Part I.--Pollination Studies of Seed Production.

Unsatisfactory yields of sweet-clover seed 1

Previous investigations of the pollination of sweet clover 2

Outline of pollinating experiments 3

Structure of the flowers of Melilotus alba 4

Development of the floral organs of sweet clover 5

Fertilization in Melilotus alba 8

Development of the seed 8

Mature pollen of sweet clover 9

Germination of the pollen 9

Cross-pollination and self-pollination of sweet clover 10

Artificial manipulation of sweet-clover flowers 10

Seed production of Melilotus alba under ordinary field

conditions 13

Efficiency of certain kinds of insects as pollinators of

sweet clover 14

Relation of the position of the flowers on Melilotus alba

plants to seed production 19

Influence of the weather at blossoming time upon seed

production 20

Insect pollinators of sweet clover 21

Effect of moisture upon the production of Melilotus alba seed 22

Sweet-Clover Seed · 第 7 / 10 章