Weeds





Have you ever noticed that some weeds are killed by one particular

method, but that this same method may entirely fail to kill other kinds

of weeds? If we wish to free our fields of weeds with the greatest ease,

we must know the nature of each kind of weed and then attack it in the

way in which we can most readily destroy it.






The ordinary pigweed (Fig. 56) differs from many other weeds in that it

lives for only one year. When winter comes, it must die. Each plant,

however, bears a great number of seeds. If we can prevent the plant from

bearing seed in its first year, there will not be many seeds to come up

the next season. In fact, only those seeds that were too deeply buried

in the soil to come up the previous spring will be left, and of these

two-year-old seeds many will not germinate. During the next season some

old seeds will produce plants, but the number will be very much

diminished. If care be exercised to prevent the pigweed from seeding

again, and the same watchfulness be continued for a few seasons, this

weed will be almost entirely driven from our fields.



A plant like the pigweed, which lives only one year, is called an

_annual_ and is one of the easiest weeds to destroy. Mustard, plantain,

chess, dodder, cockle, crab grass, and Jimson weed are a few of our most

disagreeable annual weeds.



The best time to kill any weed is when it is very small; therefore the

ground in early spring should be constantly stirred in order to kill the

young weeds before they grow to be strong and hardy.






The wild carrot differs from an annual in this way: it lives throughout

one whole year without producing seeds. During its first year it

accumulates a quantity of nourishment in the root, then rests in the

winter. Throughout the following summer it uses this nourishment rapidly

to produce its flowers and seeds. Then the plant dies. Plants that live

through two seasons in this way are called _biennials_. Weeds of this

kind may be destroyed by _cutting the roots below the leaves_ with a

grubbing-hoe or spud. A spud may be described as a chisel on a long

handle (see Fig. 58). If biennials are not cut low enough they will

branch out anew and make many seeds. Among the most common biennials are

the thistle, moth mullein, wild carrot, wild parsnip, and burdock.









A third group of weeds consists of those that live for more than two

years. These weeds are usually most difficult to kill. They propagate by

means of running rootstocks as well as by seeds. Plants that live more

than two seasons are known as _perennials_ and include, for example,

many grasses, dock, Canada thistle, poison ivy, passion flower, horse

nettle, etc. There are many methods of destroying perennial weeds. They

may be dug entirely out and removed. Sometimes in small areas they may

be killed by crude sulphuric acid or may be starved by covering them

with boards or a straw stack or in some other convenient way. A method

that is very effective is to smother the weeds by a dense growth of

some other plant, for example, cowpeas or buckwheat. Cowpeas are to be

preferred, since they also enrich the soil by the nitrogen that the

root-tubercles gather.






Weeds do injury in numerous ways; they shade the crop, steal its

nourishment, and waste its moisture. Perhaps their only service is to

make lazy people till their crops.





=EXERCISE=



You should learn to know by name the twenty worst weeds of your

vicinity and to recognize their seeds. If there are any weeds you

are not able to recognize, send a sample of each to your state

experiment station. Make a collection, properly labeled, of weeds

and weed seeds for your school.





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