High value vegetables preferentially receive more inputs than other vegetable crops to help them cope with unfavorable weather and nutritional deficiencies, but extremes of heat, drought, salinity, and flooding will be unavoidable in a warming world. Some vegetable cultural practices to cope with these stressors already exist, but the development of well adapted cultivars will take long-er. Little work has been done to assess the genetic variability of most vegetables to cope with less than optimum growing conditions. Improved production systems that can cope with climate extremes must allow vegetables to produce under high temperatures, greater drought stress, increased soil salinity, and periodic flooding. This will involve a combination of improved cultivars and modified production systems. Most research on the effect of environmental stress has been done on tomato and there is a great need for more research on other vegetables.High temperatures decrease pollen productivity and viability dutch buckets system, and inhibit photosynthesis in tomato resulting in reduced fruit set, smaller and lower quality fruits, and ultimately a reduction in yield.

Drought is the single biggest cause of crop failures worldwide  and vegetables are particularly susceptible as most are succulent plants consisting of generally more than 90% water . Soil salinity is an increasing threat; high soil salinity afflicts about 20% of cultivated land and 33% of irrigated land worldwide . Many globally important vegetables, including onion, are sensitive to soil salinity while cucumbers, eggplants, crucifers, peppers and tomatoes are only moderately sensitive . Vegetable production in the tropics is often limited during the rainy season as most vegetables are highly susceptible to flooding. Genetic variation in this characteristic is limited, particularly in tomatoes, which rapidly wilt and die following a short period of flooding, particularly at high temperatures . Breeding vegetables for heat tolerance has proved easier than breeding for drought, salinity, or flooding tolerance . AVRDC has developed cultivars of tomato and Chinese cabbage with good adaptation to hot and humid tropical environments since the early 1970s. These improved lines initiated the successful cultivation of tomato and Chinese cabbage in the lowland tropics. The heat tolerant lines of tomato show no reduction in pollen viability from heat stress and produce a fruit set 15% higher than heat sensitive cultivars under the same conditions.

More improved lines are needed for future climatic scenarios, and these must be able to match the yields of conventional cultivars under favorable growing conditions. New cultivars must be developed from both existing tomato lines and from the relatively unexploited wild relatives of tomato.It also varies with crop developmental stage . Some wild relatives of tomato have good drought and salinity tolerance , but this is often genetically linked to undesirable fruit characteristics such as small fruit size and low fruit set and yield. Developing vegetables that are more tolerant of environmental extremes should not be limited to only those of global importance. Many indigenous land race vegetables from the tropics already are well adapted to the climatic conditions likely to be more widespread in the future. Many are highly nutritious and familiar to small-holder farmers, dutch buckets and can provide excellent opportunities to help farmers cope with climate change. In the case of most vegetable crops, biodiversity and genetics are delivered in a marvelous package known as the seed.

The special techniques of seed production, such as seed treatment for the control of planting diseases and viruses, and the combination of breeding improvement program such as development of hybrids and the incorporation of biotechnology, cannot be efficiently carried by individual growers. By these reasons in modern vegetable production the seed business is usually conducted as a distinct industry. High tech seed industry is a key part of modern horticulture that combines, seed production, genetic improvement, seed production, storage, and distribution. One of the main factors that determine success in vegetable production is biodiversity and genetic capacity. No practical breeding program can succeed without large numbers of lines  to evaluate, select, recombine, and inbreed . This effort must be organized, so valid conclusions can be reached and decisions made. Scientists, breeders, support people, and facilities, budgets, and good management are requirements to assure success in the vegetable seed business. Science must be state of the art to maximize success in a competitive business environment.