettuce plants has begun cultivated since
approximately 2,500 years ago, with the proven presence of ancient writings
about plants (lettuce) about 500 years BC.
Wild lettuce types often have leaves and stems are thorny, do not form a
head and leaves a bitter taste, and contains a lot of sap. This plant breeding
may be emphasized in order to obtain plants that are not prickly, slow
flowering, large seeded and does not spread, not gummy, and not bitter. Other
aspects include fewer wild shoots, leaves and a large width, and shape of the
head. That form is a head of lettuce cultivated plant more, which was first
named as "cabbage lettuce" in 1543.
During this time, lettuce used as a vegetable leaf for salad and touted
as the king salad because the texture is very fine. Lettuce consumed raw and
can be found in a salad or hamburger.
Condition
Of Growth
Lettuce plants can grow well in damp and cold weather or cool air that
is at a temperature between 15-20 °C, with a soil pH between 5.0 to 6.5. The
preferred soil type of lettuce is dusty loam, sandy loam, the soil still
contains humus and no stagnant. Nevertheless, the lettuce is still tolerant of
soils poor in nutrients as long as irrigation and organic fertilizers were
adequate. The soil should be neutral reaction. If the soil is acidic, lettuce
leaves turn yellow. Therefore, for acidic soils calcification should be done
first before planting. These plants can be grown in lowland or highland, but
the best result is grown in the highlands. Lettuce grown in the lowlands tend
to be fast flowering and seed in it.
Description
Of Lettuce
Lettuce plants (Lactuca sativa), including vegetable crops belong to the
leaf and seasonal crops (short-lived). Plants grow shorter height ranges from
20 cm - 40 cm or more, depending on the type and variety. No lettuce plants
that make up the crop (collection leaves closer together form the head) and
there are varieties that do not form a crop. Leaf lettuce plant height ranging
from 30 cm - 40 cm and head lettuce plant height ranges from 20 cm - 30 cm.
Morphologically, the vital organs contained in lettuce plants is as follows.
Leaf of lettuce plant has a shape, size, and color vary depending on the
variety. For example, the type of lettuce that make up the crop has a leaf
shape or a round or oval with size or large broad leaves, leaves dark green,
light green, and there is a rather dark green. While that does not form a type
of lettuce crop, the leaves are elliptical, large, jagged leaf edges (curling),
and leaves dark green, light green, and red. Lettuce has a petiole width and
bones pinnate leaves. Petiole is strong and smooth. The leaves are soft and crunchy
when eaten, and has a slightly sweet flavor. Lettuce generally has a length of
20 cm - 25 cm and a width of 15 cm or more.
Lettuce plant has a real trunk. On lettuce plants that make up the crop,
stems are very short and barely visible and is located on the bottom inside the
ground. Whereas lettuce that do not form the crop (leaf lettuce and stem lettuce)
has a longer stem and visible. Stem is robust, sturdy, strong and with a
diameter ranging from 5.6 cm - 7 cm (stem lettuce), 2 cm - 3 cm (leaf lettuce),
as well as 2 cm - 3 cm (head lettuce).
Lettuce plants have a root system stable and fibers. Root fibers
sticking, growing spreads, in all directions at a depth of 20 cm - 50 cm or
more. While stable roots grow straight into the center of the earth. Lettuce
plant roots can grow and thrive in soil that is fertile, friable, easily
absorbs water, and soil depth deep enough.
Seeds of lettuce plants flattened oval, hairy little hard, brown, old,
and very small, the length of 4 mm and a width of 1 mm. Lettuce seeds are
enclosed seeds and dashed two, may be used for the propagation of plants.
Flowers of lettuce plants yellow, grows dense in a series. Flowers have
a long flower stalk that reaches 80 cm or more. Lettuce plants grown in
temperate zones (subtropical) easily or quickly bear fruit.
Lettuce
Varieties
Lettuce has long been known by the society. In the beginning, there are
only a few varieties (types) of lettuce. With the development of human
civilization and technology, has now found new varieties are superior to
previous generations are countless more. Thus providing great expectations for
increased production of lettuce in Indonesia and other countries. In addition,
the issuance of new varieties whose production is higher than previous varieties
also give great hope to increase the income and welfare of farmers.
In Indonesia there are lettuce from local varieties and imported
varieties. However, in general, grown by farmers is imported variety, because
the production of local varieties are generally still lower than the imported
varieties. Imported varieties more outstanding in the Indonesian market from
different countries yielding seeds, for example Peto Seed (USA, United States),
Yasui (Taiwan), Known You Seed (Taiwan), Liong You Seed (Taiwan), Qiang Nong
Seed (Taiwan), Sakata Seed (Japan), Takil Seed (Japan), Hungnong seed (Korea),
Nunhems seed (the Netherlands), and so forth, all of which can give high
yields. Every year continuous seed companies that produce new varieties. Each variety
has different advantages. This difference can be seen in terms of the
productivity of the plant (leaf production/crop), adaptability to the
environment, resistance to pests and diseases, as well as the taste of the
leaves.
There are types of lettuce categorized by head
formation or leaf type. Each of these lettuce varieties offers a unique flavor
and texture, and growing different types of lettuce will be a surefire way to
generate interest in eating a healthy diet. Some lettuces also keep better than others and all these characteristics
are described in detail below.
1. Crisphead
or Iceberg. Crisphead
lettuce, more commonly known as iceberg, has a tight head of crisp leaves. This familiar pale green lettuce
forms a tight, cabbage-like head. Often found in the local salad bar, it
is actually one of the more difficult lettuce varieties to grow. This lettuce texture is crisp and its flavor
very mild. This lettuce variety is not fond of hot summer temps or water
stress and may develop rotting from the inside out. Start iceberg lettuce via seed directly sown 18-24 inches apart
or started indoors and then thinned 12-14 inches between heads.
Some iceberg lettuce varieties
include: Ballade, Crispino, Ithaca, Legacy, Mission, Salinas, Summertime and
Sun Devil, all of which mature in 70-80 days.
2. Summer
Crisp, French Crisp or Batavian.
Somewhat between the lettuce types Crisphead and Loose leaf, Summer
Crisp is a large lettuce variety resistant to bolting with great flavor. It has
thick, crisp outer leaves which can be harvested as a loose leaf until the head
forms, while the heart is sweet, juicy and a bit nutty.
Different types of lettuce for
this variety are: Jack Ice, Oscarde, Reine Des glaces, Anuenue, Loma, Magenta,
Nevada and Roger, all of which mature within 55-60 days.
3. Butterhead,
Boston or Bibb. One of
the more delicate varieties of lettuce, Butterhead is creamy to light green on
the inside and loose, soft and ruffled green on the exterior. A head of Boston lettuce resembles a flowering
rose. Bibb lettuce - also called limestone - forms a smaller, cup-shaped head. These
different types of lettuce may be harvested by removing the entire head or just
the outside leaves and are easier to grow than the Crispheads, being more
tolerant of conditions. Less likely
to bolt and rarely bitter, the Butterhead lettuce varieties mature in about
55-75 days spaced similarly to the Crispheads.
A butterhead lettuce can be recognised by its
soft leaves which are arranged rather like the petals of an old English rose.
Often the centre has a much crisper head but nothing as crisp as iceberg or the
average Cos. The leaves have lots of taste to them and overall are sweet. A
butterhead lettuce have a soft “buttery”
texture and a sweet, mild flavor.
Not only are butterhead lettuces tasty but they
are easier to grow and faster to mature compared to Cos and Iceberg types.
Their ability to withstand cold temperatures is also accompanied by an ability
to withstand higher temperatures compare to the other types. Several varieties
can be planted in the autumn for harvest in spring much earlier than most other
lettuce varieties. So just a couple of varieties of butterhead lettuce and with
a bit of planning you can be eating your very own lettuce for seven months of
the year. There are many old varieties still available although in the 1950s
the butterhead lettuce (and to some degree the Cos) was overshadowed almost
completely by the ubiquitous Iceberg type lettuces. In the 90s though the
butterhead lettuce started the comeback because of its superior taste,
appearance and nutritional value.
These varieties of lettuce
include: Blushed Butter Oak, Buttercrunch, Carmona, Divina, Emerald Oak, Flashy
Butter Oak, Kweik, Pirat, Sanguine Ameliore, Summer Bib, Tom Thumb, Victoria,
and Yugoslavian red and are extremely popular in Europe.
4. Romaine
or Cos. Romaine
varieties are typically 8-10 inches tall and upright growing with spoon-shaped,
tightly folded leaves and thick ribs. Coloration is medium green on the
exterior to greenish white inside with the outer leaves sometimes being tough
whilst the interior foliage is tender with wonderful crunch and sweetness. ‘Romaine’ comes from the word Roman
while ‘Cos’ is derived from the Greek island of Kos. In the UK it is commonly called Cos lettuce
although in France and the USA it is called Romaine - there is no difference
between the two other than the different names. Romaine lettuce is a key
ingredient of the famous dish Caesar Salad.
The typical Cos lettuce has upright leaves
which form a relatively tight head. The inner leaves are a much lighter green compared to
the outer leaves because the sun has not reached them so easily. As far as
nutrition is concerned this type is high in nutrients but only in the outer
green leaves, the inner whiter leaves have almost no nutrient value at all. The
inner leaves are crisp and crunchy with very little taste, the outer leaves are
softer and have a sharp and sweet, slightly earthy taste.
For many years lettuce has not only been eaten
raw but often quickly cooked, mainly grilled and Cos stand up to cooking better
than all the other types.
Lettuce is a plant which does not like excesses
of heat but the Cos is better than all the other types at growing in warmer
conditions. As far as growing is concerned the Cos lettuce has no major drawbacks and is easily
cultivated if a few basic rules are followed.
Some different types of this
lettuce are: Brown Golding, Chaos Mix II black, Chaos Mix II white, Devil’s
Tongue, Dark Green Romaine, De Morges Braun, Hyper Red Rumple, Little
Leprechaun, Mixed Chaos black, Mixed Chaos white, Nova F3, Nova F4 black, Nova
F4 white, Paris Island Cos, Valmaine, and Winter Density, all of which mature
within around 70 days.
5. Loose
leaf, Leaf, Cutting or Bunching.
This type of lettuce comprises a number of varieties that don’t form heads, but
consist of large, loosely packed leaves joined at a stem. The Loose leaf
have rows of leaves loosely
arranged around the centre. Unless your appetite for salad is rather large the leaves, rather than the whole
lettuce, are harvested as and when needed which allows more leaves to grow. Harvest
these varieties either whole or by the leaf as they mature. Plant at weekly
intervals starting in early April and again mid August and thin Loose leaf
lettuce to 4-6 inches apart. Loose leaf varieties are slow bolting and heat
resistant.
The leaves are either green or shaded to deep
red at the edges, and may be ruffled or smooth. Their degree of crispness is
midway between romaine and butterhead, their taste is mild and delicate. Red
leaf and green leaf are popular varieties. Oak leaf, both red and green, forms
smaller heads, with flatter leaves shaped like big, floppy oak leaves. For home
gardeners, loose leaf lettuce has an advantage over other types: If you pick leaves
individually instead of pulling the whole head from the ground, the leaves will
continue to replace themselves throughout the season.
The beauty of loose leaf lettuce is the vast
array of colours, textures, shapes and tastes. Probably the best way to grow
loose leaf salads for the beginner is to buy a packet of mixed seeds. Mixing
different types of loose leaf lettuce together for a salad allows you to cut a
few leaves from each plant and gives them the chance re-grow.
A wide variety of colors and shapes
guaranteed to stimulate the sight and the palate are available in the following
lettuce varieties: Austrian Greenleaf, Bijou, Black Seeded Simpson, Bronze
Leaf, Brunia, Cracoviensis, Fine Frilled, Gold Rush, Green Ice, New Red Fire,
Oakleaf, Perilla Green, Perilla Red, Merlot, Merveille De Mai, Red Sails, Ruby, Salad Bowl, and
Simpson Elite, which will all mature within a 40-45 day time period.
6. Stem
lettuce or Asparagus lettuce. Stem lettuce type has the characteristics, the
plants do not form the crop, the leaves are large and long round with a length
up to 40 cm and a width of about 15 cm, leaves ravel, petiole width, leaf there
is a dark green, and there are light green (depending on the variety), the
bones of pinnate leaves. Plant stem length ranging from 30 cm-40 cm, large and
sturdy with diameters ranging from 5.6 cm - 7 cm, white greenish or whitish
green, smooth and crisp. It is widely grown in China, and is also known as
Chinese lettuce. The only variety available in the United States is called
celtuce. Stem lettuce has a mild flavor that is sometimes described as “nutty
cucumber.” Stem lettuce is good in salads, but can also be cooked like a
vegetable. This type is resistant to heat and cold conditions, so it can be
cultivated in lowland and upland.
The descriptions of some varieties of lettuce that has a good market and
high economic value of the four types of lettuce above is as follows.
a. Georgia
This variety is a hybrid type and the kind of
head lettuce. Plants grow compact and have little outside leaf. The crop is large,
dense, greenish white, and short center. Heavy crop ranged from 1 to 1.3 kg.
b. General
This variety is a hybrid type and including
Head lettuce types such as Georgia. Plants grow faster, cercospore leaf spot
disease resistance, heat resistance. The crop is large, dense and uniform.
c. Red
Rapid
This variety is hybrids type and the kind of leaf
lettuce type (Cutting lettuce or Leaf lettuce). Flowering plants is slow, so
the harvest period grew longer. Broad leaves and large, the edges wavy leaves,
and the leaves are red to dark red.
d. Grand
Rapid
This variety is a hybrid type and the kind of leaf
lettuce. Plants grow faster, broad adaptability, can grow well in winter. This
type is heat resistant and can be grown throughout the year. Green leaves.
e. Sueh-Li-Hung
2
This variety is a hybrid type and the kind of leaf
lettuce. Plants grow very strong, heat resistant and cold resistant, highly
branched, is not easy flowering, disease resistance of wet rot and viruses.
Green leaves and serrated. Harvesting plants 20 days after transplanting.
Potential production reached 1.8 kg per plant. The leaves are suitable for
sauerkraut.
f. Sueh-Li-Hung
This variety is a hybrid type and the kind of leaf
lettuce. Plant grow strong, branched, fertile, disease resistant, and pests.
The leaves are straight and serrated leaf edge. The leaves are suitable for
sauerkraut.
g. Celtuce
This variety is a hybrid type and the kind of steam
lettuce. Plants grow strong, easily grown, disease resistance, and short-lived.
Large stems of plants with stem diameters of 6 cm and a length of 30 cm,
white-green, light green flesh, smooth and crisp. The leaves are elliptical,
large, stemmed wide, bright green, straight and serrated leaf edge. The leaves
can also be used as a vegetable.
h. Beseeming
This variety is a hybrid type and the kind of
stem lettuce. Plants grow fast and strong, large-sized trunk midline 5.6 cm and
a length of 30 cm-40 cm, white-green, and light green flesh-colored stems, as
well as light blight disease-resistant plants. Leaves the plant has a size of
approximately 40 cm long and 15 cm wide, elliptical with flat leaf edge.
Potential production of 0.5 kg/plant. The stems can be cooked in soups,
pickles, and leaves can be used as a vegetable.
i. Majesty
This variety is a hybrid type and the kind of
stem lettuce. Plants grow fast and strong, cercospore leaf spot disease
resistant, resistant to cold and hot weather. Sturdy stems, light green, large
with a diameter of about 7 cm, whitish light green flesh, crispy and suitable
for sauerkraut. The leaves are elliptical with flat leaf edge. Young leaves can
be used for vegetables.
j. Bau-Sin
This variety is a hybrid type and the kind of
head lettuce. Plants grow shorter, crop is large, smooth, crisp, and tastes
good. The lettuce is suitable to be cooked, and sauerkraut.
k. King
Mustard
This variety is a hybrid type and the kind of leaf
lettuce. Plants grow big and cold resistant. The leaves are wide, straight,
thick, fibrous soft, green and purple.
l. Other
varieties
In addition to the varieties mentioned above,
there are many varieties of other, for example, Dabota, Alps, Marina, Kaisser,
Gento, Great Lakes, Okayama salad, Ontario, All the Year Round, Webb's
wonderfull, Tom Thumb, Ballade, Santa Maria, Great Lakes 54, and so on which
are hybrids and include the type of head lettuce. Paris Island, Paris White
Winter Density, Barcarolle, and so is the type of hybrid and including fragile
lettuce types. New Red Fire, Salad Bowl, Sunglow, Prize Head, Vulcan, Plato,
Green Wafe, Vit, Red salad bowls, Eland, and so on which are hybrids and include
the type of leaf lettuce.