- 17 - 



Disease Resistance in Potatoes « To (l) cooperate closely 

 with potato breeding project in incorporating disease resistance 

 in new potato varieties; (2)advance our fundamental knowledge 

 of nature of disease resistance, factors influencing infection, 

 symptom expression, and transmission; (3) develop means of 

 eliminating at early stage susceptible potatoes from a population 

 segregating for disease resistance; (4) use accepted procedures 

 in identifying resistant seedlings in a progeny segregating for 

 disease resistance; (5) evaluate clonal lines for resistance to 

 disease; and (6) maintain good quality seed of advanced selections 

 and parental stocks by greenhouse indexing and carefully main- 

 tained field seed plots. 



Bot., Farm Crops 85 



Potato Improvement Through Parental Line 3reeding . (l) 

 Expand study of methods of using inbreeding and outbreeding; 

 (2) obtain information on efficiency of using various possible 

 methods of combining and obtaining a hi#i degree of homozygosity 

 of desirable characters and utilization of clones in obtaining 

 improved varieties. 



Hort. 2128 (NC-35) Coop. ARS 



Commercial Culture of Truck Crops and Greenhouse Vegetables. — 

 g. Cultural Practices to Improve Irish Potato Yields and Storage 

 Keeping Quality . To (1) make field tests of adaptability of 

 newly introduced varieties to soil and climate of the commercial 

 potato section of Missouri; (2) compare market and storage qualities 

 of these varieties with predominant varieties to find early 

 varieties of both red and white types with more uniformity, better 

 appearance and shipping, handling and storage qualities; (3) 

 attempt a correlation of yield and internal breakdown with 

 fertilization practices and level of exchangeable soil potash; 

 and (4) evaluate seed treatment with pentachloronitrobenzene as 

 practical control of Actinomyces scabies. 



Hort. 121-g 



The Development of New Varieties of Potatoes with Superior 

 Disease Resistance. Yield and Quality . To develop new varieties 

 which mature early and will be superior to present varieties in: 

 (l) resistance to soil borne diseases; (2) resistance to tuber 

 cracking at harvest time; (3) better culinary quality especially 

 to be superior in texture; (4) high ascorbic acid content; (5) 

 attractive market appearance* (6) resistance to flea beetle, 

 leaf hoppers or psyllids; (7) greater degree of heat and drought 

 endurance; (8) ability of tubers to heal wounds rapidly; and (9) 

 resistance to any other potato diseases. 



Hort. 229 



