Key Factors in Vegetable Production

Success in vegetable production whether it is organic or not is greatly depended on a well thought out plant. Key factors that should be considered carefully during the planning stage of the farming operation are: site selection, water supply and quality, crop and variety selection, and, market development. If the wrong decision is made with regard to anyone of these, the operation is doomed for failure.

Site Selection -

Minimizing potential production problems is essential to all farming operations. This is especially true for organic producers. One of the most effective means of reducing potential problems is through proper field site selection. Three points should be considered when selecting a field to produce vegetables: field topography, soil type, and water availability and quality.

Field Topography -

Topography refers to the physical characteristics of the overall field site and includes such conditions as; contour, soil depth, water and air drainage, and, the presence of rock out cropping and trees. These characteristics can have a significant influence on crop production and management. Poorly drained fields or those with low areas can become water logged during periods of excessive rain. Such conditions can enhance the incidence of diseases, reduce plant vigor and yield, and, under excessive conditions, cause plant death. Brush areas or abandoned fields and pastures can harbor insects and severe as host for plant diseases, some of which can be vectored by insects. Rock out cropping and trees within a field can become impedance to farm implements and increase difficulty of land preparation and crop establishment. . Sites with slopes of 1.5 % (18″ elevation change per 100′) or more should be avoided to prevent excessive erosion problems. An ideal topography for vegetable production is one that is nearly flat to slightly sloping, well drained, and, free of trees, rocks and low areas. Efficiency of crop maintenance, irrigation and harvest operations is greatly enhanced in fields with this type topography (6).

Soil type and quality -

Soil type refers to the physical composition or properties of the soil. Soils basically consist of decomposed mineral matter (sand, silt, and clay) and decomposed organic matter. Optimum vegetable production is achieved on well-drained sandy loam soils. Although vegetables can be grown on a wide range of soil types, most vegetables are not well adapted to heavy clay soil types. Soils of this type tend to have poor aeration and drainage and can restrict root growth. Consequently, these soils should be avoided (6). Soil is the fundamental resource base for all agricultural production systems. Unfortunately, too often, too little time is spent in selecting soil type and soil management practices. In organic production, soil health is essential. Soil quality influences its ability to provide an optimum media for growth, sustain crop productivity, maintain environmental quality, and, provide for plant and animal health (17). Therefore, soil quality and soil health is viewed as the foundation to successful organic production. Consequently, the primary management goal of an organic producer should be sustaining and improving soil quality or health over the long term. Table 1 presents important soil properties influencing soil productivity. The USDA is currently developing test kits to evaluate soil quality indicator properties. Contact your local USDA-NRCS field office to obtain a test kit.

Table 1. Soil Quality Indicator Properties

Physical properties Chemical properties Biological properties
Bulk density
Rooting depth
Water infiltration rate
Water holding capacity
Aggregate stability
pH
electrical conductivity
cation exchange capacity
organic matter
mineralizable nitrogen
exchangeable K
exchangeable Ca
Microbial biomass carbon
earthworms
enzymes
disease suppressiveness

Water -

Water is the life-blood of vegetable production. Vegetable crops generally require more total water and more frequent irrigation than most other agronomic crops. Few vegetables can be grown successfully under dryland conditions in most areas of Texas. Even in East Texas where 45 + ” of rainfall occurs annually, crops can experience period of drought stress. Therefore, only fields that have easy access to an abundant water source should be considered for vegetable production. The water source should have the capability to provide the volume required for the maximum needs of the highest water-using crop to be planted. Water needs for selected vegetables grown in Texas are listed in Table 1 of the appendix.

Water quality is equally as important as water volume in selecting a field site water source. Water source for vegetable irrigation should contain less than 400 ppm soluble salts. Therefore, avoid water sources containing high levels of toxic elements such as Sodium, Boron or Aluminum. Tables 2 and 3 are helpful in evaluating suitability of water for irrigation. The absence of an adequate supply of high quality water cannot be offset with an ideal field site having a desirable soil type. Knowledge of crop tolerance to salinity is essential if marginal quality water is to be used (6).

Table 2. Permissible Salinity Limits for Classes of Irrigation Water.

Water Classed Electrical conductivity
(umhos)
Gravimetric
Ppm
% Sodium Chlorides (Cl) Sulfates (SO4)
Class 1=(excellent)
Class 2=(good)
Class 3=(permissible)
Class 4=(doubtful)
Class 5=(unsuitable)
250
250-750
750-2000
2000-3000
3000+
175
175-525
525-1400
1400-2100
2100+
20
20-40
40-50
60-80
80+
4
4-7
7-12
12-20
20+
4
4-7
7-12
12-20
20+

Table 3. Classification of Sodium Hazard of Water Based on SAR Values.

SAR Values Sodium Hazard of Water Comments
1-10 Low Use on sodium sensitive crop such as avocados must be cautioned.
10-18 Medium Gypsum and leaching needed.
18-26 High Generally unsuitable for continuous use.
26 Very High Generally unsuitable for use.

Crop and Variety Selection -

A factor equal to the importance of good soil health to successful implementation of the organic production concept is crop and variety selection. Pest of all types occurs in abundance in most areas of Texas. However, the greatest limiting factor to successful vegetable production from a pest stand-point is the high incidence of disease outbreaks. With the reduced number of tools to combat pests available in the organic production arsenal, as compared to conventional production, even greater importance is placed on the use of resistant crops and varieties as the primary means of pest control. Table 2 of the appendix list vegetable varieties recommended for Texas. Most of the varieties listed were selected partly because they possess as high a level of resistance as available to as many diseases as possible. Therefore, organic producers who use varieties or grow species with resistance to as many diseases as available greatly increase their chances for success.

Market development -

The fact that most vegetable crops are highly perishable, the need to develop markets for produce should be established prior to planting the crop. This even more important for organically produced vegetables due to their limited or niche market status. For whatever reason one chooses to commercially produce vegetables organically, profitability is the driving force that keeps him in business. To achieve profitability, a producer must have a well thought out production and marketing plan based on sound scientific and business principles. Most startup vegetable operations generally fail due to the lack of market development or marketing skills.

Consequently, a potential grower cannot spend too much time in a developing production and marketing plan. Commercial vegetable production should always be viewed as a business first and as a farming enterprise secondly. Personnel views or beliefs are fine but establishing a business based on consumer preferences and demands make for a more successful undertaking.

In developing a sound marketing plan the following questions should be answered:
-What crops should I grow?
- How much of these crops should I produce?
- To whom or where shall I sell the produce that I will grow?
- How much real demand is there for the crops I am considering
- How much will it cost me to produce and market these crops?
- What if any are the sizes of the market windows for these crops?
- What are the risks associated with the production of these crops?

In order to effectively answer these questions one must be willing to invest considerable time conducting market research. It should be stressed that in order to market produce as organically grown, a farming operation must be “Certified Organic” by the Texas Department of Agriculture. The following (used with permission from TDA) describes the requirements of the Texas Department of Agriculture Organic Certification Program (16).

The Texas Department of Agricultureā€™s Organic Certification Program certifies crops produced under an organic farming system. That is, a system of ecological soil management that relies on building humus levels through crop rotations, recycling organic wastes, and applying balanced mineral amendments. When necessary, this system uses mechanical, botanical, or biological controls that have minimum adverse effects on health and the environment. In addition, organic crops are produced without the use of synthetic pesticides, synthetic fertilizers and synthetic herbicides. Upon demonstrating compliances with the Organic Standards and Certification, Texas Administrative Code, Title 4, Part I, Chapter 18, participants are entitled to use a marketing logo identifying their products as state certified. TDA inspects and certifies producers, processors, handlers (warehouses, distributors, brokers) and retailers of organic products.

Comments are closed.