The Anderson intelligencer. [volume] (Anderson, S.C.) 1914-1917, 1915-01-26
COTTON ROOT KNOT AllDaH0lV TO- COMBAT III

Washington. Jan %. - Cotton. root.
knot. according to Farmers Bulletin
625. not only causes great damage In
itself. but when IL is combined with
cotton ..i!.. as :S' frequently thes ca Sc,
1t greatly increases the loss from
wilt
Plants diseased with cotton root
knot are distinctly s:unted, but not
appreciably deformed. as in wilt.
and have a peculiar sickIy yellowish-
green color on both leaves and stems.
In times Of drought. affected plants
are the first to show the lack or wa-
ter and may wilt slightly in the l:Iiu-
die OF the day. !: such Il plant rs
dug up carefully. the roots will DO
found to be covered with swelling;
or gals from the size of a pinhead 10
l-2 inch or more in diameter IL one
OF these ,knots is broken open, nu-
merous pearly white, rounded b,d-
les about onc-half the size of n nm
head-thc female n, .atodes-can oil
ten be seen with the ,ked eye
Root-knot OF cotton and other
crops Is caused by these minute eel
worms. or nematodes. which bore in
to the roots and live there The ir.l.
tation of their presence causes the for.
nation OF sweliings or gals. The
mnle worms are too small to be seen
with the naked eye. but the females
when full of eggs assume Il sphcJ j.
cal shape and may often be. distin.
guished in freshly broken roots as
described above. Each female lays
several hundred eggs. and thus tho
worms are prOpagated.
Root-knot may be carried from one
field to another by any agency which
will transfer some of the nematoics
or their eggs. just as wilt is dissen,i.
mated by means of the fungus that
causes the wilt adisease. Drainase
water is perhaps one OF the most inl.
portant means of spreading rootknot.
Nursery stock also. is, commua
agency for the. introduction, Of the
nematode into new territory. Seeding
pecans. peaches. figs. mulberries or
pomegranates, and young asparagus,
cabbage. eggplant. strawberry. 20.
hecec. and tomato plants, from iIi-
tested sections may carry the. worms
in their roots or in the soil adhering
to them. In the west. where the
nematode occurs quite commonly, in
certain sections on the. potato, the
worms are carried in the .tubers.
>Attacke Many, Other. Farm Crops.
10 Unlike wilt, root-knot attacks a
very large, number OF plants, many Of
which are important farm crops.
Those subject to .root-knot injury may
be divided into two groups according
to their degree of susceptibility. The
-qrops most severely attacked by
root.knot are as follows: Soybeaii,
beet, cantaloupe., carrot. celery, ..:bur
clover, crimson Glover, .all: varieties
Of cowpeas Except Iron and Bray-
ham and other Iron 4Hybrids), cucum-
Der. eggplant. fig. lettuce. Okra. peach,
pecan. pomegrapate,. potato. satisfy,
nsquash, tobacco, tomato, and wa.e:.
melon.
= Plants less severely injured by
rOot-knot are the, following:
q, Alfalfa, asparagus, Lima bean, snnp
bean. cabbage, sweet clover, collartl,
cotton, mulberry, onion,, garden pen
swesi potato, radisti, spinach. straw
berry. sugar cane, common yetc!l,
hairy vetch.
I, A few common weeds are subject
TO nematode injury and should thc..-
fore be eradicated where the at.
tempt is being made to reduce root
knot In fields. The most severely in.
1ured, are the balloon vine. the MAJ
pop or passion flower, and the papay:.
Or melon Gewpaw. Weeds less severe.
ly affected by root:knot are may.
weed, purslane, and sweet fennel
Such varieties OF cowpeas as the
Whippoorwill,. Clay, Black, Unknown.
Red Ripper, New Era, and others arr
so susceptible ito root-knot that not
only are.they seriouslys injured, but
the growing ct them on nemat [ ode
infected fields greatly increases the
number Of worms in ths. soil; and con.
sequently the damage to subsequent
cotton or other susceptible crops. 1t
Is O common complaint OF farmers III
wilt sections that the wilt s.riotic...
ably more severe, after crOp, Of
cowpeas OF a variety which is SIS.
ceptible to root-knot. This is due TO
the fact that the nernatodes. make
points OF entrance for the wilt fun.
gus. which, then kills oRlurthertinjur..s
the plants There are, few. ..yari,..
ties OF ,cowDeas- which are highly ie.
.sistarItsSto Heniatodes. including !, tho
Iron and the; Brabham and other Iron
'hybrids. These should be the on,y
cowpeas planted on land infested witli
root-knot. t
Control Meaaures for Root-l<not.
Tho rotation and diyersihcation of
crops are OF fundamental ;imuhrtanLe g
to southern agriculture eveiy,;:aere
and become absolutely necessary
where the rootknot' Dematodes Is
present. The principles on which such