The St. Mary banner. (Franklin, Parish of St. Mary, La.) 1889-1931, 1917-12-08
Roo1-KNo1 OF COTTON AND OTHER CROPS

prepared by the United States Depart
ment Of Agriculture
Root-knot of cotton and other crops
Is caused by minute eelWorms. or nehla-
todes, which bore into the roots ana
live there. The irritation OF their pres
ence results In the formation OF lrre9a-
lar swellings. or gals, varying IN SIZE
from tiny cnlargementS on the sillali
roots to knots an inch or more IN tia-
meter on the large ones. The Lllie
worms are too small to be seen Win
the naked eye, but the females Wheh
full of eggs assume spherical sll''pe
and NAV often be distinguished IN
freshly-hroken roots as gnstehihs
pearly bodies half the size OF small
pinhead. Each female may lay sevcrai
hundred eggs, and thus the worms are
propngated.
How Root-Knot Is Spread.
Root-knot may be carried from one
field to another by any agency when
will transfer some of the neInatodeS or
their eggs, in exactly the same manner
that wilt is disseminated. Drainage
water is perhaps one of the most i'm
portant means of spreading root-knot.
| In addition, q common agency for the
Introduction of the ne1natode into new
territory is nursery stock. Seeding
pecanS, peaches, figs, mulberrieS, or
pomegranates. and young asparagus,
cabbage, eggplant, strawberry, tobacco
and tomato plants purchased from In
Tested sections may carry the worms IN
their roots or in the soil adhering to
them. In the West, where the nena-
tode occurs quite commonly on the pO-
tato, the worms are carried in the
tuberS.
Sandy Soils Most Subject to Root
Knot.
RoOt-knot is essentially disease Of
light soils. Although the disease may
occur on heavier soils than wilt. yet it
is not, as rule, serious on soils con-
tanning a large proportion Of clay. In
general. the lighter the soil the more
severe the root-knot injury. The places
Of greatest damage are usually light
sandy spots or ridges in infected fields.
In gardens which have been highly fer
tilted with stable manure rOOt-knOt Is
often very severe.
Root-knot Attaeks Many Farm Crops.
Unlike wilt, root-knot attacks very
large number of plants, many Of which
are important farm crops. Those sub
ject to root-knot injury may be d.
vided into two groups, according to
their degree Of susceptibility. Some of
the crops most severely attacked by
rOot-knOt are as follows:
Bean, soy Eggplant
Bean, lima Fig
Beet Lettuce
CantaOupe Okra
Carrot Peach
Celery Pecan
Glover, bur Pomegranate
Clover, crimson Potato
Cowpea (all varie- Satisfy
ties except Iron. Squash
Brahham and Mo- Tobacco
netta) Tomato
Cucumber Watermelon
Plants less severely injured by root
knot are the following:
Alfalfa Pea, garden
Asparagus Potato. sweet
Rean, snap Radish
Cabbage Spinach
Glover, sweet Strawberry
Collard Sugar cane
Cotton Netch. common
Mulberry Vetch. hairy.
Onion
A few common weeds nre subject to
nematode injury and should therefore
be eradicated where the attempt is be-
ing made to reduce root-knot in fields.
The most severely injured are the bal
loon vine. the maypop or passion flow
er. and the papaya or melon pawpaw.
Weeds less severely affected by root
knot are mayweed, purslane and sweet
fennel.
Some Farm Crops Resistant to Root
Knot.
Fortunately, a few farm crops are
largely or entirely immune to root