The association between plants and wind that first comes to mind might be plant damage from a strong wind such as a typhoon or monsoon. The winds this book will 1 discuss, however, are not this strong at all, but rather are only 2 m·s· or weaker, like a breeze that gently blows over a farming area. Such a breeze, in fact, instills vitality into plants and increases their growth rates. This book is an attempt to explain these beneficial effects on plants from a field perspective. One fundamental process necessary for plant growth is photosynthesis. Since it is a photochemical reaction, this synthesis has been studied with emphasis on light. Yet to shed light on dry-matter or carbohydrate production by plants, it is indispensable to pursue research not only into the mechanism of photosynthesis but also into photosynthetic production itself. I have observed various phenomena occurring in the production field, and have thereby realized it necessary to recognize photosynthesis as a phenomenon that carbon dioxide (C0 ) in the air diffuses into chloroplasts in the leaves, and to study 2 which environmental factors promote C0 diffusion into the leaves. 2 In this book, I am going to describe the effects of the natural environment on photosynthetic production, placing focus on the leaf boundary layer as an environmental factor for plant production.