Colorful red, green and yellow bell peppers have become the second leading cash crop in the Coachella Valley.
There are only about 3,000 acres in the valley, but the value of the summer and fall pepper crops totals more than $41 million, second only to Flame Seedless table grapes.
University of California Cooperative Extension Riverside County Farm Advisor Jose Aguiar told the recent Desert Vegetable Crops Workshop in Holtville, Calif., that growing bell peppers is as challenging as it is lucrative.
“If you grow peppers, you really need to be thinking ahead about problems because you will have them and you need a control plan,” he said.
Desert peppers are grown on plastic mulch and drip irrigated. Pre-plant Methyl bromide fumigation continues to be the key to getting a profitable crop, which is a yield of about 1,500 boxes per acre.
Nematodes can be a problem and ground beetles migrating from vineyards can girdle pepper plants. Aphid, psyllids and mites can be problems.
Bell peppers can be damaged by a wide array of diseases, including a new one that surfaced recently.
“We are starting to see fusarium problem and growers want to know if it is coming from the greenhouses. It is possible, but not probable because fusarium can stay in the soil a long time and be carried by wind and irrigation water,” he said.
A new problem surfaced that initially looked like nutritional deficiency, said Aguiar, but it turns out to be beet curly top virus.
“Plants would start to wilt and have a lot of yellowing and eventually the whole plant would die. Internodes were shorter. However, the roots would be fine. And it would be individual plants surrounded by healthy plants. It is a significant number of plants, but not every plant,” said Aguiar.
Bob Gilbertson, University of California, Davis plant pathologist, eventually identified the problem as beet curly top, a common virus found in California vectored by the beet leafhopper.
However, Aguiar said growers have not picked up leafhoppers in the field and that made Gilbertson's analysis surprising.
Aguiar noted that it does not take a leafhopper long to infect a plant with beet curly top. “They can feed on a plant for only a minute and it can become infected,” he explained.
Aguiar conjectured the leafhoppers are likely coming out of the foothills infecting pepper fields.
The virus has a very large host range that includes many vegetables, field crops, and weeds. Host plants for the beet leafhopper include Russian thistle, which thrives in the desert areas.
Resistant varieties are available for beans and sugar beet, but not for peppers. A statewide program to control the leafhopper vector with insecticide sprays on its breeding grounds limits the number of leafhoppers that move to agricultural areas. Control measures are not recommended for individual fields.
Aguiar said CDFA monitoring of leafhoppers could be used in a planting management plan to hopefully avoid early season damage from leafhoppers to highly susceptible seedling peppers.
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