- Preparation of the planting media
This entails collection of the top soil mixing with the well decomposed manure, heating, cooling and potting/bagging. This method of media preparation kills most of the soil pathogens especially Ralstonia solanacerium that causes BACTERIAL WILT. Thus hygiene should be observed to avoid contamination.
The dimensions of the pan should be 10cmx100cmx200cm.
- Collect the top soil then mix with manure thoroughly at the ratio of 3:1(soil: manure) at least.
- Put the mixture in a pan and heat it up
- The turning of the mixture while on fire should be after every 5 minutes
- The heating should be between 25-30minutes
- After 30 minutes heated mixture is allowed to cool down before being bagged.
- Each bag should be at least 3/4 full
- Bed preparation
The bed can be slightly raised (about 10cm high)
Plastic mulch should be placed to cover the ground to avoid possible contamination with the treated content in the bags. Arrange the bags below the drip lines on plastic mulch making sure two drip emitters’ drip in the same bag.
- Water treatment
Water used for irrigation and spraying has to be treated with calcium hypochlorite at the rate of 5-10gms per 600 – 1000lts of water. (I.e.2tea spoonful or 1 table spoonful), then left for it to be safe for use after 12 hours for both irrigation and spraying.
The pots are arranged in the green house at a pattern of two drip emitters per bag. Irrigation and spraying water should always be treated with calcium hypochlorite for at least 12 hours. The other growing procedure follows the advised agronomic practices.
- Soak the supplied nursery media in water in a bucket.
- Mix well until wet using your hand.
- Fill the tray grooves with the nursery media and press so that it occupies ¾ of each tray groove.
- Place one seed precisely at the center of each groove of the tray.
- Cover the seeds lightly by filling the remaining ¼ of the groove with media. (Squeeze this media lightly to release water before covering the seed).
- Place the trays on a raised surface preferably on a wooden pallet or suspended between the beds .This is done to improve drainage thus reducing incidences of water logging.
- Irrigation is normally done using the knapsack sprayer preferably morning and evening.
Irrigation should be done daily for the next 5 days. Start irrigating the second day using a knapsack sprayer. Irrigate as frequent as possible subject to weather as the media dries but avoid over irrigating.
From day 6, start using Bonus 19:19:19 or 20:20:20 at the rate of 10gms in every 16lts of water using a knapsack. The schedule should alternate on 3days with fertilizers and 1 day of plain water (3-1-3-1) for the crop duration until the seedlings are due for transplanting.
Hardening off should be done within 1 to 2 days prior to transplanting. This is done by intentional reduction in irrigation interval and feeding regime so that the seedlings can acclimatize to the new environment and avoid transplanting shock.
Seedlings are ready for transplanting after 21 to 28 days for tomatoes and 30-45 days for pepper and onions in nursery or when the seedlings are 7-10cms and pencil thick. Transplanting should be done in the evening preferably, or any time of the day on cool weather. Correct spacing should be observed when transplanting based on the crop canopy and if it is in planting bags, 1 seedling per bag.
|Tomato||60cm x 60cm|
|Sweet Melon||60cm x 60cm|
|Cucumber||60cm x 60cm|
|Pepper||30cm x 60cm|
Soak the soil before transplanting. This can be achieved by irrigating the beds/planting bags for three days to transplanting for 1 to 2 hours daily, or by using the watering cane prior to transplanting.
Make holes about 5-10cms deep on top of beds/ center of the planting bag, observing the spacing. Holes should be done in a zigzag pattern along the two rows of the bed, if it is on the ground.
Apply Smart fertilizer (SF); a slow release base dressing fertilizer that will help in proper root development and apical growth at the rate of 30-50gms per hole/bag. Or NPK 15:15:15 in split application of 30gms per plant then on 5th month 10-20gms.
Mix the fertilizer and the soil thoroughly within the hole/bag to avoid root scotch.
Irrigate the seedlings on the trays well before transplanting to remove air bubbles.
Lift the seedlings slowly from the tray taking caution not to damage the roots.
Make a light depression on the hole with soil and ASF mixture and bury the transplant up to the collar (same height as the nursery media).
Press gently on both sides of the media at the base of the transplanted seedling to ensure no vacuum left for it might cause root loss.
Irrigate the plants well after transplanting.
Drip irrigation system
Its gravity fed from a tank 500-1000lts on a tower 1.5m high, to increase the head. This system has an advantage of low water use as water drips on the plant only. Specified irrigation saves on water and nutrients loss by leaching and evaporation.
Young plants are quite sensitive to water stress. Regular irrigation with small water quantities in a day for the first one week after transplanting is recommended. Deep irrigation followed by 1-3 days water stress encourages deep rooting. Irrigation frequency and water quantity is determined by soil type, age of the crop, soil salinity and prevailing weather condition. Saline soils require more water due to leaching factor. In a hot weather more watering is done to counteract the effect of evapotranspiration. Light soils require more water volume and higher frequency than heavy soils.
You can determine when to irrigate by look at the crop or moisture check by handful method. **Irrigation should only be done using drips only
As a good maintenance practice; always clean the filter first before any irrigation on daily basis. Flash the system weekly to avoid clogging that cause un-uniform application.
Signs of Improper irrigation are:
|Damping off||Over irrigation|
|Wilting of plants||Both over and under irrigation|
|Flower abortion||Under irrigation *|
|Cracking of fruits||Over irrigation|
|Blossom-end rot||Under irrigation *|
- *the cause can be different from irrigation.
- Filter cleaning to be done on daily basis
- Flushing to be done on weekly basis
Bonus supplied together with irrigation water at the rate of 0.5gms /1 liter of water starting after transplanting, for the first 4 weeks. Increase application to 1gm/1Litre of water, from the 4th week onwards. This fertilizer is soluble in water and is applied through drip irrigation. When applying through drip, it’s important to premix in a bucket to dissolve completely before pouring it into the fertilizer tank.
Applied at least once per week
- MULTI- K (Potassium Nitrate)
It should be applied from 4th week of transplanting at the rate of 1gms / 1lt of water with drips. Apply at least once per week by irrigating after premixing in a bucket before pouring into the main irrigation tank. This rate should be maintained throughout the crop cycle.
NOTE: The application frequency should be at least once a week. During flowering and fruiting use much of MULTI K than BONUS in our feeding regime, i.e. 2 weeks with Multi K followed by 1 week with BONUS.
- Haifa cal. (Calcium Nitrate)
The crops need to be top dressed after 3 to 4 weeks from transplanting using Haifa cal. at the rate of 5-10gms per plant – as a ring band around the plant and has to be covered with the soil after application. If it is split application of 5gms/plant, the re-application of the same rate will be on the 5th month after transplanting.
After the application the plants have to be irrigated if the soil is not well moist.
Note: Excessive application of fertilizers has negative implications
- Excessive Nitrogen can be destructive on both leaves and fruits
with irregular water applications and Damage on fruits – High Nitrogen combined fluctuating temperatures
To correct the problem we re-apply Multicote at the rate of 5gms/plant, and observe Nitrogen application
- Excess fertilizer or manure can burn the crop.
GROCAL MGB /TECNOKEL
It’s a foliar application fertilizer with calcium concentrate for flower, fruit formation and development.
Helps in Blossom end rot control by provision of Calcium.
Application should be done after the fruiting at the rate of 40 to 50mls/knapsack. On spraying special attention should be on flowers and fruits.
Identifying Nutritional Problems
Learn to monitor the plants visually to determine if there is a potential nutrient problem.
High Nitrogen: Excessive nitrogen can result in fairly serious problems in tomatoes by shifting the plant into a vegetative plant.
How do you know if you are over-applying nitrogen? There are several symptoms, which include:
- “Balling up” of leaves in the top of plants. This term refers to the curling under of the small leaves in the terminals.
- 2. The midrib of leaves tends not to grow in a straight line. It will grow in a curved manner, resulting in growth to one side of the leaf.
- Small, vegetative growth will emerge from the top of the leaf midrib.
- Shoots of vegetative growth will grow at the ends of flower clusters. These can be removed.
- Fruit set will usually be decreased, with one or two fruit per cluster instead of four or five.
Usually, these occur on three or four clusters and will disappear when the nitrogen levels have decreased.
- Leaf growth will increase in size and will be dark green.
The chlorosis symptoms shown by the leaves are the direct result of nitrogen deficiency. A light red cast can also be seen on the veins and petioles. Under nitrogen deficiency, the older mature leaves gradually change from their normal characteristic green appearance to a much paler green. As the deficiency progresses these older leaves become uniformly yellow (chlorotic). Leaves become yellowish-white under extreme deficiency. The young leaves at the top of the plant maintain a green but paler color and tend to become smaller in size. Branching is reduced in nitrogen deficient plants resulting in short, spindly plants. The yellowing in nitrogen deficiency is uniform over the entire leaf including the veins. As the deficiency progresses, the older leaves also show more of a tendency to wilt under mild water stress and senesce much earlier than usual. Recovery of deficient plants to applied nitrogen is immediate (days) and spectacular.
Figure1: Characteristic nitrogen (N) deficiency symptom
The necrotic spots on the leaves are a typical symptom of phosphorus (P) deficiency. As a rule, P deficiency symptoms are not very distinct and thus difficult to identify. A major visual symptom is that the plants are dwarfed or stunted. Phosphorus deficient plants develop very slowly in relation to other plants growing under similar environmental conditions but with ample phosphorus supply. Phosphorus deficient plants are often mistaken for unstressed but much younger plants. Developing a distinct purpling of the stem, petiole and the lower sides of the leaves. Under severe deficiency conditions there is also a tendency for leaves to develop a blue-gray luster. In older leaves under very severe deficiency conditions a brown netted veining of the leaves may develop.
Figure 2: Characteristic phosphorus (P) deficiency symptom
The leaves on the right-hand photo show marginal necrosis (tip burn). The leaves on the left-hand photo show more advanced deficiency status, with necrosis in the interveinal spaces between the main veins along with interveinal chlorosis. This group of symptoms is very characteristic of K deficiency symptoms.
Figure 3: Characteristic potassium (K) deficiency symptoms.
The onset of potassium deficiency is generally characterized by a marginal chlorosis, progressing into a dry leathery tan scorch on recently matured leaves. This is followed by increasing interveinal scorching and/or necrosis progressing from the leaf edge to the midrib as the stress increases. As the deficiency progresses, most of the interveinal area becomes necrotic, the veins remain green and the leaves tend to curl and crinkle. In contrast to nitrogen deficiency, chlorosis is irreversible in potassium deficiency. Because potassium is very mobile within the plant, symptoms only develop on young leaves in the case of extreme deficiency.
Typical potassium (K) deficiency of fruit is characterized by color development disorders, including greenback, blotch ripening and boxy fruit
Figure 3: Characteristic potassium (K) deficiency symptoms on the fruit
These calcium-deficient leaves (Fig. 3a) show necrosis around the base of the leaves. The very low mobility of calcium is a major factor determining the expression of calcium deficiency symptoms in plants. Classic symptoms of calcium deficiency include blossom-end rot (BER) burning of the end part of tomato fruits (Fig. 3b). The blossom-end area darkens and flattens out, then appearing leathery and dark brown, and finally it collapses and secondary pathogens take over the fruit.
Figure 4: Characteristic calcium (Ca) deficiency symptoms on leaves and fruits
All these symptoms show soft dead necrotic tissue at rapidly growing areas, which is generally related to poor translocation of calcium to the tissue rather than a low external supply of calcium. Plants under chronic calcium deficiency have a much greater tendency to wilt than non-stressed plants.
Magnesium-deficient tomato leaves (Fig. 11) show advanced interveinal chlorosis, with necrosis developing in the highly chlorotic tissue. In its advanced form, magnesium deficiency may superficially resemble potassium deficiency. In the case of magnesium deficiency the symptoms generally start with mottled chlorotic areas developing in the interveinal tissue. The interveinal laminae tissue tends to expand proportionately more than the other leaf tissues, producing a raised puckered surface, with the top of the puckers progressively going from chlorotic to necrotic tissue
Figure 5: Characteristic Magnesium (Mg) deficiency
This leaf (Fig. 12) shows a general overall chlorosis while still retaining some green color. The veins and petioles exhibit a very distinct reddish color. The visual symptoms of sulfur deficiency are very similar to the chlorosis found in nitrogen deficiency. However, in sulfur deficiency the yellowing is much more uniform over the entire plant including young leaves. The reddish color often found on the underside of the leaves and the petioles has a more pinkish tone and is much less vivid than that found in nitrogen deficiency. With advanced sulfur deficiency brown lesions and/or necrotic spots often develop along the petiole, and the leaves tend to become more erect and often twisted and fruit brittle.
Figure 6: Characteristic sulfur (S) deficiency
These leaves (Fig. 6) show a light interveinal chlorosis developed under a limited supply of Mn. The early stages of the chlorosis induced by manganese deficiency are somewhat similar to iron deficiency. They begin with a light chlorosis of the young leaves and netted veins of the mature leaves especially when they are viewed through transmitted light. As the stress increases, the leaves take on a gray metallic sheen and develop dark freckled and necrotic areas along the veins. A purplish luster may also develop on the upper surface of the leaves
Figure 7: Characteristic manganese (Mn) deficiency
These leaves (Fig. 7) show some mottled spotting along with some interveinal chlorosis. An early symptom for molybdenum deficiency is a general overall chlorosis, similar to the symptom for nitrogen deficiency but generally without the reddish coloration on the undersides of the leaves. This results from the requirement for molybdenum in the reduction of nitrate, which needs to be reduced prior to its assimilation by the plant. Thus, the initial symptoms of molybdenum deficiency are in fact those of nitrogen deficiency. However, molybdenum has also other metabolic functions within the plant, and hence there are deficiency symptoms even when reduced nitrogen is available. At high concentrations, molybdenum has a very distinctive toxicity symptom in that the leaves turn a very brilliant orange.
Figure 8: Characteristic molybdenum (Mo) deficiency
This leaf (Fig. 8) shows an advanced case of interveinal necrosis. In the early stages of zinc deficiency the younger leaves become yellow and pitting develops in the interveinal upper surfaces of the mature leaves. As the deficiency progresses these symptoms develop into an intense interveinal necrosis but the main veins remain green, as in the symptoms of recovering iron deficiency.
Figure 9: Characteristic zinc (Zn) deficiency symptoms.
This boron-deficient leaf (Fig. 9) shows a light general chlorosis. Boron is an essential plant nutrient, however, when exceeding the required level, it may be toxic. Boron is poorly transported in the phloem. Boron deficiency symptoms generally appear in younger plants at the propagation stage. Slight interveinal chlorosis in older leaves followed by yellow to orange tinting in middle and older leaves. Leaves and stems are brittle and corky, split and swollen miss-shaped fruit.
Figure 9: Characteristic boron (B) deficiency symptoms on leaves and fruits
These copper-deficient leaves (Fig. 10) are curled, and their petioles bend downward. Copper deficiency may be expressed as a light overall chlorosis along with the permanent loss of turgor in the young leaves. Recently matured leaves show netted, green veining with areas bleached to a whitish gray. Some leaves develop sunken necrotic spots and have a tendency to bend downward.
Figure 10: Characteristic copper (Cu) deficiency symptoms.
These iron-deficient leaves (Fig. 11) show intense chlorosis at the base of the leaves with some green netting. The most common symptom for iron deficiency starts out as an interveinal chlorosis of the youngest leaves, evolves into an overall chlorosis, and ends as a totally bleached leaf. The bleached areas often develop necrotic spots. Up until the time the leaves become almost completely white they will recover upon application of iron. In the recovery phase the veins are the first to recover as indicated by their bright green color. This distinct venial re-greening observed during iron recovery is probably the most recognizable symptom in all of classical plant nutrition. Because iron has a low mobility, iron deficiency symptoms appear first on the youngest leaves. Iron deficiency is strongly associated with calcareous soils and anaerobic conditions, and it is often induced by an excess of heavy metals.
All these nutrient requirements are taken care of in the fertilizer pack that is provided in the kit
Figure 11: Characteristic iron (Fe) deficiency symptoms
Insect pests, diseases and weeds compete with the crop for nutrients and water. It’s important to avoid their infestation and to control their spread. Inspect crop regularly (at least twice per week) and keep records.
Check for presence of pests and disease signs, nutritional problems, deficiencies, deformities on all plant parts i.e. leaves, stems, flowers & fruits. Scouting should also be done to justify chemical application.
Insect pest is one of the major challenges in vegetable farming. For proper control, one should be in a position to identify the pest and match the product against it, taking note on PHI- pre-harvest interval.
Cutworm: Are grayish, hairless worm of waxy appearance. Usually found on the vicinity of cut plant. They hide in soil during day and emerge at night to feed on young plants.
Nematodes: They are worms that live in the soil and get food from sucking root sap. They are responsible for causing root knot Galls. They interfere with movement of water and nutrients within the plant. Crops stunt with poor response to nutrients.
Aphids: They are always found in small colonies sucking sap of tender growth on the plant.
They transit viral disease, cause necrotic spots on leaves and stems. Infested plants have curled leaves. They secrete honeydew that promote development of sooty mold on foliage and fruit which slows plants growth. Heavy infestation causes yield losses and sun burn.
Thrips: They are slender bodied with narrow fringed wings. Immature stages are yellow in color. On feeding they rasp plant surface causing small silverish blotches. They feed on young lower leaf surface, buds, flowers and fruits. On flowers they cause floral abortion affected fruits are of poor quality. They are vectors of viruses.
Leaf miner: The adults are small flies with a golden spot on its thorax between the wings. They lay eggs which hatch into small larvae that feed by mining between upper and lower leaves epidermis, making tunnels.
Act of egg laying and feeding on leaves can kill seedlings and in older plants it allows fungal diseases to enter the leaves.
‘Mining’ causes whitish blotches inside the leaves, kills the leave eventually leading to reduced yield and exposes fruits to sun burn.
Mites: They are minute red insects that hide on the underside of the leaves.
They feed on leaves and young main veins. They feed on fruits causing white speckling. They make webs around the adults making their control very difficult.
They have a high multiplication rate with a population building as from 5 days as the temperature rises.
White flies: They are white; readily fly when the plants are disturbed or when the weather is hot. They have a high multiplication rate with a population building in 20days.
Feed on leaves causing them to yellow and curl. They also secrete honey dew which makes leaves shiny and sooty. The Greenhouse whitefly is a good vector of various viruses including the Tomato Yellow Leaf Curl Virus. Their feeding also causes uneven fruit ripening.
Physical controls include use of clean tools and destruction of infested debris.
Caterpillars: Caterpillars or Boll-worms feed on leaves, flowers and fruits.
Larvae enters the fruit at the stem end, ones inside the fruit, caterpillar complete its development and becomes difficult to control with pesticides.
Their feeding result to watery messy internal cavity with excretes and cast skin.
Damaged fruits ripen prematurely and eventually may drop off.
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(To be continued in the next article)