G.F. Sheard
In presenting the closing general lecture I propose to try and assess the likely future development of protected cropping in relation to the papers that have been presented during the Conference. Dr. van Soest in his opening lecture showed that the glasshouse industry was in a highly competitive position compared with producers of vegetables in the open. The British economist Folley* surveying the future market for tomatoes in Western Europe predicts a 7% increase in consumption between 1962 and 1970 This survey relates only to tomatoes but I see no reason to doubt that the consumption of other glasshouse vegetables will not increase in a similar manner. The glasshouse industry would therefore appear to be in a very favourable economic position - its products are competitive and it has an expanding market.

It is impossible to separate economic and technical development. To maintain its economic position the industry must keep ahead in technical development but technical development is only possible in a profitable industry. I think this is clearly evident when we compare the glasshouse industry in the Netherlands and in Britain over the last twelve years. In the Netherlands we see an expanding profitable industry with a high rate of investment in technical development. In Britain we have seen an industry declining in area, not very profitable and with only limited investment in modern equipment. However, even in Britain we can quote examples showing that investment in technical development is economically profitable. To quote two specific examples:

  1. Reorganisation of a heating system raised the yield of tomatoes from 63 tons/acre to 75 tons/acre. (4 year average before and after reorganisation).
  2. Rebuilding of old glasshouses raised the yield of tomatoes from 48 tons/acre to 68 tons/ acre (6 year average before and after building). Development must however, pay for itself but can you image that these two cases did not? In Britain taking account of all current taxation allowances an investment must yield 7¾% written off over 20 years or 11¼% over 10 years if it is to be economically sound.

Under protection, crop response can be modified in two ways:

  1. By the physical manipulation of environmental factors such as temperature, humidity, nutrition, water supply and CO2 concentration to give a desired response. This approach requires a knowledge of crop reaction to these factors, many of which interact. The situation is extremely complex and expensive equipment is needed to give accurate control.
  2. By the genetic modification of the plant. Such factors as yield, earliness, setting under extremes of temperature and disease resistance can be genetically determined. Here the response is inbuilt and automatic from within the plant, requiring little or no external control. I believe that we have underestimated the role and insufficiently used the skill of the plant breeder. In the future we must use to the full the genetic potential of the species to simplify, reduce the need for and cheapen the cost of environmental control. Our plant breeder at G.C.R.I. makes the claim that "anything the environment can do the genotype can do better". I would agree and add "cheeper and easier". I now want to consider future development in relation to
DOI: 10.17660/ActaHortic.1966.4.39

Acta Horticulturae