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 Crop differences in response to nutritional conditions are well known and
 fertilizers are applied accordingly. Variety and type differences within crops
 are generally not as well recognized, .

 Understandably, plant breeders have been highly concerned with disease
 resistance, market types, appearance and adaptability to prevailing conditions
 and have given little thought to selection for nutritional factors.

 Significant differences in celery varieties between the Summer Pascal and
 the Utah variety and particularly between FFVA 2-13 and Fla. 683 selected from
 the Utah variety, indicate the variability to many nutritional factors is
 present in celery for selection. The differences between these selections
 from Utah 52-70 are probably not the extremes found within the commercial line.

 This is also clearly demonstrated in sweet corn hybrids. Some are known
 to be more sensitive to zinc deficiencies than others. Silver Queen, Winter
 Garden and Winter Green are more sensitive to manganese availability as
 affected by soil pH than lobelle and most other sweet corn hybrids.

 At least one variety of escarole exhibits severe magnesium deficiencies
 in 25% of its population when planted on some of our organic soil areas.
 This ratio always remains constant.

 In crops whose seed is normally cross pollinated or partially cross
 pollinated one might expect these ordinarily hidden types of variabilities to
 occur. The introduction of new germplasm, particularly from foreign intro-
 ductions, would certainly tend to increase this type of variability



























EES68-9
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