48 



FIG. 19. 



BINDWEED, 



Convolvulus arvensis (L). 



A very troublesome weed which winds its tough and curling stems 

 around the stalks of various plants, partially chokes them, and thereby 

 hinders their growth. It is a perennial with a very extensive creeping 

 root which penetrates far into the soil, and any piece of the root pos- 

 sessing one or more buds is capable of starting new plants, hence it is 

 necessary to clean implements very thoroughly after they have been 

 used in a field containing this weed. The stems are branched and either 

 trail on the ground or climb by twisting around some other plant. The 

 leaves are rather small, with 2-4 lobes at the base, giving them an arrow- 

 headed shape. The flowers are white or rose-colored and 1 inch across. 

 The seeds, three in number, are large, black, and angular, and are held in 

 a spherical capsule (Fig. 19). An average plant produces about 160 seeds. 



Time of flowering, June-September. Time of seeding, August-October. 



Dispersal chiefly by means of its creeping roots ; sometimes as an 

 impurity in seed grain. 



Eradication. This is a very difficult weed to eradicate and careless 

 cultivation only increases the trouble by carrying the roots from place 

 to place. Salting is recommended by some practical farmers who have 

 succeeded in eradicating this very troublesome pest ; but we cannot speak 

 from experience as to the value of this method of treatment. 



The weed may be kept in check by the frequent introduction of 

 well cared-for hoed crops into the rotation, and the shorter the rotation 

 the better. The later sown hoed crops, especially rape, are more effectual 

 than those sown earlier in the season. Before the hoed crop is sown, the 

 weed may be kept in check by going frequently over the field with a 

 broad-share cultivator, so as to cut all the plants an inch or two below 

 the surface without bringing up any of the creeping rootstocks. About 

 the 1st July the land may be sown with rape in drills, say 26 

 inches apart, and during the early growth of the crop the weeds may be 

 kept in check by means of the horse-hoe, with more or less hand-hoeing. 

 If the land has been well manured or is naturally rich in vegetable 

 matter, the rape will make a rank growth and smother some of the 

 weeds. The rape may be pastured in the fall, and in extreme cases may 

 be followed by another hoed crop, such as corn. If the corn is well 

 cultivated and hoed, most, perhaps all, of the plants will be destroyed. 



In some cases it may be advisable to summer-fallow, and in such 

 cases it is best not to plow more than is absolutely necessary, but to 

 depend mainly on the broad-share cultivator. Buckwheat sown on 

 summer-fallow and plowed under when coming into blossom, followed by 

 surface cultivation with the broad-share cultivator, will assist very much 

 in killing the weed. If necessary, the summer-fallow may be followed by 

 a hoed crop. 



