The increased appetite of Americans for various ethnic foods (Andrews, 1995) has contributed to the development of salsa-type products with varying degrees of pungency. The pungency in the product is determined by the pepper (Capsicum annuum L.) cultivar; this genus–species contains plants that have pungency values from 0 to 500,000+ Scoville Units. The industry adjusts pungency during processing to provide the desired levels in their products. In some cases, peppers with high pungency are diluted in the postharvest production process to obtain varying degrees of pungency in the final product. Some nonpungent jalapeño pepper cultivars have been developed. These types of peppers are used to provide the jalapeño flavor with a known amount of capsaicin added during processing to regulate pungency.
Most research examining cultural conditions for jalapeño peppers have focused on cultivars with some degree of pungency. For ‘TAM Mild Jalapeño 1’ and ‘Vera Cruz’, plants in stands established from transplants had higher yields than direct-seeded plants (Leskovar and Boales, 1995). In greenhouse studies with ‘Jalapa’ jalapeño, increasing nitrogen and potassium concentrations caused pod formation and Scoville Heat Units to fit a quadratic equation, whereas dry weight increased linearly (Johnson and Decoteau, 1996). Russo (1996a) determined that planting later in the season, combined with higher than the recommended rate of fertilizer, and a single harvest improved yield of the pungent jalapeño pepper ‘Mitla’.
Increasing the number of plants in proximity to each other can cause competition for water, sun, and nutrients and it is expected that plant development would possibly be detrimentally affected. For cayenne, jalapeño, paprika, Pepperoncini, and cv. Mississippi Sport peppers (all C. annuum L.), fresh pod yields decreased as in-row spacing increased with some of the highest yields occurring at the closest spacing (Decoteau and Graham, 1994; Kahn et al., 1997; Leskovar and Boales, 1995; Motsenbocker, 1996; Motsenbocker et al., 1993). However, total marketable yields for the pungent jalapeño peppers ‘TAM Jalapeño 1’ and ‘Jalapeño M’ were unaffected by varying in-row plant spacings from 10.2 to 40.6 cm (Motsenbocker et al., 1997). Increasing in-row spacing of bell pepper (C. annuum L.) plants did not consistently improve yield (Russo, 1991), and Locascio and Stall (1994) reported that increasing in-row spacing of bell pepper increased yield. These results indicate that there are differences in how different pepper types respond to varying plant populations.
Machinery exists that can be used if a single-pass strategy is desired to harvest peppers. However, height to the first flower, and consequently the first fruit, can have consequences for mechanical damage to fruit occurring during harvesting operations.
There has been little published concerning the cultural factors affecting yield of nonpungent jalapeños, a relatively new type of pepper. Russo (2003) found that if two seedlings of the nonpungent jalapeño pepper ‘Pace 105’ were established at a planting site, as opposed to a single plant, with 48 cm between planting sites in the row, yields were increased by 25%. The optimum plant population(s) for nonpungent jalapeños needs clarification. This study was undertaken to determine how plant density affected height to the first flower and yield of the nonpungent jalapeño pepper ‘Pace 105’.
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