115 articles tagged "Crop Management".

Temperature graph

This is the last installment of our series on spring temperatures for 2018. What a strange year it has been. We started out very cool until mid-April and it didn’t really warm up until early May (Fig. 1). I think every day since then has been over 80F. Although the early spring was much cooler than the last few years, right now we’ve caught up and tracking similar to where we have been for most of this decade. My guess is that harvest times will be about normal this year.    

We’re getting close to the time when growers need to make chemical thinning decisions – for many the most perplexing and risky decision they will make all year. Even with a relatively mild spring without too much interference by spring frosts, this is a tricky call to make. In most cases, there are plenty of flowers for a full crop. Remember that only about 5-10% fruit set is usually enough for a full crop. As apple crops approach petal fall, it’s time to start chemical thinning. Generally speaking, flowering has been heavy and pollinating weather favorable, therefore we expect fruit set to be fairly heavy. This is especially true in more northern areas of the state. In southern areas, bloom occurred during a time of lower temperatures so fruit set may not be as high. Growers should take into account the temperatures during bloom time and level of bee activity[Read More…]

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We all know that it in the last two weeks, temperatures have warmed up considerably, but when we plot out the growing degree days (GDD), we can see how dramatic this warming trend has been (Figure 1). In Lafayette a couple of weeks ago, we had accumulated less than 100 GDD – now we’re closing in on 300. We’re still considerably later than last year, but tracking similarly to 2013, 2014 and 2015.

rat-tail blooms

In case you blinked, we went from green tip to bloom in about three days, and by the time you read this, we will have passed through the blossom blight period. For most of the state, the late spring consisted of cool, dry weather that was not conducive to blight infection in the northern half of the state. The southern half of the state was only slightly more conducive for infection. This means that any strikes seen in the next few weeks probably came from damage from last year. Since last year was unusually wet, with a lot of susceptible rat-tail blooms, it is most likely that any fire blight infections observed as shoot and canker blight can trace their beginnings to rat-tail blooms of last year (Fig. 1). What to do now? Until a terminal bud has formed and growth has ceased, I do not recommend pruning out strikes[Read More…]


What a difference a couple of weeks of warm weather makes. Crop development is progressing rapidly with warmer weather. Apples in the south are around 10 mm, and in full bloom here in Lafayette. Peaches in southern areas of the state are still in the shuck, but barely. Folks in southern areas are getting ready to apply chemical thinners to apples, and those of us in more northern areas need to be ready to apply thinners soon.

Early spring is a good time to make the first herbicide application of the year. There are several options for fruit crops including both pre- and post-emergent herbicides. See the weed control chapter in the 2018 Midwest Fruit Pest Management Guide for a complete list of products. In most situations, there will be some emerged weeds present in the planting at this time of the year. These could be winter annuals, perennials, or recently germinated summer annuals. A post-emergent herbicide can be used to control those established weeds. A pre-emergent material can be tank mixed at this time to provide residual weed control. However, most pre-emergent herbicides will provide only 6 to 8 weeks of control as they break down in the environment. So, if applied in very early spring, they may not provide sufficient control of summer grasses (foxtail, barnyard grass, goosegrass, crabgrass, etc.). If those are weeds on[Read More…]

Of course, we all hope for a late spring to help avoid the risk of damage from late spring frosts. But when the temperature warms up then turns cold again, it leaves us in a real bind. The warm temperatures push tree development, then we want the warmer conditions for good pollinating weather. When we have open flowers but conditions not favorable for high bee activity (cool or very windy conditions), there is a risk of poor pollination and fruit set. Not only do these cool conditions limit bee activity, they result in poor growth of pollen tubes even if bees do successfully pollinate flowers. Daily temperatures of 60F or above are required for good pollen tube growth, so if there are open flowers and the temperatures have consistently been cooler than 60F, you could be in trouble. There is some evidence that apples tend to set mostly on king[Read More…]

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So far it has been a cool spring, that in the northern half of the state has helped hold back bud development. As we can see from Figure 1, in Lafayette we have only accumulated 25 growing Degree Days (GDD), and most of these were the result of two warm days (54 and 63 F) in late February. Since then we have not accumulated any more GDD, so plants have mostly not begun to show any signs of growth. This has brought the timing of growth back into line with the last few years. Note that since 2010, every year has been earlier than the long-term average (“normal” in Fig. 1).  

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FieldWatch is an easy-to-use, reliable, accurate and secure on-line mapping tool intended to enhance communications that promote awareness and stewardship activities between producers of specialty crops, beekeepers, and pesticide applicators. Originally developed at Purdue University, FieldWatch is now a non-profit company with support from producers, applicators, agricultural chemical companies and other organizations. The program allows specialty crop producers and beekeepers to enter their locations on a secure on-line map. The map is viewed by pesticide applicators so they know what crops are in the area they intend to treat. All you need to do to sign up is visit http://www.fieldwatch.com/ and follow the easy tutorials under the resources tab. Once you have an account, you should be asked to update your FieldWatch (DriftWatch) information each year. If you have not heard from FieldWatch recently, log on to to update your account information. The service is free. You can purchase signs[Read More…]

Chandler plants

Although strawberry plants can be quite cold hardy, they need protection to survive the winter. In North Carolina, growers use floating row covers to protect strawberries in the winter. In Indiana, straw mulch is a more traditional way of winter protection for strawberries grown in a matted row system. After two relatively mild winters in 2015 and 2016, I heard successful stories about growing strawberries with the plasticulture system and using row covers for winter protection in Southern Indiana. Can the system also be successful in a colder winter, like the one that just passed? Our ongoing strawberry study will provide the answer. This article provides an update from this project comparing strawberries covered with straw mulch (about 4-inch thick) and row covers (two layers of 1.5-oz/yard2 row cover laid on wire hoops) this past winter (Figure 1).   Temperature Between Dec. 27 to Jan 6, we had the coldest[Read More…]