Oct 13, 2015

Trial tests earliness, yield of colored pepper cultivars

Growing interest in local foods has led to increased production of fruit and vegetables in Iowa. One of the most commonly grown summer vegetables in Iowa is the pepper.

Within the pepper category, growers are interested in growing colored peppers, as they fetch a higher price in the market. Depending on the cultivar, maturity and yield of colored pepper varies. Weather conditions also play an important role in yield and quality. In Iowa, weather conditions can drastically vary, depending on which part of the state one is in.

Compared to green peppers, colored peppers remain on the plant for a longer time before being harvested. This ensures uniform color change but poses the risk of damage due to insects, disease and inclement weather. Given this situation, a trial was conducted at two research stations (Muscatine Island Research Station in Fruitland and Armstrong Research Station in Lewis) to evaluate earliness and yield of colored pepper cultivars.

Cultivars tested in this study included Archimedes, Bianca, Delirio, Flavor Burst, Lulton, Red Knight, Summer Sweet, Tango and Tequila. Thanks to Mark Pflumm (Seedway), Jason Williams (Siegers), Derrill Kregel (Rispens) and Brad Paulson (Rupp) for donating seeds.

Transplants were grown in 72-celled trays for six weeks and then hardened or acclimated for a week prior to planting. Standard cultural practices were followed for irrigation and fertilization.

Each cultivar consisted of 10 plants, and they were harvested eight times. All cultivars were productive, with Bianca, Flavor Burst, Lulton and Tequila the first to produce peppers that changed colors. At the Armstrong Research Station, Bianca, Flavor Burst and Tequila produced higher numbers of fruits compared to any other cultivars. Overall, plants did not perform that well at the Muscatine Island Research Station. This could be due to the sandy soils in the area, which do not hold as much water as the loamy soils at the Armstrong station. Soil type at Muscatine was a Fruitfield coarse sand with 0-2 percent slope and less than 1.5 percent soil organic matter. The largest peppers were produced on Archimedes and Summer Sweet at both farms. The cultivar Tango produced lowest in both locations.

In general, fruit and vegetables with color offer distinct nutritive advantages. Natural color pigments in produce – such as lycopene and anthocyanain (red, blue or purple color), carotenoids (orange or yellow color) and chlorophyll (green color) – may help reduce the risk of several types of cancers and heart diseases, and can improve immune system functions.

– Ajay Nair and Cynthia Haynes, Iowa State University