Specialty Coffee, from the southern Highland of Tanzania - Mbozi, Mbeya.

TOMATO, THE CROP WHICH MOST OF SMALL HOLDER FARMERS RELY ON. ''LET's TALK ABOUT TOMATO AGRONOMY''

1

Tomato Rio grande Variety

  

Tomato production in Tanzania has increased considerably in recent years.Thetomato(Lycopersiconesculentum) is popular with both small  scale farmers for its edible fruits both for export and local consumption. The major tomato producing region in Tanzania include Iringa, Morogoro, Arusha and Dodoma.

2.Plant type

Plants are either indeterminate – which when side shoots are removed, produce a continuously growing single stem – or determinate, ending in the formation of a flower cluster and a bush-like structure.

Determinate (eg ANNA F1 and TENGERU 97) plants are usually earlier to mature, because, once flowers are formed they divert all energy into filling and producing a uniform crop. They are more often used where seasons are shorter and just one crop is produced. They are bushy in character with a short main stem, and ideal for mechanical harvesting of processed crops and field cultivation of fresh tomatoes.

Indeterminate plants continue to produce flowers. Such a crop, if maintained, can make better use of an extended season. They ideally suit greenhouse production and can grow over 32.8 feet in height after 9 to 10 months.

How to select the best site for planting

Tomatoes grow best in areas with at least six hours of full sun per day during the growing season. The ideal range of temperature for tomato production is 18 – 27 centgrade degree.

Production is reduced based on the number of hours the plant spends in the shade. While tomatoes produce well on a wide range of soils, the best yields are usually seen on deep, fertile loams and sandy loam soils. The upper layer needs to be penetrable. Soil depth of 15 to 20 cm is needed to grow a healthy crop. Most soils can be modified through the use of organic matter, lime and fertilizer depending on what results soil tests yield. It is best to avoid planting tomatoes in extremely sandy or heavy clay soils that are difficult to manage when dry. In heavy clay soils, farmers should dig deeply to allow better root penetration. In addition, fields should be rotated out of tomatoes and related solanaceous crops (e.g. tobacco, pepper, and potatoes) for a period of three years.

How to prepare land

Farmers should clear all bushes and trees if there are any. Herbicides such as Round-up can be used to clear weeds like couch grass. Since tomatoes do best in deep and well-drained soils, it is good to till the land to about 8 inches deep adding local organic compost to the soil as you go. Plough the wet soil and do a second ploughing in dry soil to obtain a loose fine deep soil mix. Digging the land improves water movement in the soil.It also helps to reduce soil-borne pests and diseases by exposing the soil to the hot sun.

Nursery preparation

Soil nursery method as well as trays can be used for growing seedlings. In the soilnursery method, a fine tilth is recommended because of small sized seeds. The nursery should be raised 15 cm above the ground.Seeds should be planted at a depth of 1cm and a spacing of 15cm between the rows. The seeds are arranged along a furrow, and then covered lightly with soil. The nursery can be covered with hay or dry grass. This is done to increase moisture on the surface and prevent splash during irrigation. Watering will be done lightly using a watering can and timed in the morning to avoid conditions conducive for the development of diseases The seeds will sprout within 8 days. It will take about a month before the seedlings are ready for transplanting. Harden-off seedlings a week or two before transplanting by reducing irrigation. The farmer will be required to monitor the seedlings for pests, diseases and weeusing appropriate control methods when need arises. Farmers can also use trays for raising the seedlings. Plants raised in trays generally have a better survival rate.

Key issues to consider during nursery preparation.

•       Nursury should be establishided near to the water source

•       The site should be flat or with gentle slop to avoid water logging

•       The site for nursery establishment should be the one at which tomato was not grown for 3 years.

•       The nursery site should be near to the area where farmer wish to establish Tomato field.

Transplanting

Farmers should transplant the seedling to the field 3 to 6 weeks after sowing. A week before transplanting, harden the seedlings by reducing the application of water, but 12-14 hours before they are taken out of the seedbed they should be thoroughly watered again to avoid excessive damage to the roots. Seedlings with 3-5 true leaves are most suitable for transplanting. When removing the seedlings from the nursery, keep a large clump of soil attached to the roots to prevent them from being damaged. Transplanting should be done in the afternoon or on a cloudy day to reduce the transplanting shock. 

Before transplanting, the following should be applied by the farmers.

•       Irrigating the seedlings few hours before transplanting to easen the uprooting process .

•       Prepare the planting holes in the field

•       Transplanting should be done during evening hours

•       Transplanting should be done when tomato seedlings have 2-6 number of leaves.

A seedling transplanted with a ball of soil

6. Actual planting

Tomato field should be prepared 1 – 2 Months before transplanting .Spacing between plants and rows depends on the cultivar growth habit, soil type, cropping system and also whether the plants are to be supported by stakes or left on the ground. The common spacing is 50 cm between plants and 75 - 100 cm between rows. If the tomatoes are to be supported by sticks, then the distances between rows can be decreased to 20-40 cm. Make the holes for the plants deep enough so that the ball of soil is in the ground. Press the soil firmly and gently around the root, and water around the base of the plant to settle the soil.

7. Care after transplanting

After transplanting, mulch can be placed on the ground around the plants to protect them from heat during the first five days. Farmers should not put mulch near the plants as they can damage the stems. Mulch can also be used to control weed growth, prevent erosion and conserve water. Care should be taken not to wet the lowest leaves, as this can cause the growth of fungus.

Sources of Improved Seeds

Farmers select varieties that perform best under the local conditions.Seed can be produced by farmers from their fields. Altanatively it is advised that to optimize production, farmers should use the improved varieties which in Tanzania it is mainly supplied by Mosanto agent which is Kibo, Balton Tanzania Limited,Alpha Seed Co., Seed Co.TanzaniaTanSeed International

Varieties and Yield

Currently, Tanzania Tomato farmers prefer the improved tomato varieties than local varieties. This is mainly because the improved varieties yield better and tolerant to disease and pest . The varieties which is being increasingly adopted by Most of Tanzania farmers include Anna F1, Assila F1, Eden F1, Tanya, Tengeru 97,Roma etc.

MANAGEMENT PRACTICES

Mulching

Mulch is simply a covering over the soil that keeps moisture in, suppress weeds and protectslow-growing tomatoes from resting on the ground and developing rot. There's some extrabenefit to using organic mulches such as grasses,hay, leaves or sawdust because thesematerials unlike plastic, aluminum or other synthetic mulches decompose, providing food forthe millions of microorganisms that live in the soil, making nutrients available to your plantsand improving soil structure. Staked and trellised plants usually benefit from a mulch to savemoisture. More exposed to sun and wind than un staked plants, they lose more water throughtheir leaves.

Staking and training

Staked tomatoes provide ease of harvest and higher fruit quality by keeping fruits off the ground and resulting in less rot. Staked tomatoes are normally pruned to 1-2 main stems.Staking is done 2-3 weeks after transplanting. Wooden stakes 120-150cm long are driven intothe ground halfway between each plant or between alternating plants. Plants are trained bytying the plants with plastic twine or construction wire onto the trellis beginning 3-4 weeks after transplanting and is repeated 3 or 4 times during the growing season. The twine is tiedaround each stake and on both sides of the plant to provide vertical support. Height of thestakes and training technique varies depending on wind conditions during the growth cycle,or on traditional practices followed in the different tomato production areas of the world.

Irrigation

Sufficient moisture should present for germination or quick recovery of transplants. Tomatoplants may never recover from water stress during their early development therefore the useof water by the plant increases until the fruit load is developed. Tomato are relatively deep –rooted crop, whose roots can extend to a depth of 15cm ,thus average water requirementsranges from 600mm to 1200mm.Drip irrigation for tomatoes has gained popularity becauseof increased water use efficiency and because it allows for the application of fertilisers and pesticides with the irrigation water . With drip irrigation it is possible to closely synchroniseweekly water and nutrient application rates with the corresponding stage of cropdevelopment. However furrow and sprinkler irrigation systems can be used.

Weeding

Weeding is done after two to three weeks after transplanting depending on weed emergence.An integrated approach can be used to manage weed competition in tomato production. TheIPM program for weed control utilizes weed identification, monitoring, sanitation, alternativecultural practices, and timely herbicide applications. Cultural control practices for weed control include shallow cultivation, ploughing, hoeing, crop rotation, cover cropping,

organic or plastic mulching and herbicides. Useful crops for rotation with tomato includealfalfa, sugar beets, and onions. Solanaceous crops such as potatoes and pepper are notrecommended as rotation crops with tomato. Problem weeds in tomatoes include perennials,dodder, weeds of the nightshade family (solanaceous family), and grasses.

Pest and disease management

Tomato yields may be reduced by a myriad of insect and diseases pests. Integrated pestmanagement (IPM) is a systems approach to reduce pest damage to tolerable levels using avariety of techniques such Pest as natural enemies, genetically resistant plants, sound culturalpractices, and when appropriate, chemical pesticides

Insect pest Managment

Important insect pests of tomato include aphids, army worms, cutworms, tomato fruit worm,

leaf miners, mites, thrips, and whiteflies.

Aphids

Aphids feed on plant sap which may reduce plant vigour. Aphids may also act as vectors ofplant viruses, and may also introduce toxins into the plant, resulting in growth deformations.Growers should use natural enemies, botanical insecticides as neem extracts, removealternative host of aphids and if aphids are severely attack use systemic insecticide

Army worms

Beet army worm, Spodopteraexigua, and nutgrass army worm, S. exempta, infestations ontomato may result in up to 25% fruit losses. Armyworm is larva stage of Adult moths.Feeding by young caterpillars can reduce leaves to veins leaving behind webs.Caterpillarsnormally begin feeding on the fruit after molting. Damage to the fruit consists of superficialfeeding wounds that dry out as the fruit matures. Small caterpillars, however, may penetrate

the fruit and cause damage similar to the feeding damage caused by the tomato fruit worm.

Control by applying insecticides such as stomach poisoning and systemic.

Cutworms

These caterpillar pests which include the variegated cutworm,Peridromasaucia, and the black cutworm, Agrotisipsilon, can devastate young tomato plants,by chewing through the stems at the soil line. Cutworms are active at night.Control is warranted when high populations are present in the field prior to planting, earlyploughing to expose cutworms to predators, use repellent botanicals around the plant(s) and .Baits containing Bacillus thuringiensis or insecticides are available for cutworm controlwhen are spread within the field.

Leaf miners

Leaf miners are normally a secondary pest which are kept in check by natural enemies.However both the vegetable leaf miner, Liriomyzasativae, and the celery leaf miner, L.trifolii, may become primary pests in tomato fields where intensive pesticide use havedestroyed their natural enemies. Leaf miners are small yellow maggots which form trails

beneath the leaf epidermis as they feed.

Control

A monitoring program consists of insecticide application Insecticides which areRecommended when average counts rise above 20 pupae per pan per day. Because contactinsecticides won't reach the larvae inside the leaf, systemic are recommended.

Mites

Outbreaks of carmine spider mites, Tetranychuscinnabarinus, and the tomato russet mite,Aculopslycopersici, may occur during hot and dry weather. Tomato russet mites are tinyspider-like animals which feed preferentially on the lower stem, and then move on to feed onthe upper section of the plant and on leaves.Presence of the mites is manifested in the bronze and greasy appearance of stem and leaves.Its feeding causes leaves to become stripped with light coloured dots. Leaves may later turnyellow and drop. Silk webbing may be present when infestation is heavy. Controlled byWettablesulphur and other miticides are effective on mites.

Root-Knot Nematodes

Root-knot nematodes are microscopic round-worms which feed on the roots of plants.Symptoms on the foliage caused by the affected root system include stunting, wilting, andleaf yellowing. Infested roots develop gall-like swellings.

Control

Root knot nematodes can be controlled by soil fumigation, use of resistant varieties,

practicing crop rotation, removal of alternative host plants.

DISEASES MANAGEMENT

Early blight disease (Alternariasolani)

the fungus is seed borne the disease occur during period of warm rainy or humid weather as

well as arid zones.

Disease symptoms are; concentric lesions of dead tissue on leave and stems, as well asspotting on leaves and fruits. The disease can result in crop defoliation during wet and warmweather any time during the crop cycle.Controls include a three-year rotation, removing infected plants starting from the nurseryplanting on wide, high beds, and fungicide treatments example mancozeb.

Late blight disease (Phytophthorainfestans)

The pathogen (fungus) survives on the weeds of tomato family or volunteer tomato or potato.The disease develop faster in the cool and wet condition.

Symptoms; the disease causes severe defoliation, stem girdling, and severe fruit rot andirregular water soaked spots which turn brown and wrinkle at the surface.Control includes crop rotation, use of healthy seedlings, field sanitation after harvesting, useof wide spacing, careful monitoring and use of fungicide applications.

Bacterial wilt (Pseudomonas solanacearum)

Bacteria wilt is the most serious disease of tomatoes in the tropics and sub-tropics.Symptoms include rapid wilt and death of the entire plant without any yellowing of theleaves. If the stem is cut and placed in a glass of water, grey bacterial ooze is visible.Control The disease is difficult to control because it remains in the soil for many years.

Contaminated fields should be rotated with non-solanaceous crops. Prevent machinery andfield personnel from moving from contaminated to non-contaminated soils. The diseasepenetrates the plant through wound openings in the roots and use of resistant varieties such asimproved tomato can help to reduce the problem

Fusarium wilt (Fusariumoxysporumand F. lycopersici)

Is a soil-borne fungi which enters the plant through the root and interferes with the plant's vascular system by stopping the transpiration flow. As a consequence the lower leaves are first to turn yellow and wither. The symptoms progress and eventually the entire plant are affected, with a dark-brown discolouration in the bark of affected areas, and with live leaves limited to the branch tips.

Control

Commercial cultivars are available with resistance to the diseseaslike Tengeru 97, Assila F1 , Anna F1 and Eden F1.In addition, field sanitation, crop rotation with grass crops, soil fumigation, and soil pH near 6.5should be used for control .

Damping off disease (Pythiumspp)

The disease affects tomato seedlings at pre and post emergence because the fungal spores can

remain dormant in the soil for long period. Causes several effects including; death of seedling

before emergence and emerged seedling tends to rot at ground surface in excessive moist

nursery.

Controlled by providing good soil structure and drainage, avoid overwatering, apply woodash in seedbed, soil sterilization, use of treated seeds and thinning to adjust plant density so asto avoid moist microclimate, remove weak and diseased plant.

Blossom-end rot

This is physiological disease may cause severe yield reductions in tomato.The initial symptom will be a slight,water-soaked discolouration on the blossom-end offruits. The lesions enlarge and turn dark brown or black. An irregular water supplycompounded with a fast growing crop may promote blossom end rot. The disease resultsfrom a localized calcium deficiency in the fruit. Calcium is translocated in the plant through

the transpiration flow.

Control

Factors which have an effect on the plant's calcium supply should be monitored including

cultivar, plant nitrogen status, soil fertility, pH, and an even moisture supply in the root zone.

Nitrogen over-fertilization may accentuate blossom end rot by promoting excessive shoot

growth.

MBOLEA ZA ASILI NA UMUHIMU WAKE KATIKA KILIMO ENDELEVU

Kilimo ndiyo uti wa Mgongo wa uchumi wa mataifa mengi ya Africa hasa kusini mwa jangwa la sahara. Ingawa kilimo kinachangia kwa asilimia kubwa ya mataifa ya Afrika lakini bado serikali za mataifa husika hazijaweka msukumo chanya kuboresha sekta hii hasa katika nyanja zote mhimu zihusianazo na kilimo (Utunzanji wa afya ya udongo, Mbinu bora za kilimo, uongezaji wa thamani wa bidhaa za kilimo na utunzaji baada ya kuvuna) .
Leo nitaanza kwa kuelezea kwa mhutasari namna ambavyo afya ya udongo (Soil fertility) inaweza kutunzwa na kuendelezwa ili kuongeza uzalishaji wa mazao mbalimbali. Afya ya udongo inaathiriwa sana na aina ya virutubisho/Madini yaliyomo na hii ndiyo kusema aina ya mbolea itumiwayo katika kurutubisha mazao mbalimbali shambani inamchango wa moja kwa moja katika afya ya udongo.
Mbolea ni nini?
Mbolea ni kirutubisho cha udongo chenye uwiano sahihi wa virutubisho vyote vinavyohitajika kwa ukuaji wa mmea hasa Nitrojeni, Fosforasi na potasiam. Pia aina nyingine za virutubisho zinahitajika katika kiwango kidogo ingawa zina umhimu wake katika hatua mbalimbali za ukuaji wa mimea. Kuna aina mbili za mbolea ambazo ni Mbolea za viwandani na mbolea za asili.
Sifa za mbolea za viwandani 
(i)Zinaachia virutubisho kiurahisi
(ii)Ni rahisi kupotea katika mtindo wa gesi au kubanwa na madini mengine yaliyopo kwenye udongo
(iii)Uwiano wa virutubisho vyake unajulikana.
(iv)Ikitumiwa kwa muda mrefu inaweza kuleta madhara kwenye afya ya udongo
(v)Inayumika kwa kiasi kidogo
Sifa za mbolea za asili 
(i)Zinaachia virutubisho polepole
(ii)Zinasaidia kutunza unyevunyevu na kurekebisha sura ya udongo
(iii)Hazina madhara kwa wadudu waozeshaji(effective microorganism) na zinaweza kutumiwa kwa muda mrefu
(iv)Haihitaji gharama kubwa kutengeneza
(v) Inahitaji kiasi kikubwa kwa shamba
(Vi)Mkulima yeyote anaweza kutengeneza

Utengenezaji wa Mbolea za asili: Kuna njia kuu tatu za utengenezaji wa mbolea hizi nazo ni uozeshaji kwa kutumia biwi, Uozeshaji kwa kutumia wadudu waozeshaji na njia ya Bokashi. Tutazungumuzia kiundani zaidi katika makala zitakazofuata.