SOME EXPERIENCES WITH THE METHODS OF EXPERIMENTATION WITH GREENHOUSE CROPS IN POLAND

At the beginning of my paper I would like to express my thanks and appreciation to the Glasshouse Crops Research Institute in Littlehampton for organizing on behalf of the Commission for Protected Cultivation of the International Society for Horticultural Science the Symposium "Techniques of Experimentation in Greenhouses". All of the horticulturists, experimenting with greenhouse crops, have felt for a long time the necessity for such a discussion of the proper, scientific methods of our work. Not too many papers in the literature refer to the methods of experimenting under glass. In our work we try to solve problems. The methods of work are derived either from papers on similar problems in the literature, or from the better known methods of field experiments, corrected by our own judgement, based on experience.

With the development of the horticultural sciences we feel a steady growth of importance in greenhouse experiments, not only for solving the numerous problems, connected with the production of plants under glass, but also to obtain the answers for many basic problems, connected with the biology of horticultural plants. I wish only to mention here that the horticultural sciences, based on research work, started when Klebs was able to grown Sedum spectabile under known temperature and light conditions. He was able to observe different reactions of this plant to these ecological factors expressed in vegetative growth or flowering.

I would like to present here some of our experiences with the methods of experimenting with vegetable plants and also the equipment used for this type of work in the Research Institute of Vegetable Crops in Skierniewice. As some of you may know, some of the research work with vegetables has been carried out in Skierniewice since 1920 by the Department of the Warsaw College of Agriculture. Since 1962 we have organized in Skierniewice a special Research Institute of Vegetable Crops under the Ministry of Agriculture, with more funds available for equipment and research work. We have the ambition to equip this scientific centre as well as possible, using our good judgement and also the observations of similar research institutions in different countries. I am full of expectations that the discussion on this Symposium will end with some conclusions and recommendations concerning not only the methods of our work, but also the use of the equipment of the research stations in the different countries, in order to obtain the results which we could compare.

Very frequent and of immediate application in practical plant production is the variety and F₁ hybrid test. In such experiments we are using experimental plots containing 10–15 tomatoes in a single row, the number of randomized replications is 4–6. The plants grown soil border of the greenhouse are usually spaced 70 x 35 cm. The rows are running across the greenhouse, with the direction of our present greenhouses mostly North-South. Some of our tomatoes are grown on benches, because these tomatoes are earlier to ripen. Earliness of ripening is a factor of great economical importance. In this case we usually have replicates with 10–12 plants per plot.

Even with these simple experiments we have several questions, for which we hope to obtain the answer in the discussion during the present symposium.