formaldehyde - Sciencemadness Dot Org

320
FORMALDEHYDE
12-24 hours-. Some authorities recommend that the soil be dried thoroughly
before planting: others suggest that it merely be allowed to stand
uncovered for several days. Treating solutions containing 1 pint of formaldehyde
t-o 15 gallons of water are also commonly recommended. Damping-off
is caused by soil-borne fungi of which pythium debaryanum is the
most important member, Ogilvie and co-workers 1 " report that dampingoff
of peas. tomatoes, cucumbers, and sweet peas may be controlled successfully
by watering seed boxes with formaldehyde in dilutions of 1 to 200-600
after seeding.
Another procedure recommended for the control of damping-ofl involves
the use of formaldehyde dust produced by wetting a carrier substance,
such as infusorial earth or ground charcoal, with formaldehyde solution
and then drying 1 - K15 . Anderson 1 states that pythium debaryanum may be
controlled in tobacco seed beds by mixing each square foot of top soil with
1.5 ounces of a dust preparation made from lo parts formaldehyde (37
pei' cent,; and IS parts ground charcoal just before planting.
Fig- 20- Prevention of damping-oft of seedlings by formaldehyde treatment of soil.
Boxes were seeded siiuultaneousjy. Cards mark time of soil treatment.
Check was imtreated.
Numerous plant diseases hi addition to those already mentioned have
also been reported to respond favorably to methods of control involving
the use of formaldehyde, Reyneke 13 reports that formaldehyde vapor or
aqueous solution prevents botrytis rot but does not control dry stalk rot
in grapes. Other reported applications include the use of formaldehyde
disinfection for preventing onion smut, mushroom diseases 10 , and rust
infection in olives 17 . Also of importance to. agriculturists is the use of
formaldehyde in bee culture for disinfecting equipment polluted with
. American ioul-brood r -
Formaldehyde is sometimes employed in conjunction with other agents
which are stated to increase or modify its action as a seed or soil disinfectant,
Braun- recommends a 1:320 formaldehyde solution containing copper
sulfate in 1:80 dilution for treating wheat, barley, oats, and corn. Patented
disinfectant compositions in which formaldehyde or its polymers are
blended with other disinfectants such as phenol and mercuric chloride are
also described 8 - 4 ' 5 . One seed-disinfecting compound contains acidic, hygro-