Bacterial spot epidemics, caused by Xanthomonas campestris pv. vesicatoria (Xcv), are still considered serious risks for commercial pepper (Capsicum annuum) growers in a number of eastern, southern and midwestern states. Newly released bell pepper cultivars with the Bs2 gene for resistance to Xcv races 1, 2, and 3 were compared in 2000 under bacterial spot-free and severe (natural) bacterial spot epidemic conditions in central and eastern Kentucky where similar trials had been conducted from 1995 to 1997. In addition to the replicated bell pepper trials, 49 hot and specialty pepper cultivars were grown for observation in single plots at the same two locations. As in previous trials, there were economically important differences in resistance and marketable yields among bell pepper cultivars having the Bs2 gene; some resistant cultivars were as susceptible as susceptible checks. Others were highly resistant in spite of the presence of Xcv races 3 and 6 in the eastern Kentucky trial. Only a few were highly resistant with excellent fruit quality. With a few notable exceptions, most of the hot and specialty cultivars were very susceptible to bacterial spot. Two of the three new jalapeño cultivars carrying Bs2 were highly resistant to bacterial spot and high yielding under severe epidemic conditions.
Brent Rowell, R. Terry Jones, William Nesmith, April Satanek and John C. Snyder
Kathleen M. Sullivan and William J. Bramlage
Seven types of chile peppers were tested for differences in susceptibility to postharvest chilling injury (CI). Cherry, cubanelle, Hungarian wax (HW), poblano, serrano, and both mature-green and full-color (red) jalapeño fruit were stored at 2.5, 7, and 15 °C for 0 to 30 days. External C2H4 production at 12 and 24 hours after removal from storage and internal C2H4 concentration at 24 hours were measured. There was no significant difference in C2H4 production after the first 12 hours, but serrano produced significantly less C2H4 than the other types during the second 12 hours. Among the cultivars there were differences in the amounts of internal C2H4 measured: HW had the highest levels measured, and serrano had undetectable levels. CI has been observed on bell and some chile pepper cultivars as small black pits, and the recommended nonchilling storage temperature is 7 °C for all peppers. In this study, scald (a surface browning) was observed on HW and cubanelle fruit in addition to pitting, which occurred on all the cultivars. Susceptibility to chilling varied among pepper types in this study. HW peppers were the most susceptible, manifesting scald after 4 days at 2.5 °C and scald and pits after 16 days at 7 °C. Serrano fruit were the most resistant to CI, only pitting after 23 days at 2.5 °C, and having no symptoms after storage at 7 °C for 30 days. Cherry and poblano peppers developed pits after 8 days at 2.5 °C. Both green and red jalapeños pitted after 12 days at 2.5 °C, and cubanelles had scald after 16 days at 2.5 °C. Poblano fruit had large, deep pits after 8 days at 7 °C, cherry peppers pitted after 12 days, and both green and red jalapeño fruit pitted after 16 days at 7 °C. Both pits and scald were observed on cubanelle fruit after 23 days at 7 °C. Recommendations for storage of peppers should be expanded to accommodate differences among cultivars.
Lucia Villavicencio, Sylvia M. Blankenship, Douglas C. Sanders and William H. Swallow
Bell peppers (Capsicum annuum L.) are classified as nonclimacteric fruits while some hot peppers have been reported as climacteric. Responses of peppers to exogenously applied ethylene-releasing compounds suggest ethylene involvement in the ripening process. Ethylene production and respiration rates in 13 cultivars of pepper: `Camelot', `Cherry Bomb', `Chiltepin', `Cubanelle', `Banana Supreme', `Habanero', `Hungarian Wax', `Mesilla', `Mitla', `Savory', `Sure Fire', `Tabasco', and `King Arthur' were studied under greenhouse and field conditions. Fruit from each cultivar were harvested at different maturity stages determined by color, ranging from mature-green to full red-ripe. Carbon dioxide and ethylene production were measured by gas chromatography. Both variables were significantly different among maturity stages for all cultivars. Respiration rates were between 16.5 and 440.3 mg·kg-1·h-1 CO2. Ethylene production ranged from 0.002 to 1.1 μL·kg-1·h-1. Two patterns of CO2 production were identified: higher CO2 production for mature-green fruit with successive decreases for the rest of the maturity stages or lower respiration rates for mature-green fruit with an increase in CO2 production either when fruit were changing color or once fruit were almost totally red. A rise in CO2 production was present for most cultivars. Ethylene evolution increased significantly at maturity or before maturity in all cultivars except `Cubanelle' and `Hungarian Wax'. Respiration rates and ethylene production were significantly different among cultivars at the mature-green and red stages.
Nicacio Cruz-Huerta, Jeffrey G. Williamson and Rebecca L. Darnell
from cherry (spherical, ≈2.5 to 3.5 cm in diameter), to long-fruited (banana or cubanelle), to bell (blocky) peppers, which are the most important from an economic standpoint ( Bosland, 1996 ). In the United States, per-capita consumption of bell