Pepper (Capsicum annum) Cultivation, Conservation, and Soil Ecology in Low-Input and Certified Organic Agricultural Systems

Final Report for FW11-030

Project Type: Farmer/Rancher
Funds awarded in 2011: $19,585.00
Projected End Date: 12/31/2013
Grant Recipient: Loretta Sandoval
Region: Western
State: New Mexico
Principal Investigator:
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Project Information


The final field season in 2012 for the pepper conservation work entitled "Pepper (Capsicum annum) Cultivation, Conservation, and Soil Ecology in Low-Input and Certified Organic Agricultural Systems" was completed in winter 2012. The calculations and data interpretation was completed July 2013 and is summarized in this report.


Landrace chile peppers (Capsicum annuum var. annuum, family Solanaceae) are descendents of chile peppers historically taken through the Spanish and Portuguese trading routes in the time period of 1492 to 1590 (Andrews 1984). These unique peppers are grown in the same field areas for decades or hundreds of years in New Mexico. The landraces, in general, have a high capacity to tolerate local biotic and abiotic stresses in high elevation areas and are acclimated to local weather conditions, including low water availability. The yields for the peppers are stable, even when grown under low-input agricultural systems. In high elevation villages such as Dixon and Chimayo, New Mexico, the landrace peppers have retained characteristics of the original peppers and continue to be saved by agricultural families. The peppers are an important part of the diet for both the indigenous New Mexican tribes and Hispanics in New Mexico.

Bosland estimated that as much as 21% of the New Mexican Heirloom landraces have been contaminated by gene flow from improved open-pollinated (OP) cultivars (cited by Nabhan 2008), such as New Mexico “Sandia” or “Espanola Improved". OP cultivars are homogenous and are bred using traditional plant breeding methods (Bosland 2000). Landraces are heterogeneous, genetically diverse, and are well adapted to the locations where they have been cultivated (Bosland 2000). These seed collections would be good candidates for sustainable, low input systems.

The landrace pepper seed banks and the nutritional source for traditional farmers are currently at risk of being lost, and fewer traditional farmers are growing these peppers in New Mexico. Our research focus is conservation and sustainability of the peppers as a traditional food crops and growing landrace varieties (LR var.) using both certified organic and low input agricultural field areas. The landrace pepper are also being grown in smaller plots that may not maintain the genetic characteristics of the original peppers. Overall our research focus is to understand the fertility requirements to grow the landrace peppers for organic or low input crop production, seed conservation of the landrace varieties, and to compare these with OP cultivars such as 'Anaheim' and 'Joe E. Parker' in different treatment conditions. With this information, our goal is to improve sustainable organic practices and improve the agricultural field ecology. During the trials our purpose is to share the information with local and regional producers to potentially improve their production practices.

Project Objectives:

Objective 1: Compare each producer’s cultivation practices and individual landrace variety (LR var.) located at their farm sites (two certified organic, two pesticide free).

Measures for the farm site trials will include random sampling in the five field areas for fruit capsicum and antioxidant level testing, pod fresh weight (green) and pod dry weight (red), and pod counts per plant on 50-100 plants per field area. Disease prevalence, maturity dates, and vigor will also be recorded. Fertilizer treatments if any will be recorded for the season before and during the trials that each individual producer adds independently in their respective field areas. No suggestions will be made unless the producers request general information for cover crops or organic fertilizers before the trials begin. Any applied fertilizer treatments or other beneficial soil additives (Cover crops, Nitrogen, Phosphorus, Potassium, minor nutrients, humates, rhizobacteria or fungi) will be documented for each field area. These data would be collected for two seasons. Soil will be analyzed for baseline nutrient levels before the study begins.

Objective 2: To compare two pepper types in one field area, one landrace variety (LR var.) from composition of all seed collections used in Objective 1 and one open-pollinated (OP cv.) cultivar.

Each seed collection will be propagated in the greenhouse to determine seedling uniformity and vigor. Propagation trials in the greenhouse will be replicated three times. The landrace seedlings grown in the greenhouse will be transplanted in a row adjacent to each direct seeded field area to observe growth differences of direct seeded versus transplant (minimum 100 plants).

Two fertility treatments will used: control (no inputs 2011), and a fertility program (cover crops and rock amendments P, K, micronutrients, beneficial mycorrhizae); two propagation treatments will be used (direct seed versus transplant). This results in a total of eight treatments. Treatments combinations will be replicated three times using a split-split plot design. Main plot will be fertility program, propagation method will be subplot, and pepper type will be sub-sub plot. A pepper type sub-sub plot will be a single row of 20 plants in 20 feet (see plot designs in Appendix 1). Measures will be same as Objective 1.


Click linked name(s) to expand/collapse or show everyone's info
  • Estevan Arellano
  • Mary Campbell
  • Estevan Greigo
  • Romolo Greigo
  • Dr. Steve Guldan
  • Lawrence Theresa Herrera
  • Fred Martinez
  • Loretta Sandoval


Materials and methods:

Objective 1:

The individual cooperators/farmers' practices were observed and recorded by farm. Direct seed planting was conducted extremely early from April 10-May 10 when ground temperatures were low (8-10°C) and germination took three to four weeks. The ability of these seed banks to germinate successfully in low soil temperature is a unique characteristic of the landrace peppers. Some participants soak the seed for 24-48 hours in compost tea before planting. When plots were observed, the seedlings from the seeds that were pre-soaked in ‘compost tea’ were more vigorous and greener then control plots. No other fertilizer was added to the plots.

In 2012 Campbell Farm repeated this method and treated four 150-foot rows with compost tea (aged cattle manure) and four rows were untreated control (both treatments had seeds 24-hour soaked either with tea of plain water) in 2012 and 2013. The same results were observed - the rows that were treated with compost tea were vigorous and greener.

In 2013 there was severe drought conditions and extreme heat. The acequias which supply the water for the farms are extremely low. Campbell’s field area for the peppers was approximately 4000 sf and the plants at the end of the field area (200 linear foot rows) only received minimal water. A USDA NRCS EQIP grant received by Sandoval and Campbell assisted in the use of the small amount water available in the ditch acequia system.

The seeds were removed before the drying process. Martinez Farm placed the pods on huge tarps that are pulled into the sun daily and returned into a large warehouse free of rodents. Campbell (Rancho Arco Iris) dried the peppers on flat racks placed on shelves under portals. Smaller growers such, as the Herrera’s and Arellano in 2011-2012, created traditional ‘ristras’ to dry the pods. The pod drying process took approximately 6-12 weeks.

Seeds from 2010 and 2011 were collected from each farm by randomly taking two ounces from their seed collections. The seeds were propagated in the greenhouse with sterile mix (perlite with sphagnum moss), and seed germination rates were recorded for both controls and mycorhizzae inoculated plots. Seed germination trials were conducted for each cooperator seed bank separately in 2011, and in 2012 cooperator seeds collected in 2011 were combined, then propagated. Germination rates were recorded and are shown on table 1. The seedlings grown as transplants both years were used in the formal plots; each farmer seedling collection from the prior year were randomly added to the designated landrace plots.

The mycorhizzae-treated seedlings for the germination studies in the greenhouse for both the landrace and Anaheim peppers were the more vigorous, larger and greener seedlings, as shown in Picture 3. The landrace seeds that were treated with mycorhizzae in the greenhouse germination studies had higher germination rates than the control, as shown in table 1. The Anaheim seedlings germination rate did not increase when seedlings were treated with mycorhizzae.

Years 1 and 2:

The capsicum analysis was performed for year 1 dried peppers (see chart 1), and the samples were freeze-stored for further testing. The landrace varieties have approximately 5-10 times the Capsicum levels as the Anaheim peppers. The lab that analyzed samples at New Mexico State University is allowing samples to be stored in stable conditions for any further analysis. The second year samples collected are dried and will be sent for capsicum testing in 2013.  

The landrace peppers are thin-skinned and dry faster than the Anaheim peppers. Testing was performed all at once, when all peppers were properly dried. The vitamin C and antioxidant analysis could not be performed as of yet, due to the cost of testing being more expensive than anticipated ($50.00 per sample) with the  first year cost for capsicum analysis of 42 samples @ 20.00 = $840 (original budget amount $560.00).  

Soil analysis was conducted for formal block areas and other farm areas. The nutrient levels of all areas are low NP and average K available and pH is above 7.6 (see attached report for split-split plot area). Any amendments were recorded for all field areas. The fertilizer programs do not include mineral fertilizers of NPK, and instead, the farm areas were either planted with field peas, sugar snap peas or clover in the spring of the planting year, or spread with goat or cattle manure (very light approximately ¼ inch depth or less)in the fall of the prior year.

Disease issues associated with peppers: Wilt disease for 2011 and 2012 was present in most cooperator field areas (5-10%) and formal plots areas (less than 3%). An interesting trend was noted in discussions with cooperators that indicated wilt was present in 2010 before the trials began, then with Serenade ASO treatment in 2011 with Bacillus subtilis (QST 710) wilt disease incidences decreased. Only one cooperator and Sandoval in the plot studies (Campbell) applied Serenade ASO in 2012 (was available to all cooperators) and wilt for all plots was less than 5%. Arellano commented that since we are in severe drought, wilt for our area has historically decreased and when we receive more moisture, the wilt has increased (conversations with his mother in the 1960s). Campbell noted that she had less post-harvest fungal disease (blackening of peppers during drying), and Serenade ASO was applied when pods were green. It was not determined if this was the primary reason for low wilt incidence or a combination of cultural practices, including four-year rotation by plant family (Solanaceae) and isolating the peppers from other plant family members in the field.

The dried landrace peppers had longer storage capacity, and Campbell sold the dried pepper product from fall 2012 until July 2013 with less than 2% blackening of the pods noted. Griego (Romolo) landrace product also was sold commercially and had good color. The pods were extremely popular at market, and Campbell had approximately 50 pounds dried with seed removed that sold for an average of $75.00 a pound (average price is 25.00 in region) when selling in one ounce packages, as shown in picture 6. To give information to the public as the cooperators were marketing the pods, a handout was given out that had information about the Western SARE grant and the project that the cooperators were involved with. (as shown in Appendix.)

Objective 2: To compare two pepper types in one field area, one landrace variety (LR var.) from composition of all seed collections used in Objective 1 and one open-pollinated (OP cv.) cultivar.

The split-split plot studies were conducted in 2011 and 2012 in Sandoval’s field area. The plots included a control plot with no fertility input and a fertility treatment that was treated with a commercial mycorhizzae (MycoApply ENDO) and rock amendments if needed (rock phosphate, greensand). The amendment was applied carefully and uniformly to the plot areas. The 2011 plot field area had high weed pressure (bindweed) that was labor intensive to keep weed free but had no other problems as far as field site. The plot was analyzed for nutrient levels and the soil report is in Table 1. Year 1 plot is ‘lower field’; year 2 is “middle field” on report. The pH was 7.7-7.9 and consisted of clay to clay loam or sandy loam.

Seedlings for the transplant plots (TP) were grown in the greenhouse as per attached report ‘seedling germination trials’. The direct seed (DR) plots for all participants, including the split-split plot studies, were sowed between May 15 and June 1 and depended on the ground temperature (above 48°F at 8 am). All direct seeded plots were sowed on the same day.

The results for the Capsicum analysis are shown in chart 1. The standard deviation between the three replicates for each sample was high and may be the result of the analysis method (GC-MS extraction) or dilution issue (10X). The Capsicum results for the landrace peppers in the control plots indicate that the levels increase for the transplants versus the direct-seeded, which may indicate a stress response that is higher in the transplants then the direct seeded plots. The fertility treatment results indicate that the concentration of Capsicum for direct seeded versus the transplants are very similar and the concentration of Capsicum may be lower because the plants for the fertility treatment plots (mycorhizzae treated) had less overall plant stress than the control plots. This finding was surprising and would be an area that would require further study and comparison to 2012 data results once submitted and analyzed. Picture 5 also indicated a higher survival rate of the fertility plots versus the control plots for both the direct seeded and transplant plot areas. Plants were also, in general, healthier and had better color in the fertility treatment plots. The cooperator plot areas are shown in Pictures 12-15.

In general, the cooperators did not use any fertilizers in the field areas for the landraces, with one exception of soaking the seed in well-aged compost for 24-48 hours (Herrera and Campbell,) then planting the seed in a small area of the plot within their field area. The seedlings that were soaked in compost tea were overall greener and larger than the seedlings that did not have a pre-planting compost tea soak. No other fertilization was performed in these plots. The pH of the soil for the cooperator plots were high pH (7.7-7.8) and had very little NPK present. The difference in plant vigor with the manure tea treatment may indicate that a symbiotic relationship of the pepper plants with a fungi present in the compost that may have enhanced the uptake of nutrients. Further study needs to be preformed to indicate possible mutualism or symbiosis of the pepper plant and fungi present in the compost.

Height measurements were taken in the plots when plants were at full maturity (September 2011-2012). The heights and number of plants present in each plot type (all three replicates combined) are shown in Table 1 and 2. The plant count data for 2011 for the fertility plots versus the control indicate that the fertility treatment (mycorrhizae application) increased survival of the seedlings. The data for 2012 for the plots were not as different, and more plants survived in the control plot than in 2011.The heights for both the landrace and Anaheim plots were higher for the direct seeded plots in 2011. In 2012 the Anaheim plots were very similar in heights and landrace peppers heights were higher for the direct seeded plots only. The wilt present in both years was minimal (less than 2%).

Yield in split-split plots

The yield was measured in the split-split in 2011 and 2012. The data is shown in table 3 and Chart 2. The cooperator data will be submitted when the survey is given. The yield for the Anaheim plot (fertility) had the highest yield and weight by plant at near two pounds per plant versus the untreated control with approximately one pound per plant. The landrace plots also responded to the treatment mycorrhizae and had slightly higher yields than the control plot. The direct seeded landrace plots control versus fertility treatment yield had similar values regardless of the fertility treatment. The capsicum levels in chart 2 were higher in the control treatment plots for the landrace transplant plots. The direct seeded landrace plots had higher yield than the transplant plots for both years. The landrace seed is mass selected from direct seeded plants for many generations and using transplants may weaken the yield and the plant vigor overall. The Anaheim plots that were direct seeded and transplanted in the fertility treatment plots had the highest survival rate and also the highest yield.

There was severe drought for both growing seasons in New Mexico (2011: less than 7” rain/season, 2012: 4” rain/ season) in addition to high winds and intense heat. Plots were flood irrigated once weekly on a strict schedule and timing, approximately 0.5 inches. As stated in the experimental design, eight treatments and three replicates were done. See schematic 2 for split-split plots in field area.

In both 2011 and 2012 the split-split plot (Anaheim and Landrace accessions) with both transplanted seedlings and direct seeded seedlings had poor to strong growth. The landrace (designated LR) that was direct seeded (DS) in the ‘fertility treatment’ plots and the ‘control’ were very similar plant size and germination %, but the transplanted landrace (LR, TP) seedlings were weaker, less upright, less vigorous plants and performed poorly both in the control plots (no nutrients)and the fertility (mycorhizzae applied) treatment areas. The ‘Anaheim’ (designated open-pollinated OP) direct seeded plants and transplants had a similar trend as the landraces. The direct seed plants were also more upright and vigorous. The root structure of the direct seeded plots for both the landraces and the Anaheim’s had a taproot in the center, and the transplant plot plants had more of a fibrous root structure. The direct seeded Anaheim’s were more vigorous for both the control and the fertility plots; however, the transplants were smaller and less vigorous plants (see height data 2011-2012). Disease issues were minimal with less than 5% wilt on any plot. The direct sown seed for both the landrace and Anaheim plots had low germination (50% or less) as compared to the greenhouse germination trials which had germination rates of 60-89% (seed germination trial). Since the landrace seeds were a composite of all participants’ seeds, the source of the poor germination (a specific landrace accession) in the field was not known. However, the Anaheim results had a similar trend of poor germination for direct seeded plots versus fair to good germination for greenhouse studies. The percent germination for the landraces and Anaheims was not performed for field studies; this may be performed in further studies to determine germination rate. Overall, four seeds were sown one foot apart in plot areas 20 foot long. The transplant plots also each had four seeds per foot (80 plants possible per plot area).

Peppers were harvested in October for the split-split plot trials and placed in cardboard boxes in a greenhouse for the drying process (no direct sun under shade cloth with good ventilation). The cooperators started harvesting the peppers in late August for green, and left specific pods on the plants for seed, depending on individual specific criteria (pod color, health, vigor). The landrace peppers turned red and dried very quickly in less than four weeks, and the Anaheim pods dried in 10-12 weeks or longer. The Anaheim pods were cut open to expedite the drying process after several weeks.

Another interesting trend was seen comparing pod red maturity of the fertilization treatment direct seed and transplant plots. The pods from the direct seeded plots reached red maturity sooner after harvested during drying (darker red versus orange) than the transplanted plots. The fertility treatment plots matured faster for the same pepper type than the transplant plots, and the pods turned red with and had mature seeds (picture 1-2 seeds not shown). The landrace fertility transplant plots also turned red and the seeds were dark yellow (not shown) and reached full maturity versus immature seeds in the pods (picture 3-4). The Anaheim direct seed plot fertility treatment also matured faster than the Anaheim transplant fertility treatment (picture 5-6). The direct seeded control landrace plot also matured faster than the control transplant landrace plots (picture 7-8). These findings were seen in 2012; however, the differences were not as stark as 2011 field plot results. The field area in 2012 had clover and cover crops prior to planting, and the field area may have had more nutrients available or was less stressful for the plots; however, this area of research needs further study.

Research results and discussion:

The most important impact of the study was that the mycorrhizae-treated plots and seedling germination study indicated a significant difference in yield, plant vigor and height measurements. The Capsicum levels were lower for the fertility treatment plots and Herrera plots (which used the compost tea on their field). This may indicate less plant stress and a stable plant turgor pressure that does not need high Capsicum levels (which is an oil) to maintain the plant osmotic pressure. This area needs further study to determine if the presence of mycorrhizae has an impact on Capsicum production and regulation. The use of fungi, and especially compost tea, may be an important cultural practice change for other producers to increase nutritional uptake and efficiency of the pepper plants and disease suppression (Bacillus subtilis treatment). Since the pepper pods that were treated with fungi reached maturity quicker (as shown in the panels in Picture 16) when treated with mycorrhizae, the pepper plants may have increased seed production efficiency and better nutrient allocation. This area is an important area for organic seed production and to understand if the next generation of plants from the fungi treated plants maintain yield and vigor.

Using the one ounce package of peppers increased the farm profits of the cooperators from $15-30 a pound to $75 a pound; a two- to three-fold increase in profit. The cooperators that did not sell retail at farmers market sold out of the powder before December and sold directly from their farms. The packaging shown on picture 6 is archival acid free paper that can store the pepper pods without insect damage for several months and is low cost.

Use of the cover crop helped control erosion the second season in the farm-cooperator plots that used them. The soil quality increased if a legume was planted before the peppers, but grass (Rye) did not improve the soil quality as much. The cooperators did not use any chemicals, such as sulfur, to control wilt disease, and use of Bacillus subtilis as a preventative spray for wilt and damping off with the fungi increased plant survival in the split-split plot studies.

Participation Summary

Research Outcomes

No research outcomes

Education and Outreach

Participation Summary:

Education and outreach methods and analyses:

Publications were presented at several venues, including farmers markets and the organic farm conference. This included poster presentations, handouts (see appendix), information about the project, and field days. Picture 17 and 18 are two field days that were conducted in 2011 and 2012. This included a tour in 2011 of all the cooperators field plots in August, including the split-split plot studies. The regional Western SARE also conducted a field day on the farm and toured the farm of Sandoval and the split-split plot study. The publication (‘Simply Sustainable’- October 2012) for this field day is attached.

Education and Outreach Outcomes

Recommendations for education and outreach:

Potential Contributions

The conservation of seed banks held in this area, and regionally, is extremely vital for the future of agriculture and seed production. Use of mycorrhizae for an increase in plant efficiency and seed maturity is an area that has vast implications for agriculture and maintaining seed banks. The seed banks for the landraces are very important for other reasons, such as high nutritional sources and the potential medicinal properties of the peppers that need to be investigated further.

Future Recommendations

The Western SARE funding we received for this project was very helpful to accomplish conservation of the landrace seeds for our region. The only recommendation is to have one system to submit results and reports for stakeholders.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.