15 articles tagged "Peppers".

Figure 1. Place shadecloth on high tunnels for colored bell pepper production. Photo credit: Ajay Nair

On hot days in the summer, high tunnel growers may wonder whether to place shadecloth on high tunnels. Considering excessive heat inside the structures that may lead to plant stress, blossom drop and unmarketable fruit, there is a rational for doing it. However, it is important to realize the limitations of placing shadecloth on high tunnels in the Midwest. A few years ago, we compared the effect of 30% black shadecloth on temperature and light levels inside a high tunnel. We found shadecloth significantly decreased maximal temperatures for about 10 degrees Fahrenheit while it had no effect on nighttime temperatures.  In terms of light reduction, it ranged from 60% in a sunny day to 30% in a cloudy day. More information about this comparison can be found in the article Temperature and Light Intensity in a High Tunnel Covered with 30% Black Shadecloth in Issue 619. In our experience of[Read More…]


Tomato brown rugose fruit virus (ToBRFV) is making headlines and eliciting USDA action. Growers need to learn more about ToBRFV biology, symptoms and control. Tomato brown rugose fruit virus (ToBRFV) is a newly identified virus affecting tomato, pepper and possibly their relatives. ToBRFV first appeared in Israel in 2014. Since then, it has shown up in several other countries, including eradicated greenhouse outbreaks in 2018 and 2019 in Arizona and California. These back-to-back U.S. outbreaks indicate ToBRFV will probably be something that without good diligence has a high probability of happening again. An added concern for the U.S. industry is ToBRFV is present in countries exporting tomato and pepper fruit to the U.S.; these include Mexico (where it was widespread in 2018) and the Netherlands. The virus has not been found in Canada, but some fruit imported into the U.S. goes through Canada. The U.S. Department of Agriculture (USDA) is[Read More…]


In creating the new format of the Midwest Vegetable Production Guide for Commercial Growers 2020 (ID-56), I inadvertently left out the portion of the fruiting vegetable section that deals with Phytophthora blight of pepper. The new format allows me to update items easily; I have now added information on this important disease. Go to mwveguide.org to find the update. However, the hard copy of the Guide still lacks this information. Anyone who wants a hardcopy of the Phytophthora blight on pepper information should contact me. I apologize for any inconvenience or confusion. Please let me know of any comments or questions that you might have.


Sweet colored peppers can yield well in the protected conditions of an unheated high tunnel, but information is lacking about which varieties are adapted for high tunnel production and their performance. During 2018 we evaluated ten sweet pepper varieties at the Purdue Student Farm, West Lafayette, Indiana (Table 1). How was the evaluation conducted? The evaluation was conducted on a Mahalasville (Md), silty clay loam. The spring soil test showed 9.5% organic matter, pH 7.5, and 201 ppm phosphorus (P), 250 ppm potassium (K), 810 ppm magnesium (Mg), and 4200 ppm calcium (Ca). The cation exchange capacity was 28.4 meq/100 gram. Micro nutrients tested at 11.5 ppm zinc (Zn), 34 ppm manganese (Mn), 100 ppm iron (Fe), 2.7 ppm copper (Cu) and 2.9 ppm boron (B). Nitrogen, 60 lb. N/A from Nature’s Source® Professional 10-4-3 liquid plant food, was applied by fertigating 15 lb./A N four times at 2, 4,[Read More…]


Southern blight canker at the base of a pepper plant. Tomatoes can also be affected by this disease.

Southern blight of pepper and tomato thrives under hot, dry conditions. Usually, such conditions are more likely in August. Production under tunnels may contribute to the dry conditions that influences southern blight. This article will discuss the symptoms, biology and management of southern blight of tomato. Southern blight has a wide host range affecting many vegetable, field and ornamental crops. Tomato is the most important host. The disease is caused by the fungus Sclerotium rolfsii. This fungus is related to the one that causes white mold.The first symptom one is likely to observe of southern blight is plant wilt. At the base of the plant, one is likely to notice a canker with sclerotia that may be as large as a sesame seed (Figure 1). These sclerotia are survival structures for the fungus and allow the disease to occur in the same location years later. The sclerotia for southern blight are round,[Read More…]


After harvest, storing vegetables in optimal conditions is important to ensure the whole season’s hard work has paid off. This article discusses the optimum storage conditions for tomato, pepper, cucumber, watermelon, cantaloupe and sweet corn. Tomato Ideal storage conditions for tomatoes depend on the maturity stage of picking. If tomatoes are picked at mature green, store them in 66 to 70°F with 90 to 95% RH would encourage uniform ripening. Temperatures above 81°F reduce intensity of red color and reduce fruit shelf-life. Green tomatoes are chilling sensitive. If the temperature is below 55°F, fruit may develop chilling injury. Red tomatoes are safe to store at 50°F, however, flavor and aroma may be negatively affected compared to storing them at 55°F. Pepper Optimum storage condition for peppers is 45 to 55°F with 90 to 95% RH. Temperatures lower than 45°F may cause chilling injury. Colored peppers are in general less chilling[Read More…]


Figure 1. The small hole on pepper fruit is likely caused by corn earworm (photo by Wenjing Guan)

European corn borers used to be a serious pest of peppers. The larvae would burrow into the fruit under the cap, making it difficult to cull out infested fruit. With the widespread adoption of Bt corn by agronomic farmers, populations of corn borers have been greatly reduced. However, it appears that in the last couple of years, corn borers have been making a comeback, so management of this pest is still recommended. Corn earworms can also attack pepper fruit. They usually tunnel into the side of the fruit, making it easier to cull out infested fruit. Sometimes when fruit have been treated with insecticides, the larvae will die before they enter the fruit, leaving behind a feeding scar that will render the fruit unusable for fresh market sales. Corn borers can be controlled with Ambush®, Avaunt®, Bt®, Baythroid®, Brigade®, Coragen®, Entrust®, Exirel®, Intrepid®, Lannate®, Mustang Maxx®, Permethrin®, Radiant®, and Warrior®.[Read More…]


Figure 1. Initial symptom of blossom end rot on pepper.

In the past few weeks, we have received several reports about blossom end rot on tomatoes and peppers as the crops start to set fruit. Blossom end rot is a physiological disorder (not an infectious disease) that commonly occurs on tomatoes and peppers. Initial symptoms of the physiological disorder include dark green or brown water-soaked leisure occurring on the bottom of the fruit (Figure 1). The lesion then expands into sunken, leathery brown or black spots (Figure 2 and 3). In severe cases, the lesion can expand to half size of the fruit. The symptoms on tomatoes can be observed on fruit from fruit set to fruit the size of golf balls. Fruit on the same cluster tend to show symptoms simultaneously. On peppers, the symptoms are more likely appear during fruit expansion. The affected fruit often change color prematurely. Under moist conditions, opportunistic molds might develop on the affected tissues[Read More…]


Figure 3: Mottling of a tomato leaf caused by tomato spotted wilt virus.

Tomato spotted wilt virus can cause stunting (Figure 1), necrotic ring spots (Figure 2), mottling (Figure 3) or chlorosis (Figure 4). In Figure 5, a pepper plant is shown with a ring-like lesion due to tomato spotted wilt virus. Figure 6 is a photo of a pepper transplant with mottled lesions due to impatiens necrotic spot virus. Both TSWV and INSV can cause symptoms on many hosts including ornamentals. Figure 7 is a photo of INSV symptoms on begonia. For more information about the biology and management of these diseases see here.


A tomato leaf with necrotic rings caused by tomato spotted wilt virus.

While many virus diseases affect pepper and tomato plants, in the Midwest, the most common virus diseases of these two crops are tomato spotted wilt virus (TSWV) and Impatiens necrotic spot virus (INVV).  These diseases are usually observed in greenhouse or high tunnel situations. The two viruses, TSWV and INSV are closely related. In fact, at one time, they were both considered TSWV. Therefore, the symptoms, biology and management of these two diseases are similar. This article discusses the symptoms, biology and management of these two diseases. Both TSWV and INSV affect many hosts, including vegetables and flowering ornamentals. Symptoms vary according to host, stage of plant affected and environmental conditions. Both diseases can cause stunting, yellowing, necrotic rings, leaf mottle and more. Figure 1 shows a tomato leaf with necrotic rings caused by TSWV. Figure 2 shows a pepper transplant with ring spots caused by INSV. Additional symptoms may[Read More…]


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