New Mexican-type red and green chile ( Capsicum annuum ) is important to New Mexico’s identity and economy. Producers began experimenting with mechanical harvest in the mid-1960s, but efforts stalled in the 1970s. Adverse impact to production following the implementation of the North American Free Trade Agreement spurred renewed interest in chile mechanization. Through private and public collaboration, the red chile industry in New Mexico has successfully transitioned with more than 80% of domestic acreage currently mechanized. Green chile has proven to be more challenging with fruit damage and lack of efficient mechanical stem removal posing key obstacles. Recent identification and developments in equipment have provided necessary components for mechanization of green chile, but must be scaled-up to production volumes.

"‘NuMex Odyssey’, a New Mexico–type Green Chile Pepper for Mechanical Harvest" published on 29 Oct 2021 by American Society for Horticultural Science.

Freshwater availability is declining in most of semi-arid and arid regions across the world, including the southwestern United States. The use of marginal quality groundwater has been increasing for sustaining agriculture in these arid regions. Reverse Osmosis (RO) can treat brackish groundwater, but the possibility of using an RO concentrate for irrigation needs further exploration. This greenhouse study evaluates the water use and yield responses of five selected chile pepper (Capsicum annuum L.) cultivars irrigated with natural brackish groundwater and RO concentrate. The four saline water treatments used for irrigation were tap water with an electrical conductivity (EC) of 0.6 dS m⁻¹ (control), groundwater with EC 3 and 5 dS m⁻¹, and an RO concentrate with EC 8 dS m⁻¹. The evapotranspiration (ET) of all chile pepper cultivars decreased and the leaching fraction (LF) increased, particularly in the 5 dS m⁻¹ and 8 dS m⁻¹ irrigation treatments. Based on the water use efficiency (WUE) of the selected chile pepper cultivars, brackish water with an EC ≤ 3 dS/m could be used for irrigation in scarce freshwater areas while maintaining the appropriate LFs. A piecewise linear function resulted in a threshold soil electrical conductivity (EC_e) ranging between 1.0–1.3 dS m⁻¹ for the tested chile pepper cultivars. Both piecewise linear and sigmoid non-linear functions suggested that the yield reductions in chile peppers irrigated with Ca²⁺ rich brackish groundwater were less than those reported in studies using an NaCl-dominant saline solution. Further research is needed to understand the role of supplementary calcium in improving the salt tolerance of chile peppers.

Paprika-type chile (Capsicum annuum L.) crops are susceptible to plant population losses through pest activity, disease, and extreme weather events such as hail storms. This study was conducted to determine the influence of intensity and timing of plant population reductions on the final harvested yield of paprika-type chile so that informed decisions can be made regarding continuing or ending a damaged field. Two trials, one per year, were conducted in southern New Mexico. ‘LB-25’, a standard commercial cultivar, was direct seeded on 29 March 2016 and 4 April 2017. Plants were thinned at three different growth stages; early seedling, first bloom, and peak bloom. Plants were thinned to four levels at each phenological stage; 0% stand reduction (control; ~200,000 plants/ha), 60% stand reduction (~82,000 plants/ha), 70% stand reduction (~60,000 plants/ha), and 80% stand reduction (~41,000 plant/ha). In both years, the main effects of stand reduction had a significant impact on harvested yield, emphasizing the percentage of stand reduction has more of an impact on yield than timing in paprika-type red chile. Consistently, an 80% stand reduction in paprika-type chile significantly reduced fresh red chile yield by 26% to 38%.

Introduction: Domestic production of pepper (Capsicum spp.) is shrinking while demand within the US is growing. Lack of availability and cost of labor often present an obstacle for domestic producers both practically and economically. As a result, switching to harvesting peppers mechanically is anticipated as a key strategy to help domestic producers compete in the international market. Mechanical harvest efficiency can be improved through breeding. One important trait that mechanical harvest compatible material should have is an easy destemming trait: low force separation of the pedicel and calyx from the fruit.Methods: To detect the genetic sources underlying a novel easy destemming trait for the purpose of future breeding efforts in New Mexico pod-type green chile, we performed QTL analysis on three F2:F3 populations, coming from three New Mexico pod-type varieties: ‘NuMex Odyssey,’ ‘NuMex Iliad,’ and ‘NuMex Joe E. Parker,’ each crossed with a parent with an easy destemming trait: MUC14. Genotyping was done through genotyping by sequencing (GBS) and phenotyping was done for destemming and fruit trait measurements. Correlations between measurements were found through the R package hmisc and QTL analysis was done through R/qtl.Results: A strong relationship was seen between destemming and aspects of fruit morphology, particularly, destemming force and fruit width (Pearson’s correlation coefficient r=0.75). Major QTLs for destemming and fruit size were discovered. Of these, the largest destemming force QTLs for all populations (PVE=34.5-69.9%) were on chromosome 10, and in two populations QTLs for destemming force were found on chromosome 3 (Percent Variance Explained (PVE)=10.7-18.8%). Fruit size-related QTLs in all populations colocalized in these same areas on chromosomes 3 and 10.Discussion: This suggests that fruit shape may be genetically linked to destemming, and breeders interested in selecting for easy destemming pepper will also have to pay attention to fruit size and shape.

Brackish water is becoming an increasingly important resource for agricultural irrigation due to limited freshwater availability; however, concerns persist regarding its potential to degrade soil quality and reduce crop yields. This study evaluated the combined effects of irrigation water quality (brackish water, electrical conductivity (EC) of 2958 µS/cm; agricultural water, EC 796 µS/cm), soil type (agricultural soil and reclaimed desert soil), and compost treatments (no compost, mulch compost, Johnson-Su compost, and mulch compost incorporation) on soil health and chili pepper (Capsicum annuum) growth under greenhouse conditions. Compost amendments significantly improved plant height by 58–213%, root length by 35–166%, and wet biomass by 154–1400% compared to control treatments. Agricultural water maintained lower soil EC (0.553–0.870 mS/cm) than brackish water (0.751–1.104 mS/cm), while Johnson-Su compost most effectively reduced salinity impact on plant growth. Leached water analysis showed higher Na⁺, Cl⁻, and SO₄²⁻ mobility under brackish irrigation, with compost treatments enhancing nutrient retention and soil moisture by buffering salinity stress with carboxylic group and cation exchange capacity. Johnson-Su compost incorporation consistently mitigated the negative effects of brackish irrigation by reducing sodium accumulation, improving chloride mobility, and enhancing soil nitrogen dynamics. These results highlight that combining high-quality irrigation water and biologically active composts improves soil health and plant productivity, while brackish water use requires soil amendments to mitigate salinity risks.