Tray masks

Abstract

The present application relates to methodology and composition for growing and producing biological material, such as plants, in hydrogel substrate. The present inventors developed methodology and compositions for pouring liquid hydrogel directly into a horticulture plug tray, wherein the drainage holes are temporarily blocked or masked, thereby permitting the liquid hydrogel to set into a gel without leakage. Once the liquid hydrogel has cooled and set, the present methodology and compositions restore the drainage holes for plant growth and development.

Description

[0001] TRAY MASKS

[0002] CROSS-REFERENCE TO RELATED APPLICATION

[0003] This application claims priority benefit to United States Provisional Application no. 63 / 695,107 filed September 16, 2024, the entire contents of which are hereby incorporated herein in their entirety.

[0004] FIELD

[0005] The present application relates to methodology and composition for growing and producing biological material, such as plants, in hydrogel substrate.

[0006] INTRODUCTION

[0007] Hydrogels are commonly known water-absorbing polymers comprising mostly water and a small percentage of organic materials.

[0008] Due to their high water content, hydrogels find use in a variety of applications and industries, including food industry, cosmetics, medical devices, agriculture, and other industrial uses.

[0009] The traditional method of synthesizing, or manufacturing, hydrogel, across all manner of industries and applications, is by pouring hot liquid hydrogel into a mold, allowing the hydrogel to solidify, and then using the resultant molded hydrogel for an intended purpose.

[0010] SUMMARY

[0011] As explained below, the present inventors developed methodology and compositions for pouring liquid hydrogel directly into a horticulture plug tray, wherein the drainage holes are temporarily blocked or masked, thereby permitting the liquid hydrogel to set into a gel without leakage. Once the liquid hydrogel has cooled and set, the present methodology and compositions restore the drainage holes for plant growth and development.

[0012] Additional objects and advantages of the embodiments will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosed embodiments. The objects and advantages may be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and thus not restrictive.

[0013] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments and together with the description, serve to explain the principles of the embodiment.

[0014] In one aspect, the application provides a method for producing hydrogel directly in a horticulture plug tray with drainage holes, comprising dispensing liquid hydrogel into a horticulture plug tray, wherein the horticulture plug tray is connected to a suitably fitted tray mask, thereby blocking or plugging the drainage holes.

[0015] In one embodiment, the method further comprises removing the tray mask after the liquid hydrogel has cooled and set, thereby restoring the drainage holes in the horticulture plug tray.

[0016] In one embodiment, the tray mask comprises a grid board and one or more bungs, wherein the tray mask is customizable and suitable for any horticulture plug tray format.

[0017] In one embodiment,, one or more bungs has a Shore hardness of about 0A to about 60A. In a further embodiment, one or more bungs has a Shore hardness of about 0A, about 5A, about 10a, about 15A, about 20A, about 25A, about 30A, about 35A, about 40A, about 45A, about 50A, about 55A, and about 60A.

[0018] In one embodiment, said dispensing over-fills each plug cell in the horticulture plug tray. In one embodiment, dispensing occurs by an automated process. In another embodiment, dispensing occurs by a manual process. In one embodiment, over-fill occurs by laminar flow, non-laminar flow, turbulent flow, or compressive flow. In one embodiment, over- fill occurs by laminar flow. In one embodiment, over-fill occurs by non-laminar flow.

[0019] In one embodiment, the grid board comprises one or more built-in drain holes for overfill of liquid hydrogel.

[0020] In one embodiment, the horticulture plug tray has handles and snaps or connects into place with a suitably fitted tray mask.

[0021] In another aspect, the application provides a Tray mask, comprising a grid board and one or more bungs, wherein the tray mask is customizable and suitable for any horticulture plug tray format. In one embodiment, one or more bungs has a Shore hardness of about 0A to about 60A. In a further embodiment, one or more bungs has a Shore hardness of about 0A, about 5A, about 10a, about 15A, about 20A, about 25A, about 30A, about 35A, about 40A, about 45A, about 50A, about 55A, and about 60A.

[0022] In one embodiment, said grid board comprises one or more built-in drain holes for overfill of liquid hydrogel.

[0023] In another aspect, the application provides a Tray filling machine, comprising a heated tank that allows recirculation of liquid hydrogel, thereby preventing cooling and hardening of hydrogel.

[0024] In another aspect, the application provides a Kit for preparing and filling horticulture plug trays comprising (a) tray filling machine and (b) a tray mask with grid board and one or more bungs, customizable for any horticulture plug tray format.

[0025] In another aspect, the application provides re-usable tray masks and re-usable horticulture plug trays.

[0026] In another aspect, the application provides a method for growing a plant, comprising

[0027] (a) Dispensing liquid hydrogel into a horticulture plug tray with a tray mask, wherein the drainage holes are temporarily and / or removably plugged;

[0028] (b) Allowing the liquid hydrogel to cool and set for a sufficient time for hydrogel substrate formation;

[0029] (c) Removing the tray mask; and

[0030] (d) Growing a plant in hydrogel substrate in horticulture plug tray.

[0031] In another aspect, the application provides a horticulture plug tray comprising liquid hydrogel, wherein said liquid hydrogel does not spill or leak from one or more drainage holes.

[0032] In another aspect, the application provides a horticulture plug tray comprising liquid hydrogel and a tray mask. In one embodiment, said horticulture plug tray has handles and snaps or connects into place with a suitably fitted tray mask.

[0033] In another aspect, the application provides a method for producing a hydrogel substrate directly in a horticulture plug tray, comprising (a) Dispensing liquid hydrogel into a horticulture plug tray with a tray mask, wherein the drainage holes are temporarily and / or removably plugged;

[0034] (b) Allowing the liquid hydrogel to cool and set for a sufficient time for hydrogel substrate formation; and

[0035] (c) Removing the tray mask.

[0036] In one embodiment, the plant is a vegetable, leafy green, or herb. In a further embodiment, said plant is Lettuce (Romaine, Butter, Iceberg), Pak Choi, Basil (Thai, Cinnamon, Genovese), Arugula, Kale, Spinach, Swiss Chard, Tomato, Cucumber, Bell Pepper.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIGURE 1 shows a standard batch reactor process for manufacturing hydrogel substrates.

[0039] FIGURE 2 shows a tray mask for horticulture plug tray.

[0040] FIGURE 3 shows exemplary components of a tray mask: silicone bungs and grid board.

[0041] FIGURE 4 shows various views of an illustrative tray mask.

[0042] FIGURE 5 shows seedlings growing in hydrogel cells in horticulture plug tray.

[0043] FIGURE 6 shows a close-up image of seedlings growing in hydrogel cells in horticulture plug tray.

[0044] FIGURE 7 shows an exemplary tray filling machine for dispensing liquid hydrogel.

[0045] FIGURE 8 shows an exemplary horticulture plug tray with handles or clips that provide a connection to a tray mask.

[0046] DETAILED DESCRIPTION

[0047] Hydrogels are a commonly used material in a wide variety of industries and are almost universally made via the same process - a batch reactor. Batch reactors are common pieces of equipment, manufactured to a variety of specifications, by many different vendors. All of the various versions of batch reactors manufacture hydrogel in a similar manner - all of the material is made at once, in a single vessel, then dispensed into its final format (e.g. a mold). During this process, the entire volume of material must be heated to relatively high temperatures and then cooled to much lower temperatures so that it can be dispensed and cast. The heating process is critical to manufacturing hydrogels, as this part of the process is when the water and polymer, along with other potential additives, establish necessary chemical bonds to create a hydrogel.

[0048] Heating, also referred to as a “heat ramp”, must not use extremely high temperatures to heat the volume fast, as such high temperatures can damage the material. Likewise, cooling, also referred to as a “cool ramp”, must not use extremely cold temperatures to cool the material too quickly. Effective synthesis of hydrogel will require a steady heat ramp and a steady cool ramp, which is not only required to ensure that the material is properly manufactured, but also prevents critical failure of the equipment (batch reactor) that can result from changes in temperature that are too rapid.

[0049] Thus, the traditional method of synthesizing, or manufacturing, hydrogel, across all manner of industries and applications, involves pouring hot liquid hydrogel into a desired format (e.g., mold), allowing the hydrogel to solidify, and then using the resultant hydrogel (e.g., molded hydrogel) for an intended purpose. Because the intended recipients likely do not have the machinery for producing hydrogels, particularly at commercial scale and commercial volume, the recipients generally need to order pre-made hydrogels and have them shipped for usage.

[0050] From a commercial standpoint, it becomes costly and burdensome to ship hydrogels, especially in high volumes, as the hydrogels become heavy, require proper storage and care, and frequently need rehydration or other preparation before use. Additionally, the recipient cannot easily alter or adjust the hydrogel formulation or structure following manufacture.

[0051] The present inventors designed methodology, compositions, kits, and the like that allows an intended recipient to prepare their own hydrogels on-site, thereby avoiding the costs and labor associated with transporting pre-made hydrogels. For instance, the present inventors contemplated a liquid hydrogel pouring system, complete with machinery, materials, methodology, and the like, that facilitates preparing and pouring liquid hydrogel directly into final product, such as horticulture plug tray. A horticulture plug tray features drainage holes for proper irrigation, which while helpful for a growing plant, the drainage holes present a problem when pouring a liquid, such as a liquid hydrogel into the plug tray. The present inventors developed methodology, materials, and compositions for pouring liquid hydrogel directly into a horticulture plug tray, wherein the drainage holes are temporarily blocked or masked, thereby permitting the liquid hydrogel to set into a gel without leakage. Once the liquid hydrogel has cooled and set, the present methodology and compositions restore the drainage holes for plant growth.

[0052] In this way, the present methodology and compositions may provide a re-usable horticulture plug tray system, thereby conserving costs and reducing the use of single-use materials.

[0053] As used herein, the term tray mask refers to a grid board with one or more bungs designed for fitting with a horticulture plug tray, thereby closing or otherwise blocking the horticulture plug tray drainage holes. A grid board refers to a stiff, durable board with hole spacing that matches the drainage holes of a horticultural plug tray. The one or more bungs refer to stoppers that provides a flexible and removable seal for drainage holes. The one or more bungs are sized for a tight fit into a grid board, but can be replaced if damaged or lost. In no way limiting, the one or more bungs are constructed from silicone, thermoplastic, polyurethane, injection mold, thermal cutting, laser cutting, or other suitable material for temporarily and / or removably blocking a drainage hole. In other non-limiting embodiments, the application contemplates solid bungs as well as hollow bungs. In no way limiting, solid bungs tend to have easier casting and more economical manufacturing, whereas hollow bungs generally result from injection molding and may offer more flexibility for plugging a hole as well as removing a bung.

[0054] Of course, depending on the horticulture tray and its properties such as tray material, tray thickness, the number of drainage holes, the size of the drainage holes, and / or spacing of the drainage holes, the one or more bungs may have varying plug sizes, varying plug shapes, varying plug hardness, varying plug thickness and the like. For example, and again depending on the horticulture tray itself, the horticulture tray may have round holes or starshaped holes, thus the plugs may have varying shapes such as round shapes, cylindrical shapes, or star- shapes, such that the shape of the plug is compatible with the horticulture tray hole.

[0055] Again, depending on the horticulture tray and its properties, the one or more bungs may have varying levels of hardness. For example, and in no way limiting, the one or more bungs may have a hardness on the Shore hardness scare varying between about 0A and about 60A. In some embodiments, the one or more bungs may have a hardness of about 0A, 5A, 10A, 15A, 20A, 25A, 30A, 35A, 40A, 45A, 50A, 55A, and 60A.

[0056] In other embodiments, a horticulture plug tray connects to a tray mask through any means capable of providing a tight fit that prevents leakage yet retains the ability to remove or separate the horticulture plug tray from the tray. For example, and non-limiting, a horticulture plug tray may have handles or clips that provide a tight connection to a tray mask, thereby holding the tray mask, preventing leakage, and yet retaining the ability to separate the horticulture plug tray from the tray mask as needed, such as when the liquid hydrogel hardens or sets. In some embodiments, the application contemplates an automated process for connecting a horticulture plug tray with a tray mask, as well removing a horticulture plug tray from a tray mask.

[0057] In other embodiments, the present application contemplates a Fused Horticulture Tray, comprising a horticulture tray with drainage holes fused or otherwise connected to a removable bottom setting tray, wherein the bottom setting tray covers or otherwise blocks the drainage holes of the horticulture tray. Thus, rather than individual bung components that insert into individual holes of a horticulture tray, a fused horticulture tray comprises a horticulture tray fused to a bottom tray, thereby covering the drainage holes until after the liquid hydrogel solidifies. Upon solidification, the horticulture tray and the bottom setting tray can separate, thereby restoring the horticulture tray drainage holes.

[0058] Reference will now be made in detail to the present embodiments, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0059] The conjunction “and” or “or” can be used in the list of members, but the “at least one of’ phrase is the controlling language. For example, at least one of A, B, and C is shorthand for A alone, B alone, C alone, A and B, B and C, A and C, or A and B and C.

[0060] Technical terminology in this description conforms to common usage in horticulture, biochemistry, agriculture, and the like. This usage and these technical terms are explicated in, for example, Soils and Other Growth Media SBN 333125711 The Macmillan Press.

[0061] As used herein, a hydrogel substrate refers to a hydrogel comprising water, gelling agent, cross-linking agent, and one or more additives that support either a hydrogel itself and / or a biological material growing in or on the hydrogel substrate. As explained below, a biological material, such as a plant, herb, or leafy green, can grow in, through, or on a hydrogel substrate in the absence of any other growth medium, such as soil, coir, wood chips, peat moss, and the like. A hydrogel substrate may be formed into any shape or format, including but not limited to a hydrogel substrate cylinder, hydrogel substrate sheet, irregular porous plugs (a sponge like structure); spheres of uniform or mixed sizes, cubes of uniform or mixed sizes, noodles or fine strings, and irregular polyhedron chunks, and / or mixtures thereof.

[0062] In some embodiments, a hydrogel substrate may be dehydrated or freeze-dried for transportation, longer-term use, and / or storage. Before use, the dehydrated or freeze-dried is rehydrated with water, and referred to herein as a “rehydrated hydrogel.”

[0063] An additive or additive ingredient refers to a composition that support either a hydrogel itself and / or a biological material growing in or on a hydrogel substrate. For example, and in no way limiting, an additive may provide structural support to a hydrogel substrate in the form of tensile strength, elasticity, and the like. Similarly, an additive could support both a hydrogel itself and a biological material, such as a mushroom, by increasing water capacity and water retention. Likewise, an additive may increase ability to pass through filtration systems and permit water recirculation. Important for sterile culture, such as for mycelia culture, a hydrogel may comprise an antibacterial additive. Exemplary additives include but are not limited to:

[0064] • Opacifier: An opacifier additive is a substance added to the hydrogel to tune or control the opacity of the finished material.

[0065] • Texture: A texture additive is a substance added to the hydrogel to control physical properties of the finished material such as roughness, brittleness, elasticity, adhesive strength, and cohesive strength.

[0066] • Cationic Capacity: A cationic capacity additive is a substance added to the hydrogel to control its cationic exchange capacity, or ability to retain cations in the hydrogel material.

[0067] • Anti-Fouling: An anti-fouling additive is a substance added to the hydrogel to prevent the growth of fouling organisms like algae or bacteria.

[0068] • Humectants: A humectant additive is a substance added to the hydrogel to reduce the loss of moisture from the finished material.

[0069] • Colorant: A colorant additive is a substance added to the hydrogel to impart a desired pigment or color of the finished material. A biological material refers to any material produced or derived from a living organism. For example, and in no way limiting, a biological material could include any material from any of the five major taxonomical kingdoms of Plantae, Fungi, Protista, Archaea or Archaebacteria, and Bacteria or Eubacteria. For instance, and in no way limiting, a biological material could include plants, vegetables, leafy greens, and / or herbs.

[0070] Plants: “Plant” includes any of various photosynthetic, eukaryotic, multicellular organisms of the kingdom Plantae characteristically producing embryos, containing chloroplasts, and having cellulose cell walls. The present application includes both angiosperm (monocots and dicots) and gymnosperm plants, and includes whole plant as well as any part of a plant, such as leaf, root, shoot, stolon, tuber, runner, cane, cutting, seed, flower, etc. In no way limiting, the present methodology and compositions may be used for growing tomato, potato, soybean, maize, turfgrass, rice, oat, wheat, barley, sorghum, orchid, iris, lily, onion, palm, pine, tobacco, Eucalyptus, Populus, Liquidambar, Acacia, teak, mahogany, cotton, tobacco, mustards, orange, apple, pear, cherry, peach, plum, melons, grapes, strawberry, blackberry, raspberry, blueberry, cranberry, loganberry, bananas, citrus, sugar beet, broccoli, cauliflower, celery, cilantro, lettuce, spinach, eggplant, pumpkin, squash, cassava, sweet potato, pepper, poinsettia, geranium, almond, peanut, pistachio, walnut, bean, alfalfa, carrot, strawberry, lettuce, oak, maple, walnut, rose, mint, squash, daisy, geranium, avocado, artichoke, olives, coconut, jojoba, and cactus.

[0071] “Fruit” or “fruits” in the botanical sense refers to the seed-bearing structure in flowering plants (also known as angiosperms) formed from the ovary after flowering, including common fruits such as apples, bananas, grapes, oranges, melons, dates, coconuts, and berries, such as strawberries, but also less common fruits such as bean pods, corn kernels, tomatoes, and wheat grains. However, and as used herein, “fruit” includes any plant or part thereof safe for human or animal consumption.

[0072] “Small fruit” includes strawberry, raspberry (any color), blackberry, blueberry and / or black-raspberry. A small fruit refers to the plant itself as a whole, as well as any part thereof, such as a berry, seedling, stolon, runner, seed, leaf, cane, or root cutting.

[0073] “Vegetable” or “vegetables” in the botanical sense means any plant part consumed for food that is not a fruit or seed. However, and as used herein, vegetable may refer to any edible stems, stalks, roots, tubers, bulbs, leaves, flowers, some fruits, pulses, fungi, algae, and the like. Exemplary vegetables include but are not limited to lettuces, herbs, Brassicas, cilantro, carrot, potato, pepper, radish, lettuces, cauliflower, tomato, peas, beans, mushroom, truffle, Spirulina, and moringa. Exemplary vegetables include but not limited to Apiaceae (formerly Umbelliferae) - Celery or Carrot Family; Apocynaceae - Periwinkle Family; Asteraceae (formerly Compositae) - Daisy Family; Bignoniaceae - Bignonia Family; Boraginaceae - Forget-me-Not Family; Brassicaceae (formerly Cruciferae) - Cabbage Family; Caesalpiniaceae, Fabaceae, Mimosaceae, Papilionaceae (formerly Leguminosae) - Bean Family; Campanulaceae - Bellflower Family; Caryophyllaceae - Pink Family; Clusiaceae (formerly Guttiferae) - St. John's Wort Family; Convolvulaceae - Bindweed Family; Ericaceae - Heath Family; Geraniaceae - Geranium Family; Gesneriaceae - African Violet Family; Hydrophy llaceae - Waterleaf Family; Iridaceae - Iris Family; Lamiaceae (formerly Labiatae) - Mint or Nettle Family; Liliaceae - Lily Family; Malvaceae - Mallow Family; Musaceae - Banana Family; Oxalidaceae - Wood Sorrel Family; Papaveraceae - Poppy Family; Plumbaginaceae - Leadwort Family; Polemoniaceae - Phlox Family; Primulaceae - Primrose Family;

[0074] Ranunculaceae - Buttercup Family; Rosaceae - Rose Family; Rubiaceae - Bedstraw Family; Saxifragaceae - Saxifrage Family; Scrophulariaceae - Figwort Family; Solanaceae - Potato Family and Nightshades; and Violaceae - Violet Family.

[0075] In some embodiments, plants are selected adzuki, alfalfa, broccoli, buckwheat, cabbage, cauliflower, chia, chives, clover, dill, fenugreek, flax, garbanzo bean, garlic, kale, kidney bean, lentil bean, mung bean, mustard, navy bean, oats, peas, pinto bean, pumpkin, radish, red clover, soy bean, sunflower, wheat berry, and wheat grass.

[0076] In some embodiments, plants are selected from broccoli (seedlings for cole crops); Cauliflower, Eggplant, Zucchini (or other summer squash varieties), Radish (quick-rooting varieties like Cherry Belle), Carrot (short-root varieties like Nantes for plug starts), Beet (table beets like Detroit Dark Red), and Onion (seedling starts for green onions or bulbs)

[0077] In some embodiments, one or more plants are selected from one or more herbs and spices. In some embodiments, the spices are selected from allspice (Pimenta dioica), angelica (Angelica archangelica), anise (Pimpinella anisum), asafoetida (Ferula assa-foetida), bay leaf (Laurus nobilis), basil (Ocimum basilicum), bergamot (Monarda species), black cumin (Nigella sativa), black mustard (Brassica nigra), black pepper (Piper nigrum), borage (Borago officinalis), brown mustard (Brassica juncea), burnet (Sanguisorba minor and S. officinalis), caraway (Carum carvi), cardamom (Elettaria cardamomum), cassia (Cinnamomum cassia), catnip (Nepeta cataria), cayenne pepper (Capsicum annuum), celery seed (Apium graveolens, variety dulce), chervil (Anthriscus cerefolium), chicory (Cichorium intybus), chili pepper (Capsicum species), chives (Allium schoenoprasum), cicely (Myrrhis odorata), cilantro (Coriandrum sativum), cinnamon (Cinnamomum verum), clove (Syzygium aromaticum), coriander (Coriandrum sativum), costmary (Tanacetum balsamita), cumin (Cuminum cyminum), curry, dill (Anethum graveolens), fennel (Foeniculum vulgare), fenugreek (Trigonella foenum-graecum), file (Sassafras albidum), ginger (Zingiber officinale), grains of paradise (Aframomum melegueta), holy basil (Ocimum tenuiflorum), horehound (Marrubium vulgare), horseradish (Armoracia rusticana), hyssop (Hyssopus officinalis), lavender (Lavandula species), lemon balm (Melissa officinalis), lemon grass (Cymbopogon citratus), lemon verbena (Aloysia citrodora), licorice (Glycyrrhiza glabra), lovage (Levisticum officinale), mace (Myristica fragrans), marjoram (Origanum majorana), nutmeg (Myristica fragrans), oregano (Origanum vulgare), paprika (Capsicum annuum), parsley (Petroselinum crispum), peppermint (Mentha xpiperita), poppy seed (Papaver somniferum), rosemary (Salvia rosmarinus), rue (Ruta graveolens), saffron (Crocus sativus), sage (Salvia officinalis), savory (Satureja hortensis and S. montana), salt, sesame (Sesamum indicum), sorrel (Rumex species), star anise (Illicium verum), spearmint (Mentha spicata), tarragon (Artemisia dracunculus), thyme (Thymus vulgaris), turmeric (Curcuma longa), vanilla (Vanilla planifolia and V. tahitensis), wasabi (Eutrema japonicum), and white mustard (Sinapis alba). In some embodiments, the spices are selected from saffron, garlic, onion, and mustard seed.

[0078] In some embodiments, plants are selected from Mustard Greens, Collard Greens, Bok Choy (or close relative to Pak Choi for variety), Endive, and Watercress.

[0079] In some embodiments, plants are selected from Mint (spearmint or peppermint), Cilantro (or Coriander), Parsley (flat-leaf or curly), Rosemary, Thyme, Oregano, and Dill.

[0080] In some embodiments, plants are selected from Strawberry (day-neutral varieties like Albion for continuous production), Raspberry (primocane varieties like Heritage for plug propagation), Blueberry (dwarf varieties like Top Hat for container / plug starts), and Blackberry (thornless varieties like Triple Crown).

[0081] In some embodiments, plants are selected from Petunia (hybrid varieties for bedding plants), Marigold (French or African types for pest-repellent ornamentals), Impatiens (for shade-loving annuals), Geranium (Pelargonium, scented or zonal types), Zinnia (dwarf varieties for cut flowers), Pansy (Viola, cool-season color), and Begonia (tuberous or fibrous- rooted for indoor / outdoor). In some embodiments, plants are selected from Chili Pepper (e.g., Jalapeno or Habanero, extending from Bell Pepper), Melon (e.g., cantaloupe seedlings), and Grape (table grape vines like Thompson Seedless for propagation).

[0082] A. Hydrogel Substrate Composition

[0083] Hydrogel substrate consists of multiple categories of ingredients, each affecting specific attributes and characteristics of the desired substrate. Primary ingredient(s) is / are gelling agent(s) and cross-linking agent(s), which come from various sources, such as plants, animals, bacteria, fungi and other sources, as well as synthetic gelling agents. Gelling agents are polymeric materials comprising sugar molecules, polysaccharides, amino acids, proteins, acrylates, acrylamides, glycols, and / or vinyls. The gelling agent typically represents about 0.5- 2.5% of the solution by weight, but can vary depending on particular needs, with water representing the rest of the base solution. Cross linking agent(s) can be ionic or nonionic, having a minimum of two functional sites to create ionic or covalent chemical bonds between gelling agents. The cross-linking agent(s) typically represents about 0.001-1.0% of the solution by weight, with gelling agent and water representing the rest of the base solution. After a base solution of water, gelling agent(s), and cross-linking agent(s) have been mixed, secondary ingredients - Additives - are added to the solution to develop specific substrate attributes and characteristic for the intended use of the substrate.

[0084] Additives typically, but not in all cases, collectively represent about 0.5-2% of the solution by weight. Additives are selected to engineer specific attributes and characteristics into the substrate, based on how it is intended to be used or for which crop(s) it is intended to be optimized for. For example, for certain crops a texture or porosity additive may be included; while for other crops that additive is not beneficial, or even detrimental. Furthermore, different amounts of the same additives may be used selectively for specific crops. For example, some crops prefer a higher pH substrate, resulting in the increase of a pH additive for that crop, while other crops might prefer a lower pH substrate and use less of that same additive. In some instances, additives themselves impart secondary attributes beyond their primary attribute (e.g., for pH control); thus some crops may actually prefer the use of a different pH additive than another crop might.

[0085] Additives are used to affect hydrogel characteristics such as nutrients, color, light absorption, opacity, elasticity, brittleness, texture heterogeneity, porosity, sterility, antibacterial pH, electrical conductivity (EC), dissolved oxygen, water retention, water capacity, cohesive strength, adhesive strength to non-hydrogel surfaces, freeze-thaw hysteresis, temperature-, light- or pH-based stimuli, gas permeability, shape memory / hysteresis, solvent exchange behavior, thermal conductivity, anti-fouling properties, surface roughness, suspension of solids, compostability, biodegradability, oxidation-reduction potential, cationic exchange capacity, and time dependent release of nutrients. Many additives are known in the art and include, but are not limited to opacifier additives, texture additives, cationic capacity additives, anti-fouling additives, humectant additives, and colorant additives.

[0086] The ability to selectively assemble specific ingredients to achieve a specific type of substrate is not generally possible using traditional substrates such as peat moss, coconut coir, perlite or other similar “traditional” substrates in the agriculture market. The ability for a hydrogel to be engineered from the beginning to give, for example, a plant specifically the substrate it prefers is unique in the market and is why the embodiment is novel, especially when compared to the conventional hydrogel as an augmentation structure.

[0087] In this regard, and unlike conventional uses of hydrogel substates for agricultural purposes, the instant hydrogel substrate is a “substrate medium” or “soilless medium,” since the instant hydrogel is suitable for growing, for example, a plant in a medium that does not contain natural earth soil, in whole or primarily. Similarly, the instant hydrogel substrate finds use by itself for cultivating mushrooms or other fungi, as well as use in sterile culture. Because the instant hydrogel substrate is the substrate itself for growing or cultivating biological material, the hydrogel substrate can be shaped, molded, and formed into nearly any necessary shape or format to achieve compatibility with virtually any grow system or format.

[0088] B. Hydrogel Substrate Methodology

[0089] To manufacture a hydrogel substrate, the primary (gelling agent(s) and cross linkers) and secondary (additives) ingredients are assembled to achieve desired results. Gelling agent is hydrated in water to create a homogenous, saturated solution, which becomes the base of the substrate mix. This requires specific time to hydrate the material (gelling agent), as well as specific temperature to achieve saturation and homogeneity. Agitation is typically applied to ensure complete saturation and homogeneity. The base solution is brought to a specific temperature for a specific period of time, which are specific to the gelling agent selected.

[0090] Once the base is prepared, various additives are then incorporated to achieve various attributes and characteristics, based on the specific desired outcome or use of the substrate. A system to thoroughly mix the solution ensures complete homogenization of the material. After homogenization of the material, sparge tubes may be used to introduce or increase concentration of dissolved gases or increase porosity and the volume to mass ratio of the finished solution. Once the material has been thoroughly mixed, it can be deposited into a holding vessel for dispensing.

[0091] Dispensing of the finished solution may occur through pouring, coating, layering, spraying, or aerosolizing the solution into molds or vessels. The finished solution may also be sparged with a physical blowing agent, like air, nitrogen, or other gas, to create bubbles in solution. Upon dispensing the bubbled solution, air pockets can be trapped as the solution reaches gel point, creating porosity throughout the substrate. The finished solution may also be dispensed into a coagulation bath, also referred to as a non-solvent bath, which can facilitate in the liquid solution reaching a gel point and forming porous structures described above. The gel point, or temperature at which the finished solution turns from a flowing liquid into a semisolid, of the finished solution is higher than the required operational temperature range for growing plants in the medium.

[0092] Due to the unique nature of the material, in that it can be poured into molds, it is possible to achieve any variety of formats and / or surface area-to-volume ratios for the substrate. These include traditional formats such as “plugs”, which are commonly used in the agricultural industry, but also includes novel formats such as sheets of material with varying thickness or any other moldable format that a grower or customer may desire to accommodate their specific needs. Other illustrative examples may consider the 3D architecture of final material, including but not limited to: irregular porous plug (a sponge like structure); spheres of uniform or mixed sizes, cubes of uniform or mixed sizes, noodles or fine strings, and irregular polyhedron chunks, and / or mixtures thereof.

[0093] In no way limiting, a hydrogel substrate finds use for a variety of applications, such as a substrate for floriculture and horticulture; a substrate or base material for sterile culture and sub-culture (similar to agar culture); substrate for cultivating mushrooms; tissue culturing; cloning from plant cuttings; and the like.

[0094] C. Tray Masks: Methodology and Materials

[0095] The present inventors developed methodology and materials for dispensing liquid hydrogel directly into a horticulture plug tray, wherein the drainage holes are temporarily blocked or masked, thereby permitting the liquid hydrogel to set into a gel without leakage. Once the liquid hydrogel has cooled and set, the present methodology and compositions restore the drainage holes for plant growth.

[0096] In this way, and as shown in the appended Figures, the present methodology and compositions may provide a re-usable horticulture plug tray system, thereby conserving costs and reducing the use of single-use materials, as well as avoiding costly manufacturing and shipping of pre-formed hydrogel substrates.

[0097] As shown in the appended Figures, in some embodiments, a tray mask refers to a grid board with one or more bungs designed for fitting with a horticulture plug tray, thereby closing the horticulture plug tray drainage holes. A grid board refers to a stiff, durable board with hole spacing which matches the size, shape, thickness, and depth of the drainage holes of horticultural plug tray. The one or more bungs refers to stoppers which provides a flexible seal to drainage holes. The one or more bungs are sized for a tight fit into a grid board, but can be replaced if damaged or lost. In no way limiting, the one or more bungs are constructed from silicone, thermoplastic, polyurethane, injection mold, thermal cutting, laser cutting, or other suitable material for temporarily and / or removably blocking a drainage hole. Of course, depending on the number of drainage holes, size of the drainage holes, shape of the drainage holes, and / or spacing of the drainage holes, one or more bungs may have varying plug sizes, varying plug shapes, varying plug thickness, and the like. In some embodiments, a grid board may comprise one or more built-in drain holes for overfill of liquid hydrogel.

[0098] D. Material and Methodology for Dispensing Liquid Hydrogel directly into Horticulture Tray

[0099] In some embodiments, the present inventors contemplate material and methodology for dispensing liquid hydrogel into horticulture plug trays with tray masks, wherein the drainage holes are temporarily and / or removably plugged.

[0100] (1) Tray Filling Machine

[0101] While in no way limiting, tray filling may occur by any means, such as manually or by automated means. In one embodiment, and as shown in exemplary Figure 7, a tray filling machine (or “Tray Filler”) dispenses liquid hydrogel directly into horticulture plug trays. As known in the art, a tray filling machine or “Tray Filler” may comprise a conveyor belt, filling head, and a pump that moves liquid. Depending on the circumstances, the present application contemplates a variety of methods for filling trays, many of which involve overfilling the trays. In one embodiment, a tray filling machine or “Tray Filler” has been designed to use a wide laminar flow to fill the full width of trays. In other embodiments, a tray filling machine or “Tray Filler” may overfill by using a non-laminar flow. Overfilling may occur by any suitable technique, such as but not limited to laminar flow, non-laminar flow, turbulent flow, compressive flow, and the like. In one embodiment, and in no way limiting, overfilling may occur by a laminar flow. In another embodiment, and in no way limiting, overfilling may occur by a non-laminar flow.

[0102] Liquid that is not filled into the tray is captured by a reclaim bath below the point of liquid flow and recirculated. A Tray Filler provides several advantages, including fully Washdown Rated; electricals fully enclosed; Food grade, high temperature tubing; all wetted parts made from 308 or 316 Stainless Steel; all connections use sanitary triclamp fittings; all transfer pumps are sanitary centrifugal transfer pumps with triclamp connections; the conveyor features heavy duty casters and leveling feet; the reclaim bath features locking heavy duty casters, heat control, and a float switch to control max fluid level.

[0103] An illustrative tray filling machine may have VFD (variable frequency drive) controls, including: Conveyor On / Off and Speed (0-100%); Rubber Rollers On / Off and Speed (0-100%); Recirculating sanitary pump On / Off and Speed (0-100%); Reclaim Tank Heat On / Off (Has a max set temperature to only maintain circulating gel temperature); Tank Control On / Off (To control an electric ball valve via float switch that will open or close flow from Primary Tank to Reclaim Bath to prevent overflow).

[0104] In some embodiments, for the tank to tray filler connection, the finished solution of the Primary Tank is transferred to the reclaim bath of the Tray filler through a sanitary pump and food grade tubing. A transfer pump may be connected through an electric actuated ball valve, which could be controlled and connected to the tray filler VFD. A float switch on the reclaim tank signals the valve to close when the fluid level in the tank is high.

[0105] In some embodiments, for Filling Reclaim Bath from Primary Tank, finished solution from the Primary Tank will enter the Tray Filler system through a Triclamp port on the Reclaim Bath. The Reclaim Bath features a float switch to prevent this bath from overflowing if the finished solution isn’t used at a fast enough rate. The float switch will signal a ball valve to stop flow from the Primary Tank. The Reclaim Bath also has heat control to prevent circulating solution from gelling.

[0106] In some embodiments, for Liquid Flow through Tray Filler, the Recirculating Sanitary pump (mounted to the Reclaim Bath) will transfer liquid from the Reclaim Bath through food grade tubing to a slit manifold at the filling position. The power and speed of the pump can be controlled through the Tray Filler VFD. Upon first powering on the pump, it will take a few moments for an even laminar flow to stabilize.

[0107] In some embodiments, the Tray Filler has an exit curtain in lieu of a vacuum manifold. The present inventors discovered that an exit curtain minimizes product spill or waste compared to a vacuum manifold, as well as provides a nice finish. An exit curtain helps prevent forward splash of product onto the exit conveyor and directs overflow back into the reclaim tank.

[0108] Thus, in some embodiments, a Tray Filler may have programmable controls (speeds, heat, actuated valves) and physical settings (leveling, guard rails, roller height adjustments) to adapt to different 1020 agricultural tray designs, which commonly vary in cell count and dimensions.

[0109] In some embodiments, a Tray Filler may be a part of a larger system with other opportunities for automation (continuous conveyance vs staging). The use of a reclaim bath to recirculate liquid minimizes loss of product that is not collected into a tray.

[0110] (2) Tray Filling Methodology

[0111] The present inventors discovered that overfilling horticulture trays across the entire tray affords complete and uniform filling of horticulture trays. Unlike other flow processes that add surface coatings to items or under fill the cells of horticulture tray, the present application purposely overfills the cells to create a complete and uniform filling. For hydrogels in a horticulture tray, it is important to have complete and uniform filling across the tray so that the hydrogels solidify into a uniform size sufficient for plant seeding, growth, and eventual plant transplant.

[0112] An underfilled cell containing insufficient levels of hydrogel in a horticulture tray may not adequately support plant growth and development, and one would not want to just pour additional liquid hydrogel into an underfilled cell because this could add a natural fracture point to the hydrogel, thereby jeopardizing hydrogel stability and integrity. Thus, the present inventors determined that over-filling of the horticulture trays provides an optimal amount of hydrogel for supporting plant seeding and subsequent growth and development.

[0113] Overfilling may occur by any suitable technique, such as but not limited to laminar flow, non-laminar flow, turbulent flow, compressive flow, and the like. In one embodiment, and in no way limiting, overfilling may occur by a laminar flow. In another embodiment, and in no way limiting, overfilling may occur by a non-laminar flow.

[0114] In one embodiment, a Tray Filler has a recirculating heated bath, which prevents loss of liquid hydrogel from overfilling and prevents the liquid hydrogel from hardening or gelling.

[0115] In some embodiments, the methodology contemplates an automated process for connecting a horticulture plug tray and tray mask, as well as an automated process for removing a tray mask.

[0116] In other embodiments, the methodology contemplates manual processes for connecting a horticulture plug tray and tray mask, as well as a manual process for removing a tray mask.

[0117] E. Kits for making and dispensing liquid hydrogel into horticulture tray

[0118] As explained above, the present inventors developed materials and-methodology for dispensing liquid hydrogel into horticulture trays. That is, in one embodiment, the present inventors discovered that laminar liquid flow permits over-filling of the horticulture trays, which provides an optimal amount of hydrogel for supporting plant seeding and subsequent growth and development. In another embodiment, overfilling may occur non-laminar flow. Additionally, the present inventors developed horticulture plug trays with tray masks, as well as fused trays, wherein the drainage holes are temporarily and / or removably plugged to prevent hydrogel liquid leakage.

[0119] Thus, in some embodiments, a kit may comprise compositions for producing hydrogel substrate, a Tray Filler machine, horticulture plug trays with tray masks, and instructions.

[0120] In other embodiments, a kit may comprise compositions for producing hydrogel substrate, horticulture plug trays with tray masks, and instructions.

[0121] EXAMPLES

[0122] The following Examples provide illustrative and non-limiting disclosure. EXAMPLE 1: Production and Dispensing of Hydrogel directly in Horticulture Plug Tray using Tray Mask

[0123] As explained throughout the application, hydrogel substrate comprising plant derived polysaccharides and essential plant macro and micronutrients and can provide a complete replacement for peat sphagnum, rockwool, coco coir, biostrate, and other traditional soilless substrates used in controlled environment agriculture applications.

[0124] Using materials and methodology disclosed throughout the present application, the present inventors dispense liquid hydrogel directly into a horticulture plug tray, wherein the drainage holes are temporarily blocked or masked, thereby permitting the liquid hydrogel to set into a gel without leakage. Once the liquid hydrogel has cooled and set, the present methodology and compositions restore the drainage holes for plant growth.

[0125] In some embodiments, and as shown in illustrative Figure 7, a tray filling machine (the “Tray Filler”) dispenses liquid hydrogel directly into horticulture plug trays. In one embodiment, tray filling may use an automated process that overfills the trays over the full width of trays. Liquid that is not filled into the tray is captured by a reclaim bath below the point of liquid flow and recirculated. Other automated processes may be used, in keeping with the spirit of overfilling the horticulture plug trays to provide a hydrogel with suitable structural integrity to support plant growth and development.

[0126] Once the liquid hydrogel has cooled and set, the present methodology and compositions restore the drainage holes for plant growth.

[0127] EXAMPLE 2: Plant Growth and Development in Hydrogel

[0128] Using the materials and methodology of the present application, one of ordinary skill in the art can grow a plant, such as a vegetable, leafy green, or herb, in horticulture plug tray comprising a hydrogel substrate.

[0129] In some embodiments, a hydrogel substrate should be dibbled with a barbed dibbler to roughen the surface prior to seeding. Germination conditions should ensure that seeds do not drown in the dibble via water accumulation on the media surface. Overhead misting is not recommended unless short durations can be used.

[0130] In some embodiments, water height in ebb and flow or shallow water culture systems should be no less than about 75% of the full plug height while in a 1020 tray or other plug tray type. The present hydrogel substrate can be used for propagation of plant cuttings by sticking methods.

[0131] As shown in Figures 5 and 6, the present materials and methodology can be used for supporting plant growth and development. Illustrative plants include vegetables, leafy greens, and herbs, such as but not limited to Lettuce (Romaine, Butter, Iceberg), Pak Choi, Basil (Thai, Cinnamon, Genovese), Arugula, Kale, Spinach, Swiss Chard, Tomato, Cucumber, and Bell Pepper.

Claims

CLAIMSWhat is claimed is:

1. A method for producing hydrogel directly in a horticulture plug tray with drainage holes, comprising dispensing liquid hydrogel into a horticulture plug tray, wherein the horticulture plug tray is connected to a suitably fitted tray mask, thereby blocking or plugging the drainage holes.

2. The method of claim 1, further comprising removing the tray mask after the liquid hydrogel has cooled and set, thereby restoring the drainage holes in the horticulture plug tray.

3. The method of claim 1, wherein the tray mask comprises a grid board and one or more bungs, wherein the tray mask is customizable and suitable for any horticulture plug tray format.

4. The method of claim 1, wherein one or more bungs has a Shore hardness of about 0A to about 60 A.

5. The method of claim 1, wherein one or more bungs has a Shore hardness of about 0A, about 5A, about 10a, about 15A, about 20A, about 25 A, about 30A, about 35A, about 40A, about 45A, about 50A, about 55A, and about 60A.

6. The method of claim 1, wherein said dispensing over-fills each plug cell in the horticulture plug tray.

7. The method of claim 6, wherein said dispensing occurs by an automated process.

8. The method of claim 6, wherein said dispensing occurs by a manual process.

9. The method of claim 6, wherein said over-fill occurs by laminar flow, non-laminar flow, turbulent flow, or compressive flow.

10. The method of claim 9, wherein said over-fill occurs by laminar flow.

11. The method of claim 9, wherein said over- fill occurs by non-laminar flow.

12. The method of claim 3, wherein said grid board comprises one or more built-in drain holes for overfill of liquid hydrogel.

13. The method of claim 1, wherein the horticulture plug tray has handles and snaps or connects into place with a suitably fitted tray mask.

14. A Tray mask, comprising a grid board and one or more bungs, wherein the tray mask is customizable and suitable for any horticulture plug tray format.

15. The Tray mask of claim 14, wherein one or more bungs has a Shore hardness of about 0A to about 60 A.

16. The Tray mask of claim 15, wherein one or more bungs has a Shore hardness of about 0A, about 5A, about 10a, about 15A, about 20A, about 25A, about 30A, about 35A, about 40A, about 45A, about 50A, about 55A, and about 60A.

17. The Tray mask of claim 14, wherein said grid board comprises one or more built-in drain holes for overfill of liquid hydrogel.

18. A Kit for preparing and filling horticulture plug trays comprising (a) tray filling machine and (b) a tray mask with grid board and one or more bungs, customizable for any horticulture plug tray format.

19. Re-usable tray masks and re-usable horticulture plug trays.

20. A method for growing a plant, comprising(a) Dispensing liquid hydrogel into a horticulture plug tray with a tray mask, wherein the drainage holes are temporarily and / or removably plugged;(b) Allowing the liquid hydrogel to cool and set for a sufficient time for hydrogel substrate formation;(c) Removing the tray mask; and(d) Growing a plant in hydrogel substrate in horticulture plug tray.

21. A horticulture plug tray comprising liquid hydrogel, wherein said liquid hydrogel does not spill or leak from one or more drainage holes.

22. A horticulture plug tray comprising liquid hydrogel and a tray mask.

23. The horticulture plug tray of claim 22, wherein said horticulture plug tray has handles and snaps or connects into place with a suitably fitted tray mask.

24. A method for producing a hydrogel substrate directly in a horticulture plug tray, comprising(a) Dispensing liquid hydrogel into a horticulture plug tray with a tray mask, wherein the drainage holes are temporarily and / or removably plugged;(b) Allowing the liquid hydrogel to cool and set for a sufficient time for hydrogel substrate formation; and(c) Removing the tray mask.

25. The method of claim 20, wherein said plant is a vegetable, leafy green, or herb.

26. The method of claim 25, wherein said plant is Lettuce (Romaine, Butter, Iceberg),Pak Choi, Basil (Thai, Cinnamon, Genovese), Arugula, Kale, Spinach, Swiss Chard, Tomato, Cucumber, Bell Pepper.

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