Cover crops have been shown to improve water and soil quality, reduce erosion and capture nutrients. Choosing the right cover crop, however, can be difficult. The Midwest Cover Crops Council (MCCC) —made up of representatives from 12 Midwest states and universities, including Purdue, the province of Ontario and other agricultural stakeholders — is rolling out an improved cover crop selection tool that will help farmers make those decisions. Users select their state/province and county and then select the goals they have for cover crops — erosion control, nitrogen scavenger, fighting weeds and providing forage, etc. They also can provide information about the cash crops they are planting and drainage data for their fields. The tool offers the best cover crop options for the specified conditions. Clicking on the cover crops brings up data sheets that offer more information about each crop, seeding rates and more. “This gives good information about the species that will[Read More…]
Strawberries are primarily grown in matted row system in Indiana, in which bare-root strawberry plants are set in the spring. Runners are established. Fruit is first harvested in the second year and plantings are renovated each year for 2-3 seasons. Growers in the southern part of the state expressed interest in growing strawberries in plasticulture system, in which plants are set on raised beds covered with plastic mulch. Strawberries may be planted in fall with plug plants, or in summer with bare-root plants. Runners are removed. Fruit is harvested the following year from mother plants. Using plug plants is more feasible for large-scale production as plants can be set with a transplanter and water wheel. However, plug plants are typically not available until the end of Aug. The growing window is often short in the fall so that it is difficult for the plants to develop enough branch crowns. As[Read More…]
A common problem tomato growers face this time of year are fruit defects caused by high temperatures. Heat stress on tomatoes can lead to reduced yield and abnormal fruit development. The common physiological disorders on fruit development under heat stress include yellow shoulder, internal white tissue, and blotchy ripening. In a recent presentation by Gordon Johnson from the University of Delaware at the 2020 annual meeting of the American Society for Horticultural Science, he elaborated on the cause of internal white tissue in tomatoes, compared varieties, and provided suggestions to reduce the problem. Information in this article is summarized from this presentation and the tomato variety trial report by Gordon Johnson. Tomato white tissue (Figure 1) develops when vascular tissue of the fruit is disturbed or damaged by heat so that the tissue turns white and the fruit has a bland taste. The fruit looks normal on the outside but[Read More…]
When ground level ozone is high enough to trigger an Air Quality Action Day alert from the Indiana Dept. of Environmental Management (IDEM) it is a reminder that crops may be injured by ozone. A number of areas around the state have experienced alerts in recent days, e.g. July 14 in S. Indiana. If crops show the symptoms described below and ozone levels have been high, consider the possibility of ozone injury. Ozone is a gas with three oxygen atoms per molecule. It is formed in the air when nitrogen oxides and volatile organic compounds react in the presence of sunlight. Ground-level ozone is a primary component of smog. Ozone harms people by aggravating existing breathing problems like asthma and injuring lung tissue. It harms sensitive plants by damaging leaf tissue, reducing the capacity to photosynthesize. IDEM issues daily air quality forecasts for ground level ozone from May to September,[Read More…]
(This article is modified from one published in issue 537 of this newsletter written by Sarah E. Hulick and Steve Reiners, Department of Horticulture Science, Cornell University, NYSAES. Liz Maynard also contributed to this article.) Recent storms have brought hail to parts of Indiana. Loss of yield and quality in vegetable crops due to hail depends on the crop, stage of growth, amount of injury, and future growing conditions. Disease control is absolutely essential after hail damage. Surviving plants will also benefit from a sidedressing of nitrogen about a week after the damage occurred. The following is a summary of all the information we could find relating to hail and vegetable recovery. Bell Peppers. A study was conducted in North Carolina to determine the impact of hail on the incidence of bacterial spot. The hailstorm occurred 38 days after transplanting when the plants were still young and recovery was possible.[Read More…]
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…]
Strawberries have a rich flavor; sugar, acid, phenolic content, and aroma all together make the wonderful fruit. Many factors are assumed to affect strawberry flavor. Some are supported by scientific evidence, some may be simply people’s impressions. In this article, we discuss some of the factors that are more likely to affect strawberry flavor. Locally grown strawberries often taste better than strawberries purchased from grocery stores. Part of the reason is that strawberries shipped long distances are harvested a few days before they are fully ripe. The fruit has longer shelf-life but the flavor is sacrificed. We are testing ten strawberry varieties in a high tunnel and in an open-field in southern Indiana this spring. Regardless of cultivars, we consistently noticed better fruit quality (higher sugar content, softer, and much cleaner) for strawberries grown inside of the high tunnel than grown in the open-field (Figure 1). I do not think[Read More…]
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…]