Show CROP ROTATION BLOCKS WEEDS Cultivation Has Varying Upon Effect Effect Effect- Upon Different Growths notation flotation of crops has been ad ad- advocated advocated advocated for many generations as os one of the tho best ways to control contro weeds The reason for this Is Is' Is that weeds which thrive in one crop cro are checked by another crop with different habits of growth and and- different treatment Charlock Canada thistle shepherds shepherd's purse common wild morning glory sheep sorrel curled dock and corn sow thistle are among the weeds that do not seem seeni to be af affected at- at affected by the tho crop In which they are arc growing gro Most ost weeds weede are discouraged by byroo roo crops crOIS that require clean cul eul- cultivation cultivation during luring the sea sea- son Russian thistle lambs lambs- quarters and weed pig-weed can how how- however however ever er usually grow along with the root crop They survive not be because be- be because because cause they are ne more hardy bu but Because they produce exceedingly large argo numbers of seed so that tha there here are more plants and they have c ia e a n. better chance chanco of escapIng Ing ng the action of cultivator and hoe hoc There are but few plants lants that can survive in a field where dense growing crops are arc raised for seed After the first year of such crops crop ns as alfalfa clover and timothy and clover that are arc raised for seed as wll w ll as ns hay but few weeds can be found in the summer though they may have started in the tho spring lambs quarters horse tall knotgrass is black bind bind- bindweed bindweed weed chickweed and large field speedwell art are especially discouraged discouraged aged by b this kind of crop Because of their peculiarities of oC growth beans and peas are against certain weeds Af- Af After After ter er the clean cultivation which they hey receive early in the season the tho plants completely cover the Dandelions silvery cry cm- cm and hard head are dig dis discouraged but tall erect weeds are not hindered after they get above the mat of oC leaves On the other hand some weeds ire are associated with certain crops Greater plantain yellow mustard and black bindweed are arc fre fre- frequently frequently frequently found in cereals Bent Dent grass black bent nd goose grass are especially common in wheat quarters lambs is mo s J common in n barley than in other cereals and sheep sorrel is more frequent frequent- frequently ly y found in oats If the crops that are common- common commonly ly y produced In an agricultural section are rotated in a 8 succession that hat Is long enough It can be seen cen what an efficient means of weed control is automatically brought Into action |