100 



Kuhn; attacks a great variety of plants including straw- 

 berries, onions, beans and peas, hyacinths, and also held 

 crops. It is an extremely slender species, about i-2<;t:h 

 of an inch long, and the males and females closely 

 resemble one another. Strawberries when attacked decay 

 away at the level of the soil or just below it, and the 

 crowns and roots^ rot away. A remedy is to pull up and 

 burn the affected plants and dress the soil with either 

 lime or sulphate of potash in the proportion of I cwt. to 

 the acre. The KNOT ROOT EEL WORM (Heterodera radici- 

 cola y Greef) differs from the previous species in the male, 

 being thread-like, while the female is greatly swollen 

 except at the head end. It also goes through a more com- 

 plex life-history. This species renders its presence evident 

 by forming knot-like swellings or galls upon the roots of 

 the affected plants. It is a great enemy of cucumbers and 

 tomatoes grown in glass houses, but also attacks vines, 

 potatoes, lettuces, and many other plants in the open. 



As a temporary measure to save a growing crop, one 

 part of permanganate of potash to 200 of water applied 

 at intervals of ten days is recommended in the K.C.W 

 Bulletin. It does not harm the plants, but since it does 

 not destroy the eggs of Eelworms, no permanent value 

 can be ascribed to it. Treatment of the soil with one part 

 of carbolic acid to twenty of water, with a dressing of 

 sulphate of potash, 3 cwt. per acre, intimately mixing the 

 soil with gas lime or naphthaline, are among the remedies 

 that are recommended. When applying remedial measures 

 the soil must remain unused for at least six weeks for any 

 permanent benefit to be derived. This species, however, 

 is extremely difficult to eradicate owing to the fact it 

 produces vast numbers of eggs throughout the year, and 

 the young Eelworms are thus constantly being liberated 

 into the soil. Furthermore, most of the above methods are 

 not lasting in their effects, owing to the fact that fre- 

 quently a number of eggs remain over undestroyed, and 

 serve to start the infection afresh. When a glass house 

 is infested with Eelworms, it is often necessary where 

 possible, to remove the soil bodily and treat it by one 

 of the methods already mentioned. In the case of plants 

 grown under glass the horticulturist soon finds that the 

 conditions encourage a host of other living things. In 

 addition to Eelworms, Woodlice, insects of various kinds, 

 and fungi often enforce their presence, and under the 



