Page 6 BETTER FRUIT June, 1921 



Relation Of Bee Keeping To Fruit Growing 



By Dr. A. L. Melander, Entomologist, State College of Washington 



THIS paper will deal with two as- 

 pects of the problem suggested 

 by the title: first, the necessity 

 of having bees in the orchard if the trees 

 are to produce their maximum fruit 

 yields; second, the necessity of chang- 

 ing spraying methods if bee keepers 

 are to remain in the orchard districts. 



Bees have long been known to be of 

 value in pollinating plants, but, just 

 how far fruit trees are dependent on 

 bees is not so thoroughly known to the 

 general fruit grower. A number of 

 carefully conducted experiments have 

 been recorded in various bulletins and 

 reports from which the following cita- 

 tions have been gleaned. 



Different varieties of fruit are either 

 self-sterile, partially self-fertile or else 

 entirely self-fertile. In the first in- 

 stance, bees or other agencies for the 

 transfer of the pollen grain are an abso- 

 lute essential if the fruit is to' set at 

 all. In the second instance, where flow- 

 ers are only partially self-fertile, a full 

 crop of fruit would not result if all in- 

 sects or other agencies for the transfer 

 of the pollen were eliminated. In the 

 third instance, of complete self-fertility, 

 there are abundant records to show that 

 crossing produces better fruit. Hence, 

 in every case the fruit grower will profit 

 by having bees in his orchard. In no 

 case are bees detrimental. 



Among the varieties of apples that 

 are known to be self-sterile are the Ar- 

 kansas Black, Gravenstein, Gano, Jona- 

 than, King, Mammoth Black Twig, Mis- 

 souri Pippin, Rome Beauty, Rhode 

 Island Greening, Transcendent Crab, 

 Wealthy, Winesap, Yellow Bellflower 

 and York Imperial. 



Among those only partially self- 

 fertile are included the Ben Davis, Spit- 

 zenburg, Wagner and Yellow Trans- 

 parent. 



Among those that are self-fertile are 

 the Baldwin, Grimes Golden, Dutchess 

 of Oldenburg and Yellow Newtown. 



Experiments conducted by the Ore- 

 gon Experiment Station have shown 

 that while the Spitzenburg is regarded 

 as partially self-fertile, it produces only 

 three per tent of fruit when self-polli- 

 nated, but when receiving pollen from 

 the Arkansas Black it will set 70 per 

 cent of its fruit. Similarly pollen from 

 the Ortley, Jonathan, Baldwin or Red 

 Cheek Pippin produces a heavy set on 

 Spitzenburg while pollen from the Yel- 

 low Newtown produces only about 40 

 per cent set. Such experiments are the 

 result of hand pollination, but are indi- 

 cative of what would happen when bees 

 visit from flower to flower. 



Other varieties of fruit show a simi- 

 lar variation as to fertility. 



Most pears require cross pollination 

 since they are only partially, if at all, 

 capable of setting fruit when self- 

 fertilized. The California Experiment 

 Station has demonstrated that plums 

 and prunes will present a vastly heavier 

 crop when cross-pollinated, both being 

 more or les3 self-sterile. 



Of the cherries, the Royal Ann, Bing, 

 Black Tartarian, Lambert and Black 

 Republican are self-sterile. Thirteen 

 varieties of almonds experimented with 

 at the California Experiment Station 

 were wholly self-sterile. Peaches have 

 also been deomnstrated to be almost en- 

 tirely dependent on the visits of bees if 

 a good crop is to ensue. 



Of the smaller fruits, raspberries, 

 blackberries, strawberries, cranberries, 

 etc., are all abundantly visited by bees 

 and the amount of fruit that would set 

 is entirely proportional to the number 

 of visits. 



THE question of the distribution of 

 pollen by wind has been settled at 

 the Oregon Experiment Station by fast- 

 ening slips of vaselined glass in and 

 near apple trees. So few pollen grains 

 were caught on the sticky glass as to 

 prove conclusively that wind is not at all 

 an agency in carrying across apple 

 pollen grains from one flower to an- 

 other. 



It has been proved that if blossoms 

 do not receive pollen grains they fail to 

 set. This io the main explanation for 

 the familiar "June drop." 



It requires one pollen grain for each 

 seed, five pollen grains must therefore, 

 fall upon and enter each apple flower, 

 while the strawberry or raspberry would 

 require many more grains. 



When a pollen grain falls on the 

 sticky stigma, the female part of the 

 fiower, it starts to grow down a tube 

 carrying the sperm cells into the inner- 

 most parts of the blossom. The union 

 of a sperm cell with an egg cell starts 

 the growth of the seed. Unless all 

 seeds are started, the fruit becomes mis- 

 shapen in its growth, if it does not drop 

 entirely from the tree. Hence a complete 

 pollenation with healthy viable pol- 

 len is the first requisite in the setting of 

 a fruit crop. As shown some varieties 

 of pollen srcm to be better adapted 

 than others in insuring a complete fer- 

 tilization. Even in case of self-fertile 

 varieties, pollen from other blossoms or 

 better from other trees, or perhaps bet- 

 ter still from other varieties, is needed 

 for best results. 



It is interesting to note that con- 

 trary to popular opinion pollen grains 

 do not affect the color of the apple. A 

 Spitzenburg pollenated by an Arkansas 

 Black is no darker than if pollenated by 

 a Yellow Newtown, bu many more ap- 

 ples would set from the Arkansas Balck 

 pollen than if the pollen were obtained 

 from a Yellow Newtown tree. The for- 

 mer pollen is more effective, more like- 

 ly to' start the complete production of 

 seeds, hence the result is larger and 

 better formed apples even though the 

 color is not affected. 



Mlany millions of years ago the first 

 flowers came into existence and also the 

 first bees. Since that time, these two 

 developments of nature have worked up 

 an inter-dependence so that the midifi- 

 cations of flowers as we now know them 

 have been developed through the agency 

 of bees. In a corresponding way the 

 bees have become modified in their body 

 parts, as an adaptation to floral struc- 

 ture. 



FLOWERS develop showy petals to 

 attract the bees. Nectar is produced 

 at the bottom of the floral parts to 

 force the bee to dip down as far as pos- 

 sible in securing it. Pollen is produced 

 in over-abundance as a delicious food 

 for the bees. Bees in their turn have 

 developed a long tongue for lapping up 

 the nectar, a crop for storing it for the 

 flight home, a body covered with re- 

 markable pronged hairs for collecting 

 the pollen and adaptations on the legs, 

 the pollen baskets, for scraping together 

 and transporting the pollen load. 



In the visits to flowers, bees come in 

 contact with the pollen — the little grains 

 covering their body are then rubbed on 

 the sticky stipma often as a result of a 

 remarkable arrangement in the forma- 

 tion of the flower parts. After polle- 

 nation, the stickiness of the stigma dries 

 up so that the flower is receptive only 

 for a few days, usually at the beginning 

 of the blossoming period. As a further 

 result of pollenation. the nectar ceases 

 to be produced and the petals drop 

 quickly. The flower is no longer at- 

 tractive to bees. 



Some trees have a tendency to over- 

 set fruit, requiring costly thinning in 

 commercial orchard practice, might be 

 rendered less prolific if bees are with- 

 held or if sprayed with some corrosive 

 spray that would destroy the stigmatic 

 surface. The only drawback to such a 

 recommendation is that if carried out 

 one would not be sure of a setting of 

 fruit at all. Most fruit men would pre- 

 fer to thin a super-abundance of fruit 



