Relative Time of Anthesis in Pistillate and Staminate Cucumber Flowers

Staminate (male) floral buds of cucumber plants reach anthesisat consecutive nodes of the main shoot at regular time intervals;however, pistillate (female) buds reach anthesis earlier thanmale ones, thus causing a marked deviation from the linear chronologicalsequence of male anthesia along the main shoot. Measured indays, this relative precedence of the female is greatest inwinter planting time, when short days and low temperatures causea shift towards femaleness in the whole plant, and it is smallestin late summer planting when environmental conditions favourmale tendency. There are also varietal differences in this respect—inone variety (Beth Alpha) the female precedes the male by a longerperiod of time than in another variety (Yorkstate Pickling).The position of the female flower on the main shoot does notseem to play an important role in this respect, but, as a rule,the precedence is greater for the first female than for thesecond or third female developing on the main shoot. It is suggested that the relative enhancement of one type ofsex organs (carpels) is a continuous process which determinesfirst the final sex type of the flower and later causes it toreach anthesis earlier.