The first step is to attract outstanding students into vegetable breeding programs with modern, exciting and relevant curricula that provide clear paths for obtaining knowledge, experience and skills needed for success in attractive jobs that are currently available in plant breeding globally. For all countries, vegetable products are critical for good nutrition, healthy living and a dynamic business sector. Development of new, genetically improved vegetable cultivars that are profitable for growers and that meet the needs of consumers will contribute to a vital, dynamic vegetable industry world-wide. The ready supply of a wide range of affordable vegetable crops in most developed countries has led to a marked complacency about the need for ongoing R & D vegetable breeding programs.Consequently, many governments world-wide have scaled back funding for vegetable breeding and production programs.Most research driven universities have now disbanded horticulture/ horticultural breeding departments and merged them into plant science/plant biology departments with a very strong focus on the molecular sciences. This erosion has been concentrated in what historically have been viewed as vital disciplines for vegetable breeding such as plant breeding, agronomy, pathology, and entomology. Nonetheless, as indicated above, there are a basic need for research and breeding on vegetable crops given by the current consumer demands for affordability, safety and continuity of supply; increasing needs to achieve sustainable practices; and the need to deal with challenges arising from a more variable climate, the loss of productive soils through urban encroachment, and the loss of low-cost labour.
The concepts of sustainability of vegetable crops relate both to the use of resources,stackable planters such as water and nutrients, in a manner which considers future needs, and the responsible use of compounds such as pesticides which will not compromise the quality of the environment . Improved vegetable cultivars are also important since there are cultivars more apropriated for sustainable production. Vegetable breeding can be important for genetic enhancement of vegetables, and for an eco-friendly organic horticulture that will reduce human carbon footprints.Pressure on water resources for urban, industrial, recreational, conservation and other uses all appear to have higher priority within societies than the availability of water for vegetable crop production. Current demands on water from both river and subterranean sources are outstripping availability resulting in attention being given to water harvesting options with on-farm dams, the use of waste water and to the use of more efficient cultural practices. Research is urgently needed to resolve issues such as the development of drought tolerant vegetable crops, the management of crops under managed water deficits, dealing with increased salinity, and the use of low quality water. Integrated crop production systems have been shown to be effective on a number of vegetable crops for reducing the number of pesticide applications and for shifting to new control compounds that have less persistence in the environment and which are of lower overall toxicity. Producers have behaved responsibly and with some urgency to ensure the adoption of new practices. GMOs cultivars can also be important for sustainable production . Genetic engineering has the potential to address some of the most challenging biotic constraints faced by vegetables growers, which are not easily addressed through conventional plant breeding alone. Transgenic vegetable crops, enable also breeders to bring favorable genes, often inaccessible by conventional methods, into elite cultivars, improving their value considerably and offering unique opportunities for controlling insects and other pathogens . Technology transfer from both university and government sources in many developed countries has markedly declined over the past two decades and have been re-placed with a greater provision of services from the private sector. Paradoxically, the demand for information from public providers has nonetheless increased as providers of information in the private sector seek to stay abreast of the latest developments and as producers seek to secure the best advice possible.
This can be very important for sustainable production and better knowledge of the vegetable producers about the cultivars available. In developing countries, where often the provision of knowledge from both private and public sectors may be poorly developed, the demand for useful and relevant information is growing as vegetable enterprises become more sophisticated and often more focussed on exporting their vegetable produces. In parallel with such changes, there has been an unprecedented expansion of methods by which to transfer information-mobile phones, the internet, laptop computers, private and public networking, and so on. Equally, there is a growing expansion of the types of information that can be accessed including that from remote sensing, environmental monitoring, image analysis and others. The challenges relate not to the availability of information, but to the provision of relevant knowledge and the more effective means of transmitting the specific information that is required. Vegetable producers have rapidly adopted many of these technologies contributing for their success as farmers. The major challenge facing vegetable producers in the future will be to filter the information that is available into useful knowledge that will allow them to be more effective and efficient in their various enterprises. Regular consumption of a vegetable rich diet has undeniable positive effects on health since phytonutriceuticals of vegetables can protect the human body from several types of chronic diseases. The mechanism by which vegetables decrease risk of disease is complex and largely unknown. Various components of the whole food are likely to contribute to the overall health benefit. Various phytonutriceuticals with antioxidant properties may work directly by quenching free radicals or indirectly by participating in cell signaling pathways sensitive to redox balance . Nutrients such as potassium contribute to blood pressure regulation. The dietary fiber content and type of different vegetables may also contribute to the overall health benefit, such as improving bowel transit, lowering cholesterol, helping manage blood glucose concentrations, and by transporting a significant amount of minerals and phytochemicals linked to the fibre matrix through the human gut .
Finaly, increaseing vegetables in the diet may reduce the intake of saturated fats, trans fats, and foods with higher caloric density,stacking pots all of which may be related to a healthier overall diet . A major activity over the past 2 3 decades has been the promotion of health benefits that can be gained through the consumption of various vegetables. This has been most evident from the various “5 a Day” and similar promotional programmes to promote fruits and vegetables consumption. These activities that have been a success have not just included fresh vegetable and fruit products but have also embraced products based on juice, dried products and extracts, many of which have extensive on-label claims. The reality is that many such claims have not in fact been clinically proven and regulators are increasingly requiring label claims to either be substantiated or removed. Clearly, there is a need for considerably more research in this area in order to fully specify the presumed health benefits in many vegetables . This is an exciting area of endeavour where there is a convergence of horticultural science with medical and nutri-tional research. Notwithstanding the need to prove many of the specific health claims that are made for many vegetable crops, the consumption of vegetables per capita in markets such as the United States of America has in-creased over the past 2 3 decades. However, consumer preferences have changed markedly during that same period with a growing pattern of interest in convenience, year-round availability and with novelty. No doubt the perceived health benefits of some of these vegetable crops have also helped to enhance consumption. Because each vegetable contains a unique combination of phytonutriceuticals , a great diversity of vegetables should be eaten to ensure that individual’s diet includes a combination of phytonutriceuticals and to get all the health benefits. The availability of a large diversity of vegetables year-round, allied to increase in mean per capita incomes in recent years and knowledge of vegetable health benefits, have enable consumers to include a variety of health promoting phytonutriceuticals in their diet .
Nutritional quality as understood by the consumers and available at a moderate price may encourage enhanced consumption, thereby conferring an important marketing incentive to vegetable plant breeding. Re-search on the health benefits of vegetables, from a horticultural and breeding perspective, needs to focus on key areas in the near future such as: i) to continue the evaluation of phytonutriceuticals content among older versus newer major cultivars; ii) to identify the genetic mecanisms that regulate the syntesis of their key phytochemicals, such as the glucosinolates, thiosulfides and flavonoids, in order to develop cultivars rich in a variety of phytochemicals and in order to ensure that a mixture of phytochemicals enters into the human diet; iii) to study the potencial change in the balance of these compounds ; and iv) to identify the optimum conditions for mantaining these phytochemicals after harvest and processing since studies have shown that the biovailability of some of the phytochemicals increase dramatically after storage and processing and others de grade rapidly. Genetic engineering enables vegetable breeders to in-corporate desired transgenes into elite cultivars, thereby improving their value considerably. It further offers unique opportunities for improving nutritional quality and bringing other health benefits . Many vegetable crops have been genetically modified to improve traits such as higher nutritional status or better flavour, and to reduce bitterness or anti-nutritional factors . Transgenic vegetables can be also used for vaccine delivery. Consumers could benefit further from eating more nutritious transgenic vegetables, e.g. an increase of crop carotenoids by metabolic sink manipulation through genetic engineering appears feasible in some vegetables . Genetically engineering carrots containing in-crease Ca levels may boost Ca uptake, thereby reducing the incidence of Ca deficiencies such as osteoporosis. Fortified transgenic lettuce with zinc will overcome the deficiency of this micronutrient that severely impairs organ function. Folates deficiency, which is regarded as a global health problem, can also be overcome with transgenic tomatoes with folate levels that provide a complete adult daily requirement. Transgenic lettuce with improved tocopherol and resveratrol composition may prevent coronary disease and arteriosclerosis and can con- tribute to cancer chemopreventative activity. Food safety and health benefits can also be enhanced through transgenic approaches, e.g. rural African re-source-poor consumers will benefit eating cyanide-free cultivars of cassava. Biotechnology-derived vegetable crops will succeed if clear advantages and safety are demonstrated to both growers and consumers. A major trend over the past decade, possibly as a con-sequence of smaller households and more dedication to leisure activities, has been the shift towards the consumption of fresh rather than frozen vegetables. Modern consumers do not store vegetable products for long periods within the household and are able to discern the difference in quality between vegetables that have been stored for short versus long periods. The challenge for breeding and horticultural science is, therefore, to refine methods for short term storage so that premium quality is retained rather than to focus on long-er-term storage for prolonged marketing. Interestingly, this potentially transforms the approaches that can be taken for chilling sensitive vegetables where long-term storage techniques have not been routinely available.
The option to provide for new approaches that can be used for quality retention during short-term storage should be an absolute priority. Maturity at harvest is the most important determinant of storage-life and of final fruit-vegetable quality. Many vegetables, in particular leafy vegetables, and immature fruit-vegetables , attain optimum eating-quality prior to reaching full maturity. This often results in delayed harvest, and consequently in produce of low quality.The method of harvesting can significantly impact upon the composition and post- harvest quality of vegetables. Mechanical injuries can accelerate loss of water and vitamin C resulting in increased susceptibility to decay-causing pathogens. Most fresh vegetables are harvested by hand. Root crops and some commodities destined for processing are mechanically harvested. Management of harvesting operations, whether manual or mechanical, can have a major impact on the quality of harvested vegetables. Proper management procedures include selection of optimum time to harvest in relation to product maturity and climatic conditions, training and supervision of workers, and proper implementation of effective quality control. Expedited and careful handling, immediate cooling after harvest, maintenance of optimum temperatures during transit and storage, and effective decay-control procedures are important factors in the successful post-harvest handling of vegetables. Attention must be paid to all of these factors, regardless of the method of harvesting used. These factors are nevertheless more critical in the case of mechanically harvested commodities. It should be noted that any practice that reduces the number of produce handling steps will help minimize losses. Field packing of produce at the time of harvest can greatly reduce the number of handling steps in preparation vegetables for marketing. Mobile field packing stations with adequate shading are used for vegetables that do not require washing as part of their preparation for marketing. Within each vegetable there is a range of genotypic variation in composition, quality, and post-harvest-life potential.