GRA PE-BREEDING 279 



As soon as the stigma is ready to receive the pollen, the bag 

 is removed and pollen from the male parent is applied, after 

 which the bag is again put on the flower to remain until the 

 grapes are well set. By examining the stigmas in the flowers 

 of uncovered grapes, the operator can tell approximately 

 whether the covered stigma is ready to receive pollen. The 

 time required after covering depends, of course, on the age of 

 the bud when emasculation takes place. It is, by the way, 

 best to delay emasculation until just before the flowers open, 

 but one must be certain that the anthers have not discharged 

 their pollen before the flower has been emasculated. 



Emasculation is a simple operation. The essential organs 

 of the grape-flower are covered by a small cap ; this in some 

 grapes must be removed before the anthers can be reached. 

 In many native grapes, however, the cap and the anthers may 

 be removed at one stroke by the operator. The best tool for 

 this is a small pair of forceps. Each of the blades of the for- 

 ceps in working with native grapes should have a sharp cutting 

 surface, but with Vinifera sorts, where the cap must be re- 

 moved before the anthers can be reached, forcep blades with 

 a flat surface are best. There is, of course, some danger when 

 the buds are well developed that the pollen may be squeezed 

 out and so reach the stigma or adhere to the instrument and 

 thus contaminate future crosses. The first danger must be 

 avoided carefully by the skill of the operator, while the second is 

 easily overcome by sterilizing the forceps in alcohol. An effort 

 should be made to fertilize as many of the flowers in the cluster 

 as possible, but success is not always certain ; when there is 

 doubt, the uncertain flower should be removed from the cluster. 



The flower from which the pollen is to be taken must be pro- 

 tected from wind and insects; otherwise pollen from another 

 flower may be left on it. Protection should be given by tying 

 the flowers in a bag while still in bud. There are various 

 ways of obtaining pollen from ripe anthers and applying it to 



