Cultivation guide for cowpea classes
Cultivation Guide for
Cowpea Series
1, Sowing Time
Timely sowing. For the
open-field cultivation, these varieties can be sown for three times a year. The
main way to achieve high benefit is to arrange the sowing time within the best
cultivation and benefit period. For the Spring cultivation, the sowing time is
in middle and late Mar., covered with mulching film aftre sowing, and enter
market in late May. For the Summer cultivation, the sowing time is in early
May, and enter market in middle Jul. For the Autumn cultivation, the sowing is
in early Aug., and enter market in early and middle Sept.
2, Requirement of Cultivating Circumstance and
Conditions.
2.1, Temperature
The cowpeas are heat-resistant crops. The
lowest sprouting temperature is about 8-12 degree centigrade, and the proper
temperature is 25-30 degree centigrade. The suitable temperature for sowing is
about 20-25 degree centigrade, and 25-28 degree for blossom and fruiting. These
varieties are more resistant to high temperature, and some of them will
normally grow, blossom and fruiting under about 33 degree centigrade condition.
The cowpeas are sensitive to low temperature. The growth will be restrained
when the temperature is bellow 10 degree centigrade, frosted bellow 5 degree
centigrade and die in zero degree centigrade.
2.2, Illumination
The cowpeas belong to short-day crops, but
most of the varieties do not strictly require the time of illumination. Shorten
the illumination time will forward the blossom and fruiting, and lower the first
blossom node. The plants require sufficient illumination in both blossom and
fruiting period, otherwise, it will causes dropping of flowers and pods.
2.3, Moisture
The cowpeas have deep root system, and the
water absorbing power is strong, and the transpiration amount is small, so they
are more drought-resistant. The plant requires proper amount of moisture in
growing period. But when the soil moisture is too high, it will easily causes
yellowing and dropping of leaves, even root-roting, death of seedling and
dropping of flowers and pods, and it also goes against the activity of root
nodules.
3, Season of Cultivatin and Selection of Varieties
For most areas in south China
For the cultivation in Spring, it is suggested
to select varieties such as Jinlubao
Cowpea , Taiwan
For Summer cultivation, it is suggested to
select varieties such as Karachi Cowpea, Santoni Cowpea, Hongkong Oil-Green
Cowpea, Summer-Treasure Productive No. 3 Cowpea, and so on.
For Autumn cultivation, all the varieties of
Linong are basically suitable for sowing.
4, Cultivation Techniques
4.1, Transplanting in Spring Cultivation
For Spring cultivatin, transplanting after
culture of seedling will ensure the full stand, and promote precocity and
increase yield. Culture seedlings in high plastic tunnel or low tunnel, and
arrange sowing time according to different cultivation modes.
For cultivation in low tunnel, culture the
seedlings in middle to late March, set the plants in tunnels at the beginning
of April, and harvest from the middle to late May to middle July. For
cultivation with ground film, culture the seedlings in late March to the
beginning of April, set the plants in open-field in middle April, and harvest
in early June to middle August.
Before sowing, select seeds carefully, then
sun the seeds for 1-2 days. It usually does not need sprouting. For to protect
the root system, it is better to use nutrient pot or nutrient clod to culture
seedlings. Sow 3-4 grains of seeds into one pot, water the soil to keep moist,
and then build up low plastic tunnels covered with thin films. From germination
to transplanting, maintain the seedbed temperature in about 20 degree
centigrade, not higher than 25 degree or lower than 15 degree centigrade. Keep
the seedbed soil moist, pay attention to the ventilation, strictly prevent
attack by cold wind and frost, and improve the illumination condition, so as to
culture strong seedlings.
4.2, Preparation of Soil and Supply of Base Manure
As the root system of cowpeas is deep,
it is resistant to barren soil and drought, but not to rain and waterlogging.
The cowpeas are widely adaptable to soil. Avoid continuous cropping, otherwise
the plants will be invaded by diseases easily. Because the planting density is
high, and the vegetative growth and reproductive growth process at the same
time, it requires abundant quantity of fertilizer. Along with ploughing and
preparing of field, supply per acre of field with 12000-18000kg of finished
organic manure such as human excreta or pig and duck dung, adding 180kg of
calcium phosphate and 450kg of wood ashes, 30-600kg of potassium sulphate, or 180-240kg
of compound fertilizer. Prepare the soil carefully and form ridge, mainly by
high one. Generally, the ridge is about 1.4m wide including ditch and 17-20cm
high, planted in two rows. For Spring cultivation, it is usually cultivated
with mulching film. After forming ridge, cover them with milching film. The
films should be strained and covered flat, clinging on ground.
4.3, Plant Setting or Direct Sowing
4.3, Plant Setting or Direct Sowing
For Spring cultivation,
it is usually cultivated by transplanting after culture of seedling. It is
better to choose young seedlings and set earlier, which is call ‘Planting Buds’
by farmers, that means to set plants when the first pair of main leaves are
still unfold after germination. If for culture of seedling in nutrient pot, the
transplanting can be delayed to the appearance of the 2nd-3rd compound leaf.
For open-field cultivation, it is better to set in middle and late April.
Generally, the width of the ridge including ditch is about 1.4m, planted in two
rows, each hole planted in 2-3 plants, and the planting distance is about
24-27cm. Cultivate 19200-22400 plants per acre. Choose sunny and warm day to
transplant. Water the root with clear water or 10% human excreta, to benefit
the revival.
For Summer and Autumn
cultivation, it usually cultivated by derect sowing. If the soil is droughty,
irrigate it first. Sow 4-5 grains of dry seeds into each hole, in 2-3cm deep,
and then press tightly. Before seedlings coming up of earth, cover the ridge
with sunshade net, to benefit the germination. It costs about 12kg of seeds per
acre. For Summer cultivation, the growth and development is in the seasons full
of high temperature, highlight and rainstorm, the fruiting period is short, and
the fruiting fastigium comes within the high temperture period which is full of
frequent rainstorm, these will result in low and unstable yield, and increasing
the difficulty in field management. Pay attention to the excessive growth of
stems and leaves, no podding and abnormal pods phenomenons in early stage, and to prevent senilism in the late
period.
In addition, it is the outbreak period for diseases and pests in
Summer seasons. Therefore, it is better to arrange the sowing time rationally,
select disease-resistant varieties, and cultivate on high ridge with deep ditch,
so as to abate the occuring of diseases and insect pests, and to ensure the
normal growth.
A, Selection of Field
The cowpeas fear
continuous cropping as other beans, because it will retains abundant of
pathogens and pests in the fiel which is continuously cropped by cowpeas. After
the germination of seedling, the diseases will spread rapidly, so do the insect
pests, therefore, the loss of yield will be serious. After the pods are harvested,
the radix of diseases and pests sources will inceases. If the field is still
cultivated with cowpea by the coming year, the damages of diseases and insect
pests will be more serious, resulting in the increase of supplying amount and
times of pesticide. In that case, it will be difficult to make sure that the
content of toxic substance of pods is not out of limit. Therefore, the
cultivation of cowpea should be alternated with shallot and garlic, or rotated
with poaceae crops for 2-3 years, which will substantially reduce the
occurrence rate of diseases and insect pests in the field.
Cultivate on the field
which has fertile soil with well irrigation and drainage, and is not continuous
cropping for more than one year, so as to lay the foundation for reducing the
use of pesticide and pollution to the environment.
B, Preparation of soil
In Summer, the ploughing
depth should be above 30cm, and sun the soil for 2-3 days. Then prepare the
soil carefully, to make the field flat and the soil in small pieces, and then
form the ridge regularly.
C, Supplying of Base
Manure
For each acre of field,
supply 18000-30000kg of finished pollution-free farmyard manure, 180-300kg of
calcium super phosphate, 900kg of wood ashes, and 24000kg of BYM, or 360kg of NutriSmart
301 and 180-240kg of ammonium hydrogen carbonate as base manure. After forming ridge
regularly, furrow in the enter ridge and supply the manure above into the
chimbs. This will reduce the loss of fertilizer when washed out by rains or
leekage, concentrate the nutrient for the growth, and increase the use ratio of
fertilizer.
The requirement of
variety for Summer sowing is that, high podding rate, resistance to high
temperature, long period of podding, high yield and commodity character, and
strong resistibility.
For Summer cultivation,
as it rains a lot, if for ridge cultivation mode, choose deep ditch and high ridge.
The ridge should be more than 15cm high, and about 30-40cm wide including
25-30cm deep ditch. This complement of ridge and ditch will helps to timely
drain the waterlogging, irrigate to fight against drought, promote the growth
of root system, profit the absorbing of water and fertilizer, provide the
plants with moisture and nutrient in time, and ensure the abnormal growth
The timely sowing of
cowpea in Summer cultivation is critical to the achievement of high yield and
benefit. Therefore, the best period for sowing, growth and development, and
harvest should be combined organically. Try best to sow seeds before the
increasing of rain, so as to win as much suitable podding time as possible. For
Summer cultivation, it is usually sown from May to Jul., and supply for the low
season market in Aug. and Sept., as to achieve good benefit.
The sowing principles
are as follow. The variety which are middle late maturity is sown first, and
then the precocious ones. The seeds are generally sown in dry state. The sowing
requires sufficient moisture, if not, it will causes poor germination and
rotten buds. The planting distance is about 60cm by 35cm, in two rows with 2-3
plants in each hole, about 21800 plants per acre.
4.4, Field Management
For derect sowing and transplanting, after
the germination or suvival of seeldings, thin or complementarily plant the
seedling in time. The complementary planting of seedling should be done from
the unfolding of the first compound leaf to the second one. For thinning, retain
3 plants of strong seedlings in each hole, and thin the rest ones. After the
complementary planting, pour human excreta to ensure the survival. From the
survival after setting or trimness of seelding to the building of shelf,
cultivate in time to benefit the soil breath, so as to support the growth of
root system and occuring of rhizobium.
When the plant outgrows 5-6 pieces of leaves,
the shelf can be built. The shape of the shelf can be A-bracket or better be
inverse A-bracket. The intersection height of the bamboo stickers is about
0.8-1.0m, with one third of height bellow the intersection and two third above.
This will benefit the ventilation and illumination, and also picking. When the
vines grow to be 30cm long, lead them onto the shelf artificially in time in
the sunny day afternoon. The training includes wiping out buds and low side
branches, top removal of chief vine, and wipping off old leaves. Wipe out the
branches which are bellow the first inflorescence on the chief vines. When the
chief vine spreads to the top of the shelf, the top removal can be done, and
also to the side branches after the podding in late period. In the growing
acme, cut off the old and sick leaves in low layers, so as to reduce nutrient
consumption, improve ventilation and illumination, and promote the blossom and
fruiting.
Before blossom and podding, the cowpeas do
not require much fertilizer and water. If the fertilizer and water is supplied
too much, the vines and leaves will grow prosperously, and the blossom and
podding node will be higher, resulting in reducing the quantity of
inflorescence and side vines, and easily forming unfruitful vines in middle and
low layers. Therefore, the fertilizer and water supply must be controlled in
the early period, to promote the forming of first inflorescence, increase the
inforescence quantity on chief vines and reduce the occuring of side vines.
Entering the blossom and podding acme, increase the supply of fertilizer and
water, to promote growth, more blossom and podding. In harvest acme, as the
numbers of rootnodules reduce, and the activity will also decline, the plant
require more fertilizer and water, so the top dressing should be heavy, so as
to promote the forming of side vines and buds, and blossom and podding, prelong
the picking period, and increase yield. The management of fertilizer and water
is as follow. Control at first and then promote, to prevent vines and leaves
from excessive growth, and also senilism. The top dressing should mainly by
finished human excreta, nitrogen and potash fertilizer. The first time of top
dressing can be done after the survival of seedlings in transplanting
cultivation, or germination of seedling in derect sowing cultivation. For each
acre of field, supply in 4500kg of finished human excreta. The second time of
top dressing is done before building the shelf, supplying 6000kg of finished
human excreta per acre. After the first inflorescence pods, in every 7 days, supply
fertilizer heavily by pouring human excreta or fertilizer by water, and 60kg of
urea and 30kg of potassium sulphate, or 90kg of compound fertilizer per acre.
In the whole growing period, top dressing for 4-6 times.
From Jul. to Sept., it is the blossom and
fruiting acme for the Summer and Autumnn cowpeas, and the plant is in abundant
need of moisture. If run into high temperature and droughty weather, the
watering times and quantity should be increased, to keep the soil moist. For to
cool down the earth temperature and increase the temperature difference from
daytime to night, the watering is better done at nightfall, and make sure not
be at noon. The watering should not be flooding, so as to prevent waterlogging
in the filed and impacting the growth and development.
5, Prevention and Control of Diseases and Insect Pests
For Autumn cultivation,
the main diseases are rust, stalk
break and virus diseases. They are caused mainly by high temperature and humidity.
Prevent and control in the early stage. For rust disease, spray 1000 times of
triadimefon or 500 times of moncozeb for control. For stalk break disease,
spray 1500 times of procymidone, phosethyl Al(Miconazole nitrate), or
diethofencarb for control. For virus disease, the control is mainly by prevention.
In high temperature weather, spray oxadixyl mancozeb on leaf once every 7-10
days. The damping off disease occurs mainly in the seedling stage, spray
tachigaren on leaf for control. And in the late period, use 400 times of
fosetyl-aluminium or 200ppm of streptomycin for root pouring.
The main pests includes aphid, cotton bollworm, pod borer, and so
on, and the red spider will sometimes cause damage in droughty climate. Use
acetamiprid, imidacloprid, fenvalerate, 800 times of 75% chlorothaloril, or 1500
times of 50% iprodione WP for control. Or spray 800 times of 25% meothrin for
control, or use high-efficiency and low-toxin pesticide such as BT emulsion,
7216, insecticidal bacteria, or BT-781 for control
6, Harvest
The harvest
period of cowpea is short and concentrated. If harvet too late, not only the
quality will be aged, it will also speeds up the senilism of the plant.
Generally in 10-12 days after blossom, it is the suitable harvest period when
the pods are full, with scrisp tissue, not blanch, and the beans are not yet
appearring. The yield is about 7200-15000kg per acre.
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