This book, the first and the only one written so far on this subject, has highlighted earlier literature and relatively recent studies and discoveries made on the guttation phenomenon, associated structures, and other related issues in plants. Although we now have a reasonable understanding of the major events constituting the mode of guttation and the structural components of hydathodes, which are the mouths of guttation, relatively little is known about the mechanism of guttation itself. It is, indeed, a complex phenomenon, and its mechanism is only hazily comprehended. One of the mysteries confronting scientists is how exactly the process of guttation is triggered and turned ‘on’, left ‘on’, and switched ‘off’ and why some plant species or genotypes guttate heavily, while the others do not. Therefore, to understand guttation is to understand one of the key processes of plant life. It is hoped that the insights presented in this book, along with summaries of the methods and approaches of concerned studies now being applied to the major goals, have the potential of expanding the horizon of our knowledge regarding this intriguing phenomenon. Therefore, our understanding of this biological phenomenon, and also of other mechanisms related to it for which there is, as yet, little direct evidence in literature, is crucial.

Among several plant biological phenomena, guttation remains one of the most powerful engines for chemical mobility of signal transduction in plants. In the light of new information, the influence of guttation, with respect to its impact on soil–plant–animal–environment systems ranging from maintenance of soil fertility to natural plant protection measures, leading to enhanced biological and economic yields aligned with ecosystem sustainability, and pharmaceutical and industrial implications for animal and human health care, is far more than envisaged earlier. Yet, several important aspects still remain to be studied. There is a lack of information on varietal differences in guttation among field crops though the guttation rate differs widely not only among species but among varieties thereof too. Further, there is no information on the role of vitamins in guttation according to the various genotypes of food, feed, and fiber crops, nor is the effect of the quality of light, that is, monochromatic laser light, on guttation precisely known.