DISEASES OF LEGUMINOUS PLANTS 69 



favourable conditions they germinate the following 

 summer, giving- rise to yellowish-brown trumpet- 

 shaped growths (see Fig. 19, B). Inside the trum- 

 pet shaped openings are numerous asci standing 

 erect and side by side. The ascospores are capable 

 of immediate germination, but their germ tube is 

 unable to enter direct and live parasitically, until 

 strengthened for a time by saprophytic nourishni(tnt. 

 Preventive Measures. — 



1 . Collect and destroy attacked plants. 



2. Do not grow clover too often on the same 



land. 



IV. Spot Disease of Peas {Ascochyta pisi). 



Fungi hnperfecti ; Order: Spileropsidat.es, 



Peas, possibly lucerne and other leguminous 

 plants, suffer from this disease. 



Symptoms. — Brown spots appear on the pods 

 (see Fig. 20, s\ leaves, and on the stems, at first 

 near the ground, but later on all parts. These 

 diseased areas on the stem often penetrate to the 

 water-conducting tissues and cause the plant to die 

 with symptoms of a "wilt disease". On the dis- 

 coloured areas, minute black dots (the picnidia or 

 spore cases of the fungus) appear. On the |:)od, the 

 spot may penetrate from one side to the other, de- 

 stroying the enclosed seed, or the seed may be 

 infected without killino- it, so that some (only a low 

 percentage) will germinate, thus carrying the 

 disease over to the following year. 



