Organic farming :
Organic agriculture consists of a system of farm design and management to create an eco-system, which can achieve sustainable productivity without the use of artificial external inputs such as chemical fertilizers and pesticides. The major aims of organic agriculture are production of quality agriculture products which contain no chemical residues, the development of environment friendly production methods and the application of production techniques that restore and maintain soil fertility. These are achieved by suitable crop selection and rotation, recycling of plant and animal residues, proper tillage and water management.
Organic farm products are, generally more expensive than inorganic crops. Yields drop sharply during the phase of conversion as it take some time for the soil and plants to reach equilibrium. However, yields rise again, once management systems get established.
As the present level of farming is less intensive with lower levels of application of chemical fertlisers and pesticides transition to organic farming in the State will be comparatively easier.
Organic production :
Climate and soil
The crop is grown from almost MSL to an altitude of 1500 m in tropical and subtropical regions, with an annual rainfall of 60-150 cm. Very high rainfall during its growth is harmful. When grown under hot weather, it is cultivated as an irrigated crop. The winter crop is planted from August to September. For organic farming of tomato winter crop has been found to be ideal.
Well drained sandy loam soil with high level of organic contents is best suitable for tomato cultivation. Soils with high acidity are not suitable for tomato cultivation. Three to 4 q of suitable lime can be applied in the field in an interval of three years to reduce the level of acidity to tolerable limits. There is a need to go for soil testing at the beginning of the crop season.
Crop rotation is a major component of organic farming, affecting both soil conditions and pest cycles. Tomato belong to the Solaneceae family which includes tobacco, potato and bell pepper. Rotation with non-solanaceous crops like pulses/legumes are usually recommended to avoid pests and diseases affecting tomato and also to enrich the nitrogen status of the soil.
In order to cultivate tomato organically a buffer zone of 7.5 to 15 m shall be maintained if the neighbouring farms are non-organic. The produce from this zone shall not be treated as organic.
The land may be ploughed and harrowed 3 or 4 times to obtain a fine tilth. About 10 tonnes of Farm Yard Manure (FYM) or vermi compost/compost @ 1-1.5 t per acre is applied at the last ploughing. Green manuring is recommended for areas with assured rainfall and also for irrigated crop. Beds are prepared against the slope and after levelling the bed, field channels of 50 cm breadth are prepared at intervals of 1 m.
Tomato is propagated by seeds. Seed selection is an important aspect in organic tomato production. For raising nurseries, seeds of high yielding varieties with tolerance to pests and diseases may be used. They should be carefully selected from certified organic farms or from own seed plot which is raised organically. To start with, chemically untreated seeds from local high yielding varieties could also be used, in the absence of organically produced seeds.
For organic farming of tomato, Open Pollinated Varieties (OPV) are preferred. The local varieties developed by Horticulture & Agro-Forestry Research Programme (HARP), Plandu, Ranchi viz., Swarna Lalima and Swarna Naveen are suitable for organic cultivation of Tomato. Lakshmi NP 5005 is also popular in the State as it is resistant to bacterial wilt and leaf mosaic virus.
Seeds should not be treated with any chemical fungicides or pesticides. Prior to sowing, the seeds should be treated with Trichoderma at the rate of 1 g per 150 g of seeds.
In order to grow saplings in the nursery, beds of 1m X 3m are prepared with a height of 20 cm. Twelve to 15 beds are required for raising nursery for planting 1 acre of tomato. Soils are exposed to high temperatures, to prevent possible pest and diseases attack in the plants. After the beds are prepared 20 to 25 kg of farm yard manure along with 1.2 kg Kanranj/Neem cake is applied per bed. After necessary application of water the beds are covered with thin white plastic sheets for raising the temperature without loss of moisture. Such practice will further eradicate harmful bacteria and pests.
For cultivation of tomato during Rabi season, seeds should be sown in the nursery during the month of August/September. The requirement of seed /acre is approximately 150 g. Sowing of the seeds should be done in straight lines drawn at an interval of 5 cm with 2 cm spacing between successive seeds implanted. Seeds are to be planted at a depth of 0.5 cm to 1 cm. After sowing the seed, a thin layer of soil should be used as covering . Then beds should be covered by thin nylon nets keeping a gap of one foot from the bed and fully secured from all sides by placing adequate soil on the borders of the net. This practice will prevent pest infestation in the saplings.
20 to 25 days old seedlings are used for transplantation. They are transplanted in the main field in rows with a spacing of 60 cm between rows and 50 cm distance between two successive plants. Transplantation is done on one side of the channel keeping a distance of 30 cm. In the initial period, irrigation from the field channel is found to be adequate.
Irrigation should be provided once in 7-10 days depending on the soil and weather conditions
Effective, non-chemical weed management begins with well planned, diverse crop rotations, especially those including competitive cover (smother) crops. Attention is to be given to careful site selection to avoid introduction of weed seeds and other propagules. Weeds are a big nuisance as they take up the nutrients in the soil and can also harbor insects and diseases that cause harm to tomatoes. These weeds start growing four to five weeks after transplanting the tomato saplings. Hence focus has to be on extensive weed control during this period. Weeds should not be allowed to grow in numbers. Organic weed control can be achieved by using organic matter as mulches as these restrict weed growth. Crop rotation, mulching, sanitation, and shallow tilling also help in controlling the weeds.
After transplantation, regular weeding is required to be done to remove harmful weeds from the field. The plants can be provided support with the help of small bamboo sticks to increase the production.
In order to maintain a fertile soil, organic matter should be added to it regularly. If organic farming is being performed on own land since many years, the soil will have a good nutrient content. Compost / Farmyard manures can also be added to further enrich the soil. Application of organic manure is very important for tomato cultivation. Farm yard manure of 10 t or 1-1.5 t of vermicompost per acre is generally applied. To prevent contamination, FYM can be treated with trichoderma at the rate of 500 g per a tractor load of manure. After mixing the required amount of trichoderma the manure should be allowed to remain in a heap covered with wet gunny bag for proper culturing.
It is a long-drawn observation that insect pests and diseases first strike the well nourished plants. Therefore the objective of organic methods, is to grow crops which naturally resist the onslaught of pests and diseases. Management of soil tilth, moisture and nutrient status is the first step in effective pest and disease management.
Crop rotations, which assist in breaking life cycles of insects and pests, is a traditional means of pest control. Control of tomato pests require careful monitoring and integration of cultural practices and biological control. A wide range of biological pesticides are available to keep pests below the thresh hold level.
It has been observed that organic tomato plants have fewer pest and insect problems than the conventional chemically grown tomato plants. Moreover, practicing crop rotation aids in breaking the life cycle of insects and pests thus reducing the pest menace. Trap crops are also effective in controlling pests. An example of a trap crop is sweet corn. Sweet corn attracts tomato fruit worm and thus protects the tomato crop when inter-planted with it.
Fruit Borer is one of the major threats to tomato crop. In order to prevent damage to the crop from fruit borer, marigold should be raised in the adjoining plot to divert the attention of the fruit borer. In case eggs of the insect are found on the leaves of the plant trichocard can be applied. In case, the intensity of pest attack increases, 4% solution of neem seed extract can be sprayed on plants at 15 days interval to control the insect.
Among the alternatives, biological control of pests is one of the important means for checking pest problems in tomato. Biopesticides include living organisms which can destroy pests. Use of biopesticides is one of the most appropriate and promising methods of pest management.
Ha NPV (Nuclear Polyhedrosis Virus) is used against the Heliothis armigera (fruit borer) in tomato. Trichoderma is the most widely used fungal biopesticide. It is useful against root fungi. They are ideal for seed treatment also. Trichogrammabelongs to a large group of egg parasitoids and success has been achieved against the lepidopteran pests of commercial crops like tomato. Tricho cards are used against the fruit borers. Neem based pesticides like neem cake, neem seed kernel extract (NSKE), neem leaf extract, neem oil etc., act as a repellent and antifeedent and its oil is effective against fruit borer.
Despite good management practices, diseases usually occur, presenting one of the greatest challenges to organic tomato growers. The degree of occurrence is regionally based and largely dependent on environmental conditions. Tomatoes are injured by pathogenic diseases caused by fungi, bacteria, as well as physiological disorders such as cat facing and blossom end rot, which are caused by environmental / abiotic stress. Pathogenic diseases develop through soil borne and above ground infections, and, in some instances, are transmitted through insect feeding.
Major tomato diseases include those that attack the root system (fusarium wilt, verticiliun wilt, bacterial wilt, rhizoctonia), above-ground stems and foliage (early blight, leaf spot, bacterial canker, late blight), and fruit (bacterial spot, bacterial speck, anthracnose). Thus, the disease control programme is important at each stage of growth. Organic tomato disease control programs are based on a combination of organic soil management practices, IPM practices and natural remedies.
In order to prevent bacteria borne diseases, the resistant varieties can be adopted and as a preventive measure regular crop rotation may be adopted with non solanaceous crop. Accordingly, tomato, potato, chilli and brinjal should not be cultivated successively along with tomato.
The crop will be ready for harvest in about 2- 3 months after planting. The harvesting of the tomatoes is done as per the requirement of the market and in a typical season 8 to 10 harvesting is done to feed the market as per its requirement.
The yield of irrigated tomato varies from 15 to 20 t /acre. In the present model, a conservative yield @ 10 t per acre has been assumed