APPENDIX, 



197 



were numerous, and some of the flowers were even crossed hy hand with 

 the pollen of other varieties. Since the variety had already shown itself so 

 susceptible to winter-injury, it is probable that this wholesale failure was 

 due to the weakened vitality of the pistils. 

 Avhich could not be seen with the eye alone. 



Some of the imperfect development of 

 flowers which we attribute to winter-injury 

 may be caused by unfavorable conditions dur- 

 ing the previous season, when the buds Avere 

 being formed : yet it seems likely that winter- 

 injury to pistils is more common and more 

 serious than aj^pears at first sight. These re- 

 marks on winter-injury ai-e introduced simply 

 to emphasize the fact that all blossoms which 

 do not set fruit are not sel f-sterile : and also to promote a more careful dis- 

 crimination between the various causes which decrease the setting of fruit. 



Ttl— Catherine ; injured pistil. 



RAIN MAY INJURE FRUIT BLOSSOMS. 



The unfruitfulness which often follows a rain timing the blooming sea- 

 son is sometimes confused with self-sterility. A careful fruitgrower watches 



the weather anxiously when his trees are in blos- 

 som, for he knows this is the most critical period 

 in the growth of the crop. Injury to fruit blos- 

 soms from rain is common wherever fruit is 

 grown, but is ])articularly serious along the Pa- 

 cific Coast and near the shores of the Great Lakes. 

 It has been estimated that more fruit- is lost in 

 California from cold rains during blooming time 

 than from all other causes combined. Like 

 winter-injury to fruit buds, there is no way of 

 preventing this loss except to secure a more 

 favorable location, since it is not in man's power to prevent rain, however 

 much he may be able to induce it by bombarding the sky. Nevertheless, it 

 is interesting to know in what way rain decreases the setting of fruit. 



If a rain comes while the trees are in full bloom the pollen is washed from 

 those anthers which have already opened, and is thus prevented from reach- 

 ing the stigma. Should the rain be a short one, no serious harm need result 

 from this loss of pollen, for the unopened anthers will burst and pollination 

 will begin again soon after the sun comes out. The washing away of pollen 

 has very little influence in decreasing the setting of fruit, particularly when 

 the rain is short. There will generally be enough pollen to supply the 

 pistils before or after the rain. 



. — Catiieriiie; muninl 

 flower. 



