New Mexico Chile Task Force

Stand Establishment to Lay-by

Pest Management
Irrigation
Thinning
Cultivation
Fertilization

Chile Pepper Growers Notes : Stand Establishment to Lay-by

The key to high yield and maximum profit is good management. The following recommendations are key management steps needed to produce a good chile crop. They are based on research findings and the collective experience of the industry's top growers and consultants.

Pest Management

Read the label before using any pesticide.

Do not use any chemical, whether it is an herbicide, insecticide, nematicide or fungicide, if it is not labeled for chile (peppers). If you have any question about appropriate product use, consult your County Extension Agent, New Mexico State University (NMSU) specialist, chemical company representative or New Mexico Department of Agriculture (NMDA) Pesticide Division staff (505-646-2133) before using the chemical.

Irrigation and fertilization control, and timely cultural practices, are of the utmost importance in pest management.

Insects

Scout/inspect for insects weekly during early season stand establishment, up to first bloom and flowering. You cannot spend too much time scouting during this time period.
Consult with certified crop adviser or entomology specialist to assess economic threshold. Delay spraying until the economic threshold is reached for a particular insect. This helps in preserving beneficial insects. Repeated applications of foliar insecticides can reduce beneficial insect populations, resulting in secondary pest population increases.
Once the economic threshold for spraying is reached, you must be able to react quickly where treatment is needed.
Pre-plant insecticide use.

Read and follow label directions. If in doubt, contact a crop consultant, NMDA Pesticide Division staff member or NMSU Cooperative Extension Service specialist or agent.
- Furadan 4-F and Di-Syston 15-G These insecticides have residuals of no more than two weeks after emergence. (Furadan 4-F has a Section 24(c) label that must be in the possession of applicator at the time of application.)
- Admire 2E and Platinum. These insecticides have longer residual effects, lasting four to six weeks after emergence, depending on application rates.
Insecticide use from stand establishment to first bloom.
Insects of primary concern during this growth stage are thrips, flea beetles, fleahoppers, aphids, beet leafhoppers, darkling beetles, cutworms, false chinch bugs, leafminers, beet army worms, spotted cucumber beetles, wireworms and seed corn maggots. Insecticides that control these insects at this time include:

Provado. Controls aphids, flea beetles and thrips.
Diazinon AG500. Controls aphids, wireworms, cutworms and leafminers.
Actara. Controls aphids, leaf miners and beetle control.
Azatin. Controls aphids, armyworms and leafhoppers.
Thiodan. Controls aphids, flea beetles and leafhoppers.
Dimethoate 400. Controls aphids, leafminers and maggots.
Warrior with Zeon. Controls aphids, cucumber beetles and leafhoppers.
Fulfill 50WG. Controls aphids and whiteflies.
Bacillus thurengiensis. Biologically controls various worm species.

Insecticide use during thinning. Insects of greatest concern during thinning are beet leafhoppers, flea beetles, beet armyworms, fall armyworms, aphids and spotted cucumber beetles. Chemical control for these insects includes:
- Spintor. Controls beet armyworms.
- Confirm. Controls beet armyworms and fall armyworms.
- Actara. Controls aphids and flea beetles.
- Provado. Controls aphids and flea beetles
- Warrior with Zeon. Has broad-spectrum control of listed insects.
Insecticide use from flowering to lay-by. Insects of concern during this period include stinkbugs, thrips, leafminers, leafhoppers, aphids, corn earworms, beet armyworms, pepper weevils and spider mites. Growers should consider commercial pheromone traps for early pepper weevil detection.
- Spintor. Controls leafminers and beet armyworms.
- Confirm. Controls beet armyworms.
- Actara. Controls aphids, pepper weevils and stinkbugs.
- Provado. Controls aphids and beet leafhoppers.
- Warrior with Zeon. Has broad-spectrum control of listed insects.

Diseases

During the period from stand establishment to lay-by, biotic diseases that could be present include rhizoctonia root rot, damping off, beet curly top virus, powdery mildew, bacterial leaf spot and tomato spotted wilt virus. Abiotic effects include salt injury, wind injury and herbicide injury.

Rhizoctonia Root Rot. This infection occurs in early spring with symptoms of wilting under stress showing up during the summer. Over-irrigation of seedlings should be avoided. Rhizoctonia commonly appears as one of the early damping off organisms.
Pythium spp. This infection occurs in early spring, causing damping off. Fields and seedbeds should be properly drained. Over-irrigation of seedlings should be avoided.
Curly Top Virus. Peppers of all ages are susceptible to infection but are most susceptible when young. This virus is transmitted by the beet leafhopper.
Powdery Mildew. This disease favors warm temperatures with high humidity, but can occur at any time throughout the season.
Phytophthora. Infected plants become severely wilted, but leaves remain attached. Symptoms usually don’t occur until late summer and early fall. Early season water management aids in control. Excessive soil moisture triggers and intensifies the disease. There must be good drainage so that water is not allowed to stand in fields. Severely infected plants have brown roots and white stems.
Verticillium Wilt. Severe wilting of occasional plants occurs when pod production starts. Crop rotation is essential for prevention. Severely infected plants have brown stems and white roots.
Alfalfa Mosaic Virus. Aphids carry this virus from infected alfalfa plants to chile.
Cucumber Mosaic Virus: Aphids carry this virus from cucumbers to chile. It is best to avoid planting near urban areas where cucumbers may be present in home gardens.
Blossom-end Rot: A fruit disorder associated with inconsistent watering and a calcium deficiency. It is aggravated by root pruning.
Bacterial leaf spot. This is a seed-borne disease. To control it, use only bleach-treated seed. Chemical control is marginal, at best.
Chemical Control: Read and follow label directions. If in doubt, contact a crop consultant, NMDA Pesticide Division staff member or NMSU Cooperative Extension Service specialist or agent. There is no effective chemical control for viral diseases after infection. Fungicide treatment of seeds can reduce damping off. The use of the following chemicals shows some signs of control:

Weeds

The following weeds are found to be of greatest concern in New Mexico chile fields: Field Bindweed, Johnsongrass, Purple Nutsedge, Yellow Nutsedge, Morning Glories, Oakleaf Thornapple, Spurred Anoda, Wright Ground Cherry, Barnyard and Jungle Rice Grass, Lambsquarter and Pigweed.
Chemical Control: Read and follow label directions. If in doubt, contact a crop consultant, NMDA Pesticide Division staff member or NMSU Cooperative Extension Service specialist or agent.
- Treflan. New Mexico has a Section 24(c) label for a post-emergence. For control of annual grasses and small-seeded broadleaf weeds, apply to soil surface around 5-7 inch pepper plants and incorporate into the soil after application. Treflan‚ does not control existing weeds. Destroy existing weeds by cultivation prior to application. (Section 24(c) label must be in the possession of the applicator at the time of application.)
- Dual Magnum. New Mexico has a Section 24(c) label. This chemical is used primarily for the control of yellow nutsedge, many annual grasses and some annual broadleaf weeds. It must be applied to freshly tilled, weed-free soil. It will not control established weeds. You must irrigate after application to activate the chemical. (Section 24(c) label must be in the possession of applicator at the time of application.)
- Poast and Select. These are post-emergence herbicides that target weeds including annual grasses and Johnsongrass. The minimum pre-harvest interval, for both, is 20 days after application.

Irrigation

First Irrigation
- Use best water quality source. Sodium adsorption ratio (SAR) of water should be less than 6.
- Watch the soil moisture in the root zone, not at the surface, to determine if irrigation is necessary. Over-irrigation can cause damping off, salinity burn and slow growth from cooling effect.
- Optimum irrigation time can be determined by testing soil moisture in the root zone by touch and with moisture sensors.
- Avoid irrigating when cold temperatures are anticipated. However, irrigation right before a frost can protect from frost damage if plants already have emerged.
- Use alternate row irrigation to manage salinity problems. Once initiated, you must be consistent, irrigating the same rows, up to lay-by.
Subsequent Irrigation Scheduling
- Optimum irrigation times should be determined by testing soil moisture in the root zone by touch and with moisture sensors, not by the physical surface appearance of soil and plants.
- Irrigation times vary with amount of plant foliage, wind, sunlight, temperature fluctuation and relative humidity.
- Phytophthora can develop from water standing in any part of the field at any time. Good drainage is essential at all times.
- Water stress, as exemplified by extremes of drying and wetting, increases the incidence of blossom-end rot.

Thinning

Cultivate prior to thinning to ensure a uniform bed
Early thinning promotes crop maturity. However, if curly top, damping off or seasonal wind damage are anticipated, it's better to thin late than too early.
Consider thinning plants twice. First, thin, leaving blocks of plants. Later fine-tune to leave appropriately spaced healthy plants.

Cultivation

The best cultivation is shallow, precision cultivation as close to the seed rows as possible.
Shallow cultivation controls weeds and increases soil aeration. Deep cultivation, leading to root pruning, creates an easy entry point for phytophthora root rot infection.
Timely cultivations, as soon as fields can be reasonably re-entered after irrigation, will help reduce the level of annual weed infestation. Cultivation breaks the continuity of the soil, destroying weeds that are germinating. It also helps to conserve moisture in most soils.
Cultivate throughout the growing season so that soil is thrown to the center of seed rows. This will prevent some weeds from emerging and help protect against wind damage by preventing girdling at the base of the plants. Cultivating in this way also provides plant support for heavy yields later in the season.

Fertilization

Nutrient management decisions should be based on data from soil testing and leaf petiole analysis. Do not over fertilize or under fertilize plants.
During the period from planting to first bloom, use soil test data to insure that nitrogen, phosphorus and potassium are at recommended levels.
The recommended nitrogen amendment should be split into three to four applications. These applications can be side-dressed liquid or dry.
Jalapeños require nitrogen earlier than green and red chile. They also require more nitrogen at first application in order to achieve plant size.
Consider acid-based liquid fertilizers to improve phosphorus and micronutrient availability.
Begin tissue testing from first bloom to last cultivation (sample every 7 days). Micronutrients needed in early growth can be determined only by tissue testing.
Micronutrient needs are best met by foliar applications. Time applications based on leaf petiole analysis.
A steady supply of nitrogen is needed during fruit set. Base application rates on data from petiole analysis.
Ammonium nitrogen sources may aggravate blossom-end rot by interfering with calcium uptake.

Tissue Testing (leaf and petiole analyses)

To determine if a crop is adequately nourished, have the plant analyzed during the growing season.

Table 1 shows the recommended range of nutrient levels that should be present in plant tissue. Leaf and petiole analyses will provide you with specific recommendations for your crop. To determine nitrate and phosphate levels, petiole tissue is analyzed. To determine levels of other nutrients, leaf tissue is analyzed.

Table 1. Sufficiency ranges - first bloom to fruit fill

Nutrient	Desired Range
Nitrogen (leaf)	40,000-60,000	(4 - 6%)
Nitrate (petiole)	>7,000
Phosphorous (leaf)	3,500-10,000	(0.35 - 1%)
Phosphate (petiole)	>2,500
Potassium (leaf)	40,000-60,000	(4 - 6%)
Calcium (leaf)	10,000-25,000	(1 - 2.5%)
Magnesium (leaf)	3,000-10,000	(0.3-1%)
Sulfur (leaf)	3,000-6,000	(0.3-0.6%)
Zinc (leaf)	50-200
Iron (leaf)	60-300
Manganese (leaf)	50-250
Copper (leaf)	6-25
Boron (leaf)	25-75