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Abstract: Salt tolerance of five cultivars of Capsicum annuum L. Early Jalapeno, Golden Treasure, NuMex Sweet, NuMex Joe E. Parker, and Santa Fe Grande, two cultivars of C. chinense Jacq. Habanero and Pimienta De Chiera, and one accession of C. annuum, NMCA 10652, were evaluated in a field study. Seedlings were transplanted in late May to field raised beds containing loamy sand soils in a semi-arid environment. Plants were well irrigated throughout the experiment. Three saline solution treatments, prepared by adding NaCl, MgSO4, and CaCl2 to tap water at different amounts to create three salinity levels of 0.82dSm−1 (control, tap water), 2.5dSm−1, and 4.1dSm−1 electrical conductivity (EC), were initiated on 15th June and ended in late August. Among the eight varieties, NMCA 10652 had the highest survival percentage at 100% in the 4.1dSm−1 treatment, followed by ‘Early Jalapeno’, ‘NuMex Sweet’, ‘Pimienta De Chiera’, ‘Santa Fe Grande’, ‘Golden Treasure’, and ‘NuMex Joe E. Parker’. ‘Habanero’ had the lowest survival at 28%. Compared to control, final shoot dry weight of the plants irrigated with saline solution at 4.1dSm−1 was reduced by 92% in ‘Habanero’, followed by ‘Golden Treasure’ at 80%. For fruit fresh weight in 4.1dSm−1 vs. control, ‘Habanero’ had the highest reduction at 86%, followed by ‘Golden Treasure’ at 74%, while NMCA 10652 and ‘Santa Fe Grande’ had the least at 26% and 19%, respectively. NMCA 10652, the most tolerant to salinity, had the lowest leaf Na+ accumulation, while ‘Habanero’, the most sensitive to salinity, had the highest Na+ in the leaves. For leaf Cl−, ‘Early Jalapeno’ had the highest, while ‘Habanero’ had the lowest Cl− accumulation in the leaves. Generally, sensitive varieties accumulated more Na+ and/or Cl− in leaves, except for ‘Early Jalapeno’, which was relatively tolerant to salinity but had high Na+ and Cl− accumulation in leaves. [Copyright &y& Elsevier]

High soil salinity often results in poor stand establishment, reduced plant growth, and reduced yield of many horticultural crops such as peppers (Capsicum annuum). We investigated the effects of soil salinity and soil type on seedling emergence and growth of four commercial peppers ('NuMex Joe E. Parker', 'NuMex Nematador', 'NuMex Primavera', and 'Jupiter') in greenhouse experiments. Seeds were sown in either a loamy sand or a silt loam soil in pots and irrigated with saline solutions at electrical conductivity of 0.9 (tap water), 3.0, or 6.0 dS.m&#sup1; (Expt. 1) or at 0.0 [reverse osmosis (RO) water], 0.9, or 1.5 dS.m&#sup1; (Expt. 2). No seedling emergence was observed in treatments irrigated with 3.0 or 6.0 dS.m&#sup1; solutions. The salinity at the top soil layer increased linearly with time when subirrigated with tap and saline solutions in both soil types, whereas no substantial increase in soil salinity was found when subirrigated with RO water or overhead irrigation with tap water. Salt accumulation at the top soil layer was greater in loamy sand than in silt loam. Seedling emergence percent subirrigated with RO water ranged from 70% to 80% in loamy sand and 45% to 70% in silt loam, depending on pepper cultivars. When subirrigated with tap water and saline solutions, the emergence percent ranged from 0% to 60%, depending on pepper and soil types. In Expt. 3, seedlings were germinated in commercial potting mix and grown in 1.8-L pots containing commercial potting mix. Saline solution treatments of 1.4 (control, nutrient solution), 2. 1, 2.9, 3.5, or 4.2 dSm&#sup1; were initiated when seedlings had 11 to 13 leaves. Five weeks after initiating saline water irrigation, the reduction in shoot dry weight was greater in 'Jupiter' and 'NuMex Primavera' as compared with 'NuMex Joe E. Parker' and 'NuMex Nematador', but the differences were small. [ABSTRACT FROM AUTHOR]

Chile peppers are economically important crops in southern regions of the United States. Limited information is available on irrigation management with low-quality water or on salt-affected soils. The objective of this study was to determine the relative salt tolerance of 20 genotypes of chile peppers. In Expt. 1, seeds of selected pepper types (Anaheim, Ancho, Cayenne, Paprika, Jalapeño, Habanero, and Serrano) were germinated in potting mix and seedlings were grown in 2.6-L pots. Six weeks after sowing, salinity treatments were initiated by irrigating plants with nutrient solutions of different electrical conductivities (ECs): 1.4 (control), 3.0, or 6.0 dS.m -1. After 1 month of initiating treatments, shoots were harvested and dry weights were determined. All plants survived and no visual salt injury was observed regardless of pepper variety and treatment. There were no statistical differences between control and saline solution treatments in final height and shoot dry weight of Habanero 1, 'Early Jalapeño', 'AZ-20', 'NuMex Joe E. Parker', and 'NuMex Sandia'. In Expt. 2, seeds of 20 genotypes were directly sown in 2.6-L containers filled with loamy sand. Saline water irrigation was initiated 37 days after sowing by irrigating plants either with saline (nutrient solution based, similar to Expt. 1) or nutrient solution (control). More than half the genotypes did not have 100% survival in the salinity treatment. Ancho 1, Ancho 2, Cayenne 1, 'Early Jalapeño', and 'AZ-20' had 100% survival regardless of salinity treatment. No plants of 'TAM Mild Habanero' survived when irrigated with saline water and less than half of the plants survived in the control. The relative tolerance of chile genotypes to salinity varied with substrate in some genotypes. From the combined results of the two experiments, the 20 pepper genotypes were ranked for salt tolerance based on seedling survival, visual quality, and growth. 'Early Jalapeño' and 'AZ-20' were relatively tolerant to salinity among the 20 genotypes, whereas 'TAM Mild Habanero' and 'Ben Villalon' were sensitive. Ancho 1, Ancho 2, Cayenne 1, and Cayenne 2 also had relatively high tolerance based on survival and visual quality, although shoot growth was reduced significantly. [ABSTRACT FROM AUTHOR]

The effect of drought on the growth and gas exchange of six bedding plant species--agastache [Agastache urticifolia (Benth.) O. Kuntze 'Honeybee Blue'], dusty miller (Cineraria maritima L. 'Silverdusty'), petunia (Petunia xhybrida 'Wave Purple'), plumbago (Plumbago auriculata Lam. 'Escapade'), ornamental pepper (Capsicum annuum L. 'Black Pearl'), and vinca [Catharanthus roseus (L.) G. Don 'Titan'l--was quantified under greenhouse conditions. Seeds were sown in January and seedlings were grown in the greenhouse until 18 Apr., when two irrigation treatments--drought (D, ≈18% volumetric moisture content at reirrigation) and control (C, ≈25% volumetric moisture content at reirrigation)--were initiated. Leaf net photosynthetic rate (P.), stomatal conductance (gs), and transpiration (E) were determined in response to a range of substrate moisture content (from ≈5% to 30% by volume) and temperature (from 20 °C to 40 °C). Dry weight of agastache, ornamental pepper, and vinca was unaffected by drought, whereas that of other species was reduced. Leaf area of plumbago and height of plumbago and vinca were reduced by drought. As substrate moisture content decreased from 25% to 10%, Pn, E, and gs decreased linearly in all species except petunia and plumbago. Leaf net photosynthetic rate of all species declined as leaf temperature increased from 20 °C to 40 °C. In contrast, E of all species, except petunia, increased as temperature increased. Transpiration rate of petunia increased as temperature increased from 20 °C to 30 °C, and then decreased between 30 °C and 40 °C. Although petunia had the highest Pn among the tested species, its Pn and gs declined more rapidly compared with the other species as temperature increased from 20 °C to 40 °C or as substrate moisture content decreased, indicating that petunia was most sensitive to high temperature and drought. [ABSTRACT FROM AUTHOR]