Most of the problems that arise during the production of plug seedlings and flower grasses are related to the water, substrate and fertilizer used. This article describes these three aspects in detail.
Water quality
In many cases, problems with flower quality are related to water quality. Therefore, the water index must be tested before production. Mainly from the alkalinity, salt, sodium ion concentration, pH and other factors to consider.
Alkalinity alkalinity is mainly determined by the calcium carbonate in the water, that is, liquid lime dissolved in water. Irrigation with high-alkalinity water for a long time can increase the pH of the cultivation substrate. If it is handled improperly, production may cause a great deal of problem.
Specifically, alkalinity is caused by calcium carbonate, magnesium carbonate, and sodium carbonate. As a plant, the growth of good roots and shoots is inseparable from calcium and magnesium, not too much sodium, but only the calcium and magnesium in the water is not enough for the plants, and the whole growth period of the plants needs Intake of a certain amount of calcium and magnesium, suitable calcium content: plug 60 ~ 80ppm, Caohua 80 ~ 120ppm.
(1) Adjust the water with too low alkalinity.
Many producers encounter low alkalinity, which is still relatively good, because the pH of the matrix does not increase if it is irrigated with water. However, low-alkalinity water has almost no buffering properties, so when it is poured into an acidic fertilizer, it cannot slow down the drastic fluctuations in the pH of the water. Since most fertilizers are acidic fertilizers, the pH tends to decrease. When it falls below 6.0, it will cause trace element poisoning and calcium deficiency in some plants. For most plants, the pH should not be lower than 5.5.
Plants that are sensitive to trace elements include marigolds, geraniums, impatiens, and New Guinea Impatiens. Low alkalinity water contains very little calcium and magnesium, both of which are necessary for plants. If the calcium content in the water is only 20 to 30 ppm, a calcium-containing fertilizer needs to be applied. One of the methods is to add calcium sulfate-containing gypsum fertilizer, which does not affect the pH of the substrate. Therefore, in addition to areas with very high calcium content, gypsum fertilizers can be added to the matrix of plug seedlings, and the amount of calcium sulfate is approximately 0.6 kg/m3. In addition to calcium, it can also provide a sufficient amount of sulfur because many plants lack sulfur. However, attention should be paid to the high salt content of calcium sulfate, which will increase the EC value of the matrix. Another option is the foliar spray of compounds containing calcium, so that the plants can quickly absorb and thus quickly relieve symptoms of calcium deficiency, you can spray 75 ~ 150ppm calcium nitrate foliar. Similarly, similar symptoms can be used to control the symptoms of magnesium deficiency in plants. For example, magnesium sulfate can be applied or a small amount of MgSO47H2O can be continuously added to irrigation water. Since magnesium is leached, it is not appropriate to apply too much fertilizer containing magnesium in the planting matrix. When applying liquids, borax should also be added from time to time to provide enough boron. The recommended concentration is 0.06g/L. During production, calcium can be added to the matrix, calcium can be added to the liquid fertilization, and magnesium and boron can be added to the water during irrigation.
(2) Adjust the water with high alkalinity.
If the alkalinity in the water is too high, the iron, zinc and magnesium ions in the water will be complexed. In order to make it more suitable for the growth of plants, it can be regulated by using different kinds of acids, which can neutralize calcium carbonate in lime and water. If the water alkalinity is higher than 80, it needs to be adjusted by acid.
a. Phosphoric acid: Phosphoric acid is now relatively less used to regulate the alkalinity of water, because it can lead to a part-year or two-year old grass flower. Listed in Table 1 are the elements that promote the lengthiness of some plants.
b. Citric acid: Citric acid is one of the commonly used acids for regulating water quality. The addition of citric acid can not only promote the growth of plant roots, but also increase the absorption of trace elements by plants. This may be because most of the acids will damage the root system. Citric acid is an organic acid and is non-toxic to plants. However, it can also cause harm in some places, for example, it will form complexes with certain substances, and the pH value in the water will vary greatly, so the amount of this application cannot be accurately calculated, unlike inorganic acids such as sulfuric acid. Water quality is controlled as easily as possible. Therefore, it is necessary to be very familiar with the application, and it is necessary to monitor the pH of the water at any time in order to deal with emergency situations.
c. Sulfuric acid: Sulfuric acid is the most commonly used acid for neutralizing pH. However, because sulfuric acid is highly corrosive and burnable, it will appear necrotic after the plant is contaminated, and it will even burn the root of the flower. Therefore, care must be taken when adding acid. The concentration of sulfuric acid is usually 93% and 33%. It is best to use dilute sulfuric acid with a concentration of 33%. Since 93% of the sulfuric acid contains impurities, it will have a toxic effect on plant growth, and it will also precipitate calcium ions.
d. Nitric acid: Use nitric acid to obtain the best balance of plant roots and crowns. Nitric acid can promote the absorption of calcium, make the plant grow robust, increase the nitrogen content of the water without causing symptoms of leaf spotting. However, nitric acid added pipes cannot be used for PVC products because nitric acid is corrosive. When nitric acid is added, the concentration of nitrogen can be maintained at 40-60 ppm, ensuring that scientific addition of other acids can also yield good quality seedlings. For example, a very small amount of phosphoric acid (phosphorus 20 ppm) is added; or nitric acid is added on a sunny day (light is 1000 to 2000 lux). However, this does not mean that producers must add acid to produce good plug seedlings. However, when the alkalinity of the water is too high, alkalinity is a key indicator when performing water quality tests.
Nutrients The calcium, magnesium, sodium, and boron elements are four indicators that need to be tested in water, substrates, and plant tissues. This is the basis for developing a fertilization plan.
Calcium is one of the essential elements for the development of plant roots and shoots, while magnesium is the guarantee for the dark green and sugar accumulation of the leaves, and boron plays an important role in transporting sugar to the roots. To make the roots robust, the plants can be given optimal calcium and boron concentrations. The recommended concentration of calcium is 50 to 100 ppm, and magnesium is 25 to 50 ppm for continuous irrigation. On the other hand, it is necessary to consider the relationship between calcium and magnesium. It is generally believed that the concentration of magnesium is half of that of calcium, the content of sodium should not be higher than 40 ppm, and the concentration of boron is 0.2 to 0.5 ppm. . If all four elements are well controlled, the plant's root system will develop well.
Some producers use fertilizers with N:P:K ratios of 20:20:20 and 20:10:20, but these two fertilizers do not contain calcium and the plants do not get enough calcium. The content of phosphorus in these fertilizers is 20% and 10%, respectively. Phosphorus causes the plants to grow in size, and it inhibits the absorption of calcium by plants. This is the reason why plants will experience calcium deficiency symptoms when applying these fertilizers. If the plants produced need to be supplemented with a large amount of phosphorus, or if the plants are too short, or if the pH of the substrate needs to be reduced, or if the light intensity is strong, applying these two fertilizers will give the ideal plant growth.
In addition, other factors need to be considered. For example, for plug seedlings and flower grass, it is also necessary to consider the content of other nutrient elements in the water. These include: (1) the content of chlorine must not exceed 80 ppm; (2) the content of boron is maintained at 0.5 ppm; 3) The fluorine concentration must not exceed 1 ppm.
If the production of foliage plants, boron content of not more than 0.5ppm, or part of the plant will cause boron poisoning phenomenon, the plant will die at the top of the death or burn; chlorine content of more than 80ppm will cause root burns, roots Symptoms such as rotting and necrosis of the lower leaves; excessive iron may lead to chlorosis of leaves, promotion of algae growth, and antagonistic competition with elements such as magnesium, calcium, and manganese. Excessive concentrations of boron and iron can be corrected in part by adjusting the pH of the substrate so that the pH is maintained between 6.5 and 6.8, which can reduce the absorption of the plant; in addition it can increase the calcium concentration. Producers should also be mindful of plants that are sensitive to high pH, ​​such as periwinkle, snapdragon, petunia, pansy, and primrose, because of the high pH, ​​iron deficiency and aggravation of leptosphaeria happened.
There are other factors that need to be considered in the production of water, substrates and fertilizers. Examples include the amount of soluble salts and their effect on plants. Because salt provides nutrients, it is extremely important to plants. In general, the amount of salt can be roughly known by measuring the EC value. The EC value in water should be at least 1.0 mS/cm. The EC value in the water should be kept low because some plant seeds, such as snapdragon, string of red, sea lice and balsam, are very sensitive to salinity, and the salinity will also accumulate around the seeds and roots. A certain degree will cause root death. Therefore, EC value should be treated with caution in plant production, especially in the early stages of plant growth, including the early growth of plug seedlings and seedlings that have just been transplanted. If the EC value of the water is too high, it is necessary to take leaching, fertilizer conversion, reverse osmosis, or even changing the water source.
Water temperature In general, water temperature does not have a great influence on the growth of plants. The best water temperature for impatiens is 18°C ​​to 21°C. When the water temperature is lower than 10°C, some seedlings grow unevenly, especially petunias. It has been proven that seed coats impede the rooting of germs into the matrix and impede the development of the root system. Therefore, producers sometimes use warm water to remove seed coats outside the seed. For the skin or coating of petunia seeds, the water temperature of 30°C is more favorable. Sometimes, different water temperatures can cause the Begonia growth to be inconsistent. Soaking Begonia seeds in water at 23°C will cause the seed coat to fall off after 25 seconds. Removing the seed coat of Begonia can increase the germination rate, and it is not easy to observe its rooting condition if the seed coat is preserved during the germination and long leaf stage of Begonia.
Water Quality Summary Table 2 lists the indicators of water suitable for watering grass flowers and plug seedlings. The sodium adsorption ratio (SAR) refers to the relative ratio of sodium ions and calcium ions and magnesium ions exchanged with the soil. Sodium ions are also a factor that affects root growth. Magnesium and calcium are essential elements for the growth and development of roots, but sodium ions antagonize any one of them, so that their absorption by plants is reduced. Therefore, commercial fertilizer with an N:P:K ratio of 15:16:17 is rarely applied, because the fertilizer contains sodium ions (present as sodium bicarbonate) and can harm the growth and development of plant roots.
It is recommended that producers test water for irrigation. Alkalinity, EC value, pH value, and calcium, magnesium, sodium, and boron ion levels are four indicators that must be detected in irrigation water, substrates, and plant tissues. For plug seedlings, as long as the alkalinity is reduced a little, the pH value will rise quickly because the base mass in the plug tray is very small and the buffering performance of the matrix is ​​much poorer. It is also necessary to pay attention to the plug seedlings. Calcium, magnesium, sodium (requires lower levels) and boron ion concentration.
Matrix
Certain physical and chemical properties must be considered when selecting the matrix, which can produce high-quality plug seedlings and grass flowers.
Some of the physical properties that need to be considered for physical properties are: (1) soil composition; (2) matrix moisture content; (3) matrix porosity; (4) matrix composition.
Important in the matrix are the water holding capacity, permeability, cation exchange rate (CEC) and the ability of the matrix to release water. The ability of the matrix to release water is just as important as the matrix's water holding capacity. Stone wool, for example, has a very strong water absorption capacity, but it releases water very quickly. Therefore, two points must be considered during production: What is the amount of water that can be held in the matrix? How long does it take to lose these waters? In general, the finer the material used, the higher the water holding capacity of the matrix, and it is better to add some perlite in the matrix. In North America, a certain percentage of perlite is added to the matrix during the production of plug seedlings.
(1) Porosity: If finer vermiculite is added to the matrix, the total amount of air will be reduced to almost zero, and if the ruthenium is added to the matrix, the porosity may even reach 8%. If the substrate's ability to ventilate is zero, the plant will grow poorly, even if it suffocates. For plug seedlings, if the moisture in the matrix is ​​too saturated, the seeds will begin to deteriorate after 24 to 48 hours, which is why the excess water should be expelled in time. A good producer of plug seedlings will have a good grasp of the changes in water, let the water poured out within 24 hours, and then water. Some producers often water once every two or three days, because the water in the plug seedlings is too wet.
(2) Matrix composition: Generally speaking, peat, perlite, vermiculite, and lime soil are commonly used in the matrix. Some producers also added bark compost. If they are mixed well, the effect is good. The matrix of plug seedlings is generally mixed with a large amount of moss peat, about 10% of medium-sized vermiculite, and 15% to 20% of perlite. Similar formulas can also be used for grass flower production. The difference is that the added perlite and peat should be rougher to increase the porosity in the matrix and the vermiculite content can be increased to 15%.
(3) Preparation of Substrates: How to determine whether the matrix is ​​suitable? Here is a simple and effective way to do this: Gently pry your fingers in the matrix of the tray. If the height of the matrix drops more than half, it means that the matrix used is too loose and you need to add more fine material. When judging whether the water in the prepared matrix is ​​appropriate, a simple method is to hold the substrate tightly by hand, and the fingers do not drip. After the hands are released, the matrix does not spread or slightly crack, and the moisture is suitable at this time. If fingers are dripping when gripped, it means that the water is too much. This kind of matrix is ​​not suitable for plug seedlings.
The correct method of filling the plug trays ensures that the matrix in the plug tray has sufficient air permeability, which is also the key to obtaining good substrate humidity and suitable depth. The less matrix filled in the tray, the thinner the oxygen content inside. Deeper plugs can be used to grow seedlings, so that both the moisture and the base weight are higher. Deeper plugs provide more oxygen for the seedlings and also promote root growth.
In summary, the key physical properties of the matrix are its water holding capacity and permeability. In addition, the cation exchange capacity is also related to the matrix's water holding capacity, permeability, and water release capacity.
Chemical Properties The chemical properties of the matrix need to be considered: (1) matrix composition; (2) suitable pH in the matrix; (3) EC value of the matrix; (4) nutrients in the matrix.
The pH of the matrix is ​​an important indicator in the production of plug seedlings and grass flower. If the pH is too high or too low, the nutrients in the matrix cannot be used by plants. Most producers test the pH once a week. For most plants, including perennials, a pH of 5.5 to 6.5 is appropriate (Figure 1). From the time of sowing until the plants are sold, the plants need a suitable pH to grow well. The problem of plant growth caused by inappropriate pH values ​​is more than that caused by other factors, which is also the reason for concern about water, especially alkalinity.
But the problem is that it is difficult to keep the pH at its best. If there is a certain degree of alkalinity in the water, the pH will also increase. Conversely, if there is no alkalinity in the water, the pH will drop. This is also the reason why the initial value of the pH is controlled to be around 5.5, and it is raised to about 5.8 through fertilization. If 20-20-20 fertilizer is applied, the pH of the substrate will decrease because the content of ammonium nitrogen in the 20-20-20 fertilizer is as high as 40%, ie the fertilizer is an acidic fertilizer. Acidic fertilizers will reduce the pH in the matrix; if the pH is below 5.5, it may cause the plant to produce calcium deficiency and magnesium deficiency elements, but also the risk of excessive iron absorption.
For geranium, marigold, eustoma and impatiens, these four plants require higher pH values. Although they can grow at a pH of 5.5, the growth, development, and flowering of the plants will be better when the pH is 6.0 to 6.5. After the pH is higher than 6.5, the absorption of some nutrients will be affected. The pH of these plants is preferably kept at 6.2-6.5. The effect of pH on plants' absorption of each element is shown in Figure 2.
(1) Adjust the pH in the matrix.
If the pH is too high, it can be adjusted by: a. reducing the amount of lime; b. applying an acidic fertilizer; c. adding an acid.
If the pH is too low, methods may be used: a. adding lime; b. applying alkaline fertilizers 15-0-15 and 14-0-14 and 13-2-13-6-3); c. improving the water The alkalinity; d. Fertilizer to add potassium hydroxide or potassium carbonate fertilizer (Figure 3).
(2) Test the pH in the matrix.
If the pH falls below 4.5, you need to be aware of the growth of your plants. The method for detecting the pH value is: after watering for 1 hour, take the matrix in about 5 trays, squeeze the water out by hand, and drip it on the instrument. Only a few drops is enough for the EC meter and pH meter. Dosage. Since the value measured by the hand-squeezing method is the EC value and pH around the plant root system, the method is more accurate. The measurements were made after 1 hour of watering because the fertilizer required a period of time to balance. After 4 weeks of inspection, many traits about the matrix were known. Including: How will the characteristics of the matrix become after a long time? What is the initial pH of the matrix? Changes in traits after one week of irrigation? Change in matrix properties after 4 weeks?
a. Method 1: Test with distilled water. The trays or pots were filled with the matrix, distilled water was added, and the pH was measured after 1 hour so that the measured values ​​were more accurate. This test is performed every week thereafter for 4 consecutive weeks. It was sometimes found that the initial pH of the matrix was 5.5, and sometimes it remained at this level even after 4 weeks. However, sometimes the pH will increase, indicating that the content of lime in the matrix is ​​too high, which will affect the growth and development of the plant; if the pH value decreases, the content of lime is too small. Pansy is generally used as an indicator plant because Pansy does not affect the pH of the substrate. Petunias only have a slight effect on pH, so they can also be used as indicator plants.
b. Method 2: The test method is the same as above except that it is performed with conventional water. Plants grow faster in the second and third stages of plug seedlings and after transplantation, and they can quickly change the pH and soluble salt content of the matrix.
nutrition
Fertilizers should be preferred based on plant species, substrate pH, and water quality. There are three keys to fertilization: one is the nitrogen form: the ratio of ammonium nitrogen to nitrate nitrogen; the second is the calcium and magnesium content; and the third is the nature of the fertilizer. Before applying the fertilizer, a careful analysis of the fertilizer composition is required, including: (1) What is the nitrogen form? What is the content? (2) The content of calcium and magnesium? (3) The nature of the fertilizer? Is it acidic or alkaline? What is the value?
Ammonium nitrogen can be converted to nitrate nitrogen, which is not conducive to decomposition of ammonium nitrogen in the matrix by low temperatures, and may cause ammonia poisoning. Therefore, it is strictly prohibited to apply fertilizer containing ammonium nitrogen below 15°C. Nitrate will increase the pH while ammonium nitrogen will lower the pH. Even urea will reduce the pH of the matrix. Some fungicides (such as Subdue and Truban) destroy microorganisms in the matrix, converting ammonium nitrogen to nitrate nitrogen. When using these fungicides for irrigation, avoid the use of fertilizers with high levels of ammonium nitrogen.
Acidic fertilizer 20-20-20 is an acidic fertilizer, it contains 40% of ammonium nitrogen, its potential acidification capacity is 400; 20-10-20 contains 20% of ammonium nitrogen, its acidification capacity is 200; 21-7-7 is a special fertilizer for blueberries and rhododendrons. Its potential for acidification is very strong at 1700; the fertilizer part of 15-5-17 is alkaline, but most of it is acidic because it contains urea and Ammonium phosphate promotes a decrease in pH. In most cases of production, plants do not require high levels of ammonium nitrogen or phosphorus. Now the factory has tended to produce 15-5-17, while producing less of the first three fertilizers. Many fertilizers are rarely used, such as 14-4-14 and 15-5-20.
Alkaline fertilizers such as 15-0-15, 14-0-14, and 13-2-13-6-3 all increase the pH of the matrix. If the calcium and magnesium elements in the water are not enough, then they can be used. A kind of fertilizer, especially the last one, because of its relatively high content of calcium and magnesium.
The influence of environmental factors on environmental factors also affects the type of fertilizer used. For example, a basic fertilizer can be applied if the light is low, and acidic fertilizers such as 15-5-17 or 20-10-20 can be applied if the light is strong, and the latter can make the plant grow faster. For temperatures below 16°C, fertilizers containing ammonium ions are generally not applied. The type of fertilizer applied affects the balance of vegetative and reproductive growth of the plant. The three fertilizers KNO3, 15-5-17 and 14-0-14 can all promote plant flowering because they all contain higher potassium. Potassium nitrate is often used on plants such as pansy, four-season begonia and petunia to promote flowering. And 20-20-20 and 20-10-20 can promote the vegetative growth of plants because of their higher phosphorus and ammonium nitrogen/urea content.
Plants respond differently to different elements: Primroses are sensitive to phosphorus and petioles tend to grow; petunias tend to be long in the case of high levels of ammonium nitrogen and phosphorus; pansy can be caused by high nitrogen levels. Absolutely, but regardless of the use of nitrate nitrogen or ammonium nitrogen, in the case of high phosphorus content will not be long. If it is desired that the impatiens grow faster, then 20% of the fertilizer containing phosphorus can be applied; most producers also apply 15-5-17, 13-2-13-6-3, 14-0-14 and KNO3.
It should be noted that the type of the medium, the characteristics of the organic material, etc. will have a certain influence on the pH value; fertilizer and rain will also affect the pH value; other influencing factors include soil texture structure, organic matter type, trace elements in the soil, etc. Although small, pH changes to varying degrees.
Root development and the industrial production of fertilizers place great emphasis on the good development of the root system. To obtain a good root system, one of the important factors is moisture, in addition to the nitrogen and calcium content, and sometimes related to the continuous application of phosphorus (concentration 20 ppm). Although phosphorus can indeed promote root development, it should not be used in too much quantity. Ammonium nitrogen, urea and phosphorus can promote the growth of the upper part of the plant, but it will make the plant weak and the roots unfavorable. Producers should not pay too much attention to the above-ground part of the plant, because changing its growth is faster. It should focus on the development of the roots, and pay attention to the nitrate nitrogen, calcium, and boron content of the fertilizer used to make the roots develop better.
It is best not to add slow-release fertilizers to the matrix of controlled-release fertilizer plugs, and it is better not to add to the upper basin base in flower production, because the 14-14-14 fertilizers normally irrigated can provide enough nitrogen sources. If the temperature during production is between 14°C and 15°C, ammonia poisoning may also occur; if the production temperature is around 20°C, fertilizers with relatively low ammonium nitrogen and phosphorus may be used. After the plant has grown into a finished product, it also requires a certain amount of nutrients in the substrate because the purchaser pays great attention to the growth of the plant.
The definition of Finished Pharmaceutical Product can be found in § 4 (1) of the Medicines Law. It reads: "Finished drugs are drugs that are prepared in advance and sold in specific packaging to the consumer..." The drugs are mostly in the form of tablets, capsules, drops, liquids, ointments and suppositories. For Phytotherapy (healing with plants) numerous drugs are also available in pharmacies in which drugs or drug preparations are processed. One distinguishes between the drug preparations: the chopped drug to prepare a tea, the milled drug (= drug powder) and the dried extract for the manufacture of tablets, capsules and pills, tincture for the preparation of drops and the fluid extract for juices, salves and other ointments to name a few. A finished drug with a drug formulation is called an "herbal medicine" or phytopharmacon (plural: phytopharmaceuticals).
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