KNLA Summer Event
July 18 & 19
John C. Pair Horticultural Research Center, Haysville
For more information, contact [email protected]
Turf & Ornamentals Field Day
Thursday, August 1
K-State Research & Extension Center, Olathe
The K-State Turf and Ornamentals Field Day will be held Thursday, August 1 at the Research & Extension Center in Olathe (35230 W. 135th). The field day program is designed for all segments of the turf industry – lawn care, athletic fields, golf courses, and grounds maintenance. Included on the program are research presentations, problem diagnosis, commercial exhibitors, and equipment displays. There will be time to see current research, talk to the experts and get answers to your questions.
1 hour of pesticide recertification credit is available in both 3A and 3B, as well as GCSAA education points. For more information and to register, go to: https://2019turfday.eventbrite.com
Daylily Leaf Streak
Daylilies are a great fit for Kansas. There are many varieties that grow well here. I particularly like browsing the photo gallery at the Flint Hills Daylily Society chapter (https://www.flinthillsdaylily.org/gallery) for my favorite ones. They are mostly problem free but I did recently see some daylily streak (Aureobasidium microstictum) on a recent walk. It isn’t that common in Kansas, but wet conditions this spring likely the triggered the disease.
Daylily leaf streak starts as long yellow streaks that turn a reddish brown. Heavily infected leaves scorch back and die early.
The disease is favored by moderate temperatures and wet conditions. Daylily streak can spread by splashing water droplets. Although you can’t manage the rain, you can time irrigation so that your plants are watered in the morning. This allows leaves to dry out quickly and reduce conditions that favor disease development. A mature daylily planting can be crowded leading to poor air circulation and prolonged periods of leaf wetness. Good plant spacing will improve air flow and help to dry out plants quickly. The disease can also be moved on tools, so avoid working around wet plants
Inspect plants when purchasing them and always start with healthy, disease-free plants (ie no spots on the leaves). If just one plant in the landscape is showing symptoms, you might be able to stay ahead of the disease by picking off and dispose infected leaves. Daylily leaf streak will overwinter in the leaf litter, so cleaning up the flower bed will help to reduce the amount of disease that is carried over to the next growing season. If daylily leaf streak shows up annually, it might be worth isolating the problem daylily from the rest of the planting.
The best strategy for managing day lily leaf streak…is through the use of resistant cultivars. Disease susceptibility varies and lists of resistant varieties are not easily available. A few varieties reported by Clemson University are: Betty Bennet, Edna Spalding, Ella Pettigrew, Globe Trotter, Nancy Hicks, Pink Superior, Ron Rousseau, Sudie, Tropical Tones, Upper Room, and Winsome Lady. (https://hgic.clemson.edu/factsheet/daylily-diseases-insect-pests/) (Judy O’Mara)
How to Pick a Ripe Melon
Telling when a melon is ready to be harvested can be a challenge, or it may be quite easy. It all depends on the type of melon. Let’s start with the easy one. Muskmelons are one of those crops that tell you when they are ready to be picked. This can be of help to not only harvest melons at the correct time but also choose good melons when shopping. As a melon ripens, a layer of cells around the stem softens so the melon detaches easily from the vine. This is called “slipping” and will leave a dish-shaped scar at the point of stem attachment. When harvesting melons, put a little pressure where the vine attaches to the fruit. If ripe, it will release or “slip.”
When choosing a melon from those that have already been harvested, look for a clean, dish-shaped scar. Also, ripe melons have a pleasant, musky aroma if the melons are at room temperature (not refrigerated).
Watermelons can be more difficult and growers often use several techniques to tell when to harvest.
1. Look for the tendril that attaches at the same point as the melon to dry and turn brown. On some varieties this will need to be completely dried before the watermelon is ripe. On others it will only need to be in the process of turning brown.
2. The surface of a ripening melon develops a surface roughness (sometimes called “sugar bumps”) near the base of the fruit.
3. Ripe watermelons normally develop a yellow color on the “ground spot” when ripe. This is the area of the melon that contacts the ground.
Honeydew melons are the most difficult to tell when they are ripe because they do not “slip” like muskmelons. Actually, there is one variety that does slip called Earlidew, but it is the exception to the rule. Ripe honeydew melons become soft on the flower end of the fruit. The “flower end” is the end opposite where the stem attaches. Also, honeydews should change to a light or yellowish color when ripe, but this varies with variety. (Ward Upham)
Tomatoes often have problems with cracking caused by pressure inside the fruit that is more than the skin can handle. Cracks are usually on the upper part of the fruit and can be concentric (in concentric circles around the stem) or radial (radiating downward from the stem). We don’t know everything about cracking but here is what we do know.
Tomatoes have a root system that is very dense and fibrous and is quite efficient in picking up water. Unfortunately, the root system can become unbalanced with the top of the plant. Early in the season it may be small in relation to the top growth resulting in blossom-end rot when the weather turns hot and dry. Later it may be so efficient that it provides too much water when we get rain or irrigate heavily after a dry spell. This quick influx of water can cause the tomato fruit to crack. Therefore, even, consistent watering can help with cracking. Mulching will also help because it moderates moisture levels in the soil. However, you can do everything right and still have problems with cracking in some years.
We have evaluated varieties for cracking during our tomato trials at K-State. It takes several years worth of data to get a good feel for crack-resistant varieties but we have found some real differences. Some varieties crack under about any condition and others are much more resistant. The difference seems to be pliability of skin rather than thickness — the more pliable the skin the more resistance to cracking.
The old variety Jet Star has been the most crack resistant of any we have tested including the newer types. Unfortunately, Jet Star is an indeterminate variety that puts out rampant growth.
Newer varieties with more controlled growth are often more attractive to gardeners. Mountain Spring, Mountain Pride, Mountain Fresh, Floralina and Sun Leaper are smaller-vined types that have shown good resistance to cracking. (Ward Upham)
Tan or White Drupelets on Blackberry and Raspberry Fruit
Blackberry and raspberry fruit will often develop white or tan drupelets on the berry. Though we are not completely sure of the cause in all cases, two commonly given reasons are stinkbug damage and sunscald. Damage has been attributed to stinkbugs if the pattern of off color (not white) drupelets is random. Stinkbug damage is caused by the insect feeding on the blackberry receptacle and injuring drupelets on either side. Damaged drupelets are often scattered. Sunscald damage will be on the side of the fruit exposed to the sun and has several to many drupelets in an area being affected.
Neither condition affects the eating quality of the fruit unless the stink bug releases the “stink” with which it is associated rendering the fruit inedible. By the time damage is seen, it is too late for control. (Ward Upham)
If you have grown grapes before, you have likely discovered that birds like grapes as much as you do. There are two methods homeowners can use to protect the fruit. The first is bagging where a paper bag is placed over the cluster and secured with a twist tie or staple. The bag can be left until it is time for harvest as flavor and color are determined by sunlight hitting the leaves rather than the cluster.
The second method is to net the crop. The most common and least expensive netting is the lightweight, black, polypropylene type with a square mesh size of ½” x ½”. This can be difficult to install and remove as it tends to stick to itself and to the vines. However, it is effective. Woven mesh bird netting is also effective and easier to work with but is more expensive.
If your trellis has a wire at six feet high, purchase a net that is at least 14 feet wide so that it can be draped over the grapes and secured along the bottom edge with clothes pins. Nets that are 17 feet wide are less common but give more material to work with and are therefore easier to secure. (Ward Upham)
Most spider mites like summer weather. Look for stippling on the upper surface of the leaves as well as some fine webbing on the underside of the leaves. These tiny arthropods (they are not true insects) are often difficult to see due to their size and their habit of feeding on the underside of leaves. If mites are suspected, hold a sheet of white paper beneath a leaf and tap the leaf. Mites will be dislodged and can be seen as tiny specks on the paper that move about.
Spider mite control can be challenging. A strong jet of water can be used to remove the mites but may not be as easy as it sounds. A high-pressure directed spray is needed to dislodge the mites. Since spider mites feed on the underside of the leaves, the spray is most effective if it comes from below. This can be difficult to accomplish with a thumb over the end of the hose.
Some gardeners use a water wand hooked to a shut-off valve. The water breaker is then replaced by a brass nozzle. Specialized spray wands can also be used. For example, Mite-Y-Fine (miteyfine.com) has a wand that makes spraying the underside of leaves easy. Spraying once will not be enough. It is recommended to use 3 sprays spaced 3 to 4 days apart.
Horticultural oils and insecticidal soaps (Safers, for example) can also be helpful. Spray early in the morning when temperatures are cooler and plants have rehydrated. Resprays will likely be needed. (Ward Upham)
Green June Beetle
These large beetles feed on sweet corn, blackberries, and peaches. They look much like the common May beetle, or June bug, but have a dull, velvety green color. The underside is more of an iridescent green. These beetles have poor navigational skills and seem to fly until they hit something. They also make a buzzing sound somewhat like a bumblebee. Unfortunately, they are also about the size of a bumblebee and so cause concern for many gardeners even though they cannot harm people. As noted above, they may damage crops.
A number of general-use insecticides, including acetamiprid (Ortho Flower, Fruit & Vegetable Insect Killer), carbaryl (Sevin) and malathion, may be used to discourage feeding. See table below for what can be used and the number of days between application and harvest.
Insecticide Peaches Blackberries, raspberries Sweet Corn
Carbaryl 3* 7 2
Malathion 7 1 ——–
Acetamiprid 7 1 ——-
* Days to harvest
Sevin has a two-day waiting period between spraying and harvest on sweet corn and a three-day waiting period on peaches. There is a seven-day waiting period for Sevin on blackberries, so malathion, with a one-day waiting period, may be a better choice. Acetamiprid has a 7 day waiting period on peaches and a 1 day waiting period on blackberries and raspberries. (Ward Upham)
Contriubtors: Judy O’Mara, Instructor, Plant Pathology; Ward Upham, Extension Associate
(K-State Research and Extension)