3.2 Common Crops and Their Uses
3.3 Common Production Practices of Vegetable Crops
3.4 Vegetable Crop Economics
3_Vegetable-Crops
Vegetable Crops
Overview
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Introduction
Lesson Objectives
- Identify examples of vegetable crops.
- Select examples of common vegetable crops from the list provided.
- Identify common uses of vegetable crops.
- Select common uses of vegetable crops from the list provided.
- Explain common production practices for vegetable crops.
- Describe common vegetable crop production practices.
- Evaluate the economic impact of vegetable crops.
Key Terms
vegetable crops - plants grown with parts that are to be consumed by humans or other animals as food
Introduction
Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is applied to plants collectively to refer to all edible plant matter, including the flowers, fruits, stems, leaves, roots, and seeds. An alternative definition of the term is applied somewhat arbitrarily, often by culinary and cultural tradition. It may exclude foods derived from some plants that are fruits, flowers, nuts, and cereal grains, but include savory fruits such as tomatoes and courgettes, flowers such as broccoli, and seeds such as pulses.
Common Crops and Their Uses
Vegetable crops are eaten by humans and animals and valued for their high nutritional content. Vegetable crops are generally classified as warm season or cool season according to the temperature ranges they require or prefer. Figure 5.3.1 shows a wide range of vegetables and their growing season in the state of Tennessee.
Warm-season vegetables are most productive in higher temperature ranges (late spring, summer) and are better able to grow and produce a quality crop through summer heat. They are damaged or killed by frost and freezing conditions; even cool, non-freezing temperatures may prevent them from growing and yielding well. Therefore, growers should pay attention to local frost dates when selecting planting times.
Cool-season vegetables can withstand temperatures below 32° F (how far below varies by crop and situation) and are generally more productive and have higher quality produce when grown during cooler spring and fall seasons. Because of these attributes, cool-season crops are planted in the late winter or early spring to avoid the hottest part of the summer. They can often be seeded again in the late summer to provide another crop during the fall season.
New vegetable varieties are constantly being developed throughout the world. Since it is impossible to list and describe all of them, only some of the better performing commercial types are listed in the specific crop section (Figure 5.3.2), either alphabetically or in order of relative maturity from early to late. These varieties are believed to be suitable for commercial production under most conditions in the southeastern US.
Common Production Practices of Vegetable Crops
The development of various types of tillage practices was an integral part of the evolution of modern farming approaches. Tillage is helpful in crop production systems for purposes of weed management, incorporation of amendments such as lime and fertilizer, burial of crop residues to facilitate other field operations, disease management, and the preparation of a seedbed that is conducive to crop establishment. While the use of tillage practices provides a number of benefits to crop producers, researchers have also learned that the soil disturbance associated with tillage has some drawbacks. In a nutshell, tillage over time results in the degradation of several soil properties that are important to crop productivity.
One of these properties is organic matter content. Organic matter is important because it contributes to the water and nutrient holding capacity of soil and to the maintenance of a desirable soil structure. These soil properties, in turn, allow soil to better support the weight of equipment and workers. In warm southern climates the loss of organic matter due to tillage is even more pronounced than in cooler climates. Tilled soil is also less hospitable to a variety of soil organisms including microbes, insects, and other small animals. When present in adequate numbers these are beneficial for various reasons.
When minimum tillage is used, soil structure is improved by the release of exudates of various organisms that glue soil particles together into larger, more desirable aggregates. Plant roots benefit from the increased presence of pore spaces in the soil such as earthworm channels, and plant diseases may also be reduced by the increased diversity of soil microorganisms. Adoption of minimum tillage in vegetable production is possible but requires careful planning and preparation. Making a transition to minimum tillage will affect several vegetable production field operations. For example, one common objective of minimum tillage is to retain crop residues on the soil surface. These residues are beneficial for reducing soil erosion but also may interfere with the seeding of crops, particularly small-seeded vegetable crops. Similarly, cultivation, often an important measure for controlling weeds in vegetables, may require different equipment than what the farmer is able to use in conventionally tilled fields. In general, it may be best to start with those vegetables that are grown similarly to agronomic row crops or to use crops that can be established by transplanting through crop residues. Row crop examples include sweet corn and cowpeas. Examples of vegetables that are easily transplanted include tomato, pepper, squash, and watermelon.
Growers interested in adopting minimum tillage practices should begin by learning about the practices currently employed by agronomic crop producers and others who grow vegetables using reduced tillage. One such practice is to limit tillage and seedbed preparation to a narrow strip where the crop will be planted. This may be done in combination with the use of cover crops that are killed by rolling and crimping prior to tilling the strip. This method has been used successfully for vegetables such as tomatoes and cucurbits.
Many soils that are not productive due to poor physical properties can be restored and made more productive through the continued use of cover crops. Cover crops can provide many benefits to soils that include reducing the buildup of soilborne disease and arthropod pests, increasing soil organic matter, suppressing weeds, improving soil structure, promoting beneficial soil microorganisms, improving nutrient cycling, and reducing soil erosion. Each cover crop can offer different potential benefits to a production system and not every cover crop will work for each grower’s intended purpose. Many cover crops can reduce or limit the build-up of soil-borne disease and insect pests that damage vegetable crops.
Prevalent disease and insect pressure should be considered when selecting a cover crop, as some cover crops could increase the severity of these issues. In some cases, specific cultivars of cover crops can differ in their host status to various plant-parasitic nematodes.
With intensive cropping, working the soil when it is too wet or has experienced excessive traffic from heavy equipment will damage the soil. These practices cause soils to become hard and compact, resulting in poor seed germination, loss of transplants, and shallow root formation of surviving plants. Such soils can easily form crusts on the surface, become compacted, which make them difficult to irrigate properly. Combined, these practices will yield negative consequences for your soil; poor plant stands, poor crop growth, low yields, and loss of income. In some cases, sub-soiling in the row might help improve aeration and drainage, but its effect is limited and short term. Continued and dedicated use of cover crops will aid in preventing these conditions. It may take several years of continued use to observe some of the benefits that cover crops can provide to soils.
Cover crops can also be planted in strips for wind protection, preceding the planting of the cash crop. Annual rye seeded before November can be a good choice for use in wind protection. Cover crops reduce nutrient loss during the winter and early spring. Cover crops may deplete the soil moisture. If this is a concern, cover crops should be disked or plowed before soil moisture is depleted.
Seeding dates suggested in the following section are for the central part of the Southeastern United States and will vary with elevation and northern or southern locations.
Vegetable Crop Economics
For over 5 years, the United States has reported harvesting over 2 million acres of vegetable crops. This number has been steadily decreasing. In 2016, there were 2.6 million acres of crops harvested versus 2.2 million acres harvested in 2021. The annual market value of vegetable crops has fluctuated up and down, running 13.6 billion dollars in 2016 down to 12.7 billion dollars in 2021.
Dig Deeper
Vegetable crops | Cabbage | Onion | Pepper | Tomato | Watermelon |
https://www.marketnews.usda.gov/mnp/fv-nav-byCom?navClass=VEGETABLES&navType=byComm
Kemble et al.’s 2022 Southeast U.S. Vegetable Crop Handbook is a free online resource available from the Southeastern Vegetable Extension Workers Group
Attributions
2022 Southeast United States Vegetable Crop Handbook by the SEVEW Group. Copyright © Used with Permission.
The Tennessee Vegetable Garden: Garden Planning, Plant Preparation and Planting by Natalie Bumgarner, University of Tennessee. Copyright © Used with Permission.
USDA Definition of Specialty Crop by the United States Department of Agriculture is in the Public Domain.
Vegetable by Wikipedia is licensed CC BY-SA.
Vegetable Statistics by the United States Department of Agriculture National Agricultural Statistics Service is in the Public Domain.