Plant Science Day


Field Plots on Display During Plant Science Day
Wednesday, August 5, 1998

Click on Title to see abstract

1 Chinese Chestnut Trees

2 Sheet Composting with Oak and Maple Leaves

3 Supersweet Corn Trials

4 Control of Tipburn on Romaine Lettuce with Leaf Compost Amendments and Leaf Mulch

5 Okra Trials

6 The "Deer" Tick Ixodes scapularis

7 Key Diagnostic Protein for Human Ehrlichiosis Identified

8 Lyme Disease in Ticks from Connecticut Citizens

9 Nutrition of Hydroponic Lettuce

10 American Chestnut Trees

11 Foreign Predators of Hemlock Woolly Adelgid

12 Spread of Apple Scab by Secondary Infections

13 Disease Resistant Apple Trial

14 Growth Retardant on Rhododendron

15 Management of Fungicide Resistance and Anthracnose Leaf Spot in Euonymus

16 Dried Biosolids as Fertilizer for Turf

17 Biosolids Compost in Container Media for Ornamental Plants

18 Wine Grape Trials

19 Manganese and Salt to Control Fusarium of Asparagus

20 Composting Leaves Using the Static Pile Method

21 Question and Answer Tent

22 Potential New Apple Pests

23 Control of Botrytis Fruit Rot in Red Raspberry

24 Fiber Flax Nursery

25 New Hybrid Chestnut Orchard

26 Control of Blight on American Chestnuts

27 Crop Rotation as a Biocontrol for Verticillium Wilt of Tomato, Potato, and Eggplant

28 Hop Trial

29 Fungicides to Control Tomato Powdery Mildew

30 Effect of Pruning on Severity of Tomato Powdery Mildew

31 Seasonal Development and Dispersal of the Apple Scab Fungus

32 Experiment Station Associates

33 The Coverts Project and Connecticut’s Forest Stewardship Program

34 Agricultural Applications in Molecular Biology

35 Microbial Control of Mosquitoes

36 Potential for Biological Control of Black Vine Weevil

37 Connecticut Weeds and Wild Plants

38 Bell Atlantic Telephone Transmission Silo

39 Use of Cultivar Resistance and Baking Soda to Manage Powdery Mildew of Pumpkin

40 Effect of NaCl on Rhizoctonia Crown Rot of Table Beets

41 Fertilizer Types and Rates to Control Verticillium in Eggplant and Tomato

42 Biological Control of Mexican Bean Beetle

43 Minimum Fertilization for Home Gardens Amended by Leafmold

44 Chestnut Species and Hybrids

45 Nursery and Bee Inspections

46 Gypsy Moth Fungus Resting Spore Persistence: Implications for Control

47 Nurserymen’s Garden

48 Butterfly and Bird Garden

49 Connecticut Native Woody Shrubs

50 Factors Affecting the Availability to Bacteria of Toxic Chemicals in Soil

51 Effect of Biological Fungicides on Rhizoctonia Crown Rot of Impatiens.

52 Winter Squash Trials

53 Medicinal Herb Variety Trial

54 Conventional or Organic Fertilizer for Salad Greens

55 Asparagus Nursery

56 Susceptibility of Tomato Cultivars to Powdery Mildew

57 Novel Fungicides to Control Mildew of Flowering Plants

58 Curiosity Garden

59 Utilization of Compost and Cover Crops in Corn Production

60 Rocky Hill American Chestnut Trees

61 Orchard Chestnuts

62 Corn Genetics

63 Seedling Chestnut Trees in a Tree-Tube Trial

64 Apple Variety Trial

65 NE-183 Apple Variety Trial

66 Dwarf hybrid chestnut trees

67 Dense Planting of American Chestnuts

S. Anagnostakis
These Chinese chestnut trees, planted by Donald Jones in 1941, were selected by chestnut grower W.C. Deming of Litchfield and grafted by the Hartford Park Department. The second tree from the gate is a graft of the cultivar ‘Bartlett’ that was developed by the Bartlett Tree Co. in Stamford. All have been used by us and by the American Chestnut Foundation in crosses with American chestnut trees to produce blight resistant forest and orchard trees.

A. Maynard
Many homeowners have a predominance of oak trees in their backyards. Oak leaves are known to be more resistant to decomposition than maple leaves. This experiment is investigating whether this difference in the rate of decomposition leads to decreased yields in soils amended with oak leaves compared to maple leaves and unamended controls. Undecomposed oak and maple leaves were layered about 6 inches thick in the falls of 1995, 1996, and 1997 and incorporated into the soil by rototilling. Yields from plots amended with oak leaves were compared to plots amended with maple leaves and the unamended controls. Last year, plots amended with either oak or maple leaves had the greatest lettuce yields (1.5 lbs/plant) compared to the unamended controls (1.3 lbs/plant). Plots amended with maple leaves and the unamended controls had the greatest eggplant yields (13 lbs/plant) compared to plots amended with oak leaves (12 lbs/plant). There were no differences in the yield of peppers between the treatments with an average yield of 6 lbs/plant. The experiment will be continued to see whether there are any cumulative effects.

D. Hill
More acres of sweet corn are harvested in Connecticut than any other vegetable. The New England Agricultural Statistics Service estimated that 4500 acres were harvested in Connecticut in 1997. The 1996 crop was valued at 7.9 million dollars or 42% of the cash value of all vegetables produced in the state. In 1995-1997, we tested six cultivars each of bicolor, yellow, and white supersweet varieties that contained up to 32% sugar and maintained sweetness up to 10 days compared to 2-3 days with normal sweet corn. Supersweet corn requires soil temperatures above 60-65 F to germinate and isolation from other corn types to prevent cross pollination. "New breed" types of supersweet corn have recently been developed which combine the traits of normal sugary types, sugar enhanced types, and supersweet types into one ear. These new hybrids can be planted in cooler soil (50-55 F) and are more suited to early plantings. They do not require isolation and the sugar content is about 28%. We are testing bicolor, yellow, and white cultivars for earliest planting dates, yield, and keeping quality of harvested ears. In April 22-23 plantings at Windsor and Mt. Carmel, the "new breed" types had germination rates averaging 89% under clear plastic or Remay compared to 67% in supersweet cultivars.

D. Hill and A. Maynard
Tipburn in lettuce is a browning of leaf margins in rapidly growing inner leaves. During times of moisture stress, the supply of calcium, a slowly translocated mineral, cannot keep pace with leaf growth. Calcium impoverished cell tissue collapses and turns brown and renders the head unmarketable. In this experiment, we are lessening moisture stress with pre-plant applications of leaf compost to improve the moisture holding capacity of the soil and/or by mulch to lessen evaporation or water from the soil surface. The two cultivars grown, Kalura and Plato, were highly susceptible to tipburn in cultivar trials in 1996. Three plantings are scheduled for harvest in late June through late August, when tipburn is most prevalent as the crops near maturity. In the first crop harvested in late June-early July, no tipburn was observed in either cultivar as the crops never became moisture stressed because of the extremely wet growing season.

D. Hill
A survey by the Connecticut Department of Agriculture of clientele who purchase native-grown produce at the 53 farmers markets and the 150 growers that supply these markets identified okra, sweet potatoes and leeks as the most popular of specialty vegetables. Okra, a traditional southern vegetable, can be grown in the Northeast with relative ease by proper selection of cultivars with short maturities and use of transplants. Okra is a popular vegetable grown for use in soups, stews, and gumbos. In this trial we are testing the yield and quality of seven cultivars of okra grown from transplants.

6. THE "DEER" TICK Ixodes scapularis
K. Stafford Assisted by M. Burelle, C. Mustante, M. Harma, R. Ferrucci, and J. Scace
The blacklegged tick ("deer" tick) transmits the agents of Lyme disease, human babesiosis and human granulocytic ehrlichiosis. Tick abundance was high in 1998 and a record number of Lyme disease cases are expected this year. Learn to recognize the tick and prevent tick bites. Live ticks may be viewed under the microscope.

L. Magnarelli and J. Ijdo (Yale University)
Assisted by T. Blevins
Human and horse sera were analyzed for antibodies to granulocytic ehrlichiae, tick-transmitted bacteria that cause human and equine granulocytic ehrlichiosis. A major surface protein of the infectious agent, called the HGE-44 antigen, was found to be frequently recognized, immunologically, by patients having low white blood cell and platelet counts. Studies revealed that the HGE-44 antigen is highly sensitive and specific and, thus, is an excellent diagnostic marker for this disease. The use of this antigen is currently being evaluated in automated diagnostic tests that are more cost-effective than methods previously applied.

J. Anderson Assisted by B. Hamid, M. Vasil, and B. Parker
Ticks which have fed on humans are tested for the presence of Lyme disease at the request of municipal health departments. In 1997, 2,639 Ixodes scapularis ticks were tested. Of these, 20% were infected with the Lyme disease spirochete. Two-thirds of the ticks tested in 1997 were submitted by Fairfield County residents. There were 2,297 cases of Lyme disease reported in Connecticut in 1997, 20% of which were reported from Fairfield County. In 1998, more than 2,400 ticks have been tested so far, with an infection rate of 25%.

M. Gent Assisted by M. Short.
Hydroponic lettuce grown in winter can accumulate a high concentration of nitrate in leaves. Altering the composition of the nutrient solution may alleviate this problem. Lettuce was grown in a standard nutrient solution or in a solution with one third less nitrate. To observe how environment affects growth and composition, plantings were done in spring, summer, fall, and winter over two years, and in shaded and unshaded greenhouses. Feeding a standard nutrient solution in winter under low light resulted in high concentrations of nitrate, both in solution and in leaf tissue, but the nitrate concentrations were not high in spring or summer under high light. Feeding a solution with one third less nitrate lowered the solution and tissue concentrations of nitrate in winter without slowing growth, but in spring and summer, the lettuce grew more slowly than in the standard solution.

S. Anagnostakis Assisted by P. Sletten
These American chestnut trees are seedlings from Rocky Hill planted in 1988. They were first used in a study of the effect of shade on growth. Now we have pruned them heavily, and are placing various mushrooms around the roots to find out if any can grow with the tree roots and improve growth of the trees. Many have been inoculated with the blight fungus.

M. McClure and C. Cheah Assisted by R. Ballinger, B. Beebe, H. Kent, and M. Klepacki
Two ladybird beetles imported from Asia are killing the hemlock woolly adelgid, Adelges tsugae Annand, in the eastern United States. One is Pseudoscymnus tsugae Sasaji and McClure, a tiny black beetle which resembles a poppy seed. This previously unknown beetle was discovered in Japan by Dr. Mark McClure in 1992. Since then, we have reared more than 60,000 of them at the Station’s Valley Laboratory in Windsor and released them into eight adelgid-infested hemlock forests in Connecticut, one in New Jersey, and two in Virginia. P. tsugae only feeds on adelgids and possesses many other attributes of a successful biological control agent. It has overwintered for three consecutive years, reproduced and spread in the forest, and reduced adelgid densities by 47-88% in only five months. A second ladybird beetle, Harmonia axyridis Pallas, is a much larger beetle, about the size of a small pea, and mainly orange in color with black spots. Although this beetle has the annoying behavior of aggregating on the surface of light colored buildings in fall, it undoubtedly eats huge numbers of aphids and, therefore, is a great benefit to farmers and gardeners. Even though adelgids are not the preferred host of H. axyridis, it kills a significant number of A. tsugae, especially during spring in heavily infested hemlock stands.

D. Aylor Assisted by P. Thiel, J. Severino, and K. Perham
Apple scab, caused by the fungus Venturia inaequalis, is the most serious disease of apple in Connecticut. The pathogen attacks apple trees in two waves: 1) early spring infections by ascospores released from overwintering leaves on the ground are followed by 2) repeated cycles of infection by several generations of "summer" spores produced on the current crop of leaves and fruit. Potted apple trees, scattered throughout this orchard, were placed at various distances from scab-susceptible varieties to study the spread of the summer spores. Knowing the rate and extent of secondary spread of scab will help us to evaluate control options when primary control fails.

13. Disease Resistant Apple Trial
R. Kiyomoto Assisted by M. Previs and J. Bravo
Disease resistant apples are being tested for horticultural attributes, yield, and the durability of resistance. The disease resistant apples in this plot are being compared with the familiar cultivars McIntosh and Empire. The best disease resistant cultivars which are available from nurseries are Liberty, a midseason apple, and Redfree, one of the best early season apples. A very promising experimental disease resistant apple is NY75414-1, which is also in the NE-183 Trial. Resistance to scab has been overcome in one experimental variety, NY74828-12, which has only one gene for resistance to scab and is no longer a candidate for commercial potential.

M. Gent Assisted by M. Short.
Growth retardant is applied to improve the shape and flowering of rhododendron, but it can inhibit stem elongation for several years after application. In collaboration with Imperial Nurseries of Granby, we are testing the growth retardant chemical BONZITM applied to rhododendron at various stages during propagation. The chemical was applied in February, just after rooting the cuttings, in May after the first flush of growth, or in July after the second flush of growth. Four cultivars were treated with six concentrations of growth retardant. Stem elongation and branching are measured after each flush of growth this year and will be measured again next year. This study will determine how the time of application and concentration of growth retardant affect these cultivars of rhododendron

J. LaMondia Assisted by J. Canepa-Morrison and R. Ballanger
Management of anthracnose leaf spot of euonymus (Euonymus fortunei ‘Emerald & Gold’ or ‘Frosty’) caused by Colletotrichum gloeosporioides was examined. We determined by laboratory testing that resistance to a number of fungicides was common in the pathogen isolates infecting these plants. Registered fungicides applied sequentially or in mixtures were applied to foliage each week for 12 weeks at label rates. Controls did not receive fungicides. Percent defoliation was lowest for mixtures of fungicides (two active ingredients per application) (9%) and highest for plants which did not receive fungicides (35%) and thiopahanate-methyl (Domain) alone (38%). The average number of lesions per 100 leaves was lower for mixed (0.7/leaf) and sequential (1.5/leaf) fungicide treatments than for plants which did not receive fungicides (5.0) or Domain alone (3.4/leaf). Emerald & Gold had more lesions than Frosty. Fungicide-resistant isolates were recovered on media amended with fungicides (1000 ppm) and were in lowest frequency from plants treated with mixed fungicides (14-35%) compared to other treatments (39-87%). Management of leaf spot and fungicide resistance in C. gloeosporioides may be achieved by fungicide mixtures.

G. Bugbee Assisted by F. Fiondella
Biosolids (sewage sludge) from several municipalities in Connecticut is being dried at a regional facility in Waterbury. The dried biosolids is being evaluated for its effectiveness as fertilizer for turf. It is being compared to conventional 32-4-20 lawn fertilizer and a popular fertilizer derived from sewage sludge called Milorganite. All fertilizers were applied at rate of 1 lb. N/1000 sq. ft. in the spring, spring and fall, or spring, summer and fall. Few differences have occurred due to type of fertilizers. The highest quality turf was found in plots fertilized in the spring and fall and in the spring, summer and fall. The summer fertilization may be unnecessary. This research suggests that dried biosolids from Connecticut facilities could make a quality lawn fertilizer.

G. Bugbee Assisted by F. Fiondella
One method for recycling biosolids from municipal waste water treatment is to mix it with chipped wood waste, compost it and create a soil amendment. The compost is rich in organic matter and plant nutrients while concentrations of potential contaminants such as heavy metals are well below acceptable levels. A prime use for biosolids compost is in media for containerized ornamental nursery crops. Connecticut’s large nursery industry could benefit from low cost alternatives to conventional organic potting media amendments such as peat. This experiment compares the growth of 10 species of woody ornamentals, nine species of perennial flowers, and seven species of annual flowers in media containing 0, 25, 50 and 100% compost. The biosolids compost comes from the Metropolitan District Commission compost facility in Hartford. This is one of the largest in-vessel composting facilities in the world. Plants growing in all percentages of compost are doing well, with an apparent slight improvement in plants growing in media with 100% compost.

18. Wine Grape Trials
R. Kiyomoto Assisted by M. Previs and J. Bravo
Wine grape cultivars are being evaluated to provide information to the expanding wine industry in Connecticut. We are attempting to identify the best hardy French hybrid and Vinifera cultivars which can be commercially grown in Connecticut. Trials are being conducted at this site and at the Valley Laboratory in Windsor. Among the promising French hybrid cultivars which are not widely grown in Connecticut are Chambourcin, a red wine grape, and Villard Blanc, a white wine grape. The Viniferas are far less reliable than the French Hybrids. The hardiest of the Viniferas in our trials are Chardonnay, Riesling, and Cabernet Franc.

19. Manganese and Salt to Control Fusarium of Asparagus
W. Elmer Assisted by E. O’Dowd and J. White
A soilborne disease called Fusarium crown and root rot destroyed commercial asparagus production in Connecticut during the 1950’s. Applications of NaCl will suppress this disease and increase yield. Past studies have shown that applying NaCl also increased the concentration of the trace element, manganese. Since proper manganese nutrition has been associated with disease resistance, we hypothesized that applying the element alone may suppress the disease and increase marketable yields. These plots were designed to compare the individual and combined effects of NaCl and manganese on growth and disease. In 1998, the yields from NaCl-treated plots were 60% greater that of control plots, and yields from Mn-treated plots were 30% greater.

A. Maynard
Since the 1991 ban on disposing leaves in landfills, large-scale leaf composting has spread throughout Connecticut. Some 84 municipalities are currently composting their leaves. In static pile composting, leaves are piled and the internal temperature of the pile is monitored. As the leaves decompose, the temperature in the center of the pile reaches about 140 F. When the temperature decreases, the pile is turned and fresh material is introduced to the center of the pile. Turning also aerates the pile. Leaf compost is seen here in various stages of decomposition. The finished compost is used in experiments here at Lockwood Farm and at the Valley Laboratory in Windsor.

M. Inman, T. Rathier, J. Winiarski, G. O’Connor, K. Welch
Ask your questions about soils, plants, and insects here.

C. Maier Assisted by T. LaProvidenza, J. Loffredo, and C. Gibson
Since 1996, we have discovered two new exotic apple insects in Connecticut. The apple tortrix, Archips fuscocupreanus, is native to Japan, and the European green pug, Chloroclystis rectangula, is native to Europe. In their native lands, the caterpillars of these moth species sometimes cause significant injury to apple trees when they eat leaves or developing fruit. We are investigating the distribution and host range of these insects in the Northeast. To determine their distributional range, we collect caterpillars and rear them to moths or capture moths in pheromone traps. To determine the host plants, we sample caterpillars on unsprayed wild plants and rear them to adults. Thus far, we have found that the apple tortrix occurs in New Jersey, New York, Connecticut, and Rhode Island, usually within a few miles of the coast. The green pug apparently occurs throughout New England. The apple tortrix can develop on over 40 host plants, including most fruit trees that are grown commercially. By comparison, the green pug uses fewer host plants, but it can develop successfully upon most species of apple and pear. Over the next two years, we shall determine the potential of these two exotic moths to become pests of fruit trees grown in New England.

23. Control of Botrytis fruit rot in red raspberry
R. Kiyomoto Assisted by J. Bravo and M. Previs
These plots contained red raspberry cultivars tested from 1994-1997. The best cultivars from the previous trial were retained for testing the effectiveness of T22, a biocontrol formulation containing the fungus Trichoderma, as a control for Botrytis fruit rot. Results in 1997 showed T22 showed some promise in reducing, but not eliminating, fruit rot caused by Botrytis

G. Stephens Assisted by H. Stuber
The phloem or bast fibers of the fiber flax plant are the source of linen, probably the world’s oldest plant textile. The United States is the largest consumer of linen, but practically none is grown here. Efforts have been made since 1992 to reestablish fiber flax as a field crop in Connecticut. This flax nursery contains a duplicate planting of 18 lines representing 13 named cultivars or selections from the Czech Republic, France, Netherlands, and Russia. They are being evaluated for height, resistance to lodging, seed and straw yield, and total fiber content. In 1997, 65 lines from the United States, Canada and eight European countries were evaluated; in 1996, 73 lines were tested. In 1998 one new line was added. Not all 1997 samples have been processed. In 1997, average fiber content of deseeded straw from 47 lines was 27.1%. Average fiber yield was 979 lb/A. The 1997 fiber content of lines represented in 1998 ranged from 25.2-35.9%. In 1997, yield of deseeded straw over all 65 lines ranged from 2425-5740 lb/A. Seed yield averaged 523 lb/A.

S. Anagnostakis Assisted by P. Sletten
These small trees were planted as seedlings in 1990 to 1996. All are hybrids of American chestnut trees and blight resistant Chinese, Japanese, or hybrid trees. They will be grown to evaluate their blight resistance in the presence of the biological control that we assume will move over from the adjoining plot. The trees that look most like American chestnut trees, and have good blight resistance, will be used in future crosses for timber trees. Others will be developed as orchard trees for Connecticut growers. The paper bags on the trees cover hand-pollinated flowers from this year’s crosses.

S. Anagnostakis Assisted by P. Sletten
These American chestnut trees were planted in 1976 when they were 3 years old. Chestnut blight cankers were treated for 4 years, from 1978 to 1981, with our biological control using hypovirulent strains of the blight fungus. The control is working well to keep the trees alive and fruiting. Some of the trees are growing better than others. We do not know which trees were from seed collected in Wisconsin and which were from Michigan. It is possible that the difference in their ability to thrive in the presence of blight and hypovirulence indicates differences in resistance. The grafted tree in the center of the east row is from an "American" chestnut in Scientist’s Cliffs, MD, and the original tree resisted blight for many years (We suspect that it is a European hybrid). It definitely has some resistance, and is the best looking tree in the plot. Two grafted trees at the south-east corner are (Chinese X American) X American (cultivar ‘Clapper’) and have intermediate resistance to blight.

F. Ferrandino Assisted by J. White
Verticillium wilt is caused by a soilborne fungus which infects the roots and then spreads through the plant. Symptoms include overall stunting, wilting and yellowing of leaves, and, in severe cases, defoliation. This disease can result in a 30% to 50% loss in yield of eggplants and potatoes. Although there are tomato hybrids tolerant to this disease, tomato yield is still reduced through the increase in the incidence of blossom end rot in Verticillium infected plants. In this plot we are examining the effect of various rotation crops (canola, hairy vetch, and oats) on the subsequent severity of this disease.

28. Hop Trial
R. Kiyomoto Assisted by J. Bravo and M. Previs
This is a new planting (Spring 1998) of three of the most productive hop cultivars from an earlier trial (1995-97) testing 10 cultivars. In this trial, Nugget, Cascade, and Galena are planted in a randomized fashion in three replications each. The outside row to the south is Perle and the outside row to the north is Chinook.

V. Smith Assisted by J. White
Tomato cultivars available for the home garden are susceptible to powdery mildew, a disease which can quickly defoliate the plant. In this plot, we are evaluating fungicide treatments for control of this disease. Tomato plants of the cultivar Better Boy have been treated with benomyl, chlorothalonil, horticultural oil, or sulfur, or left untreated; disease control is being evaluated.

V. Smith Assisted by J. White
Tomato plants are often pruned to reduce the severity of foliar diseases and to increase yield. In this plot, we are evaluating the efficacy of pruning to reduce the effects of tomato powdery mildew. Tomato plants of the cultivar Better Boy have been pruned to one stem, two stems, or left unpruned. Severity and incidence of mildew will be evaluated, and any effects on tomato yield will be recorded.

D. Aylor Assisted by P. Thiel, J. Severino, and K. Perham
The fungal pathogen that causes apple scab is spread to developing apple tissue in the spring by airborne ascospores released from overwintering leaves in or near the orchard. The purpose of our study is to develop a mathematical model for the aerial transport of ascospores. This can be used to estimate the relative danger of infection from inoculum sources both within and outside a managed orchard. The spore samplers displayed are being used to determine aerial concentration of airborne ascospores. These concentrations are the physical link between the amount of disease inoculum on the ground and the number of infections that can potentially develop on nearby trees. The model will be used to help evaluate strategies for reducing the need for fungicide applications in the integrated management of apple scab.

Information is available on this organization formed to help the Experiment Station.

G. Hubeny
The mission of the Coverts Project, administered through the University of Connecticut, Cooperative Extension System, is to teach forest owners how participation in Connecticut’s Forest Stewardship Program can earn the woodland owner a long-term financial return while improving the health and productivity of both the forest and the wildlife that lives in it. Each year actively managed demonstration areas at the Yale Forestry Camp in Norfolk are used as outdoor classrooms to teach a select group of 30 woodland owners about preserving Connecticut’s forests and wildlife and how to put this knowledge to use on their own woodland. The project is funded by the Ruffed Grouse Society, a non-profit organization dedicated to forest wildlife conservation.

C. Vossbrinck and T. Andreadis Assisted by J. Shepard
While scientists are now discovering a myriad of things about how cells work, molecular biology has numerous practical applications. Through the techniques of gene amplification and DNA hybridization (southern blotting) we are able to find out numerous things about organisms, their genes and their relationships to each other. Practical applications in agriculture include identification of plant diseases, identification of genetic diseases, and identification of plant and animal lineages. We are identifying parasites of mosquitoes in their host and in their alternate host to understand their life cycles and to facilitate biological control of these organisms in the future.

T. Andreadis Assisted by C. Moser
Experiment Station scientists continue to search for new natural enemies of mosquitoes and to further assess their potential for development as biological control agents. Recently, a new microbial parasite of the mosquito, Culiseta melanura was discovered. This is an important finding as C. melanura is the vector of eastern equine encephalitis. The parasite is a one-celled microsporidian (protozoan) called Hyalinocysta chapmani. It is highly pathogenic and kills mosquito larvae before they can develop into adults. However, it has a complex life cycle that requires an intermediate copepod (a microcrustacean) host. This parasite has been found to infect up to 60% of a mosquito population at certain times of the year and thus appears to be an important natural enemy.

R. Cowles Assisted by R. Hiskes and S. Lamoureux
Two avenues of research will determine whether biological control of black vine weevil is feasible in Connecticut: using insect pathogenic nematodes and use of predatory ground beetles. Field trials in 1996 compared three species of insect pathogenic nematodes for their ability to prevent larval establishment in strawberries. All three nematode species, Steinernema carpocapsae, S. feltiae, and Heterorhabditis bacteriophora, suppressed black vine weevil populations when applied in May. A follow-up test this year at the Valley Laboratory in Windsor is comparing treatment date, nematode species, and nematode application rate. Predatory ground beetles may play an important role in suppressing root weevil populations. In 1998, an unsprayed field-grown yew nursery and a field with a history of intensive insecticide use were chosen to compare black vine weevil and predatory ground beetle activity. Twenty-five pitfall traps, efficient for sampling both groups of beetles, were placed in each field and emptied weekly. The unsprayed field had higher populations of predatory ground beetles than the sprayed field, and black vine weevil populations were much higher in the intensively sprayed field. One species of predator, found only in the unsprayed field, eats black vine weevil adults in laboratory tests. The larvae of predatory ground beetles are soil-dwelling generalist predators, and may be expected to eat all stages of black vine weevil larvae.

T. Mervosh Assisted by T. Abbey and D. Laiuppa
Plants commonly found in fields and landscapes of Connecticut are displayed. Information regarding taxonomy, life cycles, habitats, and toxicity or edibility of plants will be presented. Weed control questions will be addressed.

A cellular telephone transmission silo is proposed for Lockwood Farm.

W. Elmer Assisted by E. O’Dowd and J. White
Pumpkins and squashes consistently develop a foliar fungal disease called powdery mildew around the end of July or beginning of August. The lesions appear as small powdery spots on the upper and lower sides of the leaves and can cause defoliation and reductions in fruit yield. These plots are designed to compare a new disease-resistant cultivar with the standard cultivar ‘Howden’. Fungicides are also being compared to baking soda to evaluate the efficacy of this safe product for control of powdery mildew. Disease evaluations are being recorded during the season.

W. Elmer Assisted by E. O’Dowd and J. White
Rhizoctonia crown rot is major constraint on sugar and table beet production in the United States. The disease is caused by a soilborne fungus called Rhizoctonia. Beets are also salt tolerant. When the fungus is present, beets grow better when salt is applied. These plots are designed to compare the effect of NaCl with other sodium fertilizers to determine if less harmful sources of sodium can be used to suppress the disease.

41. Fertilizer types and rates to Control Verticillium in Eggplant and Tomato
W. Elmer Assisted by E. O’Dowd and J. White
Verticillium wilt of eggplant is a common disease of eggplant and tomatoes. The disease is caused by a soilborne fungus called Verticillium dahliae. The fungus is found in most soils. While there is resistance to this disease in tomato, there is none in eggplant. In 1996, studies demonstrated that less damage from the disease occurred when plants were grown with ammonium-nitrogen as opposed to nitrate-nitrogen. These plots are designed to show that less total nitrogen can be applied over the season if growers apply it as ammonium-nitrogen. Plant growth, fruit yield and disease will be monitored over the season.

K. Stoner Assisted by T. LaProvidenza and C. Gibson
The Mexican bean beetle has been successfully controlled in large plantings of soybeans with the parasitic wasp Pediobius foveolatus in New Jersey and Maryland. In order to determine their effectiveness on small plantings of garden beans in Connecticut, we released these wasps in populations of Mexican bean beetle at three farms, four community gardens, and two field plots at Lockwood Farm. We monitored Mexican bean beetle populations at these sites and at two other farms as controls. The effect of this parasitic wasp on bean beetle populations is still being studied.

D. Hill and A. Maynard
Annual amendment of soil with leaf compost prevents compacting and crusting of the soil surface and promotes root growth and infiltration of rain. In these plots, addition of one inch of leaf compost annually since 1982 has increased organic matter from 5.9 to 12.6%. Increased root growth in the amended soil allows plants to utilize nutrients in a greater volume of soil than plants in untreated soil of greater density. We are measuring the effects of reduced rates of fertilization (2/3, 1/3, 0 of normal rates) on the yields of several vegetables by comparing them with yields achieved with normal rates of leaf compost amended plots and untreated controls. We are also measuring the nutrient status of the soils in each plot throughout the growing season. Each year since 1982 yields on leaf compost amended plots under 2/3 and 1/3 fertilization have been consistently greater than on unamended plots with full fertilization.

S. Anagnostakis Assisted by P. Sletten
These trees are part of the large collection of species and hybrids of chestnut maintained by The Experiment Station. Great differences can be seen between these trees in chestnut blight resistance, form, and nut production. We are using hypovirulent strains of the blight fungus to help protect them from lethal cankers (see plot 26). Plants of all seven species of chestnut are growing here. In 1994 we planted two seedlings from the Caucuses Mountains of Russia that are true European chestnut. Two trees of the important commercial cultivar ‘Colossal’ are planted across the road.

C. Lemmon Assisted by X. Asbridge, D. Brown, I. Kettle, S. Sandrey, and P. Trenchard
Our personnel uphold laws enacted to protect Connecticut’s vegetation from injurious insects and disease. Each year we inspect 9,805 acres of nursery stock grown in over 400 nurseries for insects and disease. When problems are found, control remedies are suggested. We inspect agricultural products to be shipped to foreign or interstate destinations, and we survey Connecticut’s woodlands to find troublesome pests such as the gypsy moth and the hemlock woolly adelgid. Examples of insect pests and plant diseases are exhibited. Insect survey maps are shown. Connecticut has about 1,200 beekeepers tending 5,000 colonies of honey bees. A task of the Experiment Station is to seek and eliminate contagious bee diseases and parasitic mites. There will be displays of insects that attack ornamentals, live honey bees, a beehive and various beekeeping equipment, as well as wasps and hornets and their nests.

R. Weseloh Assisted by M. Lowry
Entomophaga maimaiga is an important fungal pathogen of the gypsy moth. We have found that resting spores of the fungus collected in 1990 have germinated every year since 1990 except this year. This may be important because it is likely that the number of resting spores in an area affect the ability of the fungus to control the gypsy moth. The fungus first became abundant in 1989, a very wet year that greatly favored the fungus. Since then, the pathogen has been very effective in controlling the gypsy moth even though weather conditions have not been as favorable as in 1989. The reason is probably because of the large number of resting spores produced in 1989 which have been germinating ever since. If these resting spores are no longer viable, it may mean that the fungus will become less effective than it has been unless May and June of future years are exceptionally wet.

E. Naughton
The Connecticut Nurserymen’s Gardens are showcases of plants introduced to the horticultural trade by Connecticut nurserymen. Similar gardens are located at the Valley Laboratory in Windsor and at the main laboratories in New Haven. All plants were donated by members of the Connecticut Nurserymen’s Association and planted in 1986-87. Introductions feature evergreen and deciduous azaleas, mountain laurel, maple, pine, hosta, iris, and many other flowering and foliage plants. A brochure containing maps of all three gardens and a brief description of the discoveries is available at the gardens.

Created by Landscape Designer A. Bell, Assisted by E. Naughton and Lockwood Farm staff,
C. Lemmon, L. Starr, J. Keegan, F. Milroyd,
J. Lenart, and J. Fengler
The garden is a joint project of The Experiment Station and the Federated Garden Clubs of Connecticut. The second stage of a butterfly and bird garden can be viewed as well as the second year growth of a butterfly meadow. A display of butterfly photographs, specimens, and live caterpillars represents the butterflies that frequent and breed in the garden and meadow. Guided butterfly identification walks will be available as well as literature on butterfly larval and nectar sources.

J. Ward Assisted by J. Barsky, K. Sacilotto, and A. Sala
Native woody shrubs offer an alternative to exotics commonly used in landscaping. This collection of shrubs was assembled in 1962. In 1976 the collection was arranged in its present form with a dry site on the gravely mound and a moist site in the shallow, plastic-lined depression. Many of these shrubs flower in spring; their flowers can be seen in the photographs. Others such as sweet pepperbush, spirea, and buttonbush flower in summer. Witchhazel flowers in autumn. Many of these shrubs attract birds which feed on the mature fruit. These shrubs survive with minimal maintenance such as occasional mowing, removal of dead or broken stems, and replenishment of mulch. They have not been fertilized, irrigated, or sprayed to control insects or disease.

J. Pignatello and J. White Assisted by J. Sanford
The primary mechanism responsible for the removal of toxic chemicals from soil is biodegradation of these compounds by bacteria. It is now known that the longer that a toxic chemical resides in soil, the more difficult it becomes for bacteria to detoxify the chemical. It is hypothesized that with the passage of time, these toxic compounds are becoming sequestered or tightly held within regions of the soil particle (organic matter) that are too small to be available to bacteria. Sequestration of compounds is also used to explain the increased difficulty of physically removing these compounds from soil and for the failure of many clean-up or remediation efforts on hazardous waste sites. Studying the exact mechanism responsible for sequestration will provide valuable information regarding the nature of soil organic matter (an area of debate) and to the estimation of risk posed from these types of contaminated sites in the environment. We have also shown that by adding a second chemical, you can increase the availability and biodegradation of the primary compound through a kind of competition within the soil particle.

51. Effect of Biological Fungicides on RHIZOCTONIA CROWN ROT OF IMPATIENS.
W. Elmer Assisted by E. O’Dowd and J. White
Crown rot is a frustrating soilborne disease that prevents many homeowners and landscapers from growing a flower bed. The fungus which causes the disease can persist in the soil for many years. Several biological fungicides have been developed in the last few years that offer an environmentally safer means to suppress this disease. These plots compare conventional fungicide with two biological fungicides for their efficacy in suppressing crown rot.

D. Hill
Winter squash varieties such as butternut, buttercup, acorn, and Hubbard have long been favorite fall crops for vegetable growers who operate roadside stands. Consumers often purchase by the bushel because they store well and can be eaten well into the winter months. Most squash varieties are long-vined and discourage home growers with limited space. New cultivars have been developed that produce fruit on shorter vines, allowing closer spacing. Last year, five short-vined and bush types were tested for yield and quality compared to the traditional long-vined Waltham type. The short-vine types (Early Butternut, Harris Butternut) and bush types (Butter Bush, Butter Boy) had yields averaging 11.8 tons/A and 12.9 tons/A respectively compared to 18.5 tons/A for long-vined Waltham and Nicklow’s Delight. Yield of short-vined and bush types can be improved by closer spacing between rows (4 and 3 feet, respectively) compared to normal 6-foot spacing for long-vined types. This year, we are repeating the evaluation of the butternut types and growing alternate rows of short-vined acorn squash.

53. Medicinal Herb Variety Trial
M. Gent Assisted by J. Bravo.
Consumers are interested in medicinal herbs for self-medication using traditional remedies. This is a trial of seed sources of commonly used medicinal herbs, to determine their suitability for the soil and climate conditions found in Connecticut. In 1998, the annual herb, pennyroyal, and the perennial herbs, achillea, hollyhock, lovage, sage, and thyme were germinated in the greenhouse and transplanted in late April. They will be harvested lightly in the fall. The other perennial herbs, horehound, hyssop, and lemon balm, were transplanted in May 1996. These plants are harvested at flowering and in early fall each year to determine yield. The dried material will be analyzed for "active ingredients", and compared with commercial preparations found in health food stores. This trial will distinguish the seed sources that are most suitable for both backyard and large-scale farmers to produce medicinal herbs in Connecticut.

M. Gent Assisted by M. Short and J. Bravo
The taste and composition of leafy vegetables may vary with time of year, and may depend on whether the crop is fertilized conventionally or using organic fertilizer in soil amended with compost. Especially in early spring and late fall, when soil temperature limits the rate of microbial transformations, the availability of various nutrients may differ depending on the method of fertilization. We are growing seven species of salad greens in this plot to determine if growth, taste and composition differ when grown with conventional compared to organic fertilizer. In 1997, a similar study was conducted using three species planted four times in the field and seven times in high tunnels. Over all plantings, the organically grown salad greens had higher concentrations of nitrogen and phosphorus in the leaves, but a taste panel could not distinguish a difference in taste between conventionally and organically fertilized salad greens.

W. Elmer Assisted by E. O’Dowd and J. White
Asparagus plantings are usually planted with
1-year-old crowns that are grown in an asparagus nursery. This plot is a small nursery that contains seedlings of several new cultivars that will be dug up next April and replanted in experimental plots.

V. Smith and J. LaMondia Assisted by J. Canepa-Morrison
Powdery mildew is a disease of tomato that causes blasting of the leaves, frying, and eventual defoliation of the entire plant. Most commercial tomato cultivars are severely affected by powdery mildew. In this plot, we are investigating differences in susceptibility to powdery mildew of eight cultivars (Better Boy, Celebrity, Grace, Heinz, Rutgers, Ultra Girl, cherry type Baxter’s Early Bush, plum types Roma and Super San Marzano) plus two breeding lines and one relative of tomato. Last year, disease severity was high on all cultivars tested, and L. hirsutum and the breeding line Hirol 3-21 were resistant to infection by the powdery mildew fungus.

V. Smith Assisted by J. White
Many ornamental plants, including annuals and perennials, are susceptible to powdery mildew diseases. These fungal diseases cause considerable disfiguration of heavily-infested plants, but usually cause little mortality. Novel alternatives to fungicide treatments for control of fungal diseases include applications of baking soda, canola oil, or neem oil. Zinnias in this plot, which are very susceptible to powdery mildew, were treated with both standard fungicides and with novel fungicide, and disease control and any damage to the plants from the treatments will be recorded.

D. Hill
This garden contains a potpourri of vegetables grown to pique the interest of home gardeners and growers of niche crops. Included are trials of globe artichokes, grown specifically for annual culture from seed. Early production is triggered by use of vernalized seed (cool moist treatment) and the use of gibberillic acid, a natural plant hormone. The Green Globe variety requires such treatments for production beginning in early July. The new Imperial Star cultivar has been selected for testing because it does not require vernalization to induce budding. In this trial, we are comparing yield and timing of production on plants grown from vernalized and unvernalized seed. Sweet potatoes are also popular among home gardeners and growers who sell vegetables at farmers markets. In these trials, we are growing Beauregard, the highest yielder among 10 cultivars tested in past years (up to 8 lbs/plant). Sweet potato slips were planted through plastic mulch in hilled and non-hilled rows to determine yield and quality under both cultures. Also included in these trials is Jilo, a tropical plant in the eggplant family, from Nigeria and Brazil. It is a highly popular vegetable grown for farmers markets in the Waterbury area.

A. Maynard
Among all vegetable crops grown in Connecticut, sweet corn has the greatest acreage. Sweet corn requires large amounts of nitrogen throughout the growing season. For that reason, it is difficult for organic growers who grow sweet corn to obtain optimum yields because nitrogen levels early in the growing season tend to be lower in soils amended with only compost and organic fertilizers. Using compost in combination with a leguminous cover crop could increase early nitrogen concentrations. However, there is very little information available on growing corn in a legume/compost rotation with virtually no work utilizing leaf compost in corn production. This experiment is comparing the yields of sweet corn grown in five compost/vetch cover crop/fertilizer combinations. Results will provide growers with the specific combination of leaf compost, leguminous cover crop, and fertilizer for optimum sweet corn production. This experiment is repeated at our Valley Laboratory in Windsor where the ground water is being monitored underneath each of the treatments for nitrate leaching. This is the first year of a 3-year experiment.

S. Anagnostakis Assisted by P. Sletten
Seed collected from selected American chestnut trees in Rocky Hill in 1985 grew into the trees planted here. We are using them as female parents in our crosses, and treating them with hypovirulence (see plot 26) to keep them alive. The white paper bags cover the hand-pollinated flowers of this year’s crosses.

S. Anagnostakis Assisted by P. Devin
This orchard of grafted nut trees was planted by Richard Jaynes in the spring of 1981. There are several named cultivars of chestnut included, and these are being used by volunteers from the Connecticut chapter of the American Chestnut Foundation in a project supervised by S. Anagnostakis. Volunteer Devin, with help from several other members, has made controlled crosses of some of the cultivars to find out if some crosses produce more nuts than others. In the fall when we harvest the nuts, they will be weighed to see whether the pollen parent had any effect on the size of the nuts, the flavor of the nuts, or the ease with which the nuts can be peeled.

N. Schultes Assisted by R. Huntley
In 1917 Donald F. Jones, a newly appointed geneticist at the Station, performed corn crosses at Lockwood Farm that laid the basis for developing double hybrid corn. In subsequent years, the once "academic" double hybrid corn was adopted by American farmers resulting in substantial increases in yield. Hybrid corn is one reason why America produces more food than it consumes. Today we combine corn genetics (performed in the field) with modern techniques of molecular biology to study genes. By understanding how corn grows at a gene level, scientists will be able to genetically engineer corn and other crops to be more productive and to guard against pests, disease and adverse weather. Corn performs a specialized form of photosynthesis called C4 that uses light energy to produce sugars more efficiently than most other crops. In this field plot we are screening corn for mutants that have altered ability to perform photosynthesis. Such mutants can arise when a transposable element (a piece of corn DNA that moves from one place on a chromosome to another) lands inside another gene, causing a disruption. The disrupted gene can now be identified and cloned in the laboratory. By identifying and understanding the genes involved in C4 photosynthesis advances in crop productivity can be obtained through recombinant DNA technology. See Barn Display on Molecular Cloning of Corn Genes

S. Anagnostakis Assisted by P. Sletten
A variety of types of tree-tubes are being tested to see which are best for growing chestnut seedlings.

64. Apple Variety Trial
R. Kiyomoto Assisted by J. Bravo and M. Previs
This orchard contains approximately 84 apple cultivars which are replicated three times. Included are some of the newest cultivars and older, but not antique, cultivars. Disease is allowed to develop in order to compare cultivars for relative resistance.

65. NE-183 Apple Variety Trial
R. Kiyomoto Assisted by J. Bravo and M. Previs
This orchard is part of the Regional Research Project NE-183, "Multidisciplinary Evaluations of New Apple Cultivars". Participants in the project include entomologists, plant pathologists, horticulturists, and economists. The orchard is replicated in 28 sites in North America. The goals are to (1) determine the limitations and positive attributes of new apple cultivars, (2) develop horticultural and pest management strategies, and (3) compare costs of production and profitability. This orchard primarily focuses on comparing the cultivars for disease resistance.

S. Anagnostakis Assisted by P. Sletten
These hybrid trees were planted by Richard Jaynes from 1970 to 1973. One of the parents in the hybrids was the dwarf species Castanea seguinii, and the selected trees that remain produce abundant nut crops and have remained small. These are important parents in our selections of orchard-type trees for Connecticut.

S. Anagnostakis Assisted by P. Sletten
In 1982 we planted 300 seedlings of American chestnut trees from Michigan in two dense plots. We have been examining them for growth as we treat them with hypovirulence for blight control (see plot 26). In 1993 we introduced a purple mushroom into the center of the northern group to see whether it would improve the growth of the trees. This year we put another root-associated mushroom in the southern group.