New Mexico Chile Task Force

Pre-Plant through Stand Establishment

Field Selection Considerations
Fall Site Preparation
Soil Testing
Equipment Maintenance and Calibration
Pest Management
Planting Practices
Emergence
Follow-up Scouting

Chile Pepper Growers Notes : Pre-Plant through Stand Establishment

The key to maximum profitable yield is good management. These growers notes for pre-plant and stand establishment are the first in a planned series of publications that will include recommendations for all phases of chile production. Recommendations are based on research findings and the collective experience of successful chile growers. Growers should consult the New Mexico Chile Task Force Web site at www.chiletaskforce.org for periodic updates to these recommendations.

Establishing a good stand is the first step, and one of the most critical, in obtaining profitable yields. A task force team of industry crop consultants, researchers and growers identified the following recommendations as key management steps needed to produce a good chile stand.

Field Selection Considerations

History.
There are many things to consider when choosing a planting site. Each topic listed below is addressed in more depth later in this report.

Weed problems. Avoid site if weed problems are excessive.
Herbicide carryover. Know what herbicide was used during previous season and the rate applied.
Nematode problems. Determine the nematode population with early fall soil sampling.
Disease. Avoid fields with a history of disease.
Salinity. Determine degree of problem with soil testing.
Previous crop. Avoid following chile with chile. A four-year rotation is needed.
Water Quality. Know irrigation water's salinity, sodium and pH levels.

Crop rotation.
The more successful growers do not follow chile with chile. They often plant chile following peanuts, corn, forage sorghums or alfalfa. Chile following a grass crop may offer improved broadleaf weed control if treatments were made to the grass crop. Also see cover crops.

Previous crop.

Crop Residues. Do not till under crops with high carbon:nitrogen (C:N) ratios, such as small grain straw and woody material. If residues are incorporated into the soil, apply extra N. Leaving residue on the soil surface can be beneficial during establishment. Organic matter on the soil surface helps to alleviate soil crusting. Crop rotations and tillage practices can have the most long-term impact on this soil property.
Pesticide Residues. Know what herbicides have been applied in the past, their carry-over rate and any potential damage that they can cause in chile crops.

Soil salinity.
Soil salts are an issue in many areas. Cotton is tolerant to salinity and is not a good indicator of how well chile will grow in a given field. Chile is moderately sensitive to soil salts and does not tolerate salinity above 3.5 deciSiemens per meter (dS/m). Chile is first affected by salinity at an electrical conductivity reading of 1.7 dS/m.

Water quality.
Surface and groundwater quality (salinity, sodium and pH) vary considerably across the state. Testing the water and soil allows growers to calculate how much extra irrigation water may be needed to reduce the effects of salinity.

Fall Site Preparation

Deep rip. Deep rip if a hard pan exists or the soil is compacted.
Laser level. Laser level for uniform flood irrigation. Use a drop-to-run ratio of 1:1000 for clay soil and 2:1000 for sandy soil.
Prepare "cantaloupe beds." Consider using 80-in. "cantaloupe beds." They have been successfully used in flood-irrigated fields with irrigation and/or salinity problems. Avoid planting in the center where salts accumulate. Practice alternate row irrigation if salinity is an issue.
Establish windbreaks. Plant small grains for windbreaks in fields susceptible to wind erosion and subsequent plant damage.
Establish uniform beds. Strive for uniformity in bed preparation.

Soil Testing

For Soil Fertility.

Take soil samples as soon as the beds are prepared in the fall. If soil is fumigated, sample soil only after it is safe to do so. It is best to sample soil and manage fields by soil type. A representative soil sample is a composite of 15 sub-samples randomly taken throughout the field that is to be managed as one unit. The top 12 inches of soil should be taken with a hammer probe or auger. Submit a minimum of 2 lbs (2 cups) for soil fertility and salinity testing.

NO3-N. A minimum of 30 ppm of nitrate-nitrogen (NO3 ) should be maintained in the soil from planting through fruit fill.
Note: Credit should be given to soil organic matter (30 lb/acre per 1% organic matter), manure N and legume N. Approximately 35% of the total nitrogen in manure is available the first year. Legumes from the previous season can contribute 60 to 150 lb N/A. If high C:N materials such as straw have been incorporated into the soil additional N may be needed to assist in its decomposition and to avoid early N deficiency in the chile seedlings.
Phosphorus (P). Request the Olsen (sodium bicarbonate) phosphorous extract to assess plant available P for chile. If test result is less than 30 ppm, apply phosphorous in a band below the seed Banded phosphorous, placed 2 inches below the seed at planting, is more effective than broadcast application. If test result if greater than 30 ppm, P application is not necessary.
Note: Cool early spring soil temperature reduces the plants ability to use phosphorus.
Potassium (K). Request test for water-soluble K, if available. Water-extractable K, less than 60 ppm, may respond to additional potassium fertilizers. Ammonium acetate extractable K is more common. Soil with more than 230 ppm K from this extract usually will not respond to additional potassium.
Micronutrients: Request micronutrient analysis using the DTPA extract. Zinc (Zn) is usually deficient in New Mexico soils (<1 ppm) and may need to be added to your fertilizer blend at planting. Iron, manganese, and copper can also be tested.

For Salinity.

Most soil testing labs also can analyze for salinity as long as a sufficient sample is submitted (at least 2 cups). However, a separate sample from the depth at which the seed will be placed can better indicate specific management practices that will be needed to control salinity effects. Specify that the lab run a saturated paste extract soil test for salinity assessment that includes electrical conductivity (EC), pH and Exchangeable Sodium Percentage (ESP) tests.

Salinity. If surface (seeding depth) EC is above 1.5 dS/m, consider seeking professional advice. Stand establishment and yield reductions will occur at the rate of approximately 14% per 1 dS/m of EC over 1.5 dS/m, especially if steps are not taken to reduce the effects of the salts.
Exchangeable Sodium Percentage. If ESP is 8% or higher, do not plant without professional advice. These fields may require more work and amendments and water than feasible. Work on amending the soil and reducing the sodium concentration at least a year before considering planting chile in the affected soil.

For Root-knot Nematodes.

Take a soil sample in the early fall from the root zone of the previous crop shortly after the last irrigation. For an adequate test, take a composite of 15 sub-samples randomly from the root zone throughout the field. Sample depth should be the top 8-12 inches. Mix the soil and place about 1 quart in a reclosable plastic bag. During transportation and storage, the soil should remain close to the temperature and moisture level at which it was sampled. Changes in the soil sample temperature may kill the nematodes, causing inaccurate test results.
For Lab Testing.
For Nematodes Specialists.

If the root-knot nematode population exceeds 150 juveniles per 500 cc, get professional advice and consider treatment before planting. This assumes you have sampled as described above (time and sample intensity). The nematode population will decrease by 50-90% during the winter. Samples taken from January through March are not as reliable because nematodes are in the egg stage and cannot be tested accurately. Site preparation mixes nematodes throughout the soil and also makes detection difficult.
If there is a history of root-knot nematodes and you are unable to take soil samples in the fall, plan to treat for nematodes. Remember that you cannot visually check a corn, sorghum or onion crop for nematodes; you must conduct a soil test. Rotations from alfalfa should be soil tested for nematodes. Nematodes are more prevalent in light sandy soils.

Equipment Maintenance and Calibration

Properly service and calibrate all precision and power equipment during the winter.

Tractors.
Fertilizer applicators.
Planters.
Sprayers.
Decappers.
Other farm equipment and vehicles.

Untimely delays caused by preventable repairs, coupled with unpredictable weather, can be disastrous to stand establishment.

Pest Management

Pesticide labeling facts.

Pesticides approved for chile may change. The pesticides discussed below are labeled for use on chile peppers at the time of publication (Feb. 2003). Constant changes in pesticide labeling may result in the loss or addition of materials. The Task Force will make all efforts post changes and maintain current information on its Web site (www.chiletaskforce.org); however, it is the legal responsibility of producers, consultants and applicators to read the entire label and check for registered uses. Addition or omission of products does not constitute a recommendation or condemnation by NMSU or the CES.
Read the label. You must follow the label directions for all pesticides (herbicides, insecticides, fungicides and nematicides) to get the best results. Failure to follow labeled instructions may result in poor control, crop damage, contract violations, legal damages and wasted time, money, and resources.
Certified pesticide applicators. Many products are restricted-use (RU) pesticides. These products can be purchased only by certified pesticide applicators. The application of these products also must be supervised by certified pesticide applicators. For more information on the certified pesticide applicator program or on pesticides registered in New Mexico, contact the NMDA Pesticide Division at (505) 646-2133.

Fungicides. Read and follow label directions. If in doubt, contact a crop consultant, NMDA or NMSU.

Pre-plant options.

At-planting options. (Apply separately, not as a mixture.)

Herbicides. Read and follow label directions. If in doubt, contact your a consultant, NMDA or NMSU.

Pre-Plant options.

K-Pam - targeted species (best applied in the fall).
Telone II (RU).

Insecticides. Read and follow label directions. If in doubt, contact a crop consultant, NMDA or NMSU. Due to increased risk of soil-inhabiting insects following grain crops, alfalfa and some vegetables, insecticide applications prior to and at planting are particularly important. Systemic insecticides applied prior to or at planting will protect plants after emergence for a short time. However, when emergence is delayed due to cool soil or when frequent irrigations have occurred prior to emergence, residual of more water-soluble insecticides will be reduced.

Pre-Plant options.

Di-Syston 15G (RU) (Or apply at planting with banding attachment; do not place on top of seed.)

At-Planting options.

Platinum.
Admire 2 F.

Furadan 4 F (RU). Special Local Need 24 (c) Label SLN NM-98002 must be in the possession of applicator at the time of application.

Nematicides. Read and follow label directions. If in doubt, contact your crop consultant, NMDA, or NMSU. Pre-Plant applications are best done in the fall while the soils are still warm and the nematode population is high. Important: Treatment must be done well in advance of planting to avoid seedling mortality.

Note: Using Telone C-17 or Telone C-35 as a soil fungicide also may control nematodes.

Pre-Plant options.

Planting Practices

Uniform, Early Planting.
Planting into cold soil increases the risk of seedling loss due to damping off, insects and environmental stress. Planting date is more critical for red chile because time in the field is directly related to dry red weight and color. Historically, early planting (prior to March 20) has resulted in better stands. The planting dates for fresh green chile should be staggered to provide continuous harvest and a consistent supply to processors.

Chile seed requires a soil temperature of between 50-55o F to begin germination, but is best at 65-70 o F. This does not preclude planting into soil temperatures below this point in anticipation of reaching this critical temperature range. Within reason, the seed will begin the pre-germination process and be able to germinate when the appropriate soil temperature is reached.

Pre-irrigate 2-4 weeks prior to planting, depending on soil texture.
If possible, use offset planting (planting near the south shoulder of the bed for east west rows) on conventional beds to reduce the adverse impact of salinity and poor irrigation practices and capture the heat from the sun.
Plant to a uniform depth. Most seeds are planted into a bed and capped with 2-4 inches of warm, moist soil. If no cap is place over the seed planting depth should not exceed _-inch and must be planted into moisture for best results. Sprinklers can help keep the seed bed moist and prevent crusting.
Ensure firm seed/soil contact at planting. Avoid compacting wet soils as it hinders stand establishment
For open-pollinated seed varieties, plant at a minimum rate of 4 lbs seed /acre (~240,000 seeds/acre).

Capping Pros and Cons.

Capping can conserve moisture, prevent cracking on heavier soils and control early-season weeds. However, too large a cap will keep soil cold and delay germination. A moist soil will retain heat better than dry soils.
No-cap plantings germinate sooner due to warmer soils. However, weed control may be more difficult. Warmer soils promote the germination of weeds such as yellow and purple nutsedge.
On capped beds that have been irrigated after planting, run a properly adjusted rolling cultivator over the beds before decapping. This will soften the soil for uniform cap removal.
Caps are not normally used with drip irrigation
It is not considered a best management practice to irrigate immediately after planting unless there is poor contact between the seed and moist soil. If moisture is low when capping, irrigate immediately after capping.
Depth of soil left after decapping is critical. The soil should be removed to just above the hypocotyl (crook) of the germinating chile. This may mean losing a few plants but you should see the chile poking through the soil surface within 12 hours after this operation. A precision decapper is essential to control depth of cut. Harrows, skids or other equipment that cannot be adjusted to precise, level depth will reduce stand and, quite possibly, yield.
Decap timing is based on seedling stage and moisture. Decapping with excess water in the soil will create a brick effect that through which most seedlings cannot emerge.
Use only a properly adjusted decapper to remove the cap from chile. Growers should be present during the set-up and execution of this is critical treatment. If the decapper does not drag a few seedlings out of the ground during decapping, its setting is too high.
If soil crusting occurs after decapping, use a loose-ringed roller to break the crust and loosen the soil on the beds. This has the added benefit of creating a rough surface that will reduce abrasion by wind-blown soil particles. Again, growers should be present during the set-up and execution of this treatment.

Emergence

Carefully monitor the germination process. Manage cultivation and irrigation on the basis of the first good flush of seedlings.
Do not over-water. Measure soil moisture at taproot, not surface, depth to determine if irrigation is necessary. Don't try to germinate all the seeds by additional irrigation; you'll lose more than you'll gain! Damping-off, salinity burn and slow growth due to the cooling effect of irrigation water hampers stand establishment. Over watering is the biggest single cause of stand loss.
Make sure that the irrigation-wetting front, which contains soluble salts, does not end up above the seed line. This is frequently a problem when both furrows are filled for irrigation or when single-furrow irrigations do not push water past the seed line. In either case, soluble salts may damage the emerging seedlings.

Follow-up Scouting

Protect chile seedlings until they begin to develop true-leaves and more extensive root systems. Nothing is more important than regular inspection of the crop during this phase of production.
Over-irrigation, insects, birds, rabbits, rodents and wind can damage a potentially good stand.