i66 



JouDial of Agriculture. 



[lo >[arch. 1910. 



It will Ije noticed from the above table that the expense of some of 

 the chemical substances is very great. Besides this, their application to 

 ihe land requires a great expenditure of time and labour, thus materially 

 adding to the cost of treatment. When powdered chemicals were used 

 ihey were cast over the soil and then dug in to a depth of 4 inches, the 

 onion seed being sown in the usual wa\ some three weeks later. The 

 .seed germinated freely and did not appear to show any ill effects from the 

 chemical treatment which the soil had undergone. Unfortunatelv, very 

 low temperatures p.re\ailed at this time, which with the almost continuous 

 rains greatly retarded the growth of the young plants. Owing to this 

 heavy rainfall some of the plots, were completely flooded, many of the 

 seedling onions being washed out of the ground. A subsequent inspection 

 of the plots showed a number of broken rows of young onions, many of 

 which had reached the height of ij inches. Almost all of these, on a 

 closer examination, were found to be diseased. On the higher ground, 

 a small number of the plants appeared to be healthy ; but even these were 

 found to contain worms in different stages of growth, fn both the stems 

 and leaves. 



EARLY STAGE AT WHICH THE GERMINATING ONION SEED IS ATTACKED BY 

 EEL- WORM. ( X 3.) 



The almost complete failure of the chemical treatment to prevent or 

 even check the attack of the nematodes was remarkable ; for it must be 

 lemembered that in some of the plots that as many as 5,000 seeds bad 

 been sown, and it was confidently expected that at least some of the plants 

 Vv^ould escape, particularly in the earlier stages of their growth. Probably 

 the majority were alreadv diseased before .showing' aboYe the surface. 



That the seed soon after its germination is attacked bv the eel-worm can 

 easily be demonstrated h\ sowing onion seed in pots filled with infected 

 soil. If the germination of the young plants is carefully examined from 

 day to day with the microscope, the worms can be seen attacking the young 

 shoots and invading them, even in the earliest stages, and in some 

 instances worms have l)een detected in the germinating seed itself. 



Carbolized lime. Naphthaline and sand (a patent preparation), and 

 calcium carbide, were used on some of the land adjacent to the plots. 

 These substances were either drilled in along with seed, or spread along 

 the furrows, so as to remain in close contact with the seed. Germination 

 was interfered with bv this method of application, and. besides, it did not 

 prevent the ravages of the worms, all of the plants e\entuall\ dying off 

 from disease. 



