Capsicum annuum is used in the horticulture industry as a banker plant for beneficial insects. It is used as a banker plant for the beneficial pirate bug (Orius insidiosus) and also for the predatory mite Amblyseius swirskii. It is traditionally considered an ornamental pepper plant but it is also edible! Scoville heat units (SHU): 30,000 – 50,000 SHU Plant produces good yields of 1″ long hot peppers. Peppers turn from dark purple, to orange, the bright red when mature. Perfect for containers, pots and beds.
|Planting Seed Depth||Soil Temp. for Germination||Days to Germination||Sunlight Requirements||Time of Year For Planting|
|1/4″||80 F to 85 F||14 to 28 days||Full Sun||Spring|
|Hardiness Zone||Seed Spacing||Row Spacing||Space After Thinning||Days to Harvest|
|9-11||1″||36 – 48″||24″||60 – 210 days|
- Explosive ember peppers can be sown outdoors in early summer when the soil temperature remains above 65° F, but greenhouse or indoor germination is recommended at a temperature of 75°-80° F.
- If you are sowing into native soil, amend heavy clay or sandy soils with organic matter.
- Sow seed directly into garden soil barely covered at 1/4″ depth.
- When saving seed, select clean seed from healthy plants that have fully matured to red peppers; store seed in a cool, dry place
- Peppers are best transplanted when well established with a root mass
- Water the soil plug prior to transplanting
- For optimizing transplant, add mycorrhizae to root mass
- Fully saturate soil after transplanting
- Water slowly and deeply, not frequently
- Add compost to increase water retention and decrease frequency of waterings
- If planting directly in native soils, try to have your soil tested for nutrient deficiencies and pH needs (alkaline or acidic soils), and correct as needed before planting
- In pots or raised beds, fertilize vegetables before or during planting with an all-purpose fertilizer containing equal amounts of N-P-K (nitrogen, phosphorous, and potassium). Dr. Earth 4-4-4 is a great all purpose fertilizer.
- Consider amending with worm castings, compost and azomite or glacial rock to provide micro-nutrient nutrition.
- If using water soluble fertilizers, use at or less than recommended strength every few weeks.
- Peppers are slow to grow and require a balanced N-P-K and a lot of sunlight for optimal growth.
- If peppers do not get enough sunlight, they will be much slower to flower. This is why there can be such a large window (60-210 days) between germination and flowering.
- To ensure proper fruit set, ensure the plants are getting a well balanced NPK fertilizer with proper calcium and magnesium levels as well.
- Magnesium is a very important element for helping with fruiting. Foliar feeding Epsom Salts at a rate of 15ml/gal of water 1-2x weekly will provide excellent results.
- If peppers are shaded out by large cannabis plants, they will still produce flowers but at a slower rate.
- Peppers that receive more shade flower at a slower rate but actually flower longer periods of time interestingly
- Pruning is usually not required unless to remove dead or diseased plant parts or to stimulate strong new flowering or fruiting growth.
- Clean up dead or spent plants at the end of the season.
- To maintain perpetual flowering for predator insects, peppers must be picked periodically. This will force new flowers to emerge which the predator insects use as a food source.
- Picking off peppers is quite a laborious process but ensures constant pollen production for the beneficial insects
- At the end of the season it is adviseable to harvest seeds for use in culinary preparation or seed storage
- Harvesting for seed is best performed with mature peppers.
- Peppers picked when purple may not exhibit mature seeds and may have lower germination rates
- Peppers picked when purple will not be very hot or useful for culinary purposes
RESEARCH ARTICLE (UNDER CONSTRUCTION)
Cannabis Horticultural Association Research Project Summer 2019
Using explosive ember pepper plants in a banker plant system for the establishment of Amblyseius swirskii for biological control of multiple pests in commercial cannabis production.
In 2019, the Cannabis Horticultural Association, in association with Matthew Gates, an entomologist from San Diego, embarked on a summertime research project to study the use of the explosive ember peppers in a banker plant system in conjuction with a recreational cannabis garden. The goal of the research was to inoculate the explosive ember peppers with Amblyseius swirskii predator mites and observe the plants over 3-4 months . The research project took place in Willow Creek, CA. This geographic region has hot-summer-mediterranean climates, but is moderated by cool nights, causing high diurnal temperature variations. Since the pepper plants were not going to be in a controlled greenhouse climate, the simplest research question asked was, “Will the mites survive and reproduce?”. The next question was, “Will the pepper plants attract other predator insects?”
Results from this study will help growers in understanding the plant phenology by promoting adoption of suitable banker plant methodologies for the explosive ember pepper plant and its associated beneficial insects.
Capsicum annuum cultivars can have unique traits that make them more effective banker plants than those cultivated for fruit production. One important difference is that they often continue to flower for a prolonged period of time, and so pollen resources exist for a longer period of time. Additionally, there are often more flowers present, having a multiplicative effect on the already prolonged flowering period. In some research, ornamental peppers were shown to increase the residual population of predatory mites that also feed on pollen. Preventative effects due to an increased pest population were observed in greenhouse trials (1).
Foraging for proteinaceous pollen is less energy-expensive than seeking and subduing prey, which can facilitate population growth rapidly for many omnivorous biocontrol agents. Various pollen can have protective effects against ultraviolet radiation through different physiological paths, as well as other effects for certain predatory mites. Some pollen is toxic to various palynivorous or pollen-feeding organisms, including predatory mites. Supplementation with other pollen sources in addition to peppers may be useful to benefit the biocontrol population benefiting from pollen. Pepper cultivars that are pubescent may produce tuft domatia, pockets of trichomes that are attractive egg sites for predatory mites due to their physically protective structure (2). However, some trichomes of solanaceous plants can also produce toxins or other compounds that inhibit predatory mite or other biocontrol existence. Without more extensive research into these interactions, it can be difficult to avoid potentially sub-optimal banker plants for various compositions of biocontrol agents.
Exploding Ember cultivars in trials geared towards Amblyseius swirskii had the highest predatory mite population out of three total cultivars tested. In cultivation trials, this cultivar was suitable to these predatory mites as well as Orius species, keeping populations fed and sheltered through heavy rains and dry heatwaves in Humboldt, California. -Matthew Gates (IPM Specialist)
Materials and Methods
Seeds of the explosive ember pepper (Capsicum annuum) were obtained from a reputable seed company. The seeds were stored for one week until experimentation.
Seed Germination and Growth
4/17/19 – 270 seeds were planted in 105 cell trays using a name brand potting soil that was pre-soaked to its saturation point. The seeds were planted approximately 1/4″ deep. 60 ml of mycorrizhae was evenly sprinkled over each tray and lightly watered in. The trays were covered with domes and placed inside a poorly insulated greenhouse.
4/24/19 -After conferring with a number of horticultural experts, it was decided that the average nighttime temperatures were too cold and would inhibit germination. Heat mats were added during the nighttime hours for a few of the trays. One tray was left without a heat mat for observation.
5/5/19 – 87 of 105 seedlings have emerged in trays with heat mats. 31 of 105 seedlings have emerged on the tray without the heat mat. As confirmed through current literature, peppers require above average soil temperatures to germinate and are slow growing.
In this experiment, peppers germinated and sprouted within 2-3 weeks in optimal to sub-optimal conditions with above average diurnal temperature fluctuations. Approximately 80% of the peppers that had heat mats germinated. Approximately 30% of the peppers without the heat mat germinated.
Seedling Growth and Transplanting
6/3/19 – The seedlings growth has been very slow. This is believed to be attributed to relatively low attention the plants received. Either from under-watering (periods of extended dry soil) as well as lack of fertilization from the relatively inert potting soil. High diurnal temperature variations is believed to play a role as well.
6/10/19 – The seedlings were transplanted into 1 gallon containers. The soil was amended with high quality compost, vermicompost, an all purpose fertilizer (NPK 4-4-4) as well as powdered micronutrients from glacial rock and vocanic ash. 15 ml of mycorrizhae was additionally sprinkled around each transplant. The plants were then moved out of the greenhouse and into full sun. *There was a subset of plants that were left in the seedling trays and subsequently transplanted 3 weeks after the first set was trasnplanted. The data for these plants was not accounted for, but the side by side flowering sets were monitored for observation and are apparent in photos from later in the summer. A total of 160 healthy plants were chosen for this research project.
6/17/19 – Peak daytime temperatures have climbed above 90° F and the peppers are growing faster.
6/20/19 – The pepper seedlings were also fed a low dose liquid fertilizer and foliar fed with epsom salts and rapidly began to grow.
7/11/19 – The early sets of flowers were finally observed , this triggered the secondary phase of the research trial which began monitoring the plants for an optimal time to release the predatory mites.
Flowering and Predator Mite Inoculation
In late July the peppers began producing high quantities of flower sites and it was decided that now would be an appropriate time to inoculate the plants with the predator mites due to the abundance of pollen. As previously described in the background above, Amblyseius swirskii were chosen as the appropriate predator mite. Amblyseius swirskii can survive and reproduce on various pollens, which may allow them to persist during periods of low pest density and improve their effectiveness as biological control agents (3).
8/5/19 – Amblyseius swirskii was delivered from a reputable insectary in bottles and was immediately released on the plants by slowly tapping and rotating the bottles across the top of the canopy.
8/6/19 – The substrate that the swirskii mites were shipped in was a combination of vermiculite and bran and left a residue on the leaf surface of the peppers. The video here highlights the rinsing procedure to clean the leaf surfaces:
8/7/19 – Representative samples of the peppers flowers and leaves were collected to confirm that Amblyseius swirskii was present.
Intercroppping Peppers with Cannabis
A small subset of plants was intercropped in a recreational cannabis garden consisting of four outdoor garden beds (4’x8′) that each contained one cannabis plant. The pepper plants and cannabis plants were monitored for growth and insect populations over the course of the summer and fall season (July-October) and the results recorded.
1. Ornamental pepper as banker plants for establishment of Amblyseius swirskii (Acari:
Phytoseiidae) for biological control of multiple pests in greenhouse vegetable production
2. Romero, G.Q., Benson, W.W., 2005. Biotic interactions of mites, plants and leaf domatia.
Current Opinion Plant Biology 8, 436–440. SAS Institute, 2009. JMP Statistics and Graphics
Guide, Version 8.0.1, SAS Institute, Cary, NC, USA.
3. Ragusa S, Swirski E. 1975. Feeding habits development and oviposition of the predaceous mite Amblyseius swirskiiAcarina Phytoseiidae on pollen of various weeds. Israel Journal of Entomology. 15: 55-62.