BACKGROUND OF THE INVENTION Bacopa monnieri L (Syn : Herpestis monnieri L., HB & K), Brahmi has been used for many years as a potent nerve tonic in the traditional Indian system of medicine (Chopra et al, 1956,111 : Glossary of Indian Medicinal Plants, Council of Scientific and Industrial Research, New Delhi, page 32). Various extracts of this perennial creeping plant have been used to enhance memory retention and to treat epilepsy and insomnia (Pandey et al 1967, Bhav Prakasah Nighantu, page 461).

The activity associated with memory retention has been localised to the saponin- containing fraction of this plant (Chatterjee et al., 1963, Indian Journal of Chemistry 1: 212; Singh et al., 1988, Playtother. Res. 2: 70). The active saponin constituents have been designated bacopasaponins A, B, C and D (Chatterjee et al., 1965, Indian J Chemistry 3: 24; Chatterjee et al., 1963, Indian J. Chemistry 1: 212; Basu et al., 1967, Indian J.

Chemistry 5: 84; Rastogi et al., 1994, Phytochemistry 36: 133-137; Garai et al., 1996, Phytochemistry 42: 815-820 ; Garai et al., 1996, Phytochemist7y 43: 447-449). On acid hydrolysis, these constituents yield a mixture of aglycones, bacogenin A1 (Kulshreshtha et al., 1973, Phytochemistry 12: 887; Kawai et al., 1973, Acta Cryst 829: 2947), bacogenin A2 (Kulshreshtha et al., 1974, Phytochemist7y 12: 1205), bacogenin A3 (Chandel et al., 1997, PIZytochemistry 16: 141) and bacogenin A4 (Kulshreshtha et al., 1973, Phytochemistry 12: 2074).

In work leading up to the present invention, it was unexpectedly discovered that one or more saponins, particularly bacopasaponins including their analogues and derivatives enhance the production of nitric oxide in plant cells and tissues. Nitric oxide has been shown to inhibit ethylene formation, which plays an important role in virtually

every phase of plant development including seed germination, fruit ripening, leaf and flower senescence, and abscission. It is well know that endogenous ethylene is often deleterious to plant produce. In particular, increased ethylene production due to trauma caused by mechanical wounding of fruits and vegetables, and the cutting of flowers greatly diminishes their post harvest quality and storage life. Endogenous ethylene production is also associated with acceleration of loss of green colour and/or the development of yellowing. It can also result in the increase of microbial growth, induction of physiological disorders and/or the development of undesirable flavours and textures. It may also cause the promotion of leaf petal damage in the case of flowers. Accordingly, reduction of endogenous ethylene concentrations by increasing nitric oxide concentrations in plant cells and tissues has been found to decrease or delay senescence and maturation of plants and plant parts.

It has also been suggested that nitric oxide is a significant component of the General Adaptation Syndrome (GAS) response to environmental stress (Leshem et al, 1996, Biol. Plant. 38: 1-18) and has been shown to increase accumulation of phytoalexins, which have been correlated with resistance in many plant-pathogen interactions (Smith, 1996, New Phytol. 132: 1-45). Increased nitric oxide levels has also been shown to increase the biosynthesis of pathogenesis-related proteins which are associated with increased resistance to invading pathogens (Durner et al, 1998, Proc. Natl. Acad. Sci. USA 95: 10328-10333) and have also been shown to inhibit the production of cyclic GMP which plays a central role in various facets of plant growth including resistance to environmental stress, bacterial and fungal infection and seed growth (Caro et al, 1998, Physiol. Plant. 104: 357-364; Delledonne et al, 1998, Nature 394: 585-588; Durner et al, 1998, Supra ; Pfeiffer et al, 1994, Phytochemistry 36: 259-262).

Having regard to the various beneficial effects produced either directly or indirectly by nitric oxide, the present discovery of enhancing the level of nitric oxide through use of the aforesaid saponin-related compounds has been reduced to practice in novel compositions and methods for treating plants and plant parts, for enhancing plant growth and crop yield, for increasing resistance to plant diseases and for generally increasing the well being of a plant.

SUMMARY OF THE INVENTION Accordingly, in one aspect of the present invention, there is provided a method for regulating the growth of a plant, said method comprising applying to said plant a growth regulating effective amount of a compound selected from a dammarane-type triterpenoid saponin or derivative or agronomically acceptable salt thereof or combinations of these.

The dammarane-type triterpenoid saponin is suitably a pseudojujubogenin glycoside. In a preferred embodiment, the dammarane-type triterpenoid saponin is a compound represented by a general formula selected from the group of consisting of :

wherein: Ri and R3 are individually and independently selected from H or any other cation, preferably a metallic cation, more preferably an alkaline metallic cation (such as K+, Na+ and the like) or alkaline earth metallic cation (such as Mg2+, Ca2+ and the like), lower alkyl including linear and branched alkyl (such as methyl, ethyl, propyl, isopropyl, isobutyl, isopentyl and the like), lower alkene including linear or branched alkenes (such as vinyl, propenyl, isopropenyl, n-butenyl, isobutenyl, isopentenyl, allyl and the like), lower alkanoyl (such as acetyl, propionyl and butyryl), benzyl, a carbohydrate moiety comprising

at least one carbohydrate monomer, modified or unmodified, branched or unbranched, the carbohydrate moiety preferably comprising five membered ring structures, six membered ring structures or both, the carbohydrate monomer preferably selected from ß-D- glucopyranosyl, ß-L-glucopyranosyl, a-L-arabinopyranosyl, and oe-L-arabinofuranosyl, and R2 is H or any other cation, preferably a metallic cation, more preferably an alkaline metallic cation (such as K+, Na+ and the like) or alkaline earth metallic cation (such as Mg2+, Ca2+ and the like), lower alkyl including linear and branched alkyl (such as methyl, ethyl, propyl, isopropyl, isobutyl, isopentyl and the like), lower alkene including linear or branched alkenes (such as vinyl, propenyl, isopropenyl, n-butenyl, isobutenyl, isopentenyl, allyl and the like), lower alkanoyl (such as acetyl, propionyl and butyryl), benzyl, a carbohydrate moiety comprising at least one carbohydrate monomer, modified or unmodified, branched or unbranched, the carbohydrate moiety preferably comprising five membered ring structures, six membered ring structures or both, the carbohydrate monomer preferably comprising a-L-arabinopyranosyl.

The compound is preferably in the form of a composition comprising an agronomically acceptable carrier or diluent.

Suitably, the compound is derived from a plant of the genus Bacopa. Preferably, said plant is Bacopa monnieri (Brahmi).

Accordingly, in another aspect, the invention provides a method for regulating the growth of a plant, said method comprising applying to said plant a growth regulating effective amount of a saponin-containing extract or fraction of Bacopa monnieri (Brahmi) optionally together with an agronomically acceptable carrier or diluent.

Preferably, the saponin-containing extract or fraction is in the form of a composition comprising an agronomically acceptable carrier or diluent.

Preferably, the saponin-containing extract or fraction comprises at least one bacopasaponin selected from the group consisting of bacopasaponin A, bacopasaponin B, bacopasaponin C and bacopasaponin D or analogue or derivative thereof.

In another aspect, the present invention provides a method for reducing the deterioration of horticultural produce, said method comprising applying to said produce a

senescence regulating effective amount of the compound as broadly described above optionally together with an agronomically acceptable carrier or diluent In yet another aspect, the invention features a method of improving the health of a plant or plant part, said method comprising applying to said plant or plant part a health- improving effective amount of the compound as broadly described above optionally together with an agronomically acceptable carrier or diluent.

According to another aspect, the invention resides in a method for treating or preventing a condition associated with reduced nitric oxide levels in a plant or plant part, said method comprising applying to said plant or plant part an effective amount of the compound as broadly described above, optionally together with an agronomically acceptable carrier or diluent, sufficient to inhibit or ameliorate said condition.

In a preferred embodiment, the condition is associated with environmental stress.

In another embodiment, the condition is associated with a pathogenic organism.

In yet another aspect, the invention encompasses a method for the treatment or prophylaxis of a condition associated with increased ethylene levels in a plant or plant part, said method comprising applying to said plant or plant part an effective amount of the compound as broadly described optionally together with an agronomically acceptable carrier or diluent sufficient to inhibit or ameliorate said condition.

In a further aspect, the invention provides a method for enhancing the nutritional content of a plant or plant part, said method comprising applying to said plant or plant part a nutritionally enhancing effective amount of a compound as broadly described above optionally together with an agronomically acceptable carrier or diluent.

In a preferred embodiment, the nutritional content relates to the Vitamin C content of the plant or plant part.

According to yet another aspect, the invention contemplates use of the compound as broadly described above in the preparation of a composition for treating plants, plant parts or horticultural produce.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a photographic representation showing increased rate of growth in tomato plants treated with a composition comprising a saponin-containing extract of Bacopa monnieri (Brahmi) as compared to control plants.

Figure 2 is a photographic representation showing increased rate of growth in corn plants treated with a composition comprising a saponin-containing extract of Bacopa monnieri (Brahmi) as compared to control plants.

Figure 3 is a graphical representation showing increased tiller numbers in rice plants treated with a composition comprising a saponin-containing extract of Bacopa mofznieri (Brahmi) as compared to control plants.

Figure 4 is a photographic representation showing significantly reduced pest infection of rice plants treated with a composition comprising a saponin-containing extract of Bacopa monnieri (Brahmi) as compared to control plants.

Figure 5 is a graphical representation showing increased shoot, root biomass and yield in groundnut treated with a composition comprising a saponin-containing extract of Bacopa monnieri (Brahmi) as compared to control plants.

Figure 6 is a graphical representation showing increased yield in groundnut treated with a composition comprising a saponin-containing extract of Bacopa monnieri (Brahmi) as compared to control plants.

Figure 7 is a graphical representation showing increased yield of tomato from plants treated with a composition comprising a saponin-containing extract of Bacopa monnie7i (Brahmi) as compared to control plants.

Figure 8 is a graphical representation showing increased yield of eggplant from plants treated with a composition comprising a saponin-containing extract of Bacopa monnieri (Brahmi) as compared to control plants.

Figures 9A and 9B are photographic representations showing increased growth of Crosandras treated with a composition comprising a saponin-containing extract of Bacopa monnieri (Brahmi) as compared to control plants.

Figures 10A and 10B are photographic representations showing increased growth of Hibiscus treated with a composition comprising a saponin-containing extract of Bacopa moniiieri (Brahmi) as compared to control plants.

Figure 11 is a photographic representation showing increased rate of flowering in corn plants treated with a composition comprising a saponin-containing extract of Bacopa monnieri (Brahmi) as compared to control plants.

Figure 12 is a photographic representation showing increased numbers of fruit in tomato plants treated with a composition comprising a saponin-containing extract of Bacopa monnieri (Brahmi) as compared to control plants.

Figure 13 is a photographic representation showing increased resistance to whiting disease in sugarcane plants treated with a composition comprising a saponin- containing extract of Bacopa monnieri (Brahmi) as compared to control plants.

Figure 14 is a photographic representation showing markedly reduced rate of deterioration in various fruits and vegetables treated with a composition comprising a saponin-containing extract of Bacopa mon7lieri (Brahmi) as compared to control plants.

DETAILED DESCRIPTION OF THE INVENTION 1. Definitions Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, preferred methods and materials are described. For the purposes of the present invention, the following terms are defined below.

The articles"a"and"an"are used herein to refer to one or to more than one (i. e. to at least one) of the grammatical object of the article. By way of example,"an element" means one element or more than one element.

The term"about"is used herein to refer to values or amounts that vary by as much as 30%, preferably by as much as 20%, and more preferably by as much as 10% to a reference value or amount.

By"agronomically acceptable carrier"is meant any substance or mixture of substances which can be utilised to dissolve, disperse or diffuse the compound incorporated therein without impairing the effectiveness of the compound and which does not create permanent damage to soil, equipment, and agronomic crops when utilised according to recommendations.

Throughout this specification, unless the context requires otherwise, the words "comprise","comprises"and"comprising"will be understood to imply the inclusion of a stated step or element or group of steps or elements but not the exclusion of any other step or element or group of steps or elements.

As used herein,"plant"and"diJ% erentiated plant"refer to a whole plant or plant part containing differentiated plant cell types, tissues and/or organ systems. Plantlets and seeds are also included within the meaning of the foregoing terms. Plants included in the invention include angiosperms, gymnosperms, monocotyledons and dicotyledons.

By"lant tissue"is meant differentiated and undifferentiated tissue derived from roots, shoots, pollen, seeds, tumour tissue, such as crown galls, and various forms of aggregations of plant cells in culture, such as embryos and calluses.

2. Coiiipositions and enethods of the invention The compositions and methods of the present invention may be applied to virtually any variety of plants. In particular, the compositions and methods of the present invention may be advantageously applied to higher plants including, but not restricted to, all species having true stems, roots and leaves, thus excluding"lower plants"such as bacteria, yeasts and moulds. Plants which may benefit according to the present invention include, but are not limited to, all crop plants, such as alfalfa, anise, asparagus, bach ciao, barley, basil, blueberry, breadfruit, broccoli, brussels sprouts, cabbage, cassava, cauliflower, celery, cilantro, coffee, coltsfoot, corn, cotton, cranberry, cucumber, dill, eggplant, fennel, grape, garlic, kale, leek, legume, lettuce, mint, mustard, melon, millet, oat, onion, parsley, parsnip, peanut, pepper, peppermint, potato, pumpkin, radish, rice, saffron, squash, sesame, sorghum, soy, spinach, squash, stevia, strawberry, sunflower, sweet potato, sugar beet, sugar cane, tea, tobacco, tomato, turnip, wheat, yam, zucchini and the like; pomes and other fruit-bearing plants, such as apple, avocado, banana, breadfruit, cherry, citrus, cocoa, fig, grape, guava, macadamia, mango, mangosteen, nut, olive, papaya, passionfruit, pear, pepper, persimmon, plum, peach, strawberry and the like; floral plants such as achillea, ageratum, alyssum, anemone, aquilegia, aster, azalea, begonia, bird-of-paradise, bleeding heart, borage, bromeliad, bougainvillea, buddleia, cactus, calendula, camellia, campanula, carex, carnation, celosia, chrysanthemum, clematis, cleome, coleus, cosmos, crocus, croton, cyclamen, dahlia, daffodil, daisy, day lily, delphinium, dianthus, digitalis, dusty miller, euonymus, forget-me-not, fremontia, fuchsia, gardenia, gazania, geranium, gerbera, gesneriad, ginkgo, gladiolus, hibiscus, hydrangea, impatiens, jasmine, lily, lilac, lisianthus, lobelia, marigold, mesembryanthemum, mimulus, myosotis, New Guinea Impatiens, nymphaea, oenothera, oleander, orchid, oxalis, pansy, pentstemon, peony, petunia, poinsettia, polemonium, polygonum, poppy, portulaca, primula, ranunculus, rhododendron, rose, salvia, senecio, shooting star, snapdragon, solanum, solidago, stock, Ti, torenia, tulip, verbena, vinca, viola, violet, zinnia and the like; leafy plants such as ficus, fern, hosta, philodendron and the like; trees such as Abies, birch, cedar, Cornus, cypress, elm, eucalyptus, ficus, fir, juniper, magnolia, mahogany,

maple, oak, palm, Picea, Pinus, Pittosporum, Plantago, poplar, redwood, Salix, sycamore, Taxus, teak, willow, yew and the like; grasses such as bent grass, calamogrostis, carex, elymus, festuca, helictotrichon, imperata, miscanthus, molina, pennisetum, phalaris, panicum, turf, and the like and thalloid plants such as algae and seaweeds such as kelp, Eucheuma, laver, nori, kombu and wakame. Other plants that may benefit by application of the compositions and methods of the present invention will be readily apparent to those of skill in the art.

The methods of the present invention, for the treatment of plants and plant parts and for the enhancement of growth in plants, are carried out by applying to the plant or plant part a compound selected from a dammarane-type triterpenoid saponin or derivative or agronomically acceptable salt thereof or combinations of these.

The triterpenoid saponin is preferably a pseudojujubogenin glycoside. Ill a preferred embodiment, the dammarane-type triterpenoid saponin is a compound represented by a general formula selected from the group of consisting of :

wherein: R1 and R3 are individually and independently selected from H or any other cation, preferably a metallic cation, more preferably an alkaline metallic cation (such as K+, Na+ and the like) or alkaline earth metallic cation (such as Mg2+, Ca2+ and the like), lower alkyl including linear and branched alkyl (such as methyl, ethyl, propyl, isopropyl, isobutyl, isopentyl and the like), lower alkene including linear or branched alkenes (such as vinyl, propenyl, isopropenyl, n-butenyl, isobutenyl, isopentenyl, allyl and the like), lower alkanoyl (such as acetyl, propionyl and butyryl), benzyl, a carbohydrate moiety comprising

at least one carbohydrate monomer, modified or unmodified, branched or unbranched, the carbohydrate moiety preferably comprising five membered ring structures, six membered ring structures or both, the carbohydrate monomer preferably selected from ß-D- glucopyranosyl, ß-L-glucopyranosyl, a-L-arabinopyranosyl, and a-L-arabinofuranosyl ; and R2 is H or any other cation, preferably a metallic cation, more preferably an alkaline metallic cation (such as K+, Na+ and the like) or alkaline earth metallic cation (such as Mg2+, Ca2+ and the like), lower alkyl including linear and branched alkyl (such as methyl, ethyl, propyl, isopropyl, isobutyl, isopentyl and the like), lower alkene including linear or branched alkenes (such as vinyl, propenyl, isopropenyl, n-butenyl, isobutenyl, isopentenyl, allyl and the like), lower alkanoyl (such as acetyl, propionyl and butyryl), benzyl, a carbohydrate moiety comprising at least one carbohydrate monomer, modified or unmodified, branched or unbranched, the carbohydrate moiety preferably comprising five membered ring structures, six membered ring structures or both, the carbohydrate monomer preferably comprising a-L-arabinopyranosyl.

Agronomically acceptable salts include, for example, metal salts such as sodium, potassium, calcium and magnesium salts, ammonium salts such as isopropyl ammonium salts and trialkylsulfonium salts such as trietliylsulfonium salts.

In a preferred embodiment of compound (I) including derivatives thereof, Rl is 3- O-a L-arabinopyranosyl and R2 is 20-O-a-L-arabinopyranosyl.

In a preferred embodiment of compound (II) including derivatives thereof, Rl is selected from the group consisting of 3-0- [o ;-L-arabinopyranosyl (1-2) a- arabinopyranosyl], 3-O- [ (3-D-glucopyranosyl (1-3) {oe-L-arabinófuranosyl (1-2)} ot-L- arabinopyranosyl] and 3-O- [a-L-arabinofuranosyl (1-2) ß-D-glucopyranosyl] pseudojujubogenin and R2 is H.

In a preferred embodiment of compounds (III), (IV) and (V) including derivatives respectively thereof, Rl is H and R3 is H.

Derivatives of the above compounds include, but not restricted to, ethoxylate derivatives, propoxylate derivatives, hydrates, aldehyde derivatives, ester derivatives, ether derivatives, alcohol derivatives, phenol derivatives, amine derivatives, other biologically or

chemically equivalent substances, and any combination of two or more of the foregoing.

In another embodiment, one or more compounds as broadly described above are derived from a plant of the genus Bacopa and preferably from Bacopa monnieri (Brahmi) or a botanical or horticultural relative thereof. Thus, for the practice of the present invention, the invention contemplates the use of a chemical fraction comprising at least one dammarane-type triterpenoid saponin from a plant of the genus Bacopa or a derivative or analogue of said triterpenoid saponin having a structure as defined above wherein said triterpenoid saponin or its derivative or chemical analogue modulates nitric oxide production in a plant. Reference herein to a plant of the genus Bacopa includes reference to Bacopa caroliniana, Bacopa egensis, Bacopa eisenii, Bacopa innominata, Baeopa monnieri, Bacopa procumbens, Bacopa repens, Bacopa rotundifolia and Bacopa stricta.

Preferably, the chemical fraction is obtained from Bacopa iiionnieri.

In another embodiment, one or more of the aforementioned compounds may be purified from a plant of the genus Bacopa by any suitable method including the methods described for example by Chatterjee et al. (1963, Indian Journal of Chemistry 1: 212), Singh et al. (1988, Phytother. Res. 2: 70), Rastogi et al. (1994, Phytochemistry 36: 133- 137) Garai et al. (1996, Phytochemistry 42: 815-820), Garai et al. (1996, Phytochemistry 43: 447-449), Kulshreshtha et al. (1973, Phytochemistry 12: 887), Kawai et al. (1973, Acta Cryst 829: 2947), Kulshreshtha et al. (1974, Phytochemistry 12: 1205), Chandel et al.

(1997, Phytochemistry 16: 141) and Kulshreshtha et al. (1973, Phytochemistry 12: 2074).

An especially preferred chemical fraction of Bacopa monnieri (Brahmi) is described in Example 1.

The compounds of the present invention are preferably in the form of a composition comprising an agronomically acceptable carrier or diluent. Thus, the compounds of the present invention may be applied in solid form. Typically, one or more compounds according to the invention are formulated in a conventional solid or liquid preparation form (e. g. powders, granules, solutions, suspensions and emulsions) together with any carrier or diluent with or without a surfactant. Examples of the solid carrier or diluent are botanical materials (e. g. flour, tobacco stalk powder, soybean powder, walnut shell powder, wooden powder, saw dust, bran, bark powder, cellulose powder, vegetable extract residue), fibrous materials (e. g. paper, corrugated cardboard, old rags), synthesised

plastic powders, clays (e. g. kaolin, bentonite, fuller's earth), talcs, other inorganic materials (e. g. pyrophyllite, sericite, pumice, sulfur powder, active carbon) and chemical fertilisers (e. g. ammonium sulfate, ammonium phosphate, ammonium nitrate, urea, ammonium chloride). Examples of the liquid carrier or diluent are water, alcohols (e. g. methanol, ethanol), ketones (e. g. acetone, methyl ethyl ketone), others (e. g. diethyl ether, dioxane, cellosolve, tetrahydrofuran), aromatic hydrocarbons (e. g. benzene, toluene, xylene, methyl naphthalene), aliphatic hydrocarbons (e. g. gasoline, kerosene, lamp oil), esters, nitriles, acid amides (e. g. dimethylformamide, dimethylacetamide), halogenated hydrocarbons (e. g. dichloroethane, carbon tetrachloride), etc. Suitable surfactants include anionic, cationic, nonionic, and zwitterionic detergents, amine ethoxylates, alkyl phenol ethoxylates, phosphate esters, PEG, polymerics, polyoxyethylene fatty acid esters, polyoxyethylene fatty diglycerides, sorbitan fatty acid esters, alcohol ethoxylates, sorbitan fatty acid ester ethoxylates, ethoxylated alkylamines, quaternary amines, sorbitan ethoxylate esters, alkyl polysaccharides, block copolymers, random copolymers, trisiloxanes, CHELACTANTSTM and blends. Surfactant preference is for polyalkylene oxides, polyalkylene glycols, and alkoxylate-fatty acids. Blends are highly effective such as our organosiloxane/nonionic surfactant SILLET@ Y14242 (Y14242) blend which use is demonstrated in our examples.

Preferred commercial aqueous surfactants include Hampshire LED3A; HAMPOSYL ; TEEPOLO ; TWEENS ; TRITONS ; LATRONTM ; PLURONIC (g) ; TETRONIC@ ; SURFONICO ; SYNPERONICO ; ADMOXV ; DAWN (D, and the like. Commercial emulsifiers for combination with organic solvent formulations include WITCANOLO, RHODASURF@, TERGITOL and TWEEN@. The compounds of the invention may also be formulated together with a spreader in an amount sufficient to promote even distribution and penetration of the active compounds of the invention. Spreaders are typically organic alkanes, alkenes or polydimethylsiloxanes that provide a sheeting action of the treatment across the phylloplane. Suitable spreaders include paraffin oils and polyalkyleneoxide polydimethylsiloxanes. Commercial spreaders include TEGOPRENS, AGRIMAX@, DOW CORNING 211, X-77@, SILWET@ and the like. Penetrants such as sodium dodecylsulphate, formamide and lower aliphatic alcohols, may be used.

Alkoxylation of an active component or otherwise chemically modifying the active components by incorporating a penetrant substance is useful because formulation without additional surfactant is achieved.

One or more active compounds of the invention are applied to a plant or plant part in an effective amount to achieve an intended purpose. The amount of said compound (s) applied to a plant or plant part should be sufficient to effect a beneficial response in the plant or plant part over time such as, for example, enhanced growth of the plant, or a reduction in the rate of senescence of a harvested plant or plant part. The amount of active compound (s) applied to the plant or plant part will depend upon the particular compound or compounds selected and the method of application. In any event, those of skill in the art may readily determine suitable amounts of the compounds of the invention, as well as the interval and number of applications, required to produce a beneficial effect as for example described herein.

The compound (s) may be solubilised in a carrier by adding the compound (s) to the carrier and allowing the compound (s) to dissolve. In some instances, the application of stirring, agitation, or even heat may facilitate the dissolution of the compound (s) in the carrier. Typically, the compound (s) of the invention is/are included in an aqueous or organic solution at a concentration of between about 0.05% by weight and about 25% by weight inclusive, preferably between about 0.1% and about 20% by weight. For example, the active compounds of the present invention are typically applied to roots or shoots or seeds as an aqueous solution at a concentration in the range from about 0.1% to 20%, preferably from about 0.1% to 3%. Typically, when using an extract of Bacopa monnieri (Brahmi), preferably prepared as described herein, the final dried extract is used at a concentration in the range of between about 0.001 g per litre and 50 g per litre, preferably between about 0.01 g per litre and about 5 g per litre, more preferably between about 0.02 g per litre and about 0.5 g per litre. When desired, the compounds of the invention may be provided in combination with any other active ingredient (s) such as other plant growth regulators (e. g. gibberellins), herbicides, insecticides and fertilisers. Generally, the compounds of the invention may be reapplied to the plant at about weekly or fortnightly intervals but such reapplication may be more frequent or less frequent depending on the plant and the intended purpose. Typically, concentrations in the range of about 0.1-20 g/L of a Bacopa monnieri extract prepared according to Example 1 have been found to be effective for seed and root treatment with application intervals for root treatment in the range of 2-30 days.

The compounds employed in the methods of the present invention may be applied to the plants or plant parts using conventional application techniques. Plants nearing or at maturity may be treated at any time before and during seed development. Fruit bearing plants may be treated before or after the onset of bud or fruit formation. Improved growth, increase in the rate and/or percentage of germination, acceleration of height and/or thickening of plants, acceleration of flowering, release from dormancy, increase tolerance to environmental stress, increased resistance to disease and reduced deterioration of perishable horticultural produce including harvested fruits, vegetables and flowers, occurs as a result of the exogenous application of one or more of the active compounds of the present invention.

The compounds of the invention may be applied to the plant at a location including leaves, shoots, root, seed, stem, flowers, and fruit. The compounds may be applied to the leaves, seed or stem by spraying the leaves with the solution containing the active compound (s). Preferably, the compound (s) are applied to the shoot or root by spraying the shoot or root, or dipping the shoot or root in a bath containing one or more of the active compounds of the invention (preferably in the form of a solution), or drenching the growing medium or soil in which the plant is being cultivated with the solution containing the said compound (s), or spray-drenching the leaves and stem of the plant such that the growing medium in which the plant is being cultivated becomes soaked or saturated with the solution containing the said compound (s).

The method of application preferably comprises root application of the active compound (s) of the invention. In this instance, the active compound (s) are typically applied to the roots of the plant using a spray although side dressing is also contemplated.

Foliar application (i. e., application to one or more leaves of the plant) may also be employed. Spray drenching is preferred in this respect. However, other means of foliar application such as dipping, brushing, wicking, misting, electrostatic dispersion and the like of liquids, foams, gels and other formulations may also be employed. Foliar sprays can be applied to the leaves of the plant using commercially available spray systems, such as those intended for the application of foliar fertilisers, pesticides, and the like, and available from commercial vendors such as FMC Corporation, John Deere, Valmont and Spraying Systems (TEEJET (D). If desired, oxidant and reductant compounds may be applied to plants in rapid sequence from separate nozzles in separate reservoirs.

Chemically compatible combined mixtures may be preferred for many applications to produce improved plant growth.

In a preferred embodiment, the active compound (s) of the invention are applied to seeds such as, for example, by adding the compound (s) to a medium in which the seeds are being cultivated, by spray drenching the seeds or by dipping the seeds in a bath containing the said compound (s). When using a dipping application, the dipping period may be from about 1 minute to 192 hours, generally from about 12 hours to 72 hours, typically from about 16 hours to 48 hours, more typically from about 6 hours to 24 hours. Those of skill in the art will appreciate that the optimal period of contacting the seeds with the compound (s) of the invention will vary depending upon the concentration of the compound (s) and the plant from which the seeds are derived. Typically, concentrations in the range of about 0. 1-20 g/L of a chemical fraction or extract of a Bacopa species (e. g., Bacopa monnieri) prepared according to the method of Example 1 have been found to be effective. For example, for effective treatment of thick-coated seeds such as palm seeds, these seeds are placed in contact with an aqueous solution of a Bacopa species (e. g., Bacopa monnieri) extact prepared according to Example 1 (5 g extract/L) for about 8 days. By contrast, for effective treatment of thin-coated seeds such as most vegetable seeds, these seeds are placed in contact with the same concentration of extract for between about 4 and 12 hours.

The active compound (s) of the present invention may also be applied to plant tissues, such as cell suspensions, callus tissue cultures, and micropropagation cultures.

Such plant tissues may be treated by adding the said compound (s) to the culture medium in which the plant tissues are being cultivated.

In the methods of the present invention, the active compound (s) is/are typically applied to the plant or plant part at a concentration ranging from about 0.05% by weight to about 25% by weight. Shoot applications will preferably be in the range from 0.3% to 3% by weight. Hydroponic applications will preferably be in the range of 0.3% to 1.2%, preferably by a pulsed exposure for up to an hour. Foliar applications of shoots by spray drenching will preferably be in the range of 0.1 to 25 kilograms per hectare. Root applications by side dressing into soil near the root zone will preferably be in the range of 0.1 to 10 kilograms per hectare. Ornamentals and other tender nursery plants meant for

indoor horticulture will frequently require lower concentrations and perhaps more frequent application than outdoor agricultural crops.

The active compound (s) of the present invention may also be applied to harvested fruits, vegetables and/or flowers. Ideally, such perishable horticultural produce should be treated with said compound (s) within a few hours after harvest before any undesirable postharvest changes have occurred. Suitably, the horticultural produce is treated with said compound (s) by dipping or spraying at a concentration ranging from about 0.05% by weight to about 25% by weight for each compound. Periods of 1-24 hours with compound concentrations of between about 0.3% to 3% by weight have been found to be effective.

The application of an extract of a Bacopa species (e. g., Bacopa !'en (Brahmi)) prepared for example as described herein at a rate of between about 0.01 g per litre and about 5 g per litre, more preferably between about 0.02 g per litre and about 0.5 g per litre for 2-6 hours is an effective treatment combination for many types of produce while for some produce a 12-24 hour exposure is acceptable. Optionally, the horticultural produce may be treated with chitosan or carboxyl methylcellulose every 24-36 hours post-harvest.

The concentration of active compound (s) and the time of exposure can be varied by raising the compound concentration and reducing the exposure times and vice versa.

It has also been found that horticultural produce including fruits and vegetables harvested from plants treated with the compound (s) of the present invention remain fresh for as much as 8-12 days without additional application of said compound (s) compared to fruits and vegetables harvested from untreated plants.

The active compounds of the present invention may be tailored for specific uses, including enhanced performance or tolerance under environmental stress (e. g. caused by increased salinity, by drought, by radiation, or by pesticides) and enhanced resistance to disease and to infection by pests; enhanced yield; enhanced nutritional content including Vitamin C content, optimising growing seasons; aftermarket caretaking; flower retention; fruit optimisation; and in all areas of agriculture in which optimal growth is beneficial.

The active compounds may also be used to reduce the rate of deterioration of horticultural produce and may be modified according to targeted natural products enhancement, activity enhancement of plant growth regulators and general yield enhancement of crops.

In order that the invention may be readily understood and put into practical effect, particular preferred embodiments will now be described by way of the following non- limiting examples.

EXAMPLES EXAMPLE 1 Preparation of bacosaponin extract from Bacopa monnieri (Brahmi) A sample of Bacopa monnieri (Brahmi) (l. Og) was macerated in 3 x 25-mL of dry acetone (dried over potassium carbonate). The macerate was filter/centrifuged each time and the residue was dried under vacuum. Ten milligrams of powdered extract was heated with 5 drops of orthophosphoric acid in a test tube (or until filter paper kept moist on the mouth of the test tube with aniline acetate turns pink).

Two hundred and fifty milligrams of powdered extract was hydrolysed by boiling with 4N; 50% (v/v) aqueous ethanolic sulphuric acid (5 mL). The ethanol was subsequently removed under vacuum. The aqueous suspension was extracted with two quantities, 5 mL each of freshly washed (phosgene free) chloroform. The combined chloroform layer was neutralised by washing with 0.1% (v/v) aqueous solution of ammonia, followed by 2 washes with water, followed by drying over anhydrous sodium sulphate and evaporating the solvent to dryness. The 0.001% (w/v) solution of the residue in methanol exhibited characteristic maxima at 269,278 and 289 nm.

EXAMPLE 2 Chromatographic fingelprint of bacosaponin extract Thin layer chromatography was carried out using silica gel G plates of 0.2-1nm thickness and a mixture of 8 parts of ethylacetate, 1 part methanol and 1 part water as the mobile phase. One mL of test solution containing the extract of Example 1 at about 1 Kg/mL is then added to 1 mL 4N aqueous sulphuric acid (A. R.). This mixture was refluxed on a water-bath for 4 hours, allowed to cool and diluted with 4 mL distilled water before the methanol was removed under vacuum. The aqueous solution was then extracted four times with chloroform (G. R., phosgene free) and the combined chloroform extract was washed with 0.1% solution of a base (e. g. ammonia), followed by twice with distilled water. The extract was dried over anhydrous sodium sulphate and the chloroform removed under vacuum. The residue was dissolved in methanol (A. R.) up to a final volume of 10

mL. The optical density (O. D.) of the solution was then determined at 278 nm against a blank. The content of bacopasaponin in the extract was calculated by running reference standard bacosaponins side by side, or by using the following linear regression curve formula : C=KXO. D. +B (where, C = concenkation of bacosaponin in, ug/mL : K= 50. 957 and B = 1. 2974 EXAMPLE 3 Promotion of growth An extract prepared according to Example 1 (which is also referred to in the Figures as Nambi or Nambi 2000) was mixed in water at room temperature to a final concentration of 5 g/L. The mixture was then heated at 90° C until the extract was dissolved. Seeds were placed in contact with this aqueous solution by dipping for about 12 to 48 hours. The treated seeds were then sowed in prepared soil and watered in the usual manner to promote growth of the plant. Additionally, 100 mL of the above solution was applied to roots of plants grown from the treated seeds at weekly intervals.

The growth of plants obtained from treated or control seeds was measured at developmental stages including the germination stage at the tip of the seeds and in subsequent growth stages of the plant. Stem thickness and height as well as leaf number and size were measured at 15-day intervals. The daytime temperature of the growth experiments ranged from about 25 to 30° C.

The data from experiments on tomato plants have revealed that the foregoing seed treatment enhances the rate of growth of the plant by about two-fold relative to control plants. The central stem diameter of treated tomato plants also increases at about twice the rate of control plants (i. e., the stem diameter of treated tomato plants at about 45 days post- sowing was about 1 cm whereas that of control plants was about 0.5 cm (see for example Figure 1).

The growth of corn plants from treated seeds was also markedly increased relative to control plants as for example shown in Figure 2.

Preliminary data obtained from experiments on banana plants has shown that when the central stem of a banana plant is cut and spray drenched with the above- mentioned solution, the treated stem grows about twice as fast as the control.

EXAMPLE 4 Release from dormancy andpromotion of germination Ten litres of solution prepared according to Example 3 was added to 20 kg of rice seeds and the seeds were allowed to germinate for about 24 to 36 hours, (typically about 36 to 48 hours for other plant seeds) in darkness. The germinated seeds were packed in a cloth bag for another 24 hrs. Ninety-five percent of the treated seeds germinated compared to only about 60 to 65% of the control seeds.

The treated germinated seeds (which have 2-mm longer germinated ends than the control) were sowed to already prepared land. Root growth in seedlings from treated germinated seeds was faster relative to control seedlings, which permits shortening the seedling period by about 25% to 30% for faster replanting. For example, the normal seedling period for rice seedlings is about 36 days, whereas a seedling period of about 26 to 30 days is possible using the above seed treatment.

EXAMPLE 5 Rice field tria A field trial was carried out on rice (Oryza sataiva) to assess the effect of the extract of Example 1 on yield parameters. Rice seeds of the variety Savitry were soaked in water containing 0.5 parts per thousand (ppt) of the extract for about 12 hours. Soaked seeds were sowed and the excess solution was drizzled on the top soil. After 120 days, the following parameters were recorded.

Total yield was 32 bags per acre. In general, the yield from this particular rice variety ranged from 20 to 23 bags per acre. Application of the extract increased the yield by 10 bags of rice per acre. The number of tillers bearing panicles ranged from 18 to 30, a 48% increase over untreated plants (Figure 3). An average of 101-105 filled grains and 18-

21 unfilled grains were obtained per panicle. The grain weight per panicle ranged from 101-105 with the average weight of 0.0228 g per grain of rice.

Another field trial was conducted on the rice variety ADT-43 to assess the effect of the above extract on yield parameters. Seeds of this variety were processed as described above with the exception that the extract was used at a concentration of 1000 ppt. General observation after 30 days were made to assess the seedling vigour parameter.

The seedlings treated with the extract appeared to be healthier than the control plants in terms of their leaf colour, shoot, root bio-mass and height. More strikingly, the extract-treated plots were completely devoid from pest infection whereas the control plots were infected with pests (see Figure 4). From this observation it was proposed that the extract of the invention would be useful for effecting disease resistance in plants.

EXAMPLE 6 Ground nut field trial #1 A field trial was carried out to assess the performance of the extract of Example 1 on yield parameters of the oil seed crop, groundnut (Arachis lzypogeae). Initially, a seed treatment method was employed by soaking the seeds in water containing 1000 ppt of extract. The seedlings were then sprayed 35 days after germination.

The results recorded after 65 days showed that shoot and biomass (dry wt) of treated plants increased by 42% and 50% respectively over control plants. The number of fully formed groundnuts in control plants ranged from 12 to 16 whilst in treated plants it ranged from 16 to 27. The overall increase in yield of treated plants was 33% over untreated plants (Figure 5).

Foliar application of extract on rice plants (approximately 21 cents.) at the stage of flowering was also performed. Ten days after application, it was observed that the number of grains in the treated plants was 120 to 130 whereas in control plants it was 70 to 75. Further a remarkable variation in the leaf colour (dark green in treated plants) was also observed related to control plants.

EXAMPLE 7 Ground nut field trial #2 Seeds of groundnut were also treated with the above extract at different concentration (500,100,1500,2000 and 5000 ppt) by soaking the seeds for about 30 minutes and drying the seeds in the absence of light before sowing. Half an acre of land was divided into six equally sized plots and the seeds treated with different concentration of extract were sowed along with control (untreated) seeds.

Initial observation revealed that the percentage of germination was 100% and the leaf colour was dark green (much healthier than that of control plants). Compared to untreated plants, an increase in yield of between 38 and 49% was observed in treated plants (Figure 6). Further, preliminary analysis of groundnut samples revealed that there were remarkable increases in weight and oil content in treated groundnut over control plants.

EXAMPLE 8 Tomato and eggplant field trials Two vegetable crops namely Tomato (Locopersicon esculentum Mill.) and Brinjal/Egg plant (Solanum melongena L.) were tested with the extract of Example 1. The objective of this trial was to evaluate the effect of the extract on final yield output. The seeds were treated with an aqueous solution containing extract at 1000 ppt and raised in the nursery and subsequently transferred to the field. The control and treated plants were planted in split plot method (randomised). The plants were given foliar spray with the above solution periodically (once a month). The final yields were recorded in terms of quantity (kilogram) from the control and treated plots. Significant increases in the yield were recorded (Figures 7 and 8) In general, diseases incidence was higher in the control plots whereas the treated plots were totally free from diseases, strongly indicating the potential antagonistic activities of the subject compounds against disease.

EXAMPLE 8 Effect on growth pe7 formance of certain flower varieties Crosandras is a flower species popularly known as Kanagambaram (in Tamil).

One week old seedlings derived through tissue culture were sprayed with an extract- containing solution prepared according to Example 7 and subsequently periodic foliar application of this solution was given once a month. A one hundred fold increase in growth of these plants was obtained two months post treatment. It was observed that the treated plants were much healthier in terms of their seedling vigour than that of control plants (see Figures 9A and 9B).

Similarly, another flower species, Hibiscus, popularly known as Semparuthy (Tamil), was also treated with the above extract-containing solution in similar manner.

Increased seedling vigour (leaf colour, plant growth and number of flowers) was also noticed in these treated plants over control plants (see Figures 10A and 10B).

EXAMPLE 9 Acceleration of Fowering Dry extract prepared in accordance with Example 1 or a solution prepared in accordance with Example 3 was used to treat the roots of flowering plants to accelerate the rate of flowering. Typically, the roots were treated 30 days before natural flowering occurred. An example of enhanced rate of flowering in treated corn plants is shown in Figure 11.

During flowering, the plants were sprayed with said solution at 15-day intervals.

For example, in trees that were already fruiting such as mango and guava trees, powdered extract was applied at a rate of between about 5 to 100 mg per tree or was dissolved in water and applied to the roots. A 5-g/L solution prepared according to the protocol in Example 3 was used to spray drench the flowers, which significantly increased the proportion of flowers converting to fruit.

For vegetable plants (e. g., tomatoes and chillies), grains (e. g., rice, wheat and corn), and tubers (e. g., carrot and beetroot), powdered extract produced according to

Example 1 was diluted in water at a rate of 5 g/L and used to spray drench the roots during the flowering stage and every 30 days thereafter. An example of enhanced fruit numbers in treated tomato plants is shown in Figure 12. <BR> <BR> <P>EXAMPLE 10<BR> Increasing resistance and treatment of whiting disease in sugarcane Ten mL of a 5-g/L solution prepared according to Example 3 was sprayed onto diseased areas of the plant as well as the root at 15-day intervals. Diseased areas were substantially ameliorated and chlorophyll was restored to the diseased tissue about 30 days after the initial treatment (Figure 13).

EXAMPLE 11 Reducing deterioration of horticultural produce The shelf-life or fruits, vegetables and ornamental flowers can be markedly increased by about 30 to 35% or more by treating the seeds of the plants from which fruits or vegetables were derived, and/or by further treatment of the plants during different stages of flowering and/or fruiting, according to protocols described for example in Examples 3 to 5.

Alternatively, a 5-g/L solution prepared according to Example 3 may be sprayed on the surfaces of cultivated fruits, vegetables and ornamental flowers. A selection of fruits and vegetables treated in this manner and exposed to the atmosphere containing airborne microbes including fungus increases their shelf life by more than 8 to 12 days when compared to untreated control fruits and vegetables (see Figure 14).

The disclosure of every publication cited herein is hereby incorporated herein by reference in its entirety.

The citation of any reference herein should not be construed as an admission that such reference is available as"Prior Art"to the instant application

Throughout the specification the aim has been to describe the preferred embodiments of the invention without limiting the invention to any one embodiment or specific collection of features. Those of skill in the art will therefore appreciate that, in light of the instant disclosure, various modifications and changes can be made in the particular embodiments exemplified without departing from the scope of the present invention. All such modifications and changes are intended to be included within the scope of the appended claims.