Tomato Cultivation & Management

Climate Requirements for Tomato cultivation

The temperature range of 10-25 °C is considered ideal for tomato cultivation. The ideal sowing temperature is 10-15 °C coupled with 400-600 mm rainfall. The best quality tomato, red in colour is developed at 21-24 °C temperature.

Soil Requirements & Land Preparation

Tomato grows very well on a wide range of soils, but it grows particularly well on deep, well-drained soils with good drainage ability. Sandy loam, red soils and medium black soils are considered most suitable for tomato cultivation. For good yield, the pH of soil must be at 7-8.5

Climate Requirements for Tomato cultivation

Soil Requirements & Land Preparation

Diseases in tomato

Early blight

Identify: This common tomato plant disease appears as bulls-eye-shaped brown spots on the lower leaves of a plant. Often the tissue around the spots will turn yellow. Eventually, infected leaves will fall off the plant. In most cases, the tomatoes will continue to ripen, even as the disease symptoms progress up the plant.

Prevent: The early blight pathogen (Alternaria solani) lives in the soil and once a garden has shown signs of the early blight fungus, it’s there to stay because the organism easily overwinters in the soil, even in very cold climates. Fortunately, most tomatoes will continue to produce even with moderately severe cases of early blight. To prevent this tomato fungal disease, mulch plants with a layer of newspaper topped with untreated grass clippings, straw, leaf mold, or finished compost immediately after they are planted. This mulch forms a protective barrier, preventing the soil-dwelling spores from splashing up out of the soil and onto the plant.

Manage: Once the fungus strikes, organic fungicides based on Bacillus subtilis or copper can help prevent or stop the spread of this tomato plant disease. Bicarbonate fungicides are also effective (including BiCarb, GreenCure, etc).

Copper (copper hydroxide, copper oxychloride, etc.

2) Chlorothalonil

3) Difenoconazole and Mandipropamid

4) Mancozeb and Zoxamide

5) Azoxystrobin

Fusarium wilt

Identify: The pathogen that causes Fusarium wilt (Fusarium oxysporum) is generally more common in warm, southern regions where this tomato plant disease can wipe out entire fields. Symptoms include drooping leaf stems. Sometimes an entire branch may wilt, often starting with the lower portion of the plant and then progressing upwards until the whole plant collapses. To confirm an infection, cut the main stem of the plant open and look for dark streaks running lengthwise through the stem. Sometimes there are also dark cankers at the base of the plant

Prevent:

The spores of this tomato plant disease live in the soil and can survive for many years. They’re spread by equipment, water, plant debris, and even people and animals. The best method of prevention is to plant resistant varieties if you’ve had trouble with Fusarium wilt in the past. Also disinfect tomato cages and stakes with a 10% bleach solution at the end of every season.

Management

: Once this tomato plant disease strikes, there’s little you can do to control it. Instead, focus on preventing it for future years.

Soil solarization can help kill fungal spores in the top few inches of soil, and crop rotation is key. There are also several biological fungicidal drenches that can be applied to soil (look for one based on the bacteria Streptomyces griseoviridis called or a granular one based on the fungus Trichoderma virens. These products may help prevent the infection from colonizing the roots of future crops.

Late blight

Identify: Late blight (Phytophthora infestans) is among the most destructive tomato plant diseases. Thankfully, it’s not very common, especially in the north where it doesn’t survive winter’s freezing temperatures without a host plant. Late blight is caused by a fungus, and it creates irregularly shaped splotches that are slimy and water-soaked. Often, the splotches occur on the top-most leaves and stems first. Eventually, entire stems “rot” on the vine, turning black and slimy. There may also be patches of white spores on the leaf undersides. In the north, the pathogen overwinters in buried potato tubers. In the south, it easily survives the winter.

Prevent: The spores of this disease are fast-spreading, moving on the wind for miles. If you live in the northern half of the continent, do not purchase potatoes and tomatoes that were grown in the south as you may inadvertently introduce late blight spores to your garden. This is not a common pathogen, but if late blight is reported in your area, there is little you can do to prevent the disease because the spores spread so rapidly. Plant only locally grown plants to help keep the pathogen out of your area.

Manage: Once late blight strikes, there is little you can do. Tear out the plants, put them in a garbage bag, and throw them out to keep the disease from spreading. Organic fungicides based on Bacillus subtilis are somewhat effective in preventing this tomato plant disease when it’s first discovered in your area.

Septoria leaf spot

Identifiy: Appearing as tiny, round splotches on the leaves, this tomato disease (Septoria lycopersici) typically starts on the lowest leaves first. The spots have dark brown edges and lighter centers, and there are usually many spots on each leaf. Infected leaves eventually turn yellow and then brown, and fall off.

Prevent: Remove diseased tomato plants at the end of the season to prevent the spores from overwintering in the garden. Cut off and destroy infected leaves as soon as you spot them and disinfect pruning equipment before moving from one plant to another.

Manage: Organic fungicides based on copper or Bacillus subtilis are effective against septoria leaf spot, especially when used as a preventative measure.

Southern Bacterial wilt

Identify: Unfortunately, once present, Southern bacterial wilt (Ralstonia solanacearum) is a tomato plant disease that spreads like wildfire. It’s soil-borne, but the bacteria that cause this tomato disease can travel by soil, water, plant debris, and even on clothes, tools, and skin. It’s naturally found in tropical regions and greenhouses, but it can arrive in the garden via infected plants that were purchased from other areas. Initial symptoms include the wilting of just a few leaves on a plant, while the rest of the foliage appears healthy. Over time, more and more leaves wilt and turn yellow until all the leaves succumb, though the stem remains upright. Slimy ooze threads out of the cut stems, and when they’re placed in water, milky streams of bacteria stream out of the cut.

Prevent: Southern bacterial wilt is soil borne and can survive for long periods in the soil on roots and plant debris. Like many other tomato diseases, it favors high temperatures and high humidity. The best way to prevent this disease is to purchase and plant only locally grown plants, or grow your own plants from seed. Southern bacterial wilt is more common in warmer regions, but has been found in Massachusetts and other northern regions as well.

Manage: There is no cure for this disease. Once confirmed, immediately remove infected plants and discard them in the trash.

Verticillium wilt

Identify: Unfortunately, once present, Southern bacterial wilt (Ralstonia solanacearum) is a tomato plant disease that spreads like wildfire. It’s soil-borne, but the bacteria that cause this tomato disease can travel by soil, water, plant debris, and even on clothes, tools, and skin. It’s naturally found in tropical regions and greenhouses, but it can arrive in the garden via infected plants that were purchased from other areas. Initial symptoms include the wilting of just a few leaves on a plant, while the rest of the foliage appears healthy. Over time, more and more leaves wilt and turn yellow until all the leaves succumb, though the stem remains upright. Slimy ooze threads out of the cut stems, and when they’re placed in water, milky streams of bacteria stream out of the cut.

Prevent: Southern bacterial wilt is soil borne and can survive for long periods in the soil on roots and plant debris. Like many other tomato diseases, it favors high temperatures and high humidity. The best way to prevent this disease is to purchase and plant only locally grown plants, or grow your own plants from seed. Southern bacterial wilt is more common in warmer regions, but has been found in Massachusetts and other northern regions as well.

Manage: There is no cure for this disease. Once confirmed, immediately remove infected plants and discard them in the trash.

Pest management in Tomato

Serpentine leaf miner

Biology

Egg: Eggs are minute in size and orange yellow in colour. The egg hatches in 4 days.
Larva: Apodous maggot feeds on chlorophyll mining in between epidermal layers. Full grown maggot measures 3 mm. Larval duration is about 7 days.
Pupa: Pupation is in soil. Some pupae are found in leaves. Pupation takes place inside a thin loose mesh of silken cocoon. Pupal period is about 7 days.
Adult: It is a pale yellowish fly, measuring 1.5 mm in length. The female fly punctures upper surface of leaf to lay eggs singly. Total life cycle takes 3 weeks.