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Tomato (Lycopers icon esculentum)

Tomato is a vegetable crop, which is widely adapted to arid humid areas. There are different varieties of tomato crop. These include; Ife plum, Ronita, Roma, local cultivates e.g. Ibadan local, Bonny best, Money maker, valiant, pork, Dwarf gem, and Marg lobe.

(i)   Environmental requirements: Tomato plant grows well in area where there is a rainfall that ranges from 50-125cm per annum. It requires a long duration of sunshine, ideal temperature lies within the range of 20-29 C. It also requires well-drained sandy-loam soil which is also rich in organic matter. It grows well in a slightly acidic soil whose pH ranges from 5.5-6.5

(ii) Method of sowing: Tomato is usually propagated by seeds. Viable seeds are sown in the seed beds. The beds or ridges are normally well tilled and ploughed to soften the hard pans of soil. The seeds are sown three per hole. Broadcasting of seeds on seed beds may lead to overcrowding of seedlings after germination. In Nigeria, sowing of tomato seeds either by drilling or broadcasting method is carried out at the beginning of the rains between March – April in the south, and between September-October in the North. The seed rate is between 5-10kg of seeds per hectare. One seed is sown per hole.

(iii) Nursery practices: Tomato crop requires nursery for proper cultivation. Seeds are prepared with dilute hydrochloric acid or with washing soda, then dried. This makes the seeds to be viable for over a long period. The seed contains a viable embryo that can germinate under good conditions. The treated seeds are then sown in soil that contain chemicals such as methylbromide or formaldehyde. It can also be sown at a spacing of 8 x 8cm in a tray or box. The seedlings are kept in a shade constructed with palm fronds to protect them from intense ultra-violet radiation from the sun. This is done to prevent the distortion of leaves in the young plant, which might result to dead spots or necrosis on the leaves.

(iv) Land preparation: Clearing of the plot that is to be used for tomato cultivation is carried out, optimum tillage is done using hoe, ploughing is carried out, then followed by harrowing during hand preparation to make seed beds.

(v) Transplanting: Transplanting of tomato seedlings from trays or box to nursery beds is done in three stages depending on the seedling size. The first transplanting is carried out when the seedlings are 15-20cm tall, second transplanting of seedlings is done at 25-30 days from planting the seedlings while the third transplanting is done when the seedlings have developed about 4-5 leaves. This is carried out in the permanent beds.

(vi) Spacing: Spacing in tomato seedlings is 60 x 75cm when staked and 60 x 90cm when unstaked.

(vii) Nutrient requirements: Tomato crop plant requires adequate supply of N. P. K fertilizer in the ratio 15:15:15. This is applied at 50kg per hectare. Compound or combined single fertiliser containing these nutrients is applied to the seedlings planted in the seed beds. Ammonium sulphate fertiliser is applied at 28kg per hectare. Note: One hectare of land is equal to 10,000m2

(viii) Staking: Staking of tomato plant is done when the plant begins to produce flowers. This increases the optimum yield of the plants.

(ix) Weed control: Weeding is carried out regularly in the beds to avoid weeds competing for nutrients with the tomato plants. It is usually done either manually or chemically, Weed control by manual labour is carried out using hoes, Herbicides are used to control weeds in the tomato plot. These chemicals are usually selective herbicides that kill the weeds and does not harm the plants.

(x) Harvesting: Mature tomato fruits are harvested when they become ripe and turn reddish. This usually starts from 8-12 weeks after planting. The peak harvesting period falls around the 15th week. Mature tomato fruits are harvested when half ripe because this helps to prevent excessive damage of the fruits due to bruising or cracking. Generally, harvesting is done manually by hand picking.

(xi) Storage: Harvested tomato fruits are perishable. The produce, therefore, cannot be stored for over a long period. Tomato fruits are transported to the market for sale. However, fruits cannot be kept fresh for longer than two days without proper refrigeration as this helps to preserve the produce for future use in small quantity. Poor storage and processing facilities are the major factors that lead to wastage of agricultural produce after harvesting in West Africa.

Tomato diseases

(a) Root Rot or Wilt Disease

Causative agent: Fungus Species: Fusariun oxysporium.
Transmission: Transmitted by air-borne and soil-borne mycelia infestation.
(i) Leaves drop off gradually.
(ii) Wilting and drying in the plant tissues.
(i) By treating with fungicides.
(ii) By practicing crop rotation.

(b) Root knot disease.

Causative agent: Nematodes.
Transmission: Transmitted by soil-borne nematodes which attack roots.
(i) Appearance of knotty mass of cells in the roots.
(ii) Stunted growth.
(iii) Rapid wilting of the plant.
(i) By breeding resistant varieties
(ii) By effective crop rotation
(iii) By using chemicals, disinfectants such as DDT, Demagon

(c) Leaf spot

Causative agent: Fungus
Species: Chadosporium SPP
Transmission: Transmitted by air-borne spores deposited on the leaves in the plant.
(i) Appearance of circular white patches on the leaves.
(ii) Dead spores deposited on the leaf spores.
(i) By spraying with fungicides.
(ii) By practicing crop rotation.
(iii) By planting resistant varieties.

(d) Bacteria wilt

Causative agent: Bacterium.
Species: Pseudomonas solaracerium.
Transmission: Transmitted by soil-borne bacteria which infest roots.
(i) Release of slimy substance from the stem.
(ii) Wilting of the infected plant.
(iii) Death of the infected plant.
(i) By practicing crop rotation.
(ii) By avoiding infected soil.

Tomato is a vegetable crop. It grows best in sandy-loams rich in organic matter. It grows well in a slightly acidic soil whose pH range is from 5.5-6.5. Tomato is propagated by seeds.