Plastics Increasingly Used In Gardening

Press, Volume XCVI, Issue 28399, 4 October 1957, Page 15

Plastics Increasingly Used In Gardening

Increasing use is being made of plastics in the nursery at Canterbury Agricultural College. Lincoln. They have been used extensively by growers overseas and they are now being tried on a limited scale in New Zealand.

The horticultural department at the college is working with them to keep its students abreast with latest developijients and to gain information which may be of value to commercial growers. Half of a tomato glasshouse at the college has been lined with transparent polythene and although it is too early yet to have conclusive results it has been found that the night temperatures are higher in this section than in the adjoining unlined part of the house. Conserves Heat Mr J. H. Glazebrook, senior lecturer in the horticultural department at the college, said that the plastic was used to conserve heat and save fuel. It acted like a double glazing keeping the warm air from escaping and the cold air out. Fuel to heat houses was one of the main items on the budget of the tomato grower. The idea, he said, was to line only those walls and ends of houses which were’ inclined to be cold. If the whole house was lined it could lead to excessive humidity and the development of disease problems associated with such conditions.

The polythene allowed exchange of air and the normal amount of light to enter the house so that it apparently made no difference to the growth of the plant. It was also cheap. In the Lincoln glasshouse it has been tacked to the framework of the house. Future Development

Asked about the possibility of polythene replacing glass altogether, Mr Glazebrook said that one of the difficulties was that present forms of polythene when exposed to sunlight did not seem to have a very long life, but there would seem to be a possibility of using the materials m a short term programme instead of glass. It was possible that in the future, with research, better forms might become available, but ne did not think that in the foreseeable future it would entirely replace glass. Perforated Strips In another house at the nursery black perforated polythene in strips is being used to mulch strawberry plants. This practice can also be used outside. The plants are pulled through the strips which extend along the rows. Mr Glazebrook said that the advantages of the practice were that it ke'pt the soil moist, prevented weeds from growing and kept the fruit clean. It- is also planned to use heavy polythene sheeting to line a reservoir to hold about 12,000 gallons of water, for which excavatiqns already have been made. The supply would be available to ease

the strain on the college water supply when there were heavy demands on it.

For a long time the horticultural department has been using plastic labels, which can be used over and Over again and are long lasting, and the college also has some fairly heavy grade plastictype pots.

Mr Glazebrook said that he understood that there was now available a lighter type of polythene pot, which would be useful for the home and commercial gardener, being light and easy to handle.