7IO Bulletin 320 



The same holds true with regard to length of stem. Some plants of 

 Countess Spencer were treated likewise in order to note the effect, and 

 for them the season was over early in August. 



The lesson is that if the grower does not intend to comply with the 

 requirements of the improved types, it is better to grow Butterfly, Captain 

 Clarke, Peach Blossom, and other small-flowered, precocious varieties. 



Fertilizers. — After sweet peas are in full flower, fertilizers may be 

 applied. The best and safest fertilizer to use is liquid manure, diluted 

 to the color of weak tea and applied once a week. It is often advantageous 

 to alternate this with sulfate of ammonia or nitrate of soda at the rate 

 of one ounce to six gallons of water. The plant responds better usually 

 to phosphorus than to nitrogen, and even potash is often beneficial. 

 Nitrate of potash and phosphate of potash dissolved at the same rate as 

 the above-named fertilizers, is of the proper strength to apply. 



Summary 



The following quotation from George Stanton is a concise summary 

 of sweet pea culture: 



" Sweet Pea Culture, condensed. — 12 words. Trench deeply; manure 

 liberally; plant thinly; stake quickly; water freely; dispod promptly." 



INSECTS AND DISEASES 



Insects 



The most troublesome insects that attack sweet peas in the United 

 States are the red spider and the green plant louse. 



The red spiders attack plants during hot, dry periods, when they are 

 to be found on the underside of the leaves. Usually they are not noticed 

 until they have become sufficiently abundant to cause considerable damage. 

 The experienced grower recognizes the favorable conditions for this insect 

 and begins syringing the plants in the evening, applying the water with 

 hose or spray pump so as to wet the lower surface of all the leaves. This 

 treatment will prevent serious attacks of the red spider. 



The green fly, or green plant louse, while often present under other 

 climatic conditions, causes greater injury during weather fa\'orable to 

 the red spider than at other times. This insect may be killed by the use 

 of tobacco extracts, dilute kerosene emulsion, or soap solution. Dusting 

 the plants with tobacco is sometimes practiced. 



Nematodes, or eelworms, do not attack sweet peas planted outdoors 

 unless infested soil from the greenhouse is used around the plants. When 

 sowing seeds in pots under glass, the proper soil is that which has been 

 steriHzed or thoroughly frozen. 



