PHYSIOLOGY AND MINERAL NUTRITION 91 



type (Burmese). The fresh weight of the green shoots at 140 days was 

 about 96 percent of the whole plant. Others ( 10) have found a similar 

 relationship. 



Flower, Gynophore and Fruit 



The fruiting parts of the peanut plant have been of special interest 

 to a number of investigators (10, 37, 45, 63, 68, 74, 81, 88, 90, 91). 

 Botanists have known for more than a hundred years that the flowers 

 were of one kind and complete, and yet the idea still persists, according 

 to the literature, that peanuts produce two kinds of flowers. Flowers are 

 borne in the leaf axils and one or more may appear in the same axil. 

 They appear first at approximately 50 days after seeding and then daily 

 throughout the flowering period. The orange-yellow flowers are fully 

 open in early morning and usually begin to wither and die by noon of the 

 same day. Therefore, an accurate record of flower production may be 

 obtained. 



Shibuya (74) found the length of the flowering period to range from 

 69 to 93 days with the bunch type. That period was 74 days in one experi- 

 ment with the runner peanut. Maximum flower production occurred 50 

 to 60 days after the first flowers appeared. The bunch peanut produced 

 approximately 600 flowers; the runner, approximately 1,000. However, 

 there was considerable variation between individual plants. 



Some data of flower production by the Dixie Runner peanut at the 

 Florida Station (10) are given in table 2. Plants produced an average of 

 644 flowers during a period of about 80 days when grown in sand culture 

 with the complete nutrient solution applied to both rooting and fruiting 

 zones (table 2) . An unbalanced nutrient supply had a pronounced effect 

 on flower production, and blossoming virtually ceased when the root 

 treatment of the plants was changed from a complete nutrient solution 

 to distilled water. The results shown in tables 1 and 2 and others obtained 

 by Shibuya (74) indicate that the runner peanut has more flowers than 

 the bunch and that the flowering period ranges from 2 to 3 months or 

 longer. 



The gynophore or peg is usually noticeable within 7 days after the 

 flower is fertilized. It is formed by division and elongation of cells back of 

 the ovaries. The organ is geotropic and by elongation it transfers the 

 ovaries from an aerial to a hypogeal position. Elongation generally ceases 

 after the gynophore has penetrated the soil to a depth of approximately 

 2 inches. Then rapid embryo development usually starts within 10 days, 

 and the fruit is mature at about 60 days after the appearance of the flower. 



