Dry beans— Production guideline —

Dry beans— Production guideline —

March 2010

Department of Agriculture, Forestry and Fisheries

2010

Printed and published by

Department of Agriculture, Forestry and Fisheries

Compiled by:

Directorate Plant Production in collaboration with the ARC

Design and layout by

Directorate Agricultural Information Services

Obtainable from

Resource Centre Directorate Agricultural Information Services Private Bag X144

PRETORIA 0001

CONTENT

General................................................................................................. 1

Cultivation practices ............................................................................. 5

Post-havest handling ............................................................................ 20

Production schedule ............................................................................. 23

Utilisation .............................................................................................. 23

Acknowledgement ................................................................................ 24

1

GENERAL

Scientific name: Phaseolus vulgaris

Common names: Small White Beans, Speckled Sugar Beans, Brown and Yellow Haricot Beans and Green Beans

Origin and distribution

The dry bean is at present regarded as one of the most important field crops in South Africa on account of its high protein content and dietary benefits. Among the pulses (i.e. annual leguminous food crops that are harvested for dry seeds) the dry bean is by far the most important. Dry beans (Phaseolus spp.) originated in Central and South America. Within sthe genus Phaseolus there are three species which are agronomic ally simportant in South Africa. Within each species there are many seed types which differ in respect of size, shape and colour. Within each type, vari-ous cultivars exist, the seeds of which differ very little from one another. However, considerable differences may occur in adaptability, growth habit, disease resistance and many other characteristics.

Production levels in South Africa

South Africa produces only 75 % of the dry beans consumed in the coun-try, the others are imported. A continuous effort is being made to obtain higher production per unit area in order to increase profitability, on the one

2

hand, and to meet the ever-increasing demand for food, and especially protein on the other. The optimal profitability, production, marketing and consumption of dry beans can only be accomplished by means of proper and purposeful research. A direct result hereof is that the average yield has increased from the 0,6 t/ha obtained in the early seventies to approxi-mately 1,2 t/ha in the eighties. It has furthermore contributed to the record crop of 108 000 t obtained in 1990.

Major production areas in South Africa

Province District Town

Mpumalanga Gert Sibande

Makaligwa

Nkangala

Secunda

Ermelo

Middelburg, Delmas

Free State Thabo Mofutsanyane Betlehem, Witsieshoek,Harrismith

North West Ngaka Modiri Malema

Dr Kenneth Kaunda

Bojanala

Mafikeng, Delareyville,Lichtenburg, Zeerust

Ventersdorp, Klerksdorp,Potchefstroom

Rustenburg, Moretele, Koster,Brits

Gauteng Ekurhuleni

Sedibeng

West Rand

Germiston, and vicinity

Vereeniging and vicinity

Randfontein and vicinity

KwaZulu-Natal uMgugundlovu

iZingolweni

Ugu

Pietersmaritzburg, Mooi River

Ezingolweni

Scottburg/Umzinto North,Pennington, Hibberdene, PortShepstone, Margate, Impenjati/Port Edward, Harding, ILembe,Port View, Cragadour

Description of the plantDry beans are warm season annual legumes with upright or bush as well as creeping type or indeterminate growth habit. The first true leaf formed after the cotyledons emerge from the soil is simple or unifoliate and all subsequent leaves are compound (with three leaflets). Small flowers (self-pollinated) are produced in clusters at various nodes on the plant and may be either white or lavender in color. Mature pod color, seed color and seed size or shape varies depending upon market class and/or variety. The

3

crop requires between 85 and 120 days from planting to maturity depend-ing on variety. The first half of this period is vegetative development and the latter half is reproductive. In vine types there is an overlap of the two periods because continued vegetative growth occurs after flowering be-gins. Flowering continues for 2 to 3 weeks so there can be new pods, half developed pods and fully developed pods as well as newly opened flowers present on many plants in early August. Pods are initially green changing to light brown or tan as they mature. Each pod can contain 2 to 4 seeds depending upon variety.

Cultivars

The National Dry Bean Cultivar Trials are conducted by the Agricultural Research Council-Grain Crops Institute (ARC-GCI) annually. The informa-tion is published by the DPO in SA Dry Beans. Dry beans are classifiedinto types according to:

Colour and seed size

Small white beans (15 to 25 g per 100 seeds), used mainly for canning purposes; 10 to 20 % of local production.

1. Red speckled or speckled sugar beans (red speckles on a beige back ground) (40 to 55 g per 100 seeds); 65 to 75 % of local production

2. Large white kidney beans (80 to 100 g per 100 seeds); 5 to 10 % of local production

4

3. Carioca beans (khaki stripes on a beige background) 20 to 25 g per 100 seeds); 3 to 5 % of local production

4. Alubia beans (large white) (45 to 55 g per 100 seeds); 1 to 5 % of local production

Growth habit

Determinate or bush type (type 1); indeterminate compact upright (type 2); indeterminate runner type (short runners) (type 3).

Growing season

Temperatures, especially during the night, determine the length of the growing season of a cultivar:

• short (85 to 94 days)

• medium (95 to104 days)

• long (105 to 115 days)

Climatic requirements

Temperature

The dry bean is an annual which thrives in a warm climate. It grows op-timally at temperatures between 18 to 24 °C. The maximum temperature during flowering should not exceed 30 °C for P. vulgaris and 26 °C fors P.coccineus. High temperatures during the flowering stage lead to abscis-sion of flowers and a low pod set, resulting in yield loss. Day temperatures below 20 °C will delay maturity and cause empty mature pods to develop.

Rainfall

Dry beans cultivated under rainfed conditions require a minimum of 400 to 500 mm rainfall during the growing season, however, an annual total of 600 to 650 mm is considered ideal.

Soil requirements

Beans have to be planted in warm soil (minimum temperatures preferably above 13 °C) after all danger of frost has passed. Beans grow well in soils with a depth of at least 90 cm, which have no deficiencies and are well drained. Sandy loam, sandy clay loam or clay loam with a clay content of

5

between 15 and 35 % is suitable. With sandy soils, problems of low fertilityor nematode damage may occur.

Beans prefer an optimum soil pH of 5,8 to 6,5, and are highly sensitive to acidic soils (pH (H2O) < 5,2 and acid saturation higher than 10 %). The beans will also not grow well in soils that are compacted, too alkaline or poorly-drained.

CULTIVATION PRACTICES

Soil preparationSeedbed preparation for the planting of dry beans follows the same pattern as that for any row crop planted in the spring. The seedbed must be deep, level and firm as this ensures better surface contact between the seed and the soil, increasing the absorption of moisture. A level seedbed also facilitates planting to a uniform depth.

PlantingThe most suitable planting date is determined by the following factors:

• Correct soil temperature

• Probability of heavy rain, which may lead to soil encrustation and restrict seedling emergence

• Possibility of high temperatures later in the season, which may cause blossom drop

6

• Length of the growing season(high temperatures dur ingflowering, rain during harvestand frost damage should beavoided)

• Crop rotation programmes (po-sition of the bean crop in the to-tal crop setup, i.e. planted after another crop such as maize)

Planting dates are restricted main-ly by the possible occurrence offrost (planting too late), rain atharvesting, resulting in poor qual-

ity (planting too early). Planting dates for dry beans in South Africa range from November to mid-January in areas where frost occurs. In frost-free areas, March and April are the best for planting beans. The large white kid-ney bean (P. coccineus) is an exception and is planted from mid-November to mid-December and is not adapted to winter production.

Spacing, plant population and planting depthThe interrow spacing for all types of beans under commercial production is 900 mm because dry beans are usually cultivated in rotation with maize.For early-maturing cultivars, especially those with a determinate growth habit, a row spacing of 750 mm is recommended in the case of mechanisa-tion. See the following table for recommendations. Planting depth is deter-mined by the soil texture and its moisture content. Generally the seeds areplaced 2,5 to 5,0 cm below the soil surface.

Spacing and plant population

Type Spacing withinrows (mm)

Spacing betweenrows (mm)

Plant population

Early maturing, determinate

75 750 177 000

Medium and latematuring

75 900 150 000

Large white kidney 100–150 900 115 000

FertilisationIt is recommended that beans be planted on soils which have been well fertilised previously.

7

General fertility is more advantageous than direct fertilisations, as beans are sensitive to high concentrations of mineral salts.

Macro-nutrients

The total withdrawal figure per 1 ton of dry bean seed produced is 36 kg N, 8 kg P and 18 kg K.

NITROGEN (N)

Guidelines for nitrogen application

Yield potential (t/ha) 1,5 2,0 2,5

N fertilisation (kg/ha) 15 30 45

Inoculation of dry bean seed is regarded as inefficient. Consequently, dry beans should be considered as incapable of satisfying all of their nitrogen requirements through N fixation. The application of all the nitrogen at plant-ing time is recommended, particularly where undercomposted material hasbeen ploughed in before planting.

Deficiency symptoms are: Lower leaves become light green and then yel-low and eventually die. Young leaves may be lighter green than normal. For fertiliser recommendations see the following table.

PHOSPHORUS (P)

Guidelines for phosphorous fertilisation

Soil analysis P application for potential (t/ha)

Ambic Bray 1 1,5 2,0 2,5

P mg/kg P fertilisation (kg/ha)

10 13 16 22 28

15 20 12 16 20

20 27 10 13 16

25 34 9 12 15

> 45 > 55 5 5 5

Under commercial production the yield responses to phosphorous fertilisa-tion are not dramatic in dry beans and P is not normally a yield-restriction factor. Under subsistence production where little fertiliser is applied, P can be a yield-limiting factor. Where the P content of the soil is lower than 20 ppm (Bray 1) it is recommended that superphosphate be broadcasted and ploughed into the soil to a depth of 15 to 20 cm before planting.

8

Phosphorous fertiliser must still be band-placed at the time of planting and in low pH soils, phosphorus can be utilised efficiently by band-placing 3,5 cm to the side and 5 cm below the seed. Deficiency symptoms are: Youngleaves are small and dark green, older leaves senesce prematurely. Plants have short internodes and reduced branching.

POTASSIUM (K)

Guidelines for K fertilisation

Soil analysis K application for potential (t/ha)

Ambic NH4OAC 1,5 2,0 2,5

K mg/kg K fertilisation (kg/ha)

40 40 22 27 32

60 59 19 24 29

80 78 17 21 26

100 98 15 19 24

> 100 > 98 0 0 0

When dry beans are grown on soils with a high clay content, potassium is not normally a limiting factor. Potassium deficiencies are most likely to occur on sandy soils with an analysis of less than 50 ppm K. The optimum leaf content is 2 % potassium.

Deficiency symptoms are: Bright yellow chlorosis of older leaves, appear-ing from the margins and then extending rapidly to the centre of leaflets.

Micro-nutrients

MOLYBDENUM (MO)

If the soil has a pH (H2O) of less than 6, a seed treatment of 100 g sodiummolybdate per 50 kg seed and/or a foliar spray of 100 g sodium molybdate per hectare should be given. If the pH (H2O) is below 5,3 and there are noRhizobia in the soil, no reaction will be achieved by applying Mo.

Deficiency symptoms are similar to those of N as it is important for N metabolism.

ZINC (ZN)

The critical level of zinc in bean tissue is 15 to 20 ppm. Levels greater than 120 ppm can decrease yields. The availability of zinc is highest in slightly acid soils (pH 6,0-6,8) and lowest at pH (H2O) above 7,4. Deficiency symp-

9

toms are pale, yellow leaves, especially between veins, and near the tips. The plants become deformed and dwarfed and may die. Pod formation is hampered and the plants are slow to mature.

MANGANESE (MN)

Deficiencies only occur on soils with a high pH value. Symptoms include small leaves with a mosaic yellowing in the interveinal areas while the veins remain prominently green. Deficiencies can be corrected by applying manganese sulphate (MnSO4) at 15 to 20 kg/ha.

BORON (B)

Boron toxicity is a more frequent problem than deficiency and symptoms include chlorosis and dwarfing. With time, the chlorosis increases and re-sembles burn, with the leaf margins curling over. Beans should not follow sunflower which has received boron fertiliser.

IRON (FE)

Deficiency occurs on calcareous or saline soils where the pH (H2O) valuesare above 7,4. Symptoms are characterised by bright yellow leaves and green veins. Deficiencies can be rectified by a 1 % FeSO4 solution or chelate used as a foliar spray.

Soil acidity (pH)

The optimum soil pH levels for dry beans are:

pH (H2O): 5,8-6,5

pH (KCl): 4,8-5,5

The percentage of acid saturation has to be lower than 10 % for the cultiva-tion of dry beans. The soluble aluminum content has to be less than 25 to 30 %. The pH can be raised (acid saturation reduced) by applications of agricultural lime. The application of lime to acid (low pH) soils can make certain micronutrients, such as molybdenum, more available to the plant. The availability of phosphorus (P) is influenced by the pH. It is readily available between pH (H2O) 6 and 7. Calcium and magnesium deficiencies can be alleviated with agricultural lime. High pH soils are often associated with an excess of sodium salts which reduce nutrient uptake. Beans will tolerate a sodium saturation percentage of up to 8 or 10 and an electrical conductivity of up to 1 mmho/cm.

10

IrrigationIrrigation offers the potential for increasing yields and enabling produc-tion in otherwise unsuitable soils. Sprinkler irrigation is the most frequentmeans of irrigation for dry beans. The sprinkler irrigation system used isdetermined by the size and shape of the lands, as well as available labour and capital. In areas where water is unrestricted (not merely supplemen-tary irrigation), the soil should be wet to field capacity to the depth of the1 m root zone before planting. As soon as the soil is sufficiently dry, theseedbed should be prepared and planted and thereafter the field shouldnot be irrigated until the seedlings have emerged. Irrigation schedulingis essential for optimum yield per unit of water. The critical, moisture-sensitive growth stages are flowering and early pod set which occur at 40to 50 % and 50 to 60 % of the growing season.

It is important that irrigation cycles be scheduled correctly, as excess mois-ture can create conditions conducive to root rot and Sclerotinia. Moisturestress can also aggravate some root rots such as Fusarium oxysporum.Irrigation should cease when a quarter of the bean pods have turned yel-low. For the correct irrigation scheduling expert advice must be obtained

Weed controlEfficient weed control is a prerequisite for high dry bean yields. Dry beanscompete poorly with weeds as they are low-growing plants and do not eas-ily overshadow weeds. Early control is extremely important because theroot system of the plant develops at this stage and some weeds secretechemical substances which inhibit plant growth. At a later stage weedshamper the harvesting and threshing processes and adversely affect thequality of the crop.

Mechanical weed control

Mechanical weed control should begin during seedbed preparation (re-move all weeds) and be repeated with a tiller between the rows whennecessary up to the flowering stage. Care should be taken that implements do not damage the crop by using row spacings which permit easy accessand taking care that roots are not damaged. Cultivation between the rowsis also advantageous because it loosens the soil and improves aerationand water penetration. Weeds in the rows have to be pulled by hand.

Chemical weed control

Chemical weed control can be implemented before planting or before and/or after emergence. Sufficient herbicides have been registered to control

11

all weeds throughout the entire growing period of dry beans. Further particulars of herbicides registered for use on dry beans are available in another publication obtainable from the ARC-GCI.

Harvesting

Dry beans have a moisture content of 50 % at physiological maturity. The beans, however, are only ready for harvesting when the moisture content drops to 16 % (the ideal being 15 %). Seeds may split during threshing when the moisture content is less than 12 % and such seeds are rejected by canners and seed companies and is difficult to clean without further seed split or broken seed coats occuring. Dry beans should be harvested when all the pods have turned yellow, but before becoming so dry that thepods begin to shatter.

Dry beans can be harvested in three ways:

• The plants are pulled by hand and threshed by driving a tractor over them on a threshing floor. Smaller quantities can be threshed by hand by beating with a stick in a hessian bag. The seed can be separated from the chaff by using the wind.

• Partially mechanised systems—the plants are pulled by hand, placed in windrows and threshed with a harvester or stacked, whereafter they are threshed with a stationary threshing machine.

• Fully automated system—the beans are pulled mechanically, raked into windrows and threshed by means of an automated combine.

The following tips may be useful:

• Beans should be pulled when the moisture content of the pods is tempor-arily high (to prevent shattering), i.e. early in the morning before the dew has evaporated.

• Mechanised harvesting must be done when there is no danger of the crop being damaged by rain.

• To prevent cracking and splitting, beans should be threshed at slow cylinder speeds with a machine with an axial flow threshing mechanism.

Pest and disease controlPests and diseases may have been partially responsible for the unstable production of the past. Incidence and severity vary between seasons ow-ing to environmental and management practices. Integrated management, using all suitable control measurements, is recommended.

12

Diseases of the roots and stem, known as Aroot rot, often occur in a com-plex and can include any of the following: Fusarium, Pythium, Rhizoctonia,charcoal rot and Sclerotium root rot (Southern blight), the first three be-ming the most frequent. The latter four can also cause rotting of seed and damping off. Root rot can be prevented to a certain degree, but not treated. Fungicides can only be applied to seed as a preventative measure againstPythium and m Rhizoctonia root rot.

13

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is

und

er s

tres

s

Str

ess

cond

ition

s, e

spe-

cial

ly d

roug

ht. P

atho

gen

occu

rs in

mos

t soi

ls, a

nd

may

be

spre

ad in

soi

l du

st (

win

d or

on

seed

s)

Cro

p ro

tatio

n w

ith m

aize

or

othe

r gr

ain

crop

; avo

id s

tres

s, p

oor

nutr

ition

and

dam

age

to s

tem

s (b

y fo

r ex

ampl

e be

an fl

y, h

oein

g,

mac

hine

ry; u

se ti

llage

whi

ch m

ini-

mis

es s

oil c

ompa

ctio

n

Fus

ariu

mye

llow

s (F

.FF

wilt

)

Fus

ariu

mox

yspo

rum

f.m

sp. p

hase

oli

Vis

ible

in fi

eld

as g

roup

s of

yello

win

g pl

ants

. Lea

ves

yello

w a

nd d

ie. I

nter

nal d

is-

colo

ratio

n of

low

er s

tem

(va

s-cu

lar

tissu

e). Y

oung

er p

lant

s st

unte

d, m

ay w

ilt a

nd d

ie

Hot

and

dry

, str

ess

cond

ition

sC

rop

rota

tion

with

gra

in c

rops

(m

aize

, whe

at, e

tc.)

; dee

p pl

ough

-in

g; a

void

str

ess

and

dam

age

to

stem

s (b

y fo

r ex

ampl

e, b

ean

fly,

hoei

ng, m

achi

nery

)

Hal

o bl

ight

Pse

udom

onas

sa

vast

anoi

pv.

iph

aseo

licol

a

Leaf

sym

ptom

s in

itial

ly a

p-pe

ar a

s sm

all,

wat

er-s

oake

d le

sion

s on

the

unde

rsid

e of

leav

es. L

esio

ns tu

rn r

eddi

shbr

own

and

beco

me

necr

otic

with

age

Coo

l and

hum

idP

lant

dis

ease

-fre

e se

ed; w

ork

bean

deb

ris in

to th

e so

il af

ter

harv

estin

g; a

pply

cop

per-

base

d ba

cter

icid

es a

s a

prev

enta

tive

mea

sure

; con

trol

wee

ds a

nd v

ol-

unte

er b

eans

16

Dis

ease

Cau

sal o

rgan

ism

Sym

pto

ms

Idea

l co

nd

itio

ns

Pre

ven

tio

n/T

reat

men

t

Pla

nt d

isea

se-f

ree

seed

; wor

k be

an d

ebris

into

the

soil

afte

rha

rves

ting;

app

ly c

oppe

r-ba

sed

bact

eric

ides

as

a pr

even

tativ

e m

easu

re; c

ontr

ol

wee

ds a

nd v

olun

teer

bea

ns.

Pod

sym

ptom

s ar

e gr

easy

,w

ater

-soa

ked

spot

s of

var

ious

size

s. L

esio

n m

argi

ns m

ay

turn

bro

wn

as th

ese

mat

ure.

Lesi

ons

norm

ally

sta

y gr

een

on d

ry p

ods.

Pla

nts

infe

cted

th

roug

hout

the

vasc

ular

syst

em (

syst

emic

infe

ctio

n)

appe

ar s

tunt

ed w

ith a

gen

-er

al li

me-

gree

n co

lour

and

are

ddis

h di

scol

orat

ion

at th

eno

des

Pow

dery

mild

ewE

rysi

phe

poly

goni

Orig

inal

ly fa

int b

lack

ened

,su

perf

icia

l sta

r-lik

e bl

otch

es,

beco

min

g w

hite

, coa

lesc

ing

to c

over

aer

ial p

arts

in a

dry

po

wde

ry fi

lm. P

ossi

ble

dryi

ng

out o

f pla

nts

and

defo

liatio

n

Hot

and

mod

erat

ely

hum

idR

esis

tant

cul

tivar

s; s

uita

ble

fung

icid

es

Pyt

hium

Pyt

hium

spp.

mP

oor

emer

genc

e, w

iltin

g an

d de

ath

of y

oung

see

dlin

gs.

Wat

er-s

oake

d, th

en g

rey

tobr

own

lesi

ons

near

soi

l sur

-fa

ce, s

prea

ding

to s

tem

s an

d ro

ots

and

lead

ing

to s

o ft r

ot.

Coo

l and

wet

soi

l co

nditi

ons

See

d tr

eatm

ent w

ith s

uita

ble

fung

icid

es; g

ood

drai

nage

; cro

p ro

tatio

n

17

Dis

ease

Cau

sal o

rgan

ism

Sym

pto

ms

Idea

l co

nd

itio

ns

Pre

ven

tio

n/T

reat

men

t

Are

as in

row

s w

ith d

ead

plan

ts b

orde

red

by s

tunt

edpl

ants

. In

seve

re c

ases

, lar

ge

area

s m

ay b

e a f

fect

ed

Rhi

zoct

onia

roo

t rot

Rhi

zoct

onia

sol

ani

Red

dish

-bro

wn

lesi

ons

on

low

er s

tem

s, b

ecom

ing

sunk

en a

nd s

prea

ding

toca

use

wilt

ing

and

deat

h of

pl

ant.

Ofte

n m

ore

seve

re a

tse

edlin

g st

age

but m

ay c

ause

st

untin

g an

d un

even

mat

ura-

tion

in o

lder

pla

nts

Mod

erat

e to

hig

h so

il m

oist

ure

and

tem

pera

ture

s

See

d tr

eatm

ent w

ith s

uita

ble

fun-

gici

des;

goo

d dr

aina

ge; d

eep

plou

ghin

g; s

hallo

w p

lant

ing;

cro

p ro

tatio

n

Rus

tU

rom

yces

ap

pend

icul

atus

Sm

all,

whi

te s

pots

dev

elop

on

leav

es, (

som

etim

es o

nly

on u

nder

side

), le

sion

s en

-la

rge

and

burs

t ope

n to

form

ra

ised

, rus

t-co

lour

ed p

ustu

les

givi

ng o

ff a

red-

brow

n du

st(s

pore

s) w

hen

rubb

ed.

Spo

res

may

bec

ome

blac

k at

end

of s

easo

n. P

ustu

les

som

etim

es s

urro

unde

d by

ye

llow

hal

o or

nec

rotic

(de

ad)

tissu

e. L

eave

s m

ay y

ello

w

and

die.

Pus

tule

s on

pod

sel

onga

ted

Mod

erat

e te

mpe

ratu

res,

al

tern

ate

wet

and

dry

pe

riods

, win

dy

Res

ista

nt c

ultiv

ars;

sui

tabl

e fu

ngic

ides

; wor

k in

pla

nt d

ebris

af

ter

harv

estin

g; r

emov

e vo

lunt

eer

bean

s

18

Dis

ease

Cau

sal o

rgan

ism

Sym

pto

ms

Idea

l co

nd

itio

ns

Pre

ven

tio

n/T

reat

men

t

Sca

bE

lsin

oë p

hase

oli

New

leav

es a

nd s

hoot

s cu

rlup

war

ds. O

n ol

der

leav

es,

grey

to li

ght-

brow

n, c

ircul

ar,

scab

-like

lesi

ons,

usu

ally

conc

entr

ated

nea

r th

e ve

ins.

Sim

ilar

lesi

ons,

dar

keni

ngw

ith a

ge, o

n th

e po

ds

Hot

and

hum

idP

lant

dis

ease

-fre

e se

ed; p

lant

re-

sist

ant c

ultiv

ars;

app

ly s

uita

ble

fung

icid

es

Scl

erot

ini a

(w

hite

mou

ld)

Scl

erot

inia

scle

rotio

rum

Ear

ly s

ympt

oms

smal

l, w

ater

-soa

ked

spot

s on

leav

es a

nd s

tem

, fol

low

ed b

y w

hite

mas

ses

of m

ycel

ium

.S

cler

otia

form

on

this

mas

s an

d tu

rn b

lack

afte

r 7–

10

days

. Drie

d ou

t, in

fect

ed

tissu

e ha

s a

char

acte

ristic

blea

ched

app

eara

nce

Hum

id, d

ense

leaf

ca

nopy

Cro

p ro

tatio

n w

ith m

aize

; use

di

seas

e-fr

ee s

eed;

sch

edul

e

Scl

erot

ium

root

rot

m

(sou

ther

n bl

ight

)S

cler

otiu

m r

olfs

iiG

rey,

wat

er-s

oake

d le

sion

s,be

com

ing

brow

n, n

ear

the

soil

surf

ace,

spr

eadi

ng to

the

tapr

oot a

nd le

adin

g to

wilt

ing

and

deat

h of

the

plan

t. Lo

wer

leav

es m

ay a

lso

be a

ffect

ed.

Cha

ract

eris

tic s

mal

l, ro

und,

lig

ht-y

ello

w to

bro

wn

scle

rotia

and

whi

te fu

ngus

gro

wth

vis

-ib

le o

n es

tabl

ishe

d le

sion

s

Dry

wea

ther

follo

wed

by

hot a

nd h

umid

con

di-

tions

Goo

d dr

aina

ge; c

rop

rota

tion;

wor

k be

an d

ebris

in a

fter

harv

estin

g;

deep

plo

ughi

ng

19

Causal organisms, symptoms, ideal conditions, prevention and treatment of important dry bean diseases are shown in the following table.

PestsThe most important pests of dry beans, the damage caused by these pestsand possible treatment are shown in the following table.

Insects Scientific name Damage Treatment

Black bean aphidGroundnut aphid

Aphis fabaeAphis craccivora

Vectors of variousviruses

Apply suitableinsecticide

Tobacco whitefly Bemisia tabaci Potential vector ofbean golden mosaicvirus

No insecticide cur-rently registered

Tobacco leafhopper Jacobiella fascialis Suck sap from leaves

No treatmentnecessary

Bean seed maggot Delia platura Maggots attack cotyledons, mineinto stems belowsoil level and pupate

Control with a seeddressing insecticide

Bean stem maggot OphiomyiaspencerellaOphiomyia phaseoli

Maggots mine intostems and pupate

No insecticide currentlyregistered

Spotted maizebeetle

Astylus atromaculatus

Adoretus tessulatusBeetles feed on pol-len, destroy flowers

No insecticide currentlyregistered

CMR beetle Mylabris oculata Destroy flowers Apply suitableinsecticide

Black maize beetle Heteronychus arator Damage stems on or beneath soilsurface

Apply suitableinsecticide

Chafer beetle Adoretus cribrosus Feed on youngleaves, petals andpollen

Apply suitableinsecticide

Bean bug Clavigrallatomentosicollis

Suck sap from leaves, stems andpods—cause wiltingof developing pods

No insecticide cur-rently registered

Tip wilter Anoplocnemis curvipes

Suck sap from stems—cause wilt-ing and dying of tipsof shoots

No insecticide cur-rently registered

Green vegetable bug

Nezara viridula Suck sap from pods—cause brown-ing of seeds inside

No insecticide cur-rently registered

20

Insects Scientific name Damage Treatment

Common cutworm Agrotis segetum Damage stems on or beneath soilsurface

Apply suitableinsecticide

African bollworm Helicoverpaarmigera

Feed into pods anddamage seeds

Apply suitableinsecticide

Cabbage semilooper

Trichoplusia orichalcea

Feed into pods anddamage seeds

Apply suitableinsecticide

American leafminer Liriomyza trifolii Larvae tunnel inleaves

Apply suitableinsecticide

South American leafminer/Potato leafminer

Liriomyzahuidobrensis

Larvae tunnel inleaves

No insecticide currentlyregistered

Bean flower thrips Megalurothrips sjöstedti

Feed in flowers, causing a rough-ened, silverytexture on pods

Apply suitableinsecticide

Bean thrips Sericothrips occipitalis

Feed in flowers, causing a rough-ened, silverytexture on pods

Apply suitableinsecticide

Bean weevil Acanthoscelides obtectus

Larvae enter seedand excavate it byfeeding

Apply suitableinsecticide

Bean gall weevil Alcidodes erythropterus

Larvae enter stems,pupate in the gallsformed

Apply suitableinsecticide

POST-HARVEST HANDLING

SortingOne should bear in mind that the appearance of dry bean seed is very important to the price obtained for the crop. Apart from the normal seed cleaning, dry beans may have to be polished and damaged seed removedto obtain full value.

Seeds should be stored at about 12 to 15 % moisture. During handling, a conveyer belt is preferred above a metal auger to reduce seed damage. Seeds should be handled gently and not dumped from heights onto con-crete or hard surfaces.

Careful handling may be more time consuming, however, it will pay off in the price received for a quality bean product.

21

Grading

Dry beans are graded in terms of the grading regulations and the price is necessarily adjusted to the quality of the product.

• Dry beans must be graded as Grade 1, Grade 2, and Grade 3 or split beans in the case of dry beans in retail quantities, provided that dry beans in retail quantities of 5 kg and more may also be graded as Undergrade.

• Dry beans can be graded as Canning Grade 1, Grade 2, Grade 3, Grade 4 (or Undergrade in the case of dry beans in bulk quantities).

A consignment of dry beans that is graded as Canning Grade, Grade 1, Grade 2, Grade 3, or Grade 4, must be of a particular form, size, colour and type of group; be free of a musty or other unacceptable odour, free of dry beans in or on which a substance occurs that renders it unsuitable for human consumption or for processing into healthy food or feed; be free of noxious seeds.

However, a consignment of dry beans in bulk quantities may contain nox-ious seeds to the extent permitted in terms of the Foodstuffs, Cosmetics and Disinfectants, Act No. 54 of 1972; be free from insects; be free of or-ganisms of phytosanitary importance as determined by Agricultural Pests Act. 1983 (Act No. 36 of 1983); and have a moisture content of not more than 14 %.

Packing

Dry beans of different grades, form groups, colour groups and type groupsmust, except in the case of the type group known as mixed dry beans, notbe packed in the same container. Undergrade dry beans must be packed

in containers, eachcontain ing 5 kg ormore of dry beans.

StorageDry bean seed should be stored in a cool,well-venti lated en-vironment and pro-tected against hightemperature and highhumidity.

22

The containers in which dry beans are packed must be:

• Manufactured from a material that will protect the contents thereof against contamination, and will not impart any undesirable flavour or odour to the contents

• So strong that it will not tear or break during normal storage, handling and transport practices

• Whole, with the exception of grain probe marks. However, grain probe marks will not be permissible in the case of dry beans in retail quantities

• Clean

• Closed properly in a manner permitted by the nature thereof

• In the case of dry beans in retail quantities, be new

MarketingThe lower local supply rate and high demand of dry beans in South Africanmarkets usually result in a realistic price increase. A maximum dryland harvest of 1,5 t/ha or 2 to 2,5 t/ha under irrigation is motivation enough to get more farmers venturing into dry bean production. However, productioncosts are normally higher than for soya-beans. Post-harvest costs are certainly higher for dry beans, both owing to the extra care needed for cleaning and storage, and the possible transportation costs. Some buyers will want the seed bagged in large food grade bags before purchasing it.

On the positive side, gross returns from dry beans can easily be higher than for soya-beans. While yields are typically lower, dry beans fetch a relatively higher price. Achieving a good net profit is dependent on choos-ing an appropriate market class and good varieties to grow, keeping production costs under control, and finding a cost effective way to clean, store, and deliver the crop. Although dry bean prices fluctuate, as a food crop they do not follow the prices of corn and soya-beans. Adding dry beans to the mix of crops on a farm can assist in spreading out the risk from changes in market prices.

Exports and imports: Export opportunities are hampered by the stringent international market requirements for dry beans. In most cases, the types of dry bean produced in South Africa are not entirely acceptable to the foreign market. In a normal production year the domestic market absorbs local production and it therefore becomes necessary to import types of undersupplied dry beans from China, the USA, Canada and other coun-tries, usually at higher prices. It will be best for farmers to strive for a better quality and market their products as early as possible so that when the

23

harvesting season starts they already have the market; the demand for dry bean is therefore high.

PRODUCTION SCHEDULES

Janu

ary

Feb

ruar

y

Mar

ch

Apr

il

May

June

July

Aug

ust

Sep

tem

ber

Oct

ober

Nov

embe

r

Dec

embe

r

Soil sampling

Soil preparation

Planting

Fertilisation

Irrigation

Pest control

Disease control

Weed control

Harvesting

Marketing

UTILISATION

Human consumptionDry beans are specific types of Phaseolus which are harvested as matured sdry seeds, as opposed to snap beans which are harvested when pods aregreen and the seeds are succulent for use as a fresh vegetable. Minimal processing is required between the production field and consumer; the beans must therefore be intact and free of blemishes as well as pesticide residue when presented for sale. Dry beans are therefore suitable protein supplements for lower-income societies.

Dry beans are used in soups, chilli dishes, baked bean and casserole reci-pes, refried bean paste, fresh salads and can be purchased dry or previ-ously canned and cooked products. Dry bean seeds contain 22 % protein, 2 % fat, 61 % carbohydrate (includes 5 % fibre) as well as adequate levels of all vitamins and minerals.

24

Animal consumption

Beans which do not meet human food quality standards can be utilised as livestock feed.

Other uses

It can be used for soil improvement because of its nitrogen fixation abil-ity and also as green manure, increasing organic matter in the soil. It is therefore best to use it in a crop rotation cycle.

ACKNOWLEDGEMENT

ARC-Grain Crops Institute is acknowledged for the contribution made in the development of this production guideline.

Thank you to the DPO for their contribution in developing the production guideline.

Further information can be obtained from:

Directorate Plant ProductionPrivate Bag X250PRETORIA 0001

Tel: +27 12 319 6072Fax: +27 12 319 6353E-mail: DPP@daff.gov.za