Aqueous formulations, incorporating a coating agent are frequently used to coat surfaces, especially growing surfaces such as turf, plant foliage and seeds, with a layer or coat of the coating agent. Examples include the application of pesticides, nutrients or biological inoculants to plant surfaces or seeds, the application of pigments or dyes to peat, bark chippings or turf, eg to form designs or markings on sports turf, such as a cricket, soccer or rugby pitches.

Such coating formulations often include a water soluble polymeric component, which is intended to enhance the adhesion of the coating agent to the surface to which it is applied. However, formulations containing a water soluble polymeric adhesion agent tend to suffer from the disadvantage that the coated surface remains tacky, and requires significant drying. Where the surface to be coated is a seed, this can lead to agglomeration of the seeds, which in turn can make them difficult to handle and sow.

In addition to the problem of tackiness, it is often difficult to remove final traces of water from the surface, which has to be removed by additional drying steps. Failure to remove non-bound water from coated seeds can result, for example, in premature germination, loss of viability, increased microflora contamination, loss of activity of the coating agent and agglomeration.

WO 03/020837 PCT/GB02/03969 Surprisingly, we have now found an aqueous coating formulation which overcomes, or at least substantially mitigates some or all of these disadvantages.

Thus, according to the invention we provide an aqueous coating formulation comprising a suspension of water insoluble polyvinylpyrrolidone (PVPP) -, an adhesion agent and a coating agent.

Water insoluble PVPP is a cross linked homopolymer of N-vinyl-2-pyrrolidone.

Typically PVPP is a free flowing white powder, preferably with a particle size range of 10 to 400 microns. Alternatively, PVPP with a particle size of 0.5 to 70 microns can be used. Such particle sizes are available commercially under the trade names AGRI, MERO AT and GRIMER. respectively.

PVPP is insoluble in both water and common solvents. In contrast, we prefer adhesion agents which are water soluble. A particularly preferred adhesion agent is polyvinylpyrrolidone (PVP), a polymer frequently used as a film forming agent, eg as a non-phytotoxic carrier, stabiliser and film former in seed coatings, is soluble in both water and many organic solvents. PVP, eg with an average molecular weight of from 5000 to 1.5 million daltons, for example with an average molecular weight of 8000, 57,500, 406,000 or 1,270, 000 daltons is commercially available and could be used as the water soluble adhesion agent of the invention.

Other adhesion agents that could be used include copolymers of PVP. Particular co- polymers that could be mentioned include vinylacetate/vinylpyrrolidone (PVP/VA) copolymers. Certain properties, eg viscosity, softening point, water solubility and

WO 03/020837 PCT/GB02/03969 Hydrophilic/lipophilic balance (HLB), of PVP/VA copolymers vary, inter alia, with the vinylpyrrolidone/vinyl acetate ratio. In general, the higher the proportion of vinyl acetate monomer, the more hydrophobic the copolymer becomes. For example, PVP/VA copolymers containing more than 60% by weight of vinyl pyrrolidone monomer are water soluble. In preparing formulations according to the invention, such copolymers may be added as a powder to the formulation mix, or as a solution, eg in water, or a lower alkanol, for example ethanol or isopropanol.

Further PVP copolymers that may be mentioned are copolymers of vinylpyrrolidone with styrene, and with dimethylaminoethyl methacrylate.

Additonal water soluble polymeric adhesion agents that may be mentioned alkylated vinylpyrrolidone copolymers and poly (methyl vinyl ether/maleic anhydride) copolymers.

In certain circumstances, the adhesion agent may also act as the coating agent, eg when the adhesion agent is a film forming agent, such as certain grades of alkylated vinylpyrrolidone copolymers. However, more generally, the adhesion agent and the coating agent will be separate. Typical coating agents include pesticides, nutrients, eg foliar feeds, dyes and/or pigments (when the formulation is intended for marking turf or playing surfaces).

A particular formulation that may be mentioned is an inoculant formulation, for coating seeds, with a microorganism having a beneficial effect on the seed, or the

WO 03/020837 PCT/GB02/03969 resulting plant. Inoculant formulations or compositions are well known and are described in, for example, EP-A-253 673.

Surprisingly, we'have found that seeds treated with inoculant formulations containing insoluble PVPP are easier to handle, less tacky and/or do not need to be subjected to additional drying steps compared to seeds treated with inoculant formulations described in EP-A-253 673.

Microorganisms that may be used in the inoculant formulation include but are not limited to bacteria of the genera Rhizobium, Bacillus, Azotobacter, Pseudomonas, Azospirillium and Cyanobacteria (blue green algae), as well as mycorrhizal fungae.

Thus according to a further aspect of the invention we provide an aqueous inoculant formulation which comprises at least one species of microorganism having a beneficial effect on a seed or a resulting plant, a suspension of a water insoluble polyvinylpolypyrrolidone and a water soluble polymeric adhesion agent.

The inoculant formulation may additionally include a carrier medium. The carrier medium is preferably peat, in particular irradiated sedge peat.

According to the invention, we further provide a seed having a coating comprising at least one species of microorganism having a beneficial effect on the seed or resulting plant, an insoluble PVPP and an adhesion agent.

WO 03/020837 PCT/GB02/03969 We prefer the adhesion agent to be water soluble. We especially prefer a water soluble, polymeric adhesion agent.

According to a further aspect of the invention we provide a method of sowing seeds, in which the seeds are sown together with an inoculant formulation as defined above.

The inoculant formulation may be applied either to the seeds at any time or to the soil at the time of sowing.

The inoculant formulations according to this invention may be used for the inoculation of dry seeds or they may be slurred with the water or water based carriers (e. g. pesticides and nutrients) when this type of inoculation is required.

The invention is illustrated by the following examples.

Example 1.

A 9.3 % suspension of the PVP/VA copolymer, product W735 (ISP) was prepared using cool clean dechlorinated water. 4.4 litres of this evenly mixed copolymer suspension were added to a premix tank. 2 x 1.6 kg units of a sterile peat based Rhizobium inoculant (HiCoat inoculant) containing greater than 4xlOe9 cfu/g of a selected strain of Bradyrlzizobitrn japonicum were added to the premix tank, along with 100 g of PVPP. Impellers and paddles in the premix tank ensured a smooth lump free preinoculant slurry preparation, and also prevent settling-out. The prepared slurry was metered onto the soybean seed at circa 385 ml/45. 45 kg soybean seed, in a seed treatment drum. Evenly coated/free flowing seeds were transferred to a 1 ton (US) mini-bulk bag and stored until planting.