Articles
REVIEW ON K.U.LEUVEN-I.W.O.N.L. RESEARCH ACCOMPLISHED ABOUT THE “DISINFESTATION OF GROWING SUBSTRATES”
Very recent doubts on possible methyl bromide (MB) involvement in stratospheric ozone depletion seem to call urgently for alternatives to MB. Recent meetings of the United Nations Environment Programme (UNEP) Methyl Bromide Technical Options Committee (MBTOC) report on the actual status of research in that respect and are still inviting for intensified research efforts.
It is however not obvious that one single molecule with comparative properties to MB will replace MB very soon, both on the level of efficiency and the level of short after-effects.
Other interesting soil fumigants such as methyl isothiocyanate (MIT) and its generators are since a long time under (re-)consideration.
The Laboratory of Phytopathology and Plant Protection K.U.Leuven studied for almost 25 years the behaviour of soil fumigants and focusses I.W.O.N.L. research programmes since 20 years on bromide residue reduction by improving the fumigation efficiency, as well as on alternative compounds and methods including different types of mulching such as improved plastic films and polymer sprays.
Furthermore, as growing techniques switched to substrate and nutrient solution methods, physical disinfestation means such as microwave irradiation and the use of ultrasonics, ozone treatment or heating were tested for the respective growing media.
Microwaves were also studied for small scale soil disinfestation.
Apart from the currently used chemical compounds (MB, MIT and 1,3-dichloropropene or DCP), azides and cyanamides were (re-)considered for certain soil disinfestating purposes.
A lot of research was performed on enhanced dissipation of fumigant residues in view of avoidance of uptake by plants or of phytotoxicity.
The use of more gastight plastic films and lower dosage in MB soil fumigation meet the actual demand for lower MB emission in view of reduction of the presumed stratospheric ozone depletion risk.