`Sugar Snap' snap peas (Pisum sativum L.) were interseeded into a stand of `Española Improved' chile pepper (Capsicum annuum L.) in July or Aug. in 1995, 1996, and 1997. Peas were interseeded as one or two rows per bed, giving planting rates of about 92 or 184 kg·ha-1, respectively. Our objectives were to determine: 1) if intercropped pea would reduce chile yield and vice versa; 2) the effects of pea planting rates and dates on pea yield. Intercropped peas reduced chile yield by about 22% in 1995, but had no significant effects in other years. Pea plants from the August intercrops reached the flowering stage but did not produce pods in 1995 or 1996; some small pods were produced from August intercrops in 1997. Final plant densities were lower and less uniform in 1996 than in 1995 or 1997. Intercropped peas yielded less than monocropped peas in all years. Pea yields ranged from 1370 to 3960 kg·ha-1 when monocropped, 31 kg·ha-1 (1996 single-row) to 646 kg·ha-1 (1995 double-row) when intercropped. In 1995 only, the double-row intercrop yielded more peas than the single-row intercrop. Pod yield/plant was reduced 80%, 98%, and 96% in 1995, 1996, and 1997, respectively, by intercropping. Estimated gross revenues for the treatments indicate that, under the price assumptions used in the study, interseeding snap peas into stands of chile in north-central New Mexico is not economically advantageous compared with monocropped chile.
Five legumes [hairy vetch (Vicia villosa Roth.), barrel medic (Medicago truncatula Gaerth.), alfalfa (Medicago sativa L.), black lentil (Lens culinaris Medik.), and red clover (Trifolium pratense L.)] were interseeded into sweet corn (Zea mays L.) at last cultivation when sweet corn was at about the V9 (early) or blister (late) stage. The effect of legume interseeding on sweet corn yield, and late-season dry-matter and N yields of aboveground portions of the legumes was determined. Sweet corn yield was not affected by legume interseeding. In 1993, legume dry-matter yields were 1420 kg·ha–1 interseeded early and 852 kg·ha–1 interseeded late. Nitrogen yields were 49 kg·ha–1 interseeded early and 33 kg·ha–1 interseeded late. In 1994, dry-matter yields were 2760 kg·ha–1 interseeded early and 1600 kg·ha–1 interseeded late. Nitrogen yields were 83 kg·ha–1 interseeded early and 50 kg·ha–1 interseeded late. In 1993, barrel medic was the highest-yielding legume with dry matter at 2420 kg·ha–1 and N at 72 kg·ha–1 interseeded early, while red clover yielded the lowest with dry matter at 340 kg·ha–1 and N at 12 kg·ha–1 interseeded late. In 1994, dry-matter and N yields ranged from 4500 and 131 kg·ha–1, respectively, for early interseeded barrel medic to 594 kg·ha–1 and 16 kg·ha–1, respectively, for late interseeded red clover.
Three legumes [hairy vetch (Vicia villosa Roth.), barrel medic (Medicago truncatula Gaerth.), and black lentil (Lens culinaris Medik.)] were interseeded into `New Mexico 6-4' chile pepper (Capsicum annuum L.) when plants were 20–30 cm tall (3 Aug., “early” interseeding) or when plants were 30–40 cm tall (16–17 Aug., “late” interseeding) in 1993 and 1994. Our objectives were to determine the effect of legume interseeding on cumulative chile yield, and late-season dry-matter and nitrogen yields of aboveground portions of the legumes. Legumes were harvested on 8 Nov. 1993 and 15 Nov. 1994. Chile yield was not significantly affected by legume interseeding. In 1993, legumes accumulated 57% more dry matter and 55% more N when interseeded 3 Aug. vs. 16 Aug. In 1994, legumes accumulated 91% more dry matter and 86% more N when interseeded 3 Aug. vs. 17 Aug. Aboveground dry-matter yields in 1993 ranged from 1350 kg·ha–1 for black lentil interseeded late to 3370 kg·ha–1 for hairy vetch interseeded early. Nitrogen yields ranged from 52 kg·ha–1 for black lentil interseeded late to 136 kg·ha–1 for hairy vetch interseeded early. In 1994, hairy vetch was the highest yielding legume with dry matter at 1810 kg·ha–1 and N at 56 kg·ha–1 interseeded early, while black lentil yielded the lowest with dry matter at 504 kg·ha–1 and N at 17 kg·ha–1 interseeded late. In the spring following each interseeding year, we observed that hairy vetch had overwintered well, whereas barrel medic and black lentil had not, except when a few plants of barrel medic survived the winter of 1994–95. Results from this study indicate that legumes can be successfully interseeded into chile in the high-desert region of the southwestern United States without a significant decrease in chile yield.
Hairy vetch (Vicia villosa Roth.), barrel medic (Medicago truncatula Gaerth.), and black lentil (Lens culinaris Medik.) were interseeded into `New Mexico 6-4' chile pepper (Capsicum annuum L.) when plants were 8 to 12 inches tall or 12 to 16 inches tall in 1993 and 1994. Hairy vetch overwintered well both years, whereas barrel medic and black lentil did not. Spring aboveground dry mass yields of hairy vetch averaged 2.11 and 2.57 tons per acre in 1994 and 1995, respectively, while N accumulation averaged 138 and 145 pounds per acre in 1994 and 1995, respectively. Forage sorghum [Sorghum bicolor (L.) Moench] dry mass yield and N accumulation were significantly higher following hairy vetch than following the other legumes or no-legume control. There was no significant difference between forage sorghum yields following barrel medic, black lentil, or the no-legume control. Fertilizer replacement values (FRV) for the legumes were calculated from regression equations for forage sorghum dry mass yield as a function of N fertilizer rate. FRV for hairy vetch were at least 7-times higher than for either barrel medic or black lentil. Hairy vetch interseeded into chile pepper and managed as a winter annual can significantly increase the yield of a following crop compared to a nonfertilized control.
The climate conditions and chemical composition of root essential oils for 17 populations of Anemopsis californica in New Mexico were examined. The objective of this study was to observe the effect of environmental conditions and management conditions on essential oil composition in different populations of A. californica. Chemical concentrations of three abundant compounds—methyleugenol, thymol, and piperitone—were determined. Maximum accumulations of each compound were associated with different mean annual temperatures, precipitation, and elevation. Similar chemical profiles were detected in root samples recollected for four populations, suggesting retention of unique chemical profiles in different populations. Vegetative propagation of wild plants under cultivated conditions did not significantly alter the chemical profile of the root essential oil. The chemical concentrations for six essential oil components of A. californica roots were determined under field conditions with varying irrigation and nitrogen (N) fertilizer regimens. The concentration of only two compounds, thymol and piperitone, was increased by increasing irrigation. The concentration of all other compounds, methyeugenol, elemicin, 1,8-cineole, and myrtenol, were independent of the irrigation rates and N fertilizer rates used in the study. These results suggest that the chemical variability observed among different populations of A. californica is primarily genetically controlled and the environmental conditions in New Mexico are conducive to the production of this medicinal plant as a high-value crop.
Field studies were conducted in 1995 and 1996 at Las Cruces, New Mexico, and Alcalde, New Mexico, to compare direct seeding to transplanting for stand establishment and yield estimates of calendula (Calendula officinalis), catnip (Nepeta cataria), lemon balm (Melissa officinalis), stinging nettle (Urtica dioica), and globemallow (Sphaeralcea spp.). Calendula established well from seed or transplants at both sites. Transplanting increased establishment of lemon balm, catnip, stinging nettle, and globemallow. Lemon balm establishment was increased by 230% to 400% at Las Cruces, and catnip establishment was increased by 84% to 100% at Alcalde by transplanting. Direct seeding resulted in little or no stand establishment for stinging nettle and globemallow at Alcalde. In 1996, transplants increased lemon balm and stinging nettle dry weight yields by a factor of three or more at both sites. Dry weight yields of transplanted catnip were 4.86 t·ha−1 in 1995 and 7.90 t·ha−1 in 1996 in Las Cruces. Alcalde yields for transplanted dried catnip were 2.43 t·ha−1 in 1995 and 5.12 t·ha−1 in 1996. Transplanted globemallow dry weight yields were 6.04 t·ha−1 in 1995 and 9.17 t·ha−1 in 1996 for Las Cruces. Transplanted stinging nettle yield in Alcalde was 5.91 t·ha−1 for plants that overwintered and were harvested in the second season. Transplanting versus direct seeding medicinal herbs has the potential to substantially increase stand establishment and yield in New Mexico, particularly in the more northern and cooler part of the state.
Field studies were conducted to determine the production potential of echinacea (Echinacea purpurea), valerian (Valeriana officinalis), mullein (Verbascum thapsus) and yerba mansa (Anemopsis californica) medicinal herbs at two sites in New Mexico. Las Cruces, N.M., is at an elevation of 3,891 ft (1,186 m) and has an average of 220 frost free days per year, whereas Alcalde, N.M., is at an elevation of 5,719 ft (1,743 m) and averages 152 frost-free days per year. In-row plant spacings of 12, 18 and 24 inches (30.5, 45.7, and 61.0 cm) were compared at both locations. The corresponding plant densities for the 12, 18 and 24 inch spacings were 14,520 plants/acre (35,878 plants/ha), 9,680 plants/acre (23,919 plants/ha), and 7,260 plants/acre (17,939 plants/ha), respectively. Data were collected on growth rates, fresh yield, and dry yield for the herbs grown at each site. All crops at both sites had highest plot yields at the 12-inch spacing, suggesting that optimum in-row plant spacings are at or below the 12-inch spacing. Yields of 1.94 ton/acre (4.349 t·ha-1) of dried yerba mansa root, 0.99 ton/acre (2.219 t·ha-1) of dried echinacea root, and 2.30 ton/acre (5.156 t·ha-1) of dried mullein leaves were realized at the 12-inch spacing at Las Cruces in southern New Mexico. Yields of 1.16 ton/acre (2.600 t·ha-1) of dried valerian root, 0.93 ton/acre (2.085 t·ha-1) of dried echinacea root, and 0.51 ton/acre (1.143 t·ha-1) of dried mullein leaves were harvested at the 12-inch spacing at Alcalde in northern New Mexico. Yields of fresh echinacea flowers were 1.56 ton/acre (3.497 t·ha-1) in Las Cruces. Yields of dried mullein flowers were 0.68 ton/acre (1.524 t·ha-1) in Las Cruces and 0.66 ton/acre (1.479 t·ha-1) in Alcalde.
Cost and return estimates are presented for selected medicinal herbs grown in a plant-spacing study at two sites in New Mexico. The selected herbs were echinacea [Echinacea purpurea (L.) Moench], valerian (Valeriana officinalis L.), and yerba mansa (Anemopsis californica Nutt.). Significant returns to land and risk were observed in the crops grown at the closest plant spacing, 12 inches (30 cm). Return to land and risk after two growing seasons from echinacea was estimated for a 10-acre (4-ha) farm to be $16,093/acre ($39,750/ha) in Las Cruces and $14,612/acre ($36,092/ha) in Alcalde.