Maintaining the quality of tomatoes is at the core of harvesting tomatoes. With the current craze in healthy diets, customers are increasingly paying close attention to quality of the produce. Poorly harvested and damaged tomatoes therefore cost farmers a lot of money. In fact, the highest losses in tomato farming are incurred during the tomato harvesting period. Healthy tomatoes are firm and uniform in colour; they also have an increased shelf life which all farmers seek to achieve. Tomato harvesting should be done by highly skilled personnel who possess advanced knowhow for increased productivity.
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Cost of Tomato Harvesting
Harvesting tomatoes is a labour intensive procedure. The initial cost of harvesting, grading, packaging and transportation are at least as high as the pre-harvest costs if not more. Sometimes costs incurred in tomato harvesting can be double those of pre-harvesting. For this reason, it is essential to calculate the costs involved prior to harvesting in order to avoid disruptions during the process as they can negatively impact the quality of the produce. Labour and the amount of time to be taken should be factored in. A simple way to calculate the cost of tomato harvesting is as follows:
Farmer A assumes that his crops will need about 6 harvests of a full day’s work. 4 handlers should be able to carry out the job in a timely manner at a cost of $1 a day. The labour costs will therefore mount to $24. The cost of harvest machinery, containers required, food for the handlers and transportation of the produce among other expenses should also be worked out.
Time of Harvesting Tomatoes
The high water content in tomatoes makes them susceptible to damage and rot hence the necessity of timely tomato harvesting. Harvesting tomatoes should neither be rushed nor delayed but carried out when tomatoes are mature. The upside of harvesting green tomatoes is that they have a longer shelf life as they are less likely to rot, especially when they are to be sold in supermarkets. The ideal time to pick tomatoes is during the cooler part of the day which is usually any time before noon. Care should be taken to shield them from direct sunlight as high temperatures result in overripe tomatoes that can easily get damaged and start to rot. Depending on the seed variety, tomatoes are often ready for picking 3 to 6 months after planting. They are harvested for about 4 to 15 times in a season. This can vary according to the climate, seed variety as well as pests and diseases.
Farmers should be able to distinguish between various levels of maturity. This allows them to harvest in the appropriate time therefore maintaining the quality and shelf life of the produce. It is important to note that tomato harvesting done at the first stage of maturity will reduce the quality of the tomatoes while harvesting between the third and fourth stage produces tomatoes of superior quality. Field-ripened tomatoes have a better flavour and overall quality compares to those ripened after picking; hence it is important to understand ripeness stages.
- Pale green stage – tomatoes will continue to ripen and develop a red colour. Care should be taken when harvesting because any slight error might cause unsatisfactory ripening.
- Early light red stage – a red tint begins to appear, usually at the bottom end; sometimes on the sunny side of the fruit.
- Light red stage – almost the whole fruit shows a rosy or light red colour. Long shelf life tomatoes are picked around this time. In hot temperatures, there is danger of over-ripening thus the need to pay close attention to the produce.
- Red or ripe stage – almost the whole fruit shows a full red colour but is still firm. Daily picking should be done to avoid over-ripening.
Tomato Harvesting method
Tomatoes are vulnerable to damage thus should be hand-picked carefully. Tomato harvesting should be done by individuals with good personal hygiene. Gloves should be worn at all times and nails cut to avoid damage. The recommended method of harvesting tomatoes is by lifting the fruit followed by a slight twist and pull. The tomatoes should then be placed carefully in containers away from direct sunlight. Nylon net bags and plastic buckets are the commonly used picking containers. These will be emptied into larger containers to be carried to the grading area thus should not exceed 25kg. Note that any damage during this period will appear as brown or black discolouration or a faster ripening that is vulnerable to decay. This can easily spread and spoil other produce in contact.
Grading is the grouping of tomatoes based on specific criteria for example size, the level of maturity or quality. Grading can either be done manually or mechanically. Mechanical grading involves use of machinery to wash and sort the tomatoes and manual grading involves washing and sorting by hand. It advisable to use sorting tables that are disinfected instead of plastic sheeting that can contaminate the tomatoes. Tomatoes should be washed and dried to disinfect them. After completion of this stage, they can then be placed in containers ready for dispatch to their final destination.
Great care should be taken when packaging tomatoes. Badly packed tomatoes can easily get damaged resulting in rot which can easily spread thus ruining the entire pack. Packaging is done according to the classification given in grading. Fresh tomatoes are packed without stems. It is possible to stack mature green tomatoes on top of each other as they are firm as less susceptible to damage. The packaging material must be new, clean and of good quality to protect tomatoes from damage during transportation.
Storage is an essential aspect of tomato harvesting as it has a direct impact on shelf life. Tomatoes are sensitive to extreme weather conditions. Chilling temperatures below 10oC for longer than 2 weeks result in un-ripe tomatoes, premature softening and increased decay. The same fate is applied to those kept at 5oC for longer than 6 to 8 days. High temperatures lead to over-ripening and vulnerability to damage and rot. Cold storage facilities should be used to store tomatoes in tropical and subtropical climates. Farmers without access to cold storages either dry or puree the tomatoes. Another way is to store them in clean green leaves that are changed every 2 to 3 days until the tomatoes have been sold. Tomatoes that are to be sold fresh for table consumption must not be stored for a long period of time. From storage, the tomatoes are then distributed to their final destination.
Yield of Tomatoes
The overall yield produced during the process of harvesting tomatoes depends on climate, seed variety and the fertility of the soil. A successful tomato harvest can yield from 10 000 to 60 000 kg per hectare, sometimes even up to 100 000 kg of tomatoes per hectare. The yield is however commonly dwindled by poor tomato harvesting methods that cause damage and allow infestation of fungal infections during storage. Tomatoes harvested too late or too early also result in declined yield hence the need for precision during tomato harvesting.
The technique of tomato harvesting determines the quantity and quality of the yield. For this reason, farmers have an obligation to understand and master the skill of tomato harvesting or else their toiling would be in vain. Great care should therefore be taken in harvesting, handling, packaging, storing as well as in the transportation of the yield. The process should be dedicated toward achieving a quality bumper harvest.