Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01C—PLANTING; SOWING; FERTILISING
  • A01C1/00—Apparatus, or methods of use thereof, for testing or treating seed, roots, or the like, prior to sowing or planting

Definitions

• the present invention relates to a method for the treatment of plant material for purposes of the eradication therefrom, or at least a reduction in the degree of incidence therein, of damaging or potentially damaging disease.
• growers are therefore faced with the problem of effectively isolating infected growing areas from previously "clean” or uninfected areas - a difficult problem indeed.
• growers are also faced with the problem of locating "clean" growing areas, whereby to satisfy the demand for their crop.
• Investigations have shown that, with certain types of plant fungal diseases, a growing area once tainted will remain unusable for a substantial period of time (perhaps several growing seasons or mere) by reason of what may be termed a residual effect of the infection. This residual infection in turn increases the likelihood of subsequent infection in surrounding areas - by reason of water action etc. (as stated earlier).
• the "scab” has been found in practice to be especially suited for "carrying", so to speak, a number of associated and more serious plant diseases, such as for example various forms of destructive blights, so-called mop-top virus, pink rot, and the dreaded Irish blight.
• the disease known as "powdery scab" is further more significant by reason of its capability of being trans ported, as by wind, water etc., from an infected growing area to a previously untainted area, thereby spreading the disease.
• a residual effect such that a previously infected area will remain tainted for a substantial period of time.
• the disease if allowed to go unchecked will result in effectively continuous infection in an ever-increasing area and on an ever-increasing scale. The consequences of this will be disastrous to the grower, not to mention the retailer and/or the consumer.
• Another method tried employs a dipping process, with seed potatoes (for example) being dipped in a chemical bath, involving chemicals considered destructive to the relevant disease micro-organisms.
• Such a dipping procedure has also been found to be unsatisfactory in that generally speaking the chemicals employed were found not to have penetrated sufficiently far into the potatoes being treated to destroy the disease-causing micro-organisms, this despite the fact that diseases such as, for example, "powdery scab", manifest themselves primarily if not solely in the outermost surface layers of a potato.
• the invention seeks to provide a method of treatment which will allow for planting even in previously contaminated ground without risking later contamination of the crop with the disease.
• the present invention seeks to provide, therefore, a method for the treatment of plant material which is responsible for both an immediate (or short-term) and a long term result.
• the present invention relates to a method for the treatment of plant material which will result in a reduction in the incidence of disease, and preferably total eradication of that disease, from a first generation plant, at the same time making such a first generation plant suitable for purposes of breeding or prop agating subsequent generations of at least equivalently disease-free plant material.
• the present invention furthermore seeks to provide a method for the production of a substantially disease-free variety of plant material, exhibiting a resistance (of sorts) to plant disease, thereby allowing for the planting thereof even in previous "tainted” or infected growing areas.
• the method in accordance with the present invention will provide propagating material suitable not only for use in "clean” growing areas, but also in previously tainted areas, thereby allowing such tainted areas to be restored to growing condition or utility.
• a method for the treatment cf plant seed material said method involving the subjection of the plant seed material to elevated or reduced temperatures, at a pressure other than atmospheric.
• the method in accordance with the present invention involves the subjection of seed material to a temperature in the vicinity of 50°C and a pressure of the order of 200 lbs. per square inch, for a period of approximately 5 minutes.
• the parameters involved in the method in accordance with the present invention will be varied to suit specific requirements, as for example variations in the size of the articles being treated, variations in the level of infection in the articles being treated etc.
• the temperature of treatment, pressure of treatment and treatment time may be varied to suit such specific requirements. It should, be noted, however, that tests have shown that treatment for any substantial period of time at temperatures above 55oC is responsible for too great a loss of plant life - the seeds will be effectively killed.
• a further variation of the method in accordance with the present invention again involves the subjection of seed material to elevated temperatures (less than 55oC) for a specified period, but this time at varying pressure levels.
• seed material could just be subjected to a temperature of, say, 50°C for a certain period at a pressure of, for instance, 200 pounds per square inch, the pressure then reduced to, say, 150 pounds per s ⁇ uare inch for a further period, and then returned to the original 200 pounds per square inch for an additional period.
• Treatment such as this has been found to fracture, rather than rupture, the spore balls without any catastrophic damage to plant cells, thereby increasing the degree of penetration of any treating chemicals and hence increasing the susceptibility to chemical attack.
• the method in accordance with the invention involves the treating of tainted or infected seed material with appropriate chemicals at elevated temperatures and perhaps varying pressures.
• a hot, pressurized chemical dipping process has been found to result in an increase in the degree of suffusion of the disease-destructive treating chemicals into the material being treated. Indeed it is suspected that such a procedure will result in "daughter” tubers or the like from treated seed material themselves including therein chemical material of a level sufficient to prevent infecting micro-organisms remaining in previously infected soil from attacking such "daughter” tubers or the like. In other words such so-called "daughter” tubers will exhibit a degree of resistance to the infection. Such a situation will allow for the replanting of previously infected frowing areas with substantially untainted plant material without risking subsequent infection of future generations of the growing crop by micro-organisms residual in the soil.
• chemicals considered suitable for the afore-mentioned hot-pressurized dipping process include mercury, formalin, a mixture of mercury and formalin, alcohol, hypo-sodium hypo-chloride, Ridomil, Difolatan, Benlate, Dithane H45, Pine Oil, Triuzin, BU-FOS, CaptanA, Diclone, Rovral, carbolic acid and/or hydrochloric acid.
• such chemicals are rather expensive, hence the preferred method involving the subjection of plant material to elevated temperatures at elevated or reduced pressures in the absence of any additional chemical material.
• An apparatus for carrying out the method in accordance with the invention may include a pressure vessel having means associated therewith for raising or reducing the temperature and/or pressure existing in the vessel to suit particular requirements. Such variation in internal temperature and pressure of the vessel may be achieved in any known manner. The actual size of the pressure vessel itself will of course be dependent on projected demand. Such an apparatus will also include means allowing for the introduction of treating chemicals thereinto.
• “Powdery scab” in particular, has been found to be susceptible to elevated temperatures.
• the vessel itself may be immersed - wholly or partially - in a suitable fluid, such as for example water, which may then be heated by any known means.
• a suitable fluid such as for example water
• means may also be included for regular stirring of the chemicals whereby to ensure uniformity of the treatment.

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• Life Sciences & Earth Sciences (AREA)
• Soil Sciences (AREA)
• Environmental Sciences (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Pretreatment Of Seeds And Plants (AREA)

Applications Claiming Priority (2)

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• 1981
  • 1981-10-09 EP EP19810902738 patent/EP0062048A4/fr not_active Withdrawn
  • 1981-10-09 WO PCT/AU1981/000144 patent/WO1982001297A1/fr not_active Application Discontinuation

Patent Citations (3)

Non-Patent Citations (1)

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