-- Marsupial Landscapes Pty Ltd. mailto:firstname.lastname@example.org Ph: 61-2-99056844 Fax : 61-2-99056244
I have been browsing the web for other persons interested in the use of hot water for controlling weeds. I have been looking at alternatives to the use of biocides for the control of weeds in the built environment ie open public space. There appears to be one or two companies world wide who have developed apparatus for the application of hot water to weeds. The apparatus as they stand at the moment have a few major flaws.
- They use in excess of 4 litres per minute of water therefore requiring a cumbersome amount of water to be transported and a continual time consuming refill on avearge every 1 to 2 hours.
- The heat exchanger is deisel fuelled; being costly, energy inefficient noisy and potentially polluting. If we are looking for sustainable and non polluting alternatives a cleaner energy source is required.
- The consequential size of the apparatus make them unable to unobtrusively operate in the public domain and the volume of water consumed and consequentially out poured causes excessive runoff on paved areas and floods garden beds.
-Tractor mounted apparatus are unable to apply control to the crop rows. Trials I have carried out have shown that Hot water at tempertures in excess of 75 degrees C will cause permanent cell collapse within 5 seconds on a majority of soft tissued plants above ground. Controlling more persistant stoloniferous, rhizomateous, corm and bulb weeds requires heating the soil to temperatures in excess of 65 degrees C. To do this the hot water must have time to penetrate the rhizosphere and be of an application temperature high enough to still be of effect at the required depth ie upto 75mm (3").
There is some concern for the other organisms present in the rhizosphere, but worm counts a few days following application are encouraging, probably due to their feeding on resultant dead tissue. Microflora counts have not been done.
Mr Hawkins, you mention in correspondance that you are familiar with hot water treatment of weeds. I would be pleased if you could refer me to any published articles, preferably prior to 1991, on the method. I am running overtime on research and would be greatfull for an early response.
Jeremy Winer Sydney.