Greenhouses hygiene tips

As a precaution against pest and disease, fumigation most also be carried out A simple and effective method is to burn sulphur cones or candles inside the house, either before or after the crop has been removed but sulphur should not be used where there are growing plants.

To fumigate, close up all ventilators and if the greenhouse is of some size, begin by lighting the cones or candles at the nu- end, and working towards the door. Sulphur fumes are irritating and must not be inhaled. Sulphur should be used at the rate of 1 pound for every woo cubic feet of air space.

As an alternative, wash down the inside and soak the soil. It is a clear liquid and should be applied with a power sprayer which will enable the liquid to penetrate all cracks of the woodwork and into the glass overlaps where pests usually congregate. The discovery that formaldehyde gas, released from formalin solution, would cure mushroom house sickness and make a greenhouse 'sweet' and clean after tomato and cucumbers, revolutionized the growing of these crops for commercial growers.

After formalin has been used 4 to 5 weeks should he allowed before new planting is done in the soil beds. The fumes given off are poisonous to plants, humans and animals and after fumigating the house, allow the gas 24 hours to achieve its maximum penetration before opening up the door and ventilators. The house should then be aired for 4$ hours to allow time for the tinnes to clear, before being worked in again.

When the house has been fumigated, an additional precaution may be taken by passing the flame of a blow lamp over the woodwork, whilst all seed boxes and pots should be sterilised by ins mersing them in a tank of formalin solution, diluted tot part m 5o of water. Or use Ster-Izal which may also be used for disinfecting the greenhouse and soil.

Should eelworin have been troublesome as it may be with tomatoes, the pest is eradicated by injecting the soil with the liquid fumigant D.I). It will be necessary to allow the soil a month for the fumes to escape before further planting is done. The greenhouse may be kept free from pests by the use of an aerosol which is a suspension of minute solids or liquid particles in gaseous fors ii, thereby creating a mist which envelopes each plant. The aerosol will consist ola metal container with a thermostatically controlled heating element to vaporise the liquid pesticide. The Mistosol 99 is suitable for the larger house. It is worked by a high speed motor of one-eighth h.p. which develops 16,ocx.) r.p.m., the spinning disc system enabling an excellent mist to be produced from the water based insecticides or disinfectants.

A more simple method is to fit a disc impregnated with pesticide (or liingicide) over an electric light bulb which when switched on, will release the fumigant with the heat of the bulb.

One of the earliest preparations to be used in aerosol form was Azobenzene, discovered by Prof. Blauvelt ol(ornell University: it will eliminate red spider from glasshouses.

Where raising ones own plants, it will be advisable to have a supply of sterilized soil always available. One method is to obtain loam ofa fibrous nature and to water it with fornialin solution or with Sterilite soil disinfecting fluid, used at a strength of 1 pint to to gallons of water. As the soil is made damp, make it into a heap 2-3 feet high and cover with a tarpaulin or plastic sheeting to retain the tunics. Leave for a week, then remove the cover to allow the soil to be turned for the fumes to escape. It should be turned several more times until quite free of any fumes. This will take about a month when it may be used.

The Autosoil electric soil steriliser is most effective. It will sterilise a bushel of soil at one time and is automatically controlled, switching off after sterilisation is complete. Steam sterilisation may be done with the Sterilatum, a machine whereby steam is driven through soil contained in a chamber, a useful method where larger quantities of soil are to be sterilised. It should be stated that soil will be sterilised in a temperature of 0o 'F. (7CC.) held for 4 hours. It is inadvisable for the temperature to exceed [ 76'F. (80°C.) and should it exceed 212°F. (100'C.). the soil will be made completely sterile and unable to support any form of plant life.