Modesto, California
March, 2000

In the hub California bell pepper growing country, a complex of virus diseases has hammered crops in recent years.

So soundly has been the beating that diseases such as cucumber mosaic, pepper mottle and tobacco etch have forced many growers out of the business.

Fortunately, last year proved to be a limited virus problem. The aphid vector responsible for spreading many of the viruses did not appear in heavy numbers until later in the season after most of the plantings were established.

Despite the respite, it’s clear the need for high yield varieties coupled with excellent horticultural characteristics is essential to the continued economic health of the pepper industry.

Pepper central

The Central Valley is a major center of bell pepper production in California. San Joaquin and Stanislaus counties boast over 4000 acres of all types of peppers, primarily bell.

Most of the production in this area occurs during midsummer to late fall. Because substantial acreage of crop is harvested during a period of shorter days with cool, humid nights, diseases like Black Mold, Botrytis, Phyopthora and physiological disorders like Sunburn and Blossom-end rot are always potential problems for producers.

Harris Moran's Bonita tops yields

Researchers at the University of California Cooperative Extension’s Stockton office held trials recently to determine which varieties resisted Pepper Spot the best and which varieties yielded the best.

In a Stockton yield trial, a Harris Moran bell pepper, yielded higher than any of the varieties tested. Bonita yielded 22.4 tons an acre.

Fruit sizing data for Bonita was equally impressive. Bonita yielded 36% Jumbo, 29% large, 14% extra large, 17% small, and 4% medium.

A high-performance, thick-walled pepper, Bonita is a vigorous plant with a continuous set. Its relative maturity is 75-80 days. It produces an elongated pendant 4-in. by 4.5 in.

Harris Moran’s Gusto shows no symptoms

Pepper Spot has been a problem on a number of varieties grown under short day, cool night conditions or late summer/fall in this area and along the coast.

There may be a relationship of calcium nutritional imbalance in the peppers contributing to the Pepper Spot problem under the mentioned conditions. Circular, gray/black spots develop under the skin in the fruit wall of some pepper varieties about the time the fruit attains a size diameter of three or more inches. As the fruit ripens, the spots slightly enlarge and turn green or yellow. A number of newer hybrid varieties show a good level of resistance or tolerance to the physiological problem.

A trial to reduce Pepper Spot (STIP) in bell peppers by using multiple foliar calcium suspension sprays was held near Dry Creek, Ca.

Researchers planted two resistant bell pepper cultivars – Gusto, by Harris Moran, and King Arthur, by Peto.

At mid-fruit development, foliar applications of two different rates of Cal Max calcium suspension were initiated. First was made Sept. 3. Additional treatments were done Sept. 10, Sept. 17, and Sept. 24.

All applications were made over the pepper plants with a handheld CO2 backpack sprayer using 8004 nozzles at 30 psi in a spray volume of 50 gal/a.

Results showed virtually no Pepper Spot in the resistant cultivars. Gusto showed no symptoms. King Arthur showed slight symptoms.

There was no increase in yield whether foliar calcium was used or not, except for the resistant cultivar Gusto where both rates of calcium suspension gave better yields than the untreated.

Gusto, an elite OP, performs as well as many hybrids. It continues to be the top choice for a vigorous and reliable OP for fresh market or processing.

Company news release
N2617