Fertigation Management of Potted Plants

Abstract

The horticultural crops considered in this chapter are characterised by the fact that the plants are grown in a restricted volume, like pots, containers, plastic trays or compressed peat blocks. In the market these crops are recognized as potted plants, bedding plants and container grown nursery stock, mostly for ornamental purposes. Another group is the raising of young vegetable and cut flower plants, due to production holdings. Although extremely diverse, all these plants are grown as single units and this makes the water supply of the plants complicated. Trickle irrigation is generally unsuitable because it is laborious, due to rapid changing crops and plant densities and besides expensive because of the large number of units per area. Exceptions are the plants grown in large containers, like balcony and patio plants, some nursery stock and subtropical trees with a long growing period and a low plant density. Overhead sprinklers induce excessive losses of irrigation water and nutrients, since a considerable amount of the irrigated water falls alongside the pots or drips from the leaf canopy mostly also alongside the pots. Moreover, the water supplied is absorbed per individual plant or plant batch, which strongly enhances the variation in the water and nutrient status of such units. To avoid these problems, potted plants already have been grown for many years on concrete floors or on container benches with sub-irrigation. Nowadays, in all modern greenhouses this is the common growing system. In contrast with vegetable and cut flower nurseries, potted plant nurseries are not always specialised in one crop, but in different plant species. Even if they are specialised in one plant type, different plant stages are present at the same time, like with Kalanchoë and Chrysanthemum.