97 articles tagged "Solanaceous Crops".

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…]

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We received calls recently reporting observations of leaf curling on tomatoes. This article discusses factors that may cause tomato leaf curling. In a similar way as other vegetables, hot and dry conditions may cause leaf curling on tomatoes. In late spring and early summer, plants that are actively growing and developing fruit have a high demand for water. Under hot and dry conditions, plants respond by rolling the leaves to reduce the surface area exposed to high radiation. Lower leaves on a tomato plant are often affected first, they may recover if environmental stresses are reduced. Leaf curling itself due to the environmental stresses is not a significant concern, but if the stress condition continues, it may eventually lead to blossom end rot fruit and decreased yield. There is a great variation among tomato varieties in terms of whether the observation of leaf curling suggests the plant is suffering water[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…]

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Botrytis gray mold can cause disease on many different host plants, enabling the fungus to easily survive and disperse between crops. Host crops include flowers such as geraniums, vegetables such as green beans and fruit such as strawberries. The disease is favored by relatively cool temperatures and high humidity. We recently observed botrytis gray mold on tomatoes grown in a greenhouse and strawberry grown on a plasticulture system in the open field. Tomato: Gray mold of tomato is one of the more common diseases of greenhouse-produced tomatoes. Although it is often a minor problem, if left unchecked, gray mold can cause yield loss. Gray mold, or as it is sometimes called, Botrytis gray mold, may cause a light gray or brown necrotic lesion on leaves (Figure 1). The lesions on leaves are sometimes wedge shaped on the margin of the leaf. Stem lesions are a similar color and may encircle[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.

We know from published research that the health and quality of a vegetable transplant affects how it will establish, grow, and yield in the field. Our recent work comparing tomato and cucurbit seedling growth in different organic growing media and with and without added fertilizer has provided some good examples of this. See Vegetable Crop Hotline issues 653 and 668 for descriptions of media. Tomatoes flowered and set fruit earlier, and had greater early yield when the seedlings were grown in a media that sustained good growth (Figure 1), or if in a media with low fertility but were provided additional nutrients from solid or liquid fertilizer (Figure 2). What does this mean for transplant producers? Plan to provide nutrients the seedlings need, either pre-mixed in the growing media or by adding fertilizer. Among the media for organic production that we tested, additional fertilizer was most beneficial to those media[Read More…]

Figure 4. Connect four stakes in a rectangle shape (A), cross the hook (12’’) with the central-string (B) and hook it to the side-strings between the two tomato plants (C).

The Florida-weave or sometimes called stake and weave is a commonly used tomato trellis system (Figure 1). It has several benefits and is easy to implement. However, sometimes the plants grow too tall and can hardly be supported by the stakes, or they may be too vigorous and break the strings. In this article, we will introduce an alternative tomato trellis system, Spanish-weave, and discuss its usage in tomato production. How to trellis tomato plants with the Spanish-weave system? Materials: tomato stakes, tomato strings, and hooks. We made the hooks from steel wire. They were made at 4-inch, 8-inch and 12-inch length (Figure 2). Prune bottom leaves of the tomato plant and suckers until the first flower cluster (Figure 3). Install tomato stakes on each side of the rows at every two tomato plants (A); Tie strings across the two wooden stakes at the beginning and the end of each[Read More…]

Two types of injury on young warm-season vegetable plants are caused by low temperatures: frost/freezing injury and chilling injury. Frost/freezing injury occurs when temperatures drop below 32°F. Ice formation in plant tissues cut cell membranes. When the tissue thaws, the damage results in fluids leaking from the cell, causing water soaked damage. Frost/freezing injury is detrimental to warm-season vegetables, such as melons, cucumbers, tomatoes, peppers, beans. To avoid damage, the best way is to plant warm-season vegetables later in the spring, after the last frost has passed. However, weather is difficult to predict, and there is a growing trend of planting early to achieve early harvests. For the early planted warm-season vegetables, here are a few suggestions that may protect plants from low temperature damages. Covering. The idea of covering the seedlings is to create a microclimate around plants. Because the heat accumulated in soil irradiate back at night, covering[Read More…]

Figure 1. Cucumbers start to wilt following a night average soil temperature was 58 °F

Chilling injury occurs when temperatures are above 32°F and below 55°F. The plant tissue becomes weakened that leads to cellular dysfunction. The most noticeable visual symptom of chilling injury is leaf and hypocotyl wilt (Figure 1). This is caused by the rapid decline in the ability of roots to absorb and transport water. It also caused by the plant’s reduced ability to close stomata. If temperatures do not improve, plants may be killed. Low temperatures also have an effect on mineral nutrient uptake of the plants. Absorption of ions by roots is difficult, as well as their movement in the above-ground parts of the plants. As a result, chilling injured plants often show symptoms similar to nutritional deficiency. Although warm-season vegetables are all susceptible to frost/freezing damage, their susceptibility to chilling injury varies among plant species. Pepper plants seem to have greater difficulty recovering after chilling injury compared to tomato[Read More…]

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…]

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