O. S. Wells and J. B. Loy protect pepper plants with a floating row cover 



crops such as corn and cereal grains 

 lack this capability, much of the nitro- 

 gen needed for growth must be pro- 

 vided as commercial fertilizer. T. M. 

 Davis, a cellular geneticist using bio- 

 technological methods, believes that 

 legumes possess symbiosis genes 

 which allow them to fix nitrogen. To 

 determine why common agronomic 

 plants cannot use rhizobia to provide 

 their nitrogen needs he uses genetic 

 engineering techniques that eventu- 

 ally may allow transfer of the symbio- 

 sis genes to non-leguminous plants. 

 He's made a start toward that goal. 

 Upon irradiating chick pea seeds he 

 found six different genes which influ- 

 ence the symbiotic process. However 

 there are many strains of soil-borne 

 rhizobia with varying capabilities of 

 fixing nitrogen, Davis, working with 

 R. P. Blakemore in Microbiology, be- 

 lieves genetic engineering may make 

 possible development of both a strain 

 of bacteria and a variety of legume 



which together create a highly effi- 

 cient nitrogen fixation system and thus 

 a more productive plant. Although 

 transferring this process to non- 

 legumes may not be easy, the prospect 

 of doing so is exciting, and if accom- 

 plished would serve to maximize use 

 of solar energy and reduce our depen- 

 dence on fossil fuels. Indeed, very 

 recently, scientists elsewhere have 

 discovered a bacterium which can 

 derive its energy from the sun and 

 convert atmospheric nitrogen into 

 plant nutrients. 



How can the yield of agronomic 

 crops be optimized and the need for 

 lime and fertilizer reduced in the 

 Northeast? This is the basic question 

 underlying the research of G. O. Estes, 

 plant nutritionist, and his students. 

 He has found varietal differences in 

 ability to grow at lower temperatures, 

 and shown variation among corn 

 genotypes in efficiency of nutrient 

 uptake suggesting that selection for 



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