ABSTRACT
Legumes are some of the most useful crops in the garden. Gardeners benefit directly from the crops which they produce and from their roots forming associations with beneficial soil microbes. These are capable of turning atmospheric nitrogen into nutrients that are then available for use by legume and subsequent crops. Practical gardening techniques for growing peas and broad beans by propagation under protection and as directly sown crops are discussed. Protected propagation of transplants permits earlier harvesting compared with directly sown crops. Some varieties mature more quickly than others and these differences may also be exploited for achieving sequential cropping. Frost sensitive legumes for example, runner beans and dwarf French beans are for preference propagated using protection. The techniques required are discussed in detail. Post-planting and sowing husbandry requirements for each legume crop is explained.
Growing legumes offers opportunities for understanding important processes leading to asexual and sexual reproduction, flower structure, pollination, fertilisation and seed development. Asexual reproduction involves coherent and uniform cell division which is achieved by a process of termed “mitosis”. Basic components of mitosis are explained. Sexual reproduction provides the essential opportunities for variation between generations. Beneficial variation provides plants with capabilities for withstanding changing environments. Variation in cell division is achieved by a process termed “meiosis” and its basic stages are discussed. Sexual reproduction involves the movement and interchange of male and female genetic instructions. These actions are followed by the formation and distribution of seed. Means by which these processes take place and the ways in which plants enlist the support of animals, wind and water for pollen and seed transport are described.
Seed used by gardeners is produced commercially using techniques which ensure its quality, viability and vigorous germination. Factors affecting seed germination, the resultant vigour of seedlings, breeding and evaluation of new varieties are outlined. Cycles of life during which seed germinates and the resultant plants grow, flower and reproduce a new generation are illustrated. Emphasis is given to the interaction between the genetic constitution of plants and their environment. This interaction is of particular significance for gardeners because the objective of gardening is the control of growth and productivity. Learning achievements are listed at the end of the chapter.
