Insect of the Week

Hey insect fans! This week we’ll be talking about the Spotted Cucumber Beetle (Diabrotica undecimpunctata), a pest of cucurbit crops that made its first appearance in the gardens this past week. (pictured below – our apologies for the small picture, this guy was FAST)

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The Spotted Cucumber Beetle is a coleopteran pest of cucurbit crops, feeding on plants in this group during both the larval and adult stages of its life cycle. As a larvae, this insect feeds on roots and shoots of growing cucurbits. As an adult, it feeds on leaves, flowers, and fruit.

The primary damage caused by this insect is not its consumption of plant material, however. Cucumber beetles carry bacteria that cause vascular wilt, and transfer them to cucurbit crops through feeding damage and fecal contamination. Vascular wilt, once established in the plant, cannot be cured and quickly causes the infected plant to wilt and die. This bacterial disease plugs up vascular tissue inside plants, blocking the flow of water and nutrients. This  blockage is what causes the initial “wilty” appearance, and is ultimately the cause of death in the plant.

Because of the severity of the problem caused by vascular wilt, it is important to scout frequently for Spotted Cucumber Beetle if you are growing cucurbit crops. If you see wilted sections of vine, it is also wise to make sure that vascular wilt is to blame for the problem. To test for vascular wilt, slice the stem of the affected plant and hold the two ends together for a few seconds. After holding the two halves together, pull them slowly apart and look for a milky, viscous sap stretching between the two ends. If this  milky sap is present, the plant has vascular wilt.

Many chemical and cultural controls are available for the control of Spotted Cucumber Beetle, but they are very diverse and highly dependent on the situation. For this reason, we’re including the link to the UW Extension page on the cucumber beetle so that you can find more detailed information if needed. Here’s the hyperlink: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDAQFjAB&url=http%3A%2F%2Fadams.uwex.edu%2Ffiles%2F2013%2F05%2FCucumber-Beetles.pdf&ei=wlboUfOrKcO1rgGdr4DwCQ&usg=AFQjCNExHH0uA0QZlChftDBntDcdqZuORg&bvm=bv.49478099,d.aWM

Thanks much for reading! Tune in again next week!

-Dave Schreiner, WMARS Intern

Garden Expo/Wisconsin Grape Growers Association – Table Grape and Pruning Program

Dormant season pruning, summer vine management and trellising, and summer pruning are three of the most important techniques a grower needs to master if he or she is to grow healthy and productive grapes.

09Sept1SomersetPortions of the presentation below were presented at the Wisconsin Commercial Fruit and Vegetable Conference and modified for the Wisconsin Garden Expo program.

The second presentation is the first section of the Wisconsin Garden Expo program and focuses on Seedless Table Grape production at the UW-Madison, West Madison Ag. Research Station.

garden Expo.Beginning Pruning 6

Garden Expo Seedless Table Grapes 7

Seedless Table Grape Report

09Sept1Trollhaugen1

Trollhaugen Seedless Table Grape

The seedless table grape trial at the station, in the garden, began in 2007.  Fifteen varieties were planted in early June.  We were all optimistic and had great hopes that at least four or five of the varieties would over-winter and produce a great crop of seedless table grapes.  The hardiness zones for the grape varieties ranged from Zone 6 to Zone 4.   Only one selection was rated at Zone 4.  Most fell in the range of 5a or 5b.

09Sept1Somerset

Sommerset Seedless Table Grapes

Now five years later, we know that 12 of those original 15 varieties have over-wintered, and produced abundant fruit that ripens in our climate, and each has a unique and unusual taste.

Our annual seedless table grape report for 2012 has a detailed account of the varieties that have over-wintered, and a description of each variety.   Please check the link below for the annual report.

seedless-table-grapes-for-wisconsin-2012a.pdf

Vanessa Seedless Table Grapes

Vanessa Seedless Table Grapes

Food Bank Harvests

Food Bank Donation – Sept 2012

Each year we conduct trials and research on various fruits and vegetables. After data and seasonal evaluations are completed we donate our produce to local food banks. This year we gave our produce to two local pantries Middleton Outreach Ministry and the Lussier Center-Food from Friends program. In total we gave over 3000lbs of produce over a 5 week period. We are proud to work with volunteers and the organizations to provide the community with healthy food.

Agriculture 101-Wisconsin Army National Guard

Soldiers receive instruction on growing root crops from garden manager Brian Emerson

On July 26 soldiers from the Wisconsin Army National Guard received training at the University Display Gardens. The instruction focused on growing techniques for grapes, apples, and vegetable crops. The training was part of a week long series ‘Agriculture 101’ that was coordinated by the UW Babcock institute. The soldiers were given an overview of many agricultural topics to help prepare them for their service dealing with civilian farmers abroad.

Insects in the Garden

STRIPED CUCUMBER BEETLE and WESTERN CORN ROOTWORM ADULTS

The heat of the year is starting to drive some populations of insects. We are starting to see increased populations of japanese beetles and large numbers of cucumber beetles http://learningstore.uwex.edu/Cucumber-Beetles-P557.aspx  and western corn rootworm adults http://hort.uwex.edu/articles/corn-rootworms.  The beetles are severely attacking the blooms and even the vegetative growth of the vine crops.

The cucumber beetle can be devastating in particular. Besides destroying blossoms they also transmit bacterial wilt(http://hort.uwex.edu/articles/vine-crops-disorder-bacterial-wilt-0), which will ultimately lead to the death of infected plants. In our garden we have not seen the numbers like we have this year. Especially this early in the season. Because we manage our vegetables organically we have sprayed for the beetle using a certified organic compound Pyganic. This pesticide effectively knocks down the population. It does not have a long-term persistence in the environment.

Irrigation

Full scale irrigation on 6/25/12

The dry weather that started last summer has continued through the winter and spring and now into the summer of 2012. Since April 1 we have received only 6.25in of rain. The lack of rain in combination with the high temperatures and strong winds last few weeks has put some of the plants under stress.

At the University Display Gardens we are lucky to have access to irrigation. Our water is from a onsite well. Near the top of the gardens we have connections to a water line. To this we connect a series of 30 ft aluminum pipes, each with an elevated sprinkler head. We connect enough pipes to reach desired beds.

We try to maintain an equivalent of 1.5inches of rain each 7-10 days. With our irrigation system in place this takes approximately 1.5 hrs for each run. We then have to move the pipes to the next rows. All together irrigation is an all day affair. It takes a lot of work. So in essence we are always hoping for rain. There is no substitute for rainwater to make plants grow.

Seedless Table Grape Trial

In 2007 we planted 15 varieties of seedless table grapes at the West Madison Research Station in the University Display Garden fruit plots. We will be releasing the full results of our trial in early January.

Below you will find our short list of favorites and a little description.

Somerset Seedless Table Grapes

Somerset Seedless

One of our favorite reds at this point is Somerset Seedless.  It has overwintered very well, and produces abundant fruit.   The berries are small but have a very complex taste.

Canadice - Red Seedless Table Grape

Canadice

Canadice is also one of our favorite reds.  The fruit is beautiful on the vine and extremely complex.  In taste testing this was everyone’s favorite red.  We are still waiting to see how it will grow in 2011.  There was some early bud damage in 2010 due to a May frost and early-April warm temperatures that resulted in our grape vines breaking bud early in mid-April.

Trollhaugen - Blue Seedless Table Grape

Trollhaugen

One of our favorite blues is Trollhaugen.  It has nice large clusters, the fruit is very spicy and more complex than the old Concord Seedless.   It has overwintered well all 4 winters.

White grapes are still a challenge in Wisconsin.  Our favorites are Interlaken, Lakemont, and Marquis.

Interlaken - White Seedless Table Grape

Interlaken

In 2009 they each overwintered well and produced abundant fruit. Many of  fruiting buds were lost during the spring of 2010 due to early bud break.  However, their fruit is a beautiful green/white with blushes of rose, and we feel worth the wait to see what another year brings.  The taste of each is so spicy and sweet that we have been known to eat five or six clusters in a taste testing session……   We will have more information on these after the 2011 growing season.

Squash Vine Borer-Update

About a month ago we discussed the arrival of the squash vine borer and our control methods. Since that time we have had incredible growth on the plants and have continued to watch for the adult moths. Since the first large influx of moths in June, we have seen a smaller second flight of the moths during the second week of July. Late last week we began to see the tell tale wilting of some vines. During the heat of the day we would see the wilt, then at night and in the morning the vine seemingly recovered. This signaled that the eggs of the moth had hatched and the larvae had burrowed into the base of the vine.  Thus compromising water uptake and subsequently fruit formation.

Total infestation rate on our squash and pumpkins is probably about 5-10%. It is interesting to note that certain varieties are affected more than others. This year ‘Triamble’, ‘Blue Magic’, and ‘Guatemalan Blue Banana’ were the prefered cultivars. All are Cucubrita maxima and all are blue fruited. Not sure if this is a coincidence, but surely something to observe in upcoming seasons.

We have tried to save the wilting vines by slicing open the base and removing the larvae.Squash Vine Borer dxtraction After the base is slit you can remove larvae with a paper clip or knife. Some of our vines contained 10 or more larvae of different sizes. After extraction we mounded soil over the base and rooting nodes furtherSquash Vine Borer larvae down the vine. The hope is to encourage secondary rooting along the vine which will supplement the compromised vascular system at the base of the plant. So far the plants seem to be recovering we will see if our efforts are enough to mature the fruits that have already set on the vine.

For more info on the squash vine borer visit http://wihort.uwex.edu/gardenfacts./XHT1136.pdf

Time to Heel the Leeks…………….

It may be time to heel the leeks again.   We have now heeled our leeks for the fourth time.   We planted the leeks in a deep trench and then began to fill the trench with soil as the leeks grew.

The last “heeling” was completed on July 27.   We mounded the soil over the shafts of the leeks to ensure that we will  have nice long, white shafts when they are harvested later in the fall.

Leeks are in the same family with onions and are truly a great vegetable to add to soups, saute and serve with other herbs and a Leek tart is terrific.