Integrated weed management for tomato production


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Integrated weed management for tomato production

  1. 1. Integrated Weed Management Strategyfor Tomato ProductionA Proposal by:Marco M. HamiliBlaisae A. JoloyohoySushmita P. LlanitaJimae Faith B. MagnayeJackielyn M. NacaitunaSubmitted to:Mrs. Sylvia Minda T. DargantesInstructor
  2. 2. Integrated Weed Management Strategy for Tomato 2Introduction Tomato is considered one of the priced plant commodities in the world. It is considered as avegetable and a fruit and has a variety of uses. Tomato is also processed into a variety of products whichare utilized in many food preparations which proves that it is very profitable (,2012). In the Philippine context, tomato ranks second in the top horticultural crops being produced andthe production industry is dominated by small scale farmers. Tomato became one of their favouritecrops to grow due to its constant demand since it is a part of the common Filipino cuisines and its highprice relative to its quality. Although it is produced widely, the average yield of the Philippines isrelatively low and insignificant as compared to the world’s average (,2012). The January-March Performance of Philippine Agriculturereport of the Department of Agricultureindicated that the volume of production of tomato declined by 1.50%.The decline was due to landconversion for other crops in the top. However, the value of production increased by 8.87%(, 2011). With these given data, it could be analysed that although the volumebeing produced decreased, the price of tomatoes increased in the market. Thus, by following the law ofdemand and supply, it is still in equilibrium which tells us that the decreased of supply was balanced bythe increase in price. This means that there is still profit for the tomato producers. In terms of production, tomato requires intensive care but the growing period does not takelong. The inputs for production are costly which is one factor causing the small-scale farmers todominate the production. The planting distance of tomato varies upon the variety – smaller varietiesrequire smaller planting area while larger varieties require larger areas. In relation to its pestmanagement, pesticide application, specifically the insecticide, is being applied once or twice per weekis a preventive measure. Insect infestation is the worst problem of tomato producers because theinsects are vectors of viruses. These viruses are carried by flies which could either be a geminivirus(could cause either Tomato Leaf Curl Virus or Tomato Yellow Leaf Curl Virus) and the Cucumber MosaicVirus. If these viruses will infest the area, the yield will be reduced from 50-100%(, 2012). Such possible instances hinder the large -scale producers toenter the production scenario since it induces the fearof large losses of profit. In the Philippines, the most commonly grown and recommended varieties are the Cherry, Apolloand Magilas. These varieties exhibit different resistance towards diseases and their high yielding abilitymade them a favourite by the Filipino farmers (, 2012). Moreover, these varietiescan thrive in open field environments, produce medium-sized fruits and it is less perishable compared tothe Green House varieties. However, in terms of weed resistance, not a single tomato variety can inhibit the growth ofthese competing organisms. The most disadvantageous factors that could induce weed growth inproducing tomatoes are the time needed for preparing the seedlings, the land preparation and theplanting distance required which could accommodate the growth of weeds. If not done quickly, weedscould emerge and compete with the tomatoes at earlier stages which could further affect the yield. Astudy conducted in line with this problem showed a 40-60% yield decrease if the weeds in area will notbe controlled (Adigun, 2005).
  3. 3. Integrated Weed Management Strategy for Tomato 3 Thus, there is a need to formulate adaptable strategies in managing the weeds in an areaplanted with tomatoes. This integrated weed management strategy for tomatois composed of review ofestablished and possible formulation of another strategy. Moreover, actual costing for eachmanagement strategies is included in order to see if the strategy is economically viable. In addition, theproponents who purposely reviewed the management systems in order to check if they are in line withthe Good Agriculture Practices (GAP), the code for organic agriculture. The GAP aims to promotesustainable production of agricultural products which are economically viable, environmentally friendlyand socio-culturally adaptable to the local folks who are the backbone of the Philippine AgricultureIndustry.Objectives At the end of the exercise, the proponents are expected to accomplish the following: 1. Identify the common weed management strategies in tomato 2. Compare the different weed management programs 3. Formulate an IWM for tomatoReview of Related Literature Tomato Production: Must-Knows Tomato or universally known as either Lycopersiconesculentum or Solanumlycopersicum, belongs to the solanaceous family and considered as one of the top produced crops in the world. Tomato production is considered as a profitable enterprise yet laborious. This makes tomatoes highly valuable and its uses in food are also indispensable. Tomatoes are considered as a “hot weather” crop which indicates it needs high humidity and light in optimum amounts and it is a “heavy feeder”, which means it needs high amounts of nutrients and water. Production requires a very friable soil which must be loose at least 30.48 cm deep and a pH which would range from 5.8-7. Planting method of tomatoes is transplanting which means that they will be grown as seedlings before exposing them to the fields which would likely to occur at 6 weeks’ time after pricking. The planting distance of tomato varies upon the growth habit. Tomatoes can either be determinate or indeterminate. The determinate growth habit does not require trellising since it will be herbaceous and erect and should be planted at least 60 cm away from each other because such varieties needs adequate air circulation. On the other hand, the varieties with indeterminate growth habit tend to crawl on the ground or climb trellises if provided. If allowed to crawl on the field, they should be planted 92 cm away from each other but if will be provided with trellises, they will be planted with a distance between rows of 51 cm and distance between hills of 5 cm (Abaygay, 2010). In terms of pest control, application of pesticides is regular due to the nature of tomato to be vulnerable especially in the fruiting period. Being a solanaceous crop, it has succulent stems which can easily be attacked by pests and its fruit can easily be damaged since it is very
  4. 4. Integrated Weed Management Strategy for Tomato 4fleshy. Application of insecticides occurs at least once a week to prevent the insects frominvading the area and carry viruses which will cause the greatest damage. Fungal diseases areabundant but can be prevented with fungicides. Usage of resistant varieties is also practiced inorder to avoid or minimize the possible damage caused by these organisms. Weed control onthe other hand is done by thorough land preparation, mulching, hand weeding and chemicalcontrol. There’s no tomato variety which could supress the growth of weeds thus the mentionedpractices are made. Weed infestation can also cause significant decrease in yield if will exceedthe threshold level (, 2012). The tomatoes will bear the first fruits 3-4 months after sowing and during a season,harvesting should occur from 4-15 times. The fruits can be harvested while it is not too ripe forlonger shelf life and the ripe ones, which are indicated by the colour red, should be separatedimmediately in order not to induce ripening to other tomatoes. Commonly, the packaging oftomatoes in the Philippines is in the form of wooden boxes which has a capacity of 25 kg perbox. The marketing of the tomato can occur by hauling them to the public market or byinstances that the buyers will go to the farm. Each tomato plant could bear 3 kg, given thatthere were no occurrences of pest or any damage due to other factors.Reported Weed Management Strategies There are weed management strategies established which are currently practiced byfarmers. The following management strategies are published by Janiya, J. D (2002): Management System 1: a. Prepare the land thoroughly and remove at least one weed flush before transplanting the tomato seedlings. b. Spread the rice straw mulch uniformly (5.0 cm thick) between the furrows after transplanting. c. Push lightly the rice straw mulch towards the base of the tomato seedlings 1 week after transplanting to fully cover the whole area with mulch. d. Remove the weeds that went through the mulch by hand weeding 25-30 days after transplanting (DAT) The costing for this management system is as follows. The rate is followed according to the assumptions: Operation and Inputs Cost Land preparation 900Php Spreading the rice straw 1200Php Pushing the rice straw towards the base of the plants 1000Php Hand weeding 3200Php Rice straw 1500Php TOTAL COST 7800Php
  5. 5. Integrated Weed Management Strategy for Tomato 5 Management strategy 1 requires 7800Php for its conduct. Relative to the cost and revenue, the amount required is not that significant. However, it is not efficient because the rice straws should be manipulated twice. Moreover, the cost of mulching material is quiet expensive and thus, it must not go to waste.Management System 2:a. Prepare the land thoroughly and remove at least one weed flush before transplanting the tomato seedlings.b. Apply fluazifop-butyl at ¼ liter product/ha for grass weed control at the 4-6 leaf stages of grasses. Onecide 15 EC does not control broadleaves and sedges.c. Remove the uncontrolled weeds by hand weeding 20-25 DAT The costing for this management system is as follows. The rate is followed according to the assumptions: Operation and Inputs Cost Land preparation 900Php Onecide 15 EC 400Php Application of Pesticide 700Php Water 50Php Hand weeding 3200Php TOTAL COST 5250Php The cost of this weed management strategy is relatively lower as compared to management system 1. However, the application of an herbicide is not friendly to the environment and with the given information, it only controls the grasses. Sedges may not be significantly present in the upland area but the broadleaves are considered more damaging compared to the grasses. This might proceed to the application of another herbicide which will control the broadleaves. In addition, hand weeding will also be done which proves that the application of the chemical control is not that effective. As established, the application of chemical control should be done in worst cases, but in this management system – that application is being defied.Management System 3:a. Prepare the land thoroughly and remove at least one weed flush before transplanting the tomato seedlings.b. Remove the weeds be hoeing and spot weeding 10, 20 and 30 DAT
  6. 6. Integrated Weed Management Strategy for Tomato 6 The costing for this management system is as follows. The rate is followed according to the assumptions: Labor and Inputs Cost Land preparation 900Php Spot weeding/Hoeing (3X) 9600Php TOTAL COST 10500Php Management System 3 is the most costly among the management strategies proposed by Janiya, D.A. (2002) yet the process is very effective in controlling weeds. However, it is labor intensive and the procedure of hoeing can damage the root system of the tomato. Another management strategy was published by the Bureau of AgriculturalResearch which is as follows:Management System 4: “By using a carabao-drawn plow or hand hoe, cultivate in between rows of plants by off barring at 14-21 DAT. Hill-up at 28-35 DAT. Spot-weed at the surrounding of the seedlings after each off-barring and hilling-up if there are standing weeds. If plastic mulch is available, mulch the area before transplanting.” The costing for this management system is as follows. The rate is followed according to the assumptions: Labor and Inputs Cost Land Preparation 900Php Off-barring 1200Php Hilling up 1200Php Spot weeding 3200Php Plastic Mulch 15000Php Application of Mulch 2000Php TOTAL COST 23500Php This management system is the most expensive among the four due to the usage of the plastic mulch. As observed, there are methods of both hilling-up and off-barring in the scenario. If analysed, this is not a practical method because it might disturb the root system and the carabao may also eat the tomato plants and may cause further damage during the harvesting period. The movement of the soil will also promote aeration but soil erosion might happen eventually. Thus, this is not a practical method of a weed management strategy because it is not efficient and very costly. In addition, it is not environmentally sound since there will be usage of plastic which at the end of the cropping season will turn into a non-biodegradable waste.
  7. 7. Integrated Weed Management Strategy for Tomato 7Assumptions The assumptions of the proposed integrated weed management systems for tomatoproduction set the scope and limitations of the location, area and source of materials to be usedfor the whole production process. The site will be at Nacaituna’s Farm, located at Kibawe, Bukidnon. The area allocated is10000 m2 and all of the materials will be bought at agricultural supply stores or productproviders of the town. The labor force will be gathered at the same area. The animals that willbe used in ploughing must be owned by the labourer. The rate of wage to be given will also berelative to the usual payment in the area and will be in a form of package per operation. The variety to be used is the Magilas and the cropping season will last for 5 monthswhere in the last 3 months will be the harvesting period. Trellising is not required since thisvariety has determinate growth habit but will be made as a support during fruiting stage. Thus,the planting distance will be 60 cm x 60 cm as recommended. Thus there would be 27, 778plants in a hectare. There would be 50 rows in the area and there would be 556 plants per row.Pruning will also be done to reach the 100% yield. 100% yield means that each plant willproduce 4 kilos of tomato for the cropping season. The soil is also assumed to be in best condition for growing tomatoes. No liming will berequired but in the next season, it will be a need. The planting process will be based upon the recommendation of the Bureau ofAgricultural Research. The recommendation includes the application of fertilizers and pesticidesand other necessary operations. The expenses will also be based from it. The planting process according to the Bureau of Agricultural Research: Seedbed Preparation 1. Make seedbed 50 cm apart with any convenient length in an area fully exposed to sunlight 2. Pulverize the soil thoroughly and add compost or dried animal manure at the rate of 5 kg per sqmeter. 3. Sterilize the soil by burning rice straw or rice hull on top of the seedbed for 4-5 hours to kill soil-bon pathogens. 4. Drench the seedbed with fungicide-insecticide solution. 5. To protect the seedlings from heavy rains, place plastic roofing. Sowing 1.Wet the seedbed thoroughly before sowing. 2.Make horizontal rows 5cm apart. 3. Sow 80-100 seeds in every 50 cm row (150-200 g of seeds are needed per hectare). 4.Cover the seeds with a thin layer of soil and place rice straw mulch. 5.Water the seedbed daily (seedlings start to emerge 3-6 days from sowing). Care of Seedlings 1. 3-5 days later germination, prick the seedlings by transferring them into a tray or seedbox toallow more space between seedlings and prevent damping-off. In the
  8. 8. Integrated Weed Management Strategy for Tomato 8 absence of seedling trayor seedbox, use paper pots (rolled), “lukong” or rolled banana leaves, and plastic bags. 2. Plant the seedlings in a soil mixture consisting of garden soil, compost (or well decomposedanimal manure and rice hull in a 2:3:1 ratio). If possible, sterilize the soil mixture by baking orthrough steam. 3. Drench the newly pricked seedlings with fungicide solution to prevent damping-off. If insectappears, spray the seedlings with appropriate insecticide. 4. For large scale production, use seedbed. In this case, pricking is not done. Instead, thinning isdone to allow more space between seedlings. 5. A week after pricking or thinning, apply starter solution (2 tbsp Ammonium Phosphate (16-20-0)or 14-14-14 dissolved in 1 gal water). 6. A foliar fertilizer may also be used. 7. 1 week before transplanting, harden the seedlings by gradually reducing the amount andfrequency of watering until the seedlings experience temporary wilting.Transplanting 1. Select healthy seedlings with 3-5 leaves 3-4 weeks after seedling emergence. 2. Transplant 2-3 seedlings per hill spaced 40 cm apart. 3. Transplant in the afternoon. 4. Press the soil gently around the base of the seedlings. 5. Water immediately. 6. Replant missing hills 5-7 days after transplanting.Trellising 1. Trellising is recommended in growing semi-determinate and indeterminate varieties. 2. Use bamboo or ipil-ipil poles as post. 3. Tie the branches to the post and train the vines using plastic straw.Nutrient Management 1. 1-2 days before planting, apply 20 g 14-14-14 per hill and mix it thoroughly with the soil. 2. 3-4 weeks after transplanting, mix 2 parts of Urea (46-0-0) with 1 part Muriate of Potash (0-0-60) and apply 1 tbsp (10g) of the mixture 6-8cm away from the base of the plants in bands (firstsidedressing). 3. Apply another 1 tbsp of the mixed fertilizer two weeks later (second sidedressing).Water Management Depending on the weather and soil, water the plants once a week until early fruiting stage. Chemical control methods will be used for the management of both insect and pathogen pests. 5 types ofdifferent pesticides will be used alternately for 10 weeks with in the growing season. The application ratewould be 200 L/ha. The products will be bought at farm gate price at 20Php per kilo. The packaging will beby 25 kg and will be placed at wooden boxes. Moreover, it will be assumed that the buyerswill be the one to go to the area for trade.
  9. 9. Integrated Weed Management Strategy for Tomato 9 The following rates for each farm operation and inputs:Table 1: Price of farm inputs Input Price per Quantity Tomato seeds (200 g) 5000Php 1 sack of Complete (14-14-14) (50 kg) 1250Php/sack 1 sack Urea (46-0-0) (50 kg) 11190Php/sack 1 sack Muriate of Potash (0-0-60) (50 kg) 1270Php/sack Plastic roofing 2000Php/ set 1 sack Ammonium Phosphate (16-20-0) (50 kg) 960Php/sack Chicken Dung 150Php / sack Sticks for trellis 2000Php Twine 1320Php Trellising Material 300Php/kg 1 sack Rice hull 10Php/sack Lannate 40 SP 1500Php/kg Provin 85 WP 1000Php/kg Hercules 750Php/L Dithane M-45 100Php/kg Vitigran Blue 35 WP 600Php/kg Water 5000Php/season Wooden boxes 15Php/box Table 2: Rate of labor for Farm Operations per head Farm Operation Rate per head (Php) Seed bed preparation 2500Php /package Sowing 2000Php /package Care of Seedlings 1500Php /package Transplanting 350Php / 1000 seedlings transplanted Trellising 150Php /head Sticking 150Php/head Hilling-up 300Php/head Pruning 2500Php/package Fertilizer Application-Side dressing 50Php/sack Fertilizer Application-Spraying 20Php/load Harvesting 10Php / box being harvested Installment of Sprinkler System 30000Php/package
  10. 10. Integrated Weed Management Strategy for Tomato 10 Revenue: Table 3: Cost Analysis of production excluding the cost for the integrated weed management strategy: Input Quantity Unit Cost Total CostLabor CostSeed bed preparation 1 2500Php 2500PhpSowing 1 2000Php 2000PhpCare of Seedlings 1 1500Php 1500PhpTransplanting 28 350Php 9800PhpTrellising 12 150Php 1800PhpSticking 3 150Php 450PhpHilling-up 3 300Php 900PhpPruning 1 2500Php 2500PhpFertilizer Application-Side dressing 22 50Php 1100PhpFertilizer Application-Spraying 125 20Php 2500PhpHarvesting 11112 10Php 111120PhpInstalling the Sprinkler System 1 10000Php 10000Php SUBTOTAL 146170PhpCost of InputsTomato seeds (200 g) 1 5000Php 5000Php1 sack of Complete (14-14-14) (50 kg) 11 1250Ph 13750Php1 sack Urea (46-0-0) (50 kg) 7 11190Php 8330Php1 sack Muriate of Potash (0-0-60) (50 kg) 4 1270Php 5080PhpPlastic roofing 1 2000Php 2000Php1 sack Ammonium Phosphate (16-20-0) (50 kg) 1 960Php 960PhpChicken Dung 20 150Php 3000PhpSticks for trellis 1 2000Php 2000PhpTwine 1 1320Php 1320PhpTrellising Material 100 300Php 30000Php1 sack Rice hull 5 10Php 50PhpLannate 40 SP 1 1500Php 1500PhpProvin 85 WP 1 1000Php 1000PhpHercules 1 750Php 750PhpDithane M-45 1 100Php 100PhpVitigran Blue 35 WP 1 600Php 600PhpWooden boxes 11112 15Php 166680PhpWater 1 5000Php 5000PhpSprinkler System 1 30000Php 30000Php SUBTOTAL 277120Php GRAND TOTAL 423290Php
  11. 11. Integrated Weed Management Strategy for Tomato 11 From the computatio, it is established that a capital of 423290Php is needed to establish a tomato farm with an area of 1 hectare. The amount is exclusive of the weed management strategy to be used. Moreover, the computed revenue is 2222240Php which at maximum and will also be used as the standard as assumed that the crops will have 100% yield and all the practices prevented the damage to the cropThe Proposed Integrated Weeding Management Strategy for Tomato Thorough Land Preparation Selective mulching Hand Weeding Diagram of the Processes of the Proposed Integrated Weed Management Strategy 1. Thorough Land Preparation Thorough land preparation requires at least 2 passes of ploughing in two different directions: one is the direction of the length and the other is following the direction of the width. The purpose of which is to loosen the roots of the weeds in the area and expose them to desiccation. The land will be exposed to direct sunlight for a week. Harrowing will follow which will have at least 2 passes to pulverize the soil in such way that it will be suitable for planting tomato. It will also follow the directions of the ploughing. Furrowing will follow the next day and will form criss-crossed with a planting distance of .75 m x .75 m which follows the high-density plant population of tomato production. This will provide closer plants and less space for weeds to grow. Moreover, each tomato plant will prevent the development of weeds due to closer canopy which will block the sunlight.
  12. 12. Integrated Weed Management Strategy for Tomato 12 Transplanting will follow immediately after the furrowing in order to establish the tomato seedlings and acclimatized them to the new environment. Moreover, the absence of the weeds at the duration will aid the seedlings to grow better since there would be no competitors for nutrients, water and sunlight.2. Selective Mulching Selective mulching refers to the method wherein the selected areas of the plant will be covered with mulch. Only the circular area near the base of the plants will be covered to reduce the cost of mulching material since almost half of the calculated. The thickness of the mulch will be 5.0 cm for each plant. Moreover, the mulching material to be used will not be primarily the rice straw due to the possibility that it will be a vector of weed propagules from its source. Dried leaves from the area will be more suitable but if not available, rice straw will be used. This step will follow right after the transplanting of the seedlings.3. Spot and Hand Weeding Spot and hand weeding will follow 20-25 days after transplanting (DAT) and will only happen if necessary. The basis for its necessity will be the growth of weeds near the tomato seedlings which will emerge from the mulch.Table 1. Field Operations’ Schedule with its corresponding purpose for the proposed Integrated Weed Management strategy Field Operation Schedule Purpose 1. Thorough land preparation 2 WBT Kill weeds (ploughing, harrowing, furrowing). Pulverize the soil Delay weed emergence 2. Selective Mulching 3 DAT Conserve moisture and prevent growth of weeds 3. Spot and Hand Weeding 20-25 DAT Remove weeds growing near the seedlings
  13. 13. Integrated Weed Management Strategy for Tomato 13 Table 2. Cost Analysis of theproposed IntegratedWeed Management Strategy: Field Operation Number of Unit Cost Total Cost Units A. Labor cost: Land preparation 4 300.00 Php 1200.00 Php Mulching 8 150.00 Php 1200.00 Php Hand weeding 16 200.00 Php 3200.00 Php SUBTOTAL 5600.00 Php B. Cost of Inputs Mulching material 50 10.00 Php 750.00 Php SUBTOTAL 750.00 Php TOTAL COST 6350.00 PhpDiscussion The four established weed management system and the proposed weed management systemare then compared according to their expenses with the overall costing for tomato production in ahectare. The table below shows overall costing of production and the profit when the total cost of inputswas deducted from the total revenue. Integrated Weed Management Systems of Tomato Management Management Management Management Management System system 1 system 2 system 3 system 4 5(Proposed Weed (Janiya, 2002) (Janiya, 2002) (Janiya, 2002) (,2012) Management Strategy)Cost of each weed 7800Php 5250Php 10500Php 23500Php 6350PhpManagementsystemCost of inputs 423290Php 423290Php 423290Php 423290Php 423290PhpTotal Cost of 431090Php 428540Php 433790Php 446790Php 429640PhpInputsTotal Revenue 2222240Php 2222240Php 2222240Php 2222240Php 2222240PhpProfit 1791150Php 1793700Php 1788450Php 1775450Php 1792600Php Based from the table above, it could be observed that the profits with the use eachmanagement system are not that far from each other. But the highest profit could be made with theusage of Management System 2 and followed by Management System 5 which is the proposed weedmanagement strategy by the proponents.
  14. 14. Integrated Weed Management Strategy for Tomato 14 If analysed further, there’s no big difference among the profit yet in terms of other factors suchas environmental soundness and efficiency, the proposed weed management strategy is on the edge.Management System 2 makes use of herbicide in order to control the weeds why is not good for theenvironment. It is also inefficient since it already used the chemical control yet it will still utilize handweeding. Furthermore, the chemical control will only control the grasses and sedges – the broadleavesand sedges will still be left in the field. Management Systems’ 1,3 and 4 are also good and economically viable but ManagementSystems’ 2 and 5 are less expensive. All of the management systems for weeds could be done due topreferences. Moreover, tomato production commonly gives high economic yield unlike other crops.Lastly, weed management in tomato can only be effective if the time frame for its use will be followed.Conclusion From the observations made, it is concluded that the proposed integrated weed management for tomato production can be an alternative choice for managing weeds. Moreover, the following conclusions were drawn: 1. The common weed management strategies used in tomato are published by Janiya, J.D. (2002) and by the Bureau of Agricultural Research (, 2012). 2. The different weed management systems ,in general, have their strengths particularly on the environmentally friendliness, economic viability .However, there are also weaknesses in terms of its efficiency 3. The proposed integrated weed management strategy for tomato can be an alternative since it is efficient, economically viable and environmentally friendly. Moreover, it is in line with the guidelines and goals of Good Agriculture Practices due to its methodologies that does not harm the environment and sustains the productivity of the crops. The proposed integrated weed management system is composed by 3 steps: a. Thorough land preparation b. Selective Mulching c. Spot weeding/hand weeding (Refer to pages 11-2 for details)ReferencesBook Source: Janiya, J.D. (2002) Weed Mangement in Major Crops of the Philippines: Yield losses, major weed species and suggested management systems in selected major crops. Philippines. Weed Science Society of the Philippines, Inc. and Crop Protection Association of the Philippines, Inc. p. 58-9
  15. 15. Integrated Weed Management Strategy for Tomato 15Electronic Journals (.pdf): Adigun, J.A (2005).Critical period of weed interference in rain fed and irrigated tomatoes in Nigerian Savannah. AgriculturaTropicaEtSubtropica. Vol 38(2) 2005.p 73-9. Retrieved on August 26, 2012 from Sources: University of Illinois (2012)Tomato.University of Illinois: Watch Your Garden Grow. Retrieved on August 24, 2012 a from Bureau of Agricultural Research (2012).Tomato.AGFISHTECH Online. Retrieved on August 22, 2012 from Cornell University (2012).Tomato MVR – Philippines.Agricultural Biotechnology Support Project II.Retrieved on August 25, 2012 from Department of Agriculture(2011). Performance of Philippine Agriculture: January-March 2011. Department of Agriculture. Retrieved on August 25, 201 from Abygay, C.(2010) Growing Tomatoes (High Value Vegetable).EntrePinoyAtbp. Retrieved on August 26, 2012 from