How to commercially grow sweet peppers and chilies outdoors
Growing peppers outdoors can be a good source of income. In a few words, pepper is a perennial plant, but growers, in most cases, treat it as an annual. Most commercial sweet pepper or chilies growers start the crop from seeds (hybrids) in an indoor protected environment. As they wait for the young seedlings to grow and be ready for transplanting, they prepare the soil. They till the land, they remove any previous cultivation remains, and they place a black plastic film through the rows. The black plastic film not only helps the soil become warmer but also controls weeds. They also design and set the drip irrigation system. When they are ready for transplanting, they make small holes in the plastic film, where they plant the seedlings. Fertilization, Drip Irrigation, and Weed Management are applied in most cases. Many growers stake the plants in order to support plant growth, improve aeration, and facilitate harvesting some weeks later. However, not all pepper plants need staking. Most commercial pepper varieties can be harvested 60-90 days after transplanting. Time from Planting to Harvesting depends on the variety, climate conditions, and the age of the seedlings planted. Harvesting can be made through hand scissors or knives and is typically performed in 1-2 sessions per week. Outdoor pepper growers may also use tractors for harvesting. After harvesting, pepper growers plow and destroy the remains of the crop. They may also rotate the crop (with cabbage, corn, legumes, and others), in order to control diseases and prevent soil depletion.
The restrictive factor when growing peppers outdoors is always the temperature. The optimum temperature is 18-26 °C (64.4-78.8 °F). The plant needs day temperature close to 23 °C (73.4 °F) and night temperature close to 18 °C (64.4 °F) in order to produce pollen. Soil temperature should not fall below 18 °C (64.4 °F). Cold weather during the growth period will inhibit the plant’s growth. Shocked plants cannot recover easily.
It is crucial to decide the growing method as well as the varieties of pepper that thrive in your area. There are two methods to grow peppers: Growing from seed or growing from seedlings.
How to Grow Peppers From Seed
Peppers are warm-season crops. They need 2-3 months from transplanting to harvesting. Producers generally prefer to sow the seeds in seedbeds in 0.5-1 cm (0.2-0.4 inches) depth under controlled conditions and then transplant them into their final positions in the field. In case you plan to grow peppers from seed, there are some facts you need to know. Pepper seeds require at least 18 °C (64.4 °F) soil temperature in order to germinate. As optimum temperatures, we consider those between 20 and 30 °C (68-86 °F). It is vital for the seeds to have optimum moisture levels in order to sprout. Producers sow two seeds in every seeding pot and they use turf as a substrate for proper aeration and drainage. Furthermore, pepper seeds need to have on average relative humidity levels close to 70-75% in order to germinate. Excessive irrigation can be harmful. In some cases, the young seedlings may need a hardening period. Producers start to remove gradually the plants outdoors two weeks before transplanting. At first, they leave them out only for two hours, and periodically they increase the time of outdoor exposure.
How to Grow Peppers from Seedlings
Farmers may also buy plants from a legitimate seller, or transplant seedlings they have grown from seeds by themselves. The right time to transplant the seedlings is when they have developed 5-6 real leaves, and they have reached a height of 15-30 cm (6-12 inches).
Soil Requirements and Preparation for Sweet Pepper and Chilies Farming
Peppers do not have strict soil requirements. They grow well in a wide variety of soils. However, the plant thrives best in medium to sandy soils with proper aeration and drainage. It is a sensitive plant to both drought and water-soaked conditions. The optimum pH levels range from 6 to 7; however, we have cases in which the plants can tolerate extreme pH levels close to 5.5 or 8. The basic soil preparation starts a couple of weeks before transplanting pepper seedlings. Farmers remove any previous cultivation remainings and weeds and plow well at that time. At the same time, farmers remove rocks and other undesirable materials from the soil.
One week later, many farmers apply a basal fertilizer such as well-rotted manure or synthetic commercial fertilizer, always after examination of their soil test results and always after consulting a local licensed agronomist. Most farmers integrate the basal fertilizer on the same day, using tillage tractors. Some growers prefer to apply it only across the planting rows, while others spread it on the entire field. Of course, the first method is more cost-saving. The next day is probably the right time to install the drip irrigation pipes.
The next and most crucial step (especially in countries with non-optimum soil temperature during the planting period) is the linear polyethylene coating. Many producers cover the rows with black or green Infrared – Transmitting (IRT) or black plastic film. They use this technique to maintain the root zone temperature at optimum levels (>21 °C or 70 °F) and prevent weeds from growing.
As far as organic pepper farming is concerned, things might be different, and farmers may utilize cover crops in order to enrich the soil. According to UC Santa Cruz Farm – Center for Agroecology & Sustainable Food Systems, the soil preparation in organic pepper farming starts the autumn before our growing season. They sow a cover crop (for example, vetch – Vicia sativa) during the fall before the year we want to grow chilies. About a month before transplanting pepper (spring), they plow and incorporate the crop into the soil, so that their field will be enriched with organic matter. About 14 days later, the tractor plows again in order to make beds. After plowing, farmers irrigate the field, although there is no crop. Sprinklers irrigate the raised beds. In this way, weeds seeds germinate. Farmers spot those weeds and remove them. This technique is most often used in rice farming. About a week later, they transplant the young pepper seedlings. Transplant is performed either very early in the morning or during the afternoon.
Pepper Planting and Plant spacing – How many chilies to plant per hectare and acre
Outdoor pepper farming starts mainly during the end of winter, provided temperatures are close to optimum levels. In some countries, pepper seedlings are transplanted outdoors during the second half of spring. Producers in countries with proper climate, continue the transplanting until early autumn. Pepper producers eventually harvest from summer to winter (June to December).
After all the preparation steps (plowing, basal fertilization, installation of the irrigation system, and plastic film covering), we can proceed with transplanting. Growers label the exact points on the polyethylene coating where they will plant the young plants. They then dig holes on the plastic and plant the seedlings. It is important to plant the seedlings at the same depth as they were at the nursery. Producers plant their pepper seedlings either on single or on twin rows. The distances may also differ between stacked and unstacked plants. A common pattern for planting unstacked plants on single rows is 0.3 m to 0.5 m (12-20 inches) distance between plants on the row and 0.5 m to 0.75 m (20-30 inches) distance between rows. For stacked peppers on single rows, they prefer 25-30 cm (10-12 inches) distance between plants on the row and 120-150 cm (47- 59 inches) distance between rows. For twin rows, many growers prefer 0.25 m to 0.3 m (10-12 inches) distance between plants on the row, 0.5 m to 0.6 m (20-24 inches) distance between rows, and 1.2-1.5 m (47-59 inches) between couples.
As a result, we will approximately plant 18000 to 45.000 plants per hectare (7.287-18.218 plants per acre). The distances and the number of plants depend on the pepper variety, the environmental conditions, the irrigation system, the pruning formation, and of course, the yield goals of the producer. (1 hectare = 2,47 acres = 10.000 square meters).
Pepper Pruning – Do peppers need pruning? – How to prune peppers
Pruning is an important procedure and provides several advantages. However, not all pepper varieties need pruning. For those who do, pruning enables farmers to control the vegetation. Moreover, pruning leaves extra space for aeration preventing fungal infections. Besides, harvesting becomes much easier. In general, unpruned peppers have a tendency to produce numerous peripheral sprouts and leaves. The extra foliage makes it difficult for the producer to manage the plant. The necessary pruning procedure includes the removal of the peripheral stems. Producers keep only the 2-4 sprouts on the plant. This way, the plant has a more flexible and manageable shape. Many producers also perform thinning. They remove the stems that grow between the sprout and the foliage. It is crucial to try not to cut the stem too close to the vein. Instead, you can consider keeping a 4 cm (1.6 inches) distance to avoid infections. On the other hand, pruning and staking increase labor costs, which may be balanced if the harvesting period is long enough. In the market, we can find determinate varieties that offer satisfactory yields without pruning.
Pepper Plants Stacking
Most pepper producers use stacking for their peppers. This technique provides several advantages. First, it prevents foliage and fruits from touching the ground. At the same time, pruning leaves extra space for aeration. Moreover, harvesting becomes much easier. Outdoors producers use stakes and tie the plants gently on them.
Pepper Water Requirements and Irrigation Systems
According to FAO, total pepper water requirements over a growing period, are 600 to 900 mm and up to 1250 mm for long growing periods and several pickings. However, pepper water requirements are totally different during the various development stages of the plant. Generally, the critical periods for peppers are fruit-set and fruit filling. Prior to those stages, water requirements are smaller.
Of course, water requirements can be totally different under different weather and soil conditions. For example, heavy clay soils normally need less irrigation than sandy soils do. Moreover, different sweet pepper and chilies varieties may also have different water requirements. Many producers in Mediterranean countries prefer to irrigate their peppers for 10 minutes every 4-5 days during early spring. This way, they force the plant to ‘seek’ for water and, as a result, to expand its roots. However, from flowering until harvesting, they irrigate their plants on a daily basis. Farmers generally prefer to irrigate their peppers early in the morning or late in the evening. Watering the foliage has been linked with disease outbreaks. In general, excess humidity, especially on foliage, may favor disease outbreaks. On the other hand, water-stressed plants are more susceptible to infections. The most commonly used irrigation system is drip irrigation. Many producers use multiple or single drip pipes of 12-20 mm diameter and 2-8 litter per hour water allotment.
Peppers are self-pollinated plants. This means that farmers do not need to use insects to boost their peppers’ pollination. According to studies, though, insects could fasten the maturing procedure of the fruit. However, producers should be really careful in case they grow together, sweet and chili peppers. If they plant chilly peppers close to sweet peppers, it is possible that the sweet peppers will convert into chilies. The reason is that very often, sweet peppers plants allow the pollen of chilies, transferred by the wind or insects, to pollinate them. In order to avoid this effect and lose the commercial value of your products, a proper technique is to leave a long distance between chilies and sweet pepper farms.
Pepper Weed Management
An important procedure when growing peppers is weed management. Pepper plants often suffer from weeds that compete with them in terms of space, access to sunlight, water, and nutrients. Furthermore, weeds may become home for pests that may attack the plants. It is necessary for all growers to have a sound weed control strategy, which may differ significantly between countries, the law framework, the means of production, the industry at which the product targets, etc. Manual weed control on a weekly basis is almost necessary in some cases (organic production).
Pepper Fertilization Requirements – Common Fertilization Programs in Chilies Farming
First, you have to take into consideration the soil condition of your field through semiannual or annual soil testing before applying any fertilization method. There are no two identical fields in the world. Thus, no one can advise you on fertilization methods, without taking into account your soil’s test data, tissue analysis, and crop history. However, we will list the most common pepper fertilization schemes used by a considerable number of farmers.
Nowadays, farmers make from 0 to 10 soil applications throughout the 2 to 3 months period from transplanting to harvesting. Some farmers apply well-rotted manure (30-40 tons per hectare) towards the rows, about two months before planting and prior to the soil disinfection. Alternatively, they may apply Calcium ammonium nitrate: 600-800 kg per hectare, and Potassium sulfate: 500 kg per hectare.
However, the most common fertilization method in chilies and sweet pepper farming is “fertigation.” This word comes from the combination of Fertilization and Irrigation. Producers inject water-soluble fertilizers inside the drip irrigation system. This way, they can provide the nutrients gradually and give the plant the proper time to absorb them. They start the fertigation a few days after planting. At this point, they apply a Nitrogen- Phosphorus- Potassium (starter) 13-40-13 or 15-30-15 fertilizer, enriched with trace elements (micronutrients). High Phosphorus levels at the first stages will help plants develop a strong root system. Additionally, micronutrients make it easier for plants to overcome any stress conditions caused by the transplanting. They continue the applications until the blooming period by adding balanced fertilizer Nitrogen – Phosphorus – Potassium 20-20-20 or 15-15-15 again enriched with trace elements. In some cases, they may increase the P again to boost blooming at this point. As the plant comes close to the fruit set, they change the ratio again to 15-5-30 or 10-15-20. At this point, they increase Potassium levels because plants have greater needs for this element to create well-shaped fruits. At this stage, the plant has also increased needs in Ca. In the case of a calcium deficiency, we will start to observe a physiological disorder called blossom end rot that causes dark areas at the bottom and the sides of the peppers. Some producers apply foliar Ca fertilization during the fruit set and repeat after 15 days.
According to another school of thought, pepper growth can be divided into three periods.
- Vegetative Growth. Days 1 to 20 from Transplanting
- Flowering and Fruit Set. Days 21 to 55 from Transplanting
- Ripening period and harvest. Days 56 to Harvest.
- During the first period, they apply (through fertigation) 2 kg N, 1 kg P2O5, and 3 kg of K2O per hectare per day.
- During the second period, farmers increase fertilization rates and apply (through fertigation) 4kg N, 1kg P2O5, and 5 kg K2O per hectare per day.
- During the third period, the rates decrease, and farmers apply again (through fertigation) the rates of the first period.
Since some pepper varieties are harvested 55 days after transplant and others may be harvested 110 days after transplant, anyone can understand that the limits of the above mentioned periods are just average numbers, and nobody should follow these directions without making his/her own research. These are just some common practices. No one should follow them without taking into consideration the pepper variety, soil condition, and other local factors. Every field is different and has different needs. Checking the soil nutrients and pH is vital before applying any fertilization method. You should always consult your local licensed agronomist.
Pepper Harvesting – How and when to harvest chilies
The majority of peppers reach their full maturity and are ready for harvesting 2-3 months after transplanting. Harvesting time depends on the pepper variety, the environmental conditions and of course the age of the transplants. In general, colored varieties mature later than green varieties do.
On large scale commercial outdoor farms, producers use mechanical equipment during harvesting. However, in most cases, producers collect peppers manually. The right time varies. Many producers harvest when fruits have an acceptable size of their variety but at the same time remain crunchy and green (for green varieties). The colored varieties should have just started to obtain the characteristic color of their variety. This is crucial, especially for peppers that are going to be transported for long distances. The harvesting period may last several months. Thus, farmers collect fruits in more than one harvesting sessions (2-3 sessions per week).
Chilies Yields per hectare and acre – Yields in Pepper Farming
A good yield after years of practice is 25 to 50 tons per hectare (22.314 – 44.628 pounds per acre). In some cases, experienced greenhouse producers may achieve a yield of up to 100 tons per hectare (89.255,87 pounds per acre). However, these yields are achieved from professional growers after several years of experience.
Most common Pepper Nutrient Deficiencies
It is crucial to understand that a plant nutrient deficiency does not necessarily mean that the soil is depleted. Plant deficiencies occur as a result of various environmental factors that lead to the plant’s inability to absorb this nutrient. Thus, farmers should consider testing both soil and plant tissue before they apply any fertilizer to their plants.
Pepper plants with N deficiency express their problem with symptoms such as small and yellow leaves, decreased growth rate, fewer flowers, and decreased or zero fruit setting. Peppers that finally bear fruits produce deformed ones. High rainfall and excessive irrigation make things worse.
The symptoms of potassium deficiency appear most of the time with characteristic interveinal chlorosis. Older foliage may wilt and turn brown and scorched. There is a low fruit setting rate, and the peppers are smaller than usual.
The most common symptom caused by Ca- deficiency is blossom end rot. By this, we refer to a flat brown area at fruit’s blossom end, that may appear at any pepper development stage. The commercial value of the fruits decreases rapidly under such conditions. Blossom end rot is an ideal environment for secondary fungal infections.
Magnesium deficiency is common to peppers and is most commonly expressed in older leaves. The most obvious Mg- deficiency symptom is the foliage discoloration, while the veins remain green.
If Phosphorus levels are low, we observe limited growth. The plant has difficulty in producing flowers, and when it does, only one out of many turns into fruit. Leaves may turn yellow and wilt, while the fruits are usually underdeveloped, and they have very few seeds.
Common Physiological Disorders on Peppers
Sunscald is caused by extended sun exposure to the fruits. Peppers develop a characteristic white area with thin dried skin at the surface that is directly exposed to the sun. The cause of that anomaly is the low foliage to fruits ratio.
Growth cracks are injuries of the fruit caused by sudden and increased water intake, especially after a prolonged drought.
Common Pest and Diseases
Lyriomyza spp is an insect that causes mines in many plants, including pepper. Adults puncture the leaves, stems, and fruits and lay their eggs. After hatching, young larvae start to feed by the tissues causing characteristic white mines. The photosynthetic ability of the plants is often greatly reduced as the chlorophyll-containing cells are destroyed. Infected leaves may fall, exposing plant stems to wind action, and the fruits to sunscald. The damage reduces the quality and the commercial value of the fruit. It has caused severe damage, especially in chili peppers in Mexico.
Management is difficult. However, there are some precautionary measures to control the attack.
Ιt is crucial to make it very difficult for the pest to approach the plants. Some precautionary measures include traps and weed removal.
Tetranychus urticae is a tiny spider mite that attacks many crops, including peppers and tomatoes. This pest overwinters in leaf debris and attacks the plants during hot and dry weather conditions. Mites attack the foliage in order to feed, causing yellow discolorations or a characteristic bronze- brown wilt that resembles flame damage. We may also observe webs between the foliage. A common practice is to monitor the population using traps constantly. If the number is above the tolerable limits, then you may consider intervening only after consulting a local licensed agronomist. There are biological as well as chemical solutions on the market, which, of course, should always be used under Good Agricultural Practices standards.
Thrips are tiny insects that damage pepper plants through holes they make on tissues in order to feed or lay their eggs. They overwinter on weeds or on plant debris, and when spring comes, they move to flowers where they feed by sucking nectar and pollen. This procedure may cause deformed flowers and blossom drop.
Sweet Pepper and Chilies Plant Common Diseases
Botrytis (Grey Mould)
Grey mold is a serious disease of pepper plant, caused by the fungus Botrytis cinerea. The pathogen is capable of surviving for long periods in the form of sclerotia. Infections are favored by high humidity levels, while wind and rain spread the spores from plant to plant. Symptoms may appear to all the overground parts of the plant. Symptoms include grey to brown lesions formed at the edges of leaves. After a while, these lesions are covered in grey mold. The leaves wither and fall. The fungus proceeds into the stem causing death of seedlings. A characteristic symptom on infected fruits is white halos that develop on peppers. If the fruit is indeed infected, then it turns soft and water-soaked.
Disease control begins with proper precautionary measures. These include weed control and safe distances between plants. The general condition of the plants (nutrients and water level, sun exposure) can also boost their immunity. We can use chemical treatment only if the problem is severe and always under supervision from a local licensed agronomist. It is also crucial to use proper sanitation, such as tools disinfection every time we touch the plants.
Alternaria (Early Blight)
Alternaria is a serious disease caused by the fungus Alternaria solani. The fungus overwinters on crop debris, seeds or weeds and is spread through the air, water, insects, and farming tools. Alternaria infects pepper plants at different stages of their development. Unfortunately, Alternaria may cause fruit rot even after harvest.
Septoria Leaf Spot
Septoria is a foliage disease caused by the fungus Septoria lycopersici. The pathogen is favored by rainy weather and attacks the leaves. It causes dark spots which resemble bacterial spot and Alternaria lesions. Unfortunately, the pathogen may remain in the soil after the crop is harvested, as it can survive on common weeds such as Solanum carolinense.
Late Blight (Phytophthora capsici)
Phytophthora is a soil-borne disease that infects almost all plant parts, leading eventually to the death of the plant. Symptoms most commonly appear on the roots and stem (stem rot). The disease then affects the leaves, as they wilt. The plant gradually gets defoliated and collapses. Fruit lesions may also appear as watersoaked areas. Fruits are then covered with white powdery mold. Unfortunately, the pathogen may overwinter in the soil for over 10 years. Pepper fruits can become infected when rain and overhead irrigation splash infested soil onto emerging fruits.
Anthracnose is another common disease of the pepper plant. It is caused by the fungi Colletotrichum spp. Infection often occurs during warm and wet weather. The pathogen may infect all plant parts. However, we observe symptoms most easily on ripen fruits. The pathogen may infect immature fruits as well, but symptoms are not visible on them. Symptoms on ripen peppers appear as circular lesions that periodically enlarge, sunken, and merge together. Under optimum humidity and temperature levels, fungus spores in pink-salmon color appear. Unfortunately, the pathogen can survive in seeds. Thus, it is essential to use pathogen-free seeds.
Downy mildew is a common greenhouse pepper disease caused by the fungi Peronospora tabacina. Symptoms appear on the upper surface of the leaves in the form of yellowish-green spots. Under conditions of high humidity in the respective areas, we observe blue to violet eruptions on the lower surface of the leaves. Heavily infected leaves die and fall. Defoliation makes the plants useless and leads to heavy crop losses.
Leveillula taurica (imperfect stage = Oidiopsis taurica) is the most common fungi species that cause powdery mildew to peppers. We may observe white powdery mildew of fungal mycelium on the upper surface of the leaves. Symptoms may also include green chlorotic angular lesions on the upper surface of the leaves. We must always disinfect our tools after we have handled an infected plant, in order to prevent the infection from spreading to healthy plants. Unfortunately, the pathogen has a very wide host range and inoculum from one host plant species can cross-infect other host plants. In California, powdery mildew inoculum can come from crops such as onion, cotton, tomato, all varieties of peppers and some weeds.