Fall Webworms Noticeable In Pecans As Summer Wains

Fall Webworms Noticeable In Pecans As Summer Wains

Fall Webworm beginning to get started on a branch tip. Image credit: Matthew Orwat

Bare limb tips and clusters of webbing in pecan trees are often the first sign that fall is right around the corner.

This webbing is caused by clusters of the larvae of the Fall Webworm (Hyphantria cunea (Drury)) which is often also called Pecan Webworm. “Fall Webworm” is a bit of a misnomer in our region since they are able to strike in spring and summer thanks to our long growing season. They are most noticeable in the fall thanks to cumulative effects of earlier feeding.

The adult form of the fall webworm is a solid white or white and brown spotted moth that emerges in late March through August in southern climates. After mating they lay orderly clusters of green eggs, usually May through August. Soon after emergence, the larvae begin creating silk webs to protect themselves as they voraciously feed on their various host plants, of which Pecan is of primary agricultural importance in this region.

Although they are capable of defoliating complete trees, especially smaller ones, most seasons they are kept in check by beneficial insects such as the paper wasp. It is beneficial for small orchards or home growers to scout their trees from June through August. If small webs are observed in young trees, it is best to prune them out with a pole saw or pole pruner and dispose of the branch. Pruning of small branches does not harm the tree, but it may be of no benefit to remove small webs in larger trees, if they are being controlled by natural enemies.

Active feeding by webworm on pecan branch tip. Image credit: Matthew Orwat

Most large pecan orchards have a routine insecticide program, so fall webworm rarely creates problems. For smaller orchards or homeowners it is difficult to spray for control, due to the cost of the equipment required to get the spray into the tree canopy. If spraying is an option, many insecticides containing spinosad or Bacillus thuringiensis (Bt) exist. Both of these products target caterpillars while not harming beneficial insect predators that feed on these worm populations. Several more toxic insecticide products exist that will control fall webworm, but they often exacerbate insect problems by killing off beneficial insects that might be controlling other insect pests.

Fall webworm is not usually a serious problem for pecan production. Fortunately, when control is warranted, there are plenty of options available.

Supplemental Material:

Insect Management in Pecans

Learn more about the fall webworm’s life cycle at the UF/IFAS Entomology Department’s Featured Creature website.

Perdue University: Fall Webworms

 

Leaves stripped by Fall Webworm. Image Credit: Matthew Orwat

Alternative Rose Options for Florida Nurseries

Alternative Rose Options for Florida Nurseries

Tea Rose, ‘Rosette Delizy’ in the landscape. Photo Credit Matthew Orwat

Today in the nursery trade, when you think of roses, your mind inevitably turns to the ‘Knockout’ rose and its offspring. That’s fine, there’s nothing wrong with Knockoutroses, it makes a great ornamental landscape plant, and it’s easy to propagate.

With all the Knockout’ mania, since the early 2000s, many garden roses, that are well adapted to the Northwest Florida climate, have been left out of both the local and national nursery trade to a large degree.

Several roses, which were grown in Florida commonly in the last hundred years, and recommended by former University of Florida president H. H. Hume in his book “Gardening in the Lower South,” are still grown here today. To obtain these roses gardeners must look to small nurseries scattered throughout central Florida and Alabama, or order them from larger nurseries in Texas where the “Texas A&M Earthkind Rose Program has taken off.

Below are a few examples of easy to grow roses, that are just as disease resistant as the ‘Knockout,’ but offer more variety in color and form that local nurseries might consider for propagation and sale. They have been grown successfully throughout southern Texas for over 30 years, and at the Washington County Extension office for the past seven years without spraying fungicides or insecticides. Several of these cultivars were also involved in a 3-year rose trial at the UF/IFAS North Florida Research and Education Center, in Quincy.

‘Belinda’s Dream’

‘Belinda’s Dream was bred by Texas A&M Professor Robert Basye in 1988, as a culmination of years of intense breeding and selection for disease resistant landscape and cut flower roses. It makes a 4-5 foot shrub that grows about 3 feet wide. Apple-green foliage clothe its pleasing shrub form. It’s free flowering but not overly vigorous, so it’s easy to keep in bounds.  Disease resistance is high, there’s rarely any blackspot of note, under no-spray conditions, and only slight powdery mildew in a few years when conditions are favorable for fungus development.

In cool spring or fall conditions, the clear pink flowers can top six inches in diameter, and contain over 200 petals, but regular hot conditions during the summer usually reduce flower size to four inches. This rose loves to be part of mass plantings, particularly when planted 3 feet apart in a triangular formation. It has a reputation as being moderately easy to propagate.

Individual flower of ‘Belinda’s Dream’ . Photo Credit Matthew Orwat

‘Belinda’s Dream’ rose in the landscape under no-spray conditions. Photo Credit Matthew Orwat

‘Rosette Delizy’

‘Rosette Delizy is a French Tea rose that was introduced to the U.S. nursery trade in the mid-1920s. Since it was bred before the days of modern fungicides, it sports excellent resistance to disease. It shows no powdery mildew, and only the occasional leaf with blackspot under no-spray conditions.

This is strictly a rose for the coastal south, since it does not like cold temperatures, and cannot thrive north of zone 7b without protection.

Color is striking, opening yellow with petal edges changing to pink as the flowers age. Cooler weather brings out deeper russet and maroon tones. It has a light “tea” fragrance. This mannerly shrub gets 4-5 feet tall and 3-4 feet wide. It requires very light pruning, and can actually be killed from heavy handed gardeners with shears in hand. Minor flaws noted in this rose are that it is somewhat sparsely foliated, and somewhat difficult to propagate.

Deeper coloration of ‘Rosette Delizy’ after cool Fall weather. Photo Credit Matthew Orwat

Typical spring display of ‘Rosette Delizy’ Image Credit Matthew Orwat

‘Madame Antoine Mari’

‘Madame Antione Mari’, a Tea rose, was introduced in 1900 when the buttonhole rose was all the rage. Massive quantities of perfectly formed delicate buds of pink and ivory quickly open into 3 inch flowers that decorate the bush like butterflies fluttering in the wind. Re-bloom is fast. Additional interest in the landscape is created by the deep red color of new foliage.

This makes a mannerly shrub for the small landscape, easily kept at 3-4 feet tall, and 5-6 feet wide by light pruning. Disease resistance is above average in a no-spray garden, with very low blackspot infection rates, and only occasional powdery mildew. This rose has been found to be easily propagated with the author reaching near 100% success rate.

Bud and open flower of ‘Madame Antoine Mari’ . Image Credit Matthew Orwat

“Madame Antoine Mari’ 3/4 open. image Credit Matthew Orwat

Mutable color changes as the petals open. Image Credit Matthew Orwat

‘Mrs. B. R. Cant at the NFREC Quincy. Photo Credit Matthew Orwat

 

‘Mrs. B. R. Cant’

No mention of easy to grow roses is complete without the mention of ‘Mrs. B. R. Cant’. In the trials UF/IFAS horticulturists performed at Quincy and Plant City, this variety was rated the best performer. It has been in continuous cultivation since 1901, and is often found at old home sites and gardens in Washington County.

This makes a large garden rose, easily topping 8 feet in height, and just as wide.  Deep pink flowers are borne profusely from March to first frost. Disease resistance is outstanding, and it’s easy to propagate. Plants are densely clothed in medium green leaves. This rose is often grown in hedges as a substitute for a fence. One of the best all-around garden roses for the gulf south.

Nursery Availability

I provide presentations at workshops on these roses multiple times a year, throughout the Florida Panhandle. The recurring question I get is, “Where are these roses available locally?”  Hopefully this article will inspire some local nurseries to offer these easy to grow roses, and others, since these are just a few of the roses available that do very well in North Florida under no spray conditions. If you are interested in propigating these roses for your nursery, contact, Matthew Orwat at UF/IFAS Extension Washington County, for more information on these, and other phenomenal garden roses.

 

When Should You Prune Fruit Trees?

When Should You Prune Fruit Trees?

Every winter season in the Florida Panhandle is different. It can be wet or dry, frigid cold or unseasonably warm. We may have early frosts and early springs, or cold snaps in late march after fruit trees flower.  Because of this variability, it is impossible to predict the perfect time to prune fruit crops in our rather variable region, but there are some tried and true guidelines for pruning the most popular fruit crops in Northwest Florida.

Image Credit Matthew Orwat

Blackberries

Blackberries are unusual in that they do not build a large structure and fruit for years on the same branches (in general). They actually fruit on previous years’ growth which then die after fruit production. The canes that produce fruit are called the floricanes. As the floricanes are producing fruit, the blackberry plants are growing primocanes. These are the new canes that will produce fruit for the next season. By then, these canes will have matured in to floricanes. A few new blackberry cultivars exist that produce fruit on new growth as well, but most Florida adapted cultivars are of the standard type. For pruning purposes, it is best to remove the floricanes just after fruiting, but be sure not to cut the new growth (primocanes) because that wood will bear next year’s fruit. For more information about the blackberry, please see UF/IFAS publication The Blackberry.

Blueberries

Image Credit: Matthew Orwat

With blueberries older canes need to be removed to make room for younger, more productive canes. When a plant reaches four to five years old it is permissible to remove about 1/4–1/5 of the oldest canes each year, which amounts to about one to three of the oldest canes. Performing this task will ensure that no cane is more than three or four years old. Thus, blueberry plantings will be in a constant state of renewal and not become excessively woody and unproductive. To keep plants from becoming too tall, mature plants can be topped in the summer directly after fruit harvest. Removal of a few inches to a foot, depending on the cultivar, will stimulate the new growth that will bear the next year’s fruit. See the UF/IFAS publication, Blueberry Gardener’s Guide for more information.

Temperate Fruit Trees

Dormant Peach Tree. Image Credit UF/IFAS Environmental Horticulture Department

Pruning of temperate fruit trees (Peaches, Apples, Pears, Persimmons) should be done during the winter dormant period in most cases. This period, generally between December and February, allows for some latitude. Pruning later in the dormant season is better in most seasons since trees are more susceptible to freeze damage after pruning, and pruning stimulates the growth of the trees. In Northwest Florida, a February pruning is usually most desirable, depending on the season’s average high temperatures. Pruning for shape is also done in the summer months if necessary. This task should be limited to removing excessive growth and dead / diseased wood. See the following UF/IFAS publications, Training and Pruning Florida Peaches, Nectarines, and Plums and The Apple for more information.

Muscadines

Prolific producing muscadine cultivar ‘Granny Val’ – Image Credit Dr. Peter C. Andersen

Once harvest concludes, it is usually a grower’s natural inclination to immediately prune their muscadine vines. Pruning after harvest in early fall is not, however, best for maintaining plant condition and optimizing next year’s yield, especially if there is an early frost. Early frosts can surprise the plant before sugars have been moved to the roots for storage during dormancy. Therefore, waiting to prune in mid-January to mid-March will ensure the vine has had adequate time to go dormant and acclimate to the winter season. For more information please see the following Panhandle Ag-e News article titled Tips for Properly Pruning Muscadines. 

Citrus

Jackson County citrus grove with branches allowed to near ground level. Image Credit Jose Perez, UF / IFAS

Pruning is not necessary for citrus in every case, as it is in many temperate fruits, to have excellent production quality and quantity. Citrus trees perform excellently with minimal pruning. The only pruning necessary for most citrus is removing crossing or rubbing branches while shaping young trees, removing dead wood, and pruning out suckers from the root-stock. Homeowners may choose to prune citrus trees to keep them small, but this will reduce potential yield in a commercial setting, since bigger trees produce more fruit.

Often, maturing Satsuma trees produce long vertical branches. It is tempting to prune these off, since they make the tree look unbalanced. To maximize yield, commercial Satsuma growers allow these branches to weep with the heavy load of fruit until they touch the ground. This allows increased surface area for the tree, since the low areas around the trunk are not bare. Additionally, weeds are suppressed since the low branches shade out weed growth. The ground under the trees remains bare, thus allowing heat from the soil to radiate up during cold weather events. The extra branches around the trunk offer added protection to the bud union as well. If smaller trees are desired for ease of harvest, ‘flying dragon’ root-stock offers dwarfing benefits, so that the mature scion cultivar size will only grow to 8-10 feet tall.

Figs

Fig Tree with ripening fruit.  Image Credit: Mary Derrick, UF/IFAS.

Figs should be pruned after fruit production, which usually occurs in early summer. In the winter it is fine to remove dead or diseased wood, but drastic trimming will reduce yield, since fruit is borne at the terminals of branches from the previous year’s growth. For more information, please consult this UF/IFAS publication, The Fig.

 

 

Late Winter Citrus Management Considerations

Late Winter Citrus Management Considerations

Both niche market farmers and home gardeners may be uncertain about late winter management of Satsuma trees.  Several questions that have come in to the Extension Office recently include: Should I prune my trees? Why are the leaves yellow? How soon should I fertilize?  The focus of this article is to provide some answers to these common questions.

Should I prune my tree?

Jackson County citrus grove with branches allowed to near ground level. Image Credit Jose Perez, UF / IFAS

This is a complicated question that is best answered with “it depends…”  Pruning is not necessary for citrus, as it is in many temperate fruits, to have excellent production quality and quantity. Citrus trees perform excellently with minimal pruning. The only pruning necessary for most citrus is removing crossing or rubbing branches while shaping young trees, removing dead wood, and pruning out suckers from the root-stock. Homeowners may choose to prune citrus trees to keep them small, but this will reduce potential yield in a commercial setting, since bigger trees produce more fruit.

Often, maturing Satsuma trees produce long vertical branches. It is tempting to prune these off, since they make the tree look unbalanced. To maximize yield, commercial Satsuma growers allow these branches to weep with the heavy load of fruit until they touch the ground. This allows increased surface area for the tree, since the low areas around the trunk are not bare. Additionally, weeds are suppressed since the low branches shade out weed growth. The ground under the trees remains bare, thus allowing heat from the soil to radiate up during cold weather events. The extra branches around the trunk offer added protection to the bud union as well. If smaller trees are desired for ease of harvest, ‘flying dragon’ root-stock offers dwarfing benefits, so that the mature scion cultivar size will only grow to 8-10 feet tall.

Why are the leaves yellow?

Leaf deficiency with heavy fruit load. Image credit Matthew Orwat, UF / IFAS Extension

Heavy fruit loads were produced in many groves throughout Northwest Florida last year. When fruiting is heavy, citrus trees translocate nitrogen and other nutrients from older leaves to newer growth and fruit. Therefore, temporary yellowing may occur and last until trees resume growing in the spring. Remember, never fertilize after early September, since fertilizing this late in the year  can reduce fruit quality and increase potential for cold injury. If a deficiency, as in the photo above persists through spring, consider a soil test, or consult a citrus production publication to determine if additional fertilizer should be added to your fertilizer program.

How soon should you fertilize?

Although most Florida citrus publications recommend fertilizing citrus in February, they don’t take into account the potential for late frost in the Panhandle. Thus it makes more sense to wait until mid-March for the first fertilizer application in this region. Citrus trees don’t require a fertilizer with a high percentage of nitrogen, so it is best for fruit quality if an analysis of around 8-8-8 with micro-nutrients is used. Fertilizer should be applied in the drip-line of the tree, not around the trunk. The drip-line of a mature tree is generally considered to extend one foot from the trunk out to one foot from the edge of the furthest branch tip from the trunk. For fertilizer quantity recommendation see the chart below.

Through awareness of the unique managements techniques inherent to Panhandle citrus production, increased yields, better quality and healthier trees can be achieved.

 

For more information on this topic please use the following link to the UF/IFAS Publication:

Citrus Culture in the Home Landscape

 

Oriental Persimmon: For the Specialty Fruit Market

Oriental Persimmon: For the Specialty Fruit Market

gardeningsolutions.ifas.ufl.edu

Oriental Persimmons Image Credit: (gardeningsolutions.ifas.ufl.edu)

A recent visit to the North Florida Research and Education Center reminded me of the potential of a specialty fruit that is often forgotten about in Northwest Florida, the Oriental persimmon. The Oriental, or Japanese, persimmon (Diospyros kaki) was introduced to the Southern United States in the mid to late 1800s. Although it is native to Japan and China, it is a close relative of the native persimmon Diospyros virginiana.

In the early 20th century the oriental persimmon was a popular fruit crop in Florida, but this industry declined due to marketing factors.  The Oriental persimmon is still a viable fruit for home gardens and specialty markets in north and central Florida, as it generally produces fruits of high quality and sufficient quantity.  Possible markets for the Oriental persimmon include direct farm sales through U-Pick, farmer’s markets, direct sales to restaurants and sales through specialty grocers.

Trees are available grafted onto local native persimmon root-stock, which enhances their ability to perform well in Northwest Florida soils.

Persimmons are divided into two types for the purposes of marketing: astringent and non-astringent. Astringent persimmons contain high concentrations of tannins which cause the mouth to pucker when eating the persimmon, if it is not fully ripe. When fully ripe, they are rich and sweet, but very soft. Non-astringent cultivars can be picked hard and ripened for 7-10 days at room temperature. Non-astringent persimmons were developed in Japan and introduced to the U.S. market in the 1980s. These have become very popular with home gardeners, since they can be eaten when firm, and have a crunchy texture. Persimmons are popular today in Asian cuisine and as a dessert, since they contain sugars at levels between 15 and 25%.

Persimmons have relatively few pests in Northwest Florida when compared to other higher maintenance fruits such as peaches and plums. Fungal leaf spot caused by species of cercospora, alternaria and anthracnose can cause premature defoliation. Fungicidal sprays are useful in controlling these diseases, if they are at high enough levels to cause tree injury. The stem and branch fungus Botrysphaeria dothidia will cause deep, elongated branch lesions similar to canker. These openings invite borers into the tree and can lead to loss of the limb structure. The best defense against this problem is a good offense; a healthy tree will be less likely to be attacked by this fungus. Dormant sprays of copper or sulfur based fungicides can also help reduce the incidence of all fungal diseases.

Fully ripe persimmon, ready for a scoop of ice cream !

Fully ripe persimmon, ready for a scoop of ice cream! (Image Credit Matthew Orwat)

The major insect pest of persimmon is scale. Thankfully, scale can be controlled with dormant oil or season all horticultural oil. Persimmon psylla can cause leaf deformation early in the season, but is not always a large enough problem to warrant control. Natural enemies often eliminate the need for chemical control. If control is necessary, several insecticides labeled for fruit trees will take care of the problem.  Twig girdlers can lay eggs on persimmon stems in September and October, and once hatched, the insect can girdle the stem and the stem will die. To control this pest it is important to remove dead and infected wood each growing season.

Out of the non-astringent cultivars, Fuyu regularly rates as the most popular and reliable cultivar. It does require thinning, since it often sets too much fruit, which can cause branches to bend and break. A good practice is to thin out 50% of the fruit during years in which fruit set is heavy.

Below is a chart of different non-astringent persimmon cultivar characteristics from the UF/IFAS Extension publication Oriental Persimmons in Florida, from April 1994 by E.P. Miller, Biologist; T.E. Crocker, Professor, Horticultural Sciences Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.

Characteristics of non-astringent cultivars. SP 101, from April 1994 by E.P. Miller; T.E. Crocker,

Characteristics of non-astringent cultivars. SP 101, from April 1994 by E.P. Miller; T.E. Crocker,


For further information please consult the following publications

ENH 388: Diospyros kaki: Japanese Persimmon

Oriental Persimmon Varieties for North Florida (previous Panhandle Agriculture article)