Dodder and its Eradication. 



(BY DR. ERIC A. NOBBS, Agricultural Assistant.) 

 Reprinted by permission of the Cape Agricultural Journal 



WITH the extension of lucerne cultivation and the increasing 

 demand for seed more and more is leing IK aid of the danger 

 of dodder and the havoc caused by this pest in our finest and most 

 valuable lands. Many farmers are still ignorant of the appearance 

 of the plague, but they are not likely long to remain in this blissful 

 state, as information 'is constantly received of its occurrence in 

 fresh kcalities. Once seen it cannot be mistaken. 



For those Ftill unfamiliar with its appearance it may best be 

 described as a tangled mass of thin yellow or brown strands, resem- 

 bling the tassel of rij ening mealie cobs, but spread upon the 

 ground twining round ihe stems of lucerne or other herbs, bearing 

 dense clusters of white or pinkie h flowers possessing a sweet but 

 sickly scent. 



To understand its habits, its simple life histx ry must be known. 

 Supposing the seed to be sown akng with ..r.cwne en a new piece 

 of land, it germinates just as do all other seeds, but scmewhatmore 

 slowly than does the lucerne, a provision whereby the presence of 

 the host is assured when the dodder needs it. Like all other 

 flowering plants, dodder begins by sending down a little root into 

 the ground, but the shoot which springs upward is a single smooth 

 stalk or thread bearing no leaves. The young dodder in its growth 

 gyrates round and round, in the direction opposite to that of the 

 hands of a watch, feeling, as it were, for a lucerne plant to grip. 

 Should none be near, ihe posterior parts of the stalk die off, and 

 the front portion grows out, thus actually creeping over the ground 

 in search of its prey. On finding a suitable host, the dodder laps 

 itself round the stem, and developes a number of processes, tech- 

 nically haustoria, which pierce into the stem and, forming an inti- 

 mate connection with the vascular system of the green plant, 

 proceed to suck from it the sap, taking sustenance and growing at 

 its host's expense. The root of the dodder disappears at an early 

 stage. The dodder grows rapidly, and sends out branches, which 

 in turn clasp other plants, and so spreads like fire through the 

 crop. The rate of growth, encouraged by all the forces which 

 should go to the nourishment of the crop, is extraordinarily rapid, 

 and any fragment broken off is capable of continued growth pro- 

 vided it reaches a suitable plantion which it can live. 



