hydroponic vegetable growing techniques The term hydroponics is derived from the Greek word hydro meaning water and ponos meaningful work. Hydroponics is a term used to describe how to grow crops without soil but using water or other porous materials with controlled nutrient delivery which contains essential elements that plants need. Was first posed by W.A. Setchell of the University of California, in connection with the success of the WF Gericke from the same university, in the development of farming techniques with water as a planting medium. Based on the growing medium used, hydroponics can be divided into three kinds, namely: The water culture This technique has long been known, that since the mid-15th century by the Aztecs. In this method the plants are grown in certain media at the bottom there is a solution containing macro and micro nutrients, so that the tip will touch the roots of plants containing the nutrient solution. Aggregate culture Growing media in the form of gravel, sand, rice husk charcoal (kuntan), and others who should be sterilized before use. Provision of nutrient media in a way to irrigate crops or by preparing a solution of nutrients in the tank or drum, and then supplied to plants through a plastic hose. Nutrient Film Technique In this way the plants are maintained in a narrow gully length, made of thin stainless sheet metal. In the channel is fed water containing nutrient solution. Then the roots will be formed around the film (thin layer) as a food crop. Factors Important in Hydroponics Cultivation Nutrient elements Provision of regular nutrient solution in hydroponics is very important, because the media only serves as a means of continuing the support of plants and water solution or excessive. Nutrients available to plants at pH 5.5 - 7.5, but the best is 6.5, because in these conditions in a state of nutrients available to plants. Macro nutrients needed in large numbers and relatively high concentration in solution. Included are the macro nutrients N, P, K, Ca, Mg, and S. Micro nutrients required only in low concentrations, which includes the elements Fe, Mn, Zn, Cu, B, Mo, and Cl. Crop nutrient needs will vary by level and type of plant growth (Jones, 1991). Nutrient solution prepared by dissolving fertilizer salts in the water. Various types of fertilizer salts can be used for nutrient solution, the selection is usually the price of fertilizer and salt solubility. Hydroponics Growing Media Types of growing media used to be very influential on plant growth and development. Good medium to make it available nutrients, moisture and good drainage is assured. The media used must be able to provide water, nutrients and oxygen and does not contain substances that are toxic to plants. The materials used as growing media in hydroponics include sand, gravel, broken bricks, husk charcoal, sponge, and so forth. The materials used as growing medium will affect the nature of the media environment. Levels of temperature, aeration and moisture of the media will vary between one medium to another medium, according to the material used as a medium. Husk charcoal (kuntan) is a black husk fuel is produced from incomplete combustion, and has been widely used commercially sabagai growing media in hydroponics systems. Husk charcoal composition is occupied by at most is 52% SiO2 and C as much as 31%. Other components are Fe2O3, K2O, MgO, CaO, MnO, and Cu in relatively small amounts as well as organic materials. Another characteristic is very lightweight, rugged so high because many circulation of air pores, high water holding capacity, color is black to absorb sunlight effectively, a high pH (8.5 - 9.0), and can eliminate the influence of particular bacterial diseases and weeds. Oxygen The presence of oxygen in a hydroponic system is very important. The low oxygen caused decreased cell membrane permeability, thereby increasing the cell wall is difficult to penetrate, lack of water plants will result. This may explain why the plant will wilt in a flooded soil conditions. The level of oxygen in the pores of the media influence the development of root hairs. Oxygen delivery can be done in various ways, such as: providing air bubbles in the solution (water culture), the replacement of the nutrient solution over and over, wash or fumigate the exposed roots in nutrient solution and provide ventilation at the site of the planting hole for aggregate culture . Water Water quality according to the hydroponics plant growth have salinity levels that do not exceed 2500 ppm, or EC has a value of not more than 6.0 mmhos / cm and contains no heavy metals in large quantities because it can be toxic to plants. Advantages and Constraints Hydroponics Some of the advantages of a hydroponic farming is the production of more extensive union plants, the plants grow faster, more efficient fertilizer use, more efficient water use, labor required fewer yng, a cleaner working environment, control of water, nutrients and pH more accurately, the problem pests and plant diseases can be reduced and can grow plants in a location that is not possible / difficult is planted in an environment such as nutrient-poor soil and rocky or in the garage (in another room) with additional light. The disadvantage is the availability and maintenance of hydroponic devices is rather difficult, requiring special skills to weigh and mix the chemicals as well as an expensive initial investment. cultivation techniques A. Media Hydroponic media that either have a neutral pH of 5.5 or -6.5. Addition, the media should be porous and can retain moisture. The media used can be divided into two stages of plant growth by: Media for the nursery or nursery For the nursery can be a media digunkan fine sand, chaff charcoal or rockwool. Fine sand is often used because it easily available and cheap, but less able to retain water and nutrients contained in it. The media used is a mixture of chaff and sawdust charcoal or coco powder. Media for mature plants Media for mature plants is almost the same as the media for seedlings, which is rather coarse sand, rice husk charcoal, rockwool and others. The ideal medium is charcoal husk. The advantage is the cleanliness and sterility of the media is guaranteed free of debris and organisms that could interfere such as worms, fleas and so that DAPT live in the sand. Media husk charcoal lighter but are more easily destroyed, its use can only be for twice the wear. Husk charcoal can be purchased in stores or make your own farm. B. Seed The selection of seed is important because plant productivity advantages teranganutng of selected seeds. Check the label on the seed, which is the expiration date, the percentage of growth and seed purity. The selection of commodities to be grown carefully taken into account regarding the pricing and marketing. Examples of vegetables that have exclusive selling points above the average rat-Recento tomatoes, Japanese cucumber, melons, Parika, lettuce, Kai-lan, melons and others. C. Hydroponics Farming Equipment The equipment required is: Container seedlings, can use a plastic pot, a small polybag, plastic tub, seedling tray, or wooden boxes. Container grown plants, commonly used measuring 30-40 cm poly bag with holes sufficiently to drain excess water when watering. Tissue paper / wet newspaper to keep the humidity Sand sifter to sift seedling media Handsprayer for watering Ladle stirring media Tweezers to extract seeds from the container seedlings Polybag size of 5 kg for the cultivation of transplant Jute yarn (which is often used as a builder) to bind to plant Bucket sprinkler D. Implementation Preparation of nursery media Prior to the nursery, seedlings media sempuran first stirred evenly. Nursery plants Seedbed big seed For large seeds such as melon and cucumber seeds, should be soaking in lukewarm water dala for 2-3 hours and immediately planted in a container that contains the media and the seedlings have been doused with water. Seeds with tweezers placed horizontally 4-5 mm below the surface of the media. Transplanting seedlings from the nursery container into a larger container can be done when high seed about 12-15 cm (28-30 days after seedling). Small seed nurseries For small seeds such as tomatoes, peppers, eggplant, etc. persemaiannya different ways with large seeds. First, prepare the container seedlings with 5-7 cm thick media. In a separate pour the seeds are mixed with sterile dry sand to taste and stir evenly. Seeds that have been mixed with sand sprinkled on the surface of media evenly seedling, then covered with a thin layer of medium seedlings (3-5 mm). After that the surface of the container seedlings covered with tissue paper that has been moistened with handsprayer then keep in the dark and seedlings aman.Wadah tip should be worn in the morning sun for 1-2 hours to allow germination to grow well and healthy. Once the seeds begin to germinate, discarded tissue paper. Once the seedlings reach a height of 2-3 cm was transferred into the pot / polybag nursery. Treatment of seedlings Tiny seeds that have germinated in the nursery container needs to be watered with plain water. Watering is not excessive, because it can cause a foul disease. Nurseries After 15-17 days old seedlings (seedlings from small seeds) need to be removed from the container seedlings into pots / polybag nursery in order to grow properly. The trick is to pull out the sprouts in a container nursery (age 3-4 weeks after seedling) carefully by hand so that the roots are not damaged and then planted in the planting hole has been made in the pot / polybag nursery. Transplanting / planting move Prior to the move of planting, growing media preparation needs to be done, namely to fill the planting medium to the polybag. Charging should be done near the planting site in the green house in order to maintain sterility of the media. Once the container planting hole and made ready for planting, transplanting it ready made. Transplanting is done by reversing the nursery pot slowly and keep the surface with the fingers (seeds squeezed between the forefinger and middle finger). If the use polybag nursery, then transplanting to be done by cutting / cutting horizontally basic polybag. Sprinkling Watering is carried out continuously, with the indicator when the growing medium with a hand-held dry. Meida growing hydroponic watering the plants are dry, so do not be late. Types and how to watering is as follows: Manual watering Watering is done by handsprayer, yells / emprat or bailer. Way of watering is as follows: At the nursery Way of watering the seeds are small enough for the handsprayer 4-5 times a day to keep the moisture media. For large seeds are used hype / emprat finely perforated or tree sprayer. At the nursery Watering is done with yells to do as much as 5-6 times a day and added to an aqueous solution of nutrients. During growth and production Watering is done by giving out the 1.5-2.5 l aqueous solution of nutrients every day. Automatic watering Watering can be done by Sprinkle Irrigation System and Drip Irrigation System, the spray and drip watering system. Power source comes from the pump. Treatment Plant. Treatment plant needs to be done include: Pruning Prune to remove unwanted branches, shoots, or branches affected by the disease. Prune to improve plant growth and production. For example in tomato recento maintained only for the production of the main stem. Fastening Plants that have been in place for 7 days of planting requires support in order to stand upright so the plants can grow a neat and orderly. Cantilever is given by binding to the plant with a rope (hemp yarn). Thinning rates (in fruit vegetables) Spacing needs to be done so that the growth rate equal pieces. However, research results on the thinning rate Gherkin cucumbers do not show different results to the thinning treatment without interest. Pest and disease control Control can be done either manually or with pesticides. Harvest and Post harvest Harvesting Noteworthy in the way harvesting fruit collection / harvest in order to obtain good quality, for example by using a knife or scissors to harvest. Yields the correct way and be careful to prevent damage to crops that can interfere with subsequent production. Criteria for each harvest different types of vegetables with each other and depending on the market. The larger the fruit is not necessarily more expensive / behavior, even including the criteria that rejects fruit harvest time is right and control over production processes need to be considered. Post-harvest handling Product marketing hydroponic cultivation is strongly influenced by post-harvest treatment. Standard sales price of production depends on the draw whether or not the products, especially from the appearance of the product (shape, color, and size). Post-harvest treatment is very important because the quality is not solely the product of the production only, but highly tegantung and determined by post-harvest handling, packaging, preparation of the system, method and product selectivity pengangkutam. Product damage may dikurangai with proper post-harvest handling that is expected to increase the value added to products sold.