NSLETTER - Horticultural Sciences | Horticultural...

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INSTITUTE OF FOOO AND AGRICULTURAL SCIENCES UNIVERSITY OF FLOAIOA VEGETARIAN FLORIDA COOPERATIVE EXTENSION SERVICE NE\NSLETTER T(AOU"°"C. Rt:Sf.ARCH ( JCTlNSI O l'li TO: FROM: August , 1982 Prepared b y Extens ion Vegeta bl e Crops Specialist s D .N. Maynard Ch airman G.A. Marlowe Professor W.M. St all Associate Professor S. P . Kovach Assi s tant Professor M. Sherman Ass is tan t Professor J. M. Ste ph e ns Associate Professor A. McDon a ld VEA-I Mul t i - Cou nty VEGETABLE AND HORTICULTURE AGENTS AND COUNTY EXT I ON DIR ECTORS phens , Extension Vegetable S pe cialist Vegetable Crops Departm e nt 1255 HS /P P Building University of Fl o rida Gainesville, FL 32 6 11 Phone: 904 / 392-2134 VEGETARIAN NEWSLETTER 82 -8 IN THIS ISSUE: I. NOTES OF I NTERES T A. New Publ icati ons B. Vegetable Crops Cale n dar II. PEST I CIDE UPDATE The Institute of Food end Agricultura l Sciences is en Equal Employment Opportunity· Affirmative Actio n Emp loyer authorized to provide research, educat ional in formation end other services only to ind ividuals end institutions that function without regard to race, color , sex, or national origin . COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS, STATE OF FLORIDA, IFAS, UNIVERSITY OF FLORIDA , U.S. DEPARTMENT OF AGRICULTURE, AND BOARDS OF COUNTY COMMISSIONERS COOPERATING

Transcript of NSLETTER - Horticultural Sciences | Horticultural...

INSTITUTE OF FOOO AND AGRICULTURAL SCIENCES

UNIVERSITY OF FLOAIOA

VEGETARIAN

FLORIDA COOPERATIVE

EXTENSION SERVICE

NE\NSLETTER T(AOU"°"C. Rt:Sf.ARCH ( JCTlNSI O l'li

TO:

FROM:

August , 1982

Prepared b y Extens ion Vegeta bl e Crops Specialist s

D.N. Maynard Ch airman

G.A. Marlowe Professor

W.M. St all Associate Professor

S. P . Kovach Assi s tant Professor

M. Sherman Ass is tan t Professor

J. M. Ste ph e ns Associate Professor

A. McDon a ld VEA-I Mul t i - Cou nty

VEGETABLE AND HORTICULTURE AGENTS AND COUNTY EXT I ON DIR ECTORS

phens , Extension Vegetable Spe cialist

Vegetable Crops Departm e nt 1255 HS /P P Building University of Fl o rida Gainesville, FL 32 6 11 Phone: 904 / 392-2134

VEGETARIAN NEWSLETTER 82 -8

IN THIS ISSUE:

I . NOTES OF I NTERES T

A. New Publ icati ons

B . Vegetable Crops Cale n dar

II. PEST I CIDE UPDATE

The Institute of Food end Agricultura l Sciences is en Equal Employment Opportunity· Affirmative Action Employer authorized to provide research, educat ional information end other services only to ind ividuals end institutions that function without regard to race, color , sex, or national origin .

COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS, STATE OF FLORIDA, I FAS, UNIVERSITY OF FLORIDA , U.S. DEPARTMENT OF AGRICULTURE, AND BOARDS OF COUNTY COMMISSIONERS COOPERATING

III. COMMERCIAL VEGETABLE PRODUCTION

A . Diagnostic Characteristics of Salt Damage

B . Interim Guidelines Risks Through Diet

Recommended for Reducing Cancer

C. Fusarium Wilt Disease of Tomato - An Old Disease Revisited

IV . HOME VEGETABLE GARDENING

A . Know Your Minor Vegetables - Guar

B . Results of the 1 982 State 4- H Horticultural Demonstra ­tion and Judging Contest

c. Second Annual Advanced Master Gardener Training

NOTE: Anyone is free to use the information in this newsletter . ever possible, please give credit to the authors.

When-

The use of trade names in this publication is solely for the purpose of providing information and does not necessarily constitute a recommendation of the product.

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I . NOTES OF INTERES T

A. New Pub li ca ti ons

( 1) " Know Your Minor Vegetables" - you agents should be advised that yo ur office may receive several requests for this mimeograp hed p ubli ca ti on VCER 17-1982 . The publication wa s " plugged " in a re ­cent newspaper article by a well - known food columnist.

I suggest that i f yo u do not wish to duplicate t his rather thic k publication to fill their requests, you mi g ht choose to mi meograph copies of the index pa ge to send them. Add a brief note indicating t h at they sho ul d c he ck the vegetable s for which the y want mor e in formation . Then you need send the m onl y a copy of those particular pages .

The Vegetable Crops Depart men t cien t supply of these publications copies per cou n ty.

does not maintain a suff i­to provide more than five

( 2) Eva l uation of Herbicides for Weed Control in Spring Transplanted Toma t o , Res e arch Repor t BRA 82 - 11 by J . P . Gilreath .

( 3) Postemerge nc e Herbicide Screening Trial -1 981, Research Report BRA 82 - 12 by J . P . Gil rea t h .

(4) Fusarium Wilt of Tomato, Research Report BRA- 13 by J . P . Jo nes , J . B . Jones and J . W. Scott . Items ( 2), (3 ), a nd (4 ) are a ll available fr om the Bradenton AREC, 500 7 60th Street, East , Bradenton , F l ori da 335 08 .

( 5) Fusarium Wilt of Tomato, Plant Pathology Circular #23 7 , by J. P . Jones , J . B . Jones and J . W. Mill er is ava i lable fr om the Fl orida Department of Agriculture and Consume r Services , Di vision of Plant Industry , Bureau of Plant Pathology , P . O. Box 1269 , Gainesvi lle, F lor ida 32602 . This publicatio n contains colored pictures of Fusarium sy mptoms .

(6) s h2

Sweet Cor n Cultivar Trial , Zellwood , Florida, Research Re port SAN 83 - 1 by J. M. White is ava i lable from the Sanford AREC, P. O. Box 909, Sa nf ord , FL 327 11.

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(7) Co sts and Returns from Vegetab le Crops in Florida , Season 1980-81 wit h Compa ri sons , Econom i c Inf o r mation Rep or t 159 , by T . G. Taylor is available from the Food & Resource Economics Depart ­ment, University of Florida, Gainesville, FL 3261 1.

( 8) Evaluation of Ca u l if low er Lines for White Curd, Res ear ch Report SAN 83 - 2 by J . M. White is availa bl e fro m the Sanford AREC, P . O. Box 909, Sanford, FL 32711.

(Stall, May nard and Stephen s )

B . Vegetable Crops Calendar

( 1) Au gust 25 - 27

( 2) September 16

Master Gar den er Agent In-Service Traini n g , Lake Yale Assembly, Eustis

21st Annual Tomato Institute, Marco Beach Ho tel, Marco Is land, Florida 9:00-3:30

(St a ll and McDonald)

III. COMMERCIAL VEGETABLE PRODUCTION

A. Dia gno sti c Characteristics o f Salt Damage

Sa lt injury to veget abl e seedings is a common " emergency " during peak planting period s in Florida. Salt inju r y is usually a seedling stage problem in the fie ld or see dl ing p l ant prod u c t ion house, but o lder plants can be severe l y damaged, too.

The sa lt level of the soil solution can change from low (and in ­nocent) to high (a nd disastrous) in a very short time dependin g on the level of moisture in t he to p few inches of the soil near the seedling. A reading of 200 - 400 ppm salt in the soil solution can double or trip­le in a few hours as hot, dry win d s pass over soil near the young seedling in a co nt ainerized t ray or plan ti ng hole i n the mulched bed.

Recognition of seed li ng sa l t inj ury is not always e a sy to distin­guish from damage caused by fungi (such as Rhizoctonia or Pythiu m);

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nematodes (such as sting or root knot); or physical abrasion due to blown sand or mechanical pinching of the seedling.

Symptoms of salt damage are seldom "t ypical" . following may be associated with salt damage of plants .

One or more of the seedlings and older

A . Seedlings

1 . Stem destruction: The soft tissue of the seedling at the soil line may "pinch in" and the seedling may fall over if the damage is severe en ough . As soon as woody tissue develops , the fall - over symp-toms decrease . The fungus Rhizoctonia causes a destruction down to the more woody vascu l ar tissue (the stele) and gives a wire - stem ap­pearance, thus appears slightly different than salt dam age. The lesion of Rhizoctonia may be quite extensive, whereas , salt damage is usually restricted to the immediate soil line zone of the seedling . Phythium fungi cause a "wetter" rot than the Rhizoctonia do , and are usually associated with rather wet soil or me dia conditions.

2 . Root destruction: Salt damaged seedlings usuall y show varying de­grees of root browning and die -b ack of the tips and these symptoms can be easily confused with similar damage caused by sting or root knot nemato des. In all three situations tissue may fall from the young roots .

3 . General: Other symptoms associated with exces s salt damage of seed or seedlings include poor ge r mination, uneven growth, wilting , ye llowin g of leaves smaller leaves, and marginal burn of leaves .

B . Older p la nts

1. Ye llowing and stunting of plant . really is) drought damage . The high salt causes the plant roots to "work harder" to the result is the same as growing the crop

Salt damage resembles ( and leve l in the soil so lution

get water f ro m the soil and under moisture stress.

2. Marginal leaf scorch . Usually the stunted , yellow plant develops a scorch or margina l leaf burn as salt damage o r drought continues .

3. Decreased root activity. The browning of root tips can be an

early symptom . uneven growth . insect damage, ish cast often

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If advanced, one notes wi l ting , smaller leaves , and In mature plan ts , roots should be checked for nematode, f u ngi and bacterial diseases. A soil crust with brown­indicates salt bu ild - up , and should be observed, too.

Id e ntification of a salt problem, determination of the extent of in j ury , and exc lu sion of other possible causes of agents which give s i milar symptoms is necessary to a sound corrective program . Even better and cheaper than correction is prevention .

(Marlowe)

B . Interim Gu id e l ines Recommended fo r Reducin g Ca nce r Risks Thr o ugh Diet

The nutriti o nal virtues o f vegetables have been extolled for cen ­turies with o ut knowing specifi call y the role they play in body func­tions. We recognize their importan ce in providi ng essential vitamins , mi nerals and roughage in a ddit i on to the i r es the ti c value of flavor, texture, and appearan c e. The following i nformation was just released s howing the beneficial associa ti on b etween v e getables a nd cancer pre­ven tion in humans.

The Nationa l Res e arch Counc i l on Diet, Nutrition and Cancer Risks has jus t re l eased a report for the National Cancer Institute which links di et with cancer. While the Committee reco gnizes that "It is no t now possib l e and may never be possible to specify a diet that pro ­t ec ts all people against all forms of cancer ", they do have evidence which sug ge sts that most co mmon cancers are influenced by diet. Cur ­rent Commi t te e recommendations are termed ''inter i m guidelines" pending addition al sci en t if i c evidence of how cer t ain substances in food may initiate, promo t e , or protect against cancer at different sites in the body .

Vegetables and fruits:

Studies of human populations s u ggest that frequent consumption of foods containing vitamin A-producing ca r otenes or vit amin C, or of vegeta ble s in the cabbage o r cruciferous family can reduce suscepti ­bility to cancer of the urinary bladder, large bowel , skin , lu ngs , stomach , and esophagus . Vitamins A and C and s ome nonnutritive chemi ­cals in crucife ro us vegetables have been shown to inhibit the forma­tion of cancer -cau sing chemicals and to reduce cancer susceptib i l ity in laboratory an i mals .

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Scientists are still not sure whether it is the vitamins them­selves, the caroten es, or other nonn utritive compounds occurring natu rall y in certain vegetables and fruits that help protect against cancer in humans. Nutrients such as vit amin A and the mineral se le ni ­um can be toxic in concentrations higher than ne eded for optimum nu­t r i ti on , therefore , it is recommended that p e op 1 e eat c i tr us fr u i ts , caroten t-rich ( dark green and deep yellow) and cruciferous vege tab les daily, rather than take high-dose nutrient supplements.

There is controversy concerning the associa tion between dietary fiber and cancer . Strongest evidence so far is that specific compon­ents of fiber, rather than fiber per se, may have protective effects.

Fats:

The Committee found the strongest evidence for a con ne ction be ­tween consumption of fats and cancer of the breast, large bowel, and prostate. It is suggested that the present 40% of calories from fat in the average American diet be reduced to about 30% of da il y calor ­ies. It was no t clear how higher fat consumption results in greater cance r susceptibility .

Salt-cured, salt-pickled, and smoked foods:

Hig her incidence of esophageal and stomach cancer occur in parts of China, Japan, and Icela nd , where such foods are eaten frequently, and therefore the Committee recommended that intake of such foods be reduced . These foods may be contaminated by the polycyclic aromatic hydrocarbons in smoke or by co mpo und s such as nitrosamines. Both types of compo unds cause cancer in laborat ory animals and are suspec­ted of causing cancer in humans .

Alcohol:

Excessive alcohol drinking, especially in combination with ci gar ­ette smoking, appears to increase the probability of cancer of the mouth , larynx, esophagus , and respiratory tract, and may also be linked with colon and rectal cancer.

Ot her diet components:

Among the o ther components studied were total ca lories consumed,

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cholesteral, protein , carbohydrates , vitamin E, essential trace minerals such as copper and z i nc . inconsisten t or too incomplete to show definite components and cancer .

the B vi tamins, and Results were either

links be t ween these

Genera l conclus ion & suggested dietary guidel i nes :

*Most common cancers are potentially p re venta bl e, for they appe ar to be dete r mined more by habit , diet, and cus t om than by genetic differences .

*Eat f ru its , vegetab l es , and whole gra in cereal pr o ducts daily. Espec ially eat citrus f r u i ts, carotene-rich (dark green and deep yellow) vegetab le s , and v eg etables in the cabbage family.

*Eat less foods high in sa turated and unsaturated fats. daily f at intake to 30 % o f calories .

*D rin k alcohol only in moderation.

The report " Diet , Nu tritio n and Cancer " is available for from the National Acade my Press , 210 1 Constit u tion Ave ., Washington, D. C . 20418 .

Reduce

$13.50 N . W. ,

(D . D. Gull, Associate Professor Vegetable Crops Depa rtment )

C . Fusarium Wilt Disease of Tomato - - An Ol d Disease Revisited

Fusarium wilt of tomat o , an o ld and familiar di sease t o tomato gr owers in Florida, has a new importance i n the Manatee-Ruskin produc ­tion area . Dr. J o h n P . Jones, Plant Pathologist at AREC Bradenton , has reporte d a new race o f the Fusarium wilt causal fungus fr om a num­ber of farms in Manatee and sou th Hil lsborough Counties .

Disease symptoms on mat ure p l ants appear firs t as l ower leaf yel ­lowin g , often on e sid ed on the plant or affectin g leaflets on one side of a petiole . Plants become increasingl y more chlorotic until th e who l e plant is affected . Plan t wi lt accompanies yellowi ng (starting

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at mid - day) and progresses for longer periods each day until the plant dies. Stems cut lengthwise characteristically exhibit a dark brown discoloration of the vascular tissue. The internal discoloration ex­tends high up the stem and is obvious in the petiole scars. Seedlings infected with 'Race 3 ' may exhibit downward curve to the lower leaves, vascular discoloration, plant stunting and wilting prior to death.

Existing fresh market tomato varieties grown in Florida are re­sistant to the more common types of Fusarium wilt caused by Race 1 and 2 of Fusarium oxysporum f .s. p. lycopersici. The new race (a probable Race 3) can be damaging on all existing Florida tomato varieties . The causal fungus is soi 1 borne and can survive for yea rs in cropped or fallow land. Acidic, sandy soils are more favorable to the causal fungus rather than the alkaline soils of south Florida . The fungus is more damaging in the 80-90°F temperature range, thus affecting spring crops more severely than fall crops. The use of ammonia cal nitrogen rather than nitrate nitrogen will also favor disease severity in in­fested fields .

The Fusarium pathogen, like most soilborne pathogens, can be spread by physical movement of infested soil on stakes , tools, vehi­cles or machinery . Run - off surface water and infected transplants may also serve to introduce this fungus i nto clean fields . Seed transmis ­sion (at least for Race 1 and 2) has not been considered an important means of spread in the past.

Present status:

Helicopter surveys by Division of Plant Industry personnel have been conducted over several areas of the state . On May 20 - 21, 91 fields were surveyed in the Manatee - south Hillsborough area. There were 25 fields (27%) positive for Fus arium wilt based upon symptom ex­pression . Several fields sampled, were confirmed to be infested with ' Race 3 ' by isolation and varietal test results obtained by Dr. ,J. P . Jones. Several infested fields sustained 50 - 80% plant loss from this pathogen .

Surveys were also conducted for about 850 acres in Gadsden coun­ty , 50 acres in Marion county, and 200 acres in Sumter county . Al­though suspect Fusarium wilt samples were collected from the loca ­tions, identification tests were negative for the 'Race 3' type of Fusarium oxysporum f .s. p . l ycopersici . To date , ' Race 3 ' is restric ­ted to the Manatee - Hillsborough county area.

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Control:

Although one source of resistance to ' Race 3 ' is known at pres ­ent , th ere are no presently available, resistant varieties . A number of yea rs will be needed for the s ucc essful breeding, in crease and re ­lease of se ed of an acceptable resistant variety to 'Race 3 '. For the present , th e fo llowing controls are suggested :

1. Known infested fields shou l d be rotated out of tomatoes (5 -7 years) or fumigated with 3 chisels per bed with a bro ad spectr um soil fumigant and planted t o fa l l crops of tomatoes only.

2 . Broad spectru m soi l fumigants (3 chisels per bed) sho uld be used on f ields in the infested area .

3 . Avoid movement of machinery, vehicles, tools , and stakes of the infested area unless they are well washed and free soil, fol low ed by steam -cl eaning .

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4 . Do not flood infested land since this will spread the causa l f u ngus .

5 . Avoid use of ditch or pond water for irrigation that may be contamina ted with t his soi l fungus .

6 . Physically separate seedl i ng production houses from produc ­tion fields.

7. Manipulate the soil pH to 6 . 5 -7. 5 (if fe asible fr om a nutri ­t i on standpo i nt ), and choose n itr ate nitrogen over a mmoniacal ni­trogen sources .

8 . Scout all tomato production fields du r ing the blossoming through f ru it maturation period . Ch eck for plant symptoms des ­cribed above . If s usp ect plan t s are found , co nta ct your nearest County Extension Agent to forward appropriate root and stem sam ­ples to : Extens i on P l ant Disease Clin i c , HSPP Building 717 , Hul l Road , Uni v ersity of F l orida , Gai nes ville , F lorida 326 11.

Isolations of Fusarium spp. from these sa mples wi l l be processed

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for 'Race 3' verification . Responses will be directed to the grower through the County Extension Office .

(G. W. Simone) (Extension Plant Pathologist)

IV. HOME VEGETABLE GARDENING

A . Know Your Minor Vegetables - Guar

Guar (Cyamopsis tetrago noloba (L . ) Taub . ), is also called "c lus ­ter bean" due to the manner in which its pods are clustered together. It was formerly referred to as Cyamopsis psoralioides.

Guar is a native plant fr om India where it is grown pri nc ipally for its green fodder and for the pods that are used for food and feed. It has so il-build ing properties since it is a legume. Today, probably the primary importance of guar is in the commercial value of its seed ­g um (galact omannan g um), according to the American Soc iet y of Agrono­my . Th i s gum has a wide variety of food and non-food uses.

Guar was introduced into the U .S. from In dia in 1903 . Product io n in the U. S. is centered around Texas, Oklahoma, and Arizona, but it is also adapted to more tropical climates, such as in Florida and Puerto Rico . Very little information is available on the use of this crop in Florida.

Description:

Gnar is a coarse, summer -an nual , upright, bushy plant , ranging from 2 to 9 feet in height . It has toothed , trifoliate le aves , small purplish flowers (along the axis of a spikelet), and hairy pods 3 to clusters. There are dwarf and tall cultivars.

drought - resista nt pointed, angular

borne in racimes 4 inches lon g in

Guar flowers are self - pollinating. out as white, then changes to a light F inally , the flower i s deep blue.

A mature unopened bud starts pink as petals begin to open.

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Climatic adaptat i on:

Guar is sensitive to cold, so should be grown during the warm season . Soil temperature of 21°C is necessa r y for seed germination . Gua r has an indeterm i nate growth habit , growing both vegetatively and setting pods fr om about 4 to 6 weeks following seedling emergence until death of the plant (cold or annual decl i ne) . Gua r is considered to be a short-day p l ant , setting more dense clusters in winter (in Puerto Rico) than summer . Good yields may be expected with 13 t o 14 hours of sunlight .

Although the plant is reported to be fai rl y drought resistant , it grows even better when irrigated . Drought during the prolonged fr uiting period seems to reduce yields .

Product i on as a vegetable:

The cu 1 tu re of guar is si mi l a r to that for soy be an (spacing and method of seeding) . If grown in the garden , which seldom is the case, it should be grown much like the cowpea (southern pe a) .

It is suggested that guar be only per acre 6 - 8-8 with 400 l bs applied at weeks after emergence) .

lightly fert il iized ( 800 planting and the res t 3

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In south Florida , try planting guar d uri ng the period September through Feb ruary, so t hat the f ruiting period coincides more or less with the shorter da y le ngths of the year . Where there is dan ge r from killing frosts, as in central and more northern areas of the state, plant a spring crop or a fall crop . Seeds weight 60 pounds per bush­el . These cult u ral suggestions are for guar grown as a vegetable plant and should not be considered for its production as an agronomic crop .

Uses as a vegeta b le:

For use as a vegetable , they become hairy and woody . bean or as a curry vegetab le.

pods must They are

be picked when yo un g before eaten mos t often as a French

(Stephens)

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B . Results of the 1982 State 4-H Horticultural Demonstration and Judging Contest

Once again the University of Florida Campus was filled with over 500 4 -H members , leaders, and agents during the State 4 -H Congress, July 26 - 30, 1982.

During the Congress, the State Horticulture Identification and Judging Contest was held on July 27 , wit h a total of 16 teams partici ­pating in this event . Marion County received first p la ce honors with Brevard and St. Johns County taking second and third, respectively.

Leigh Ann Cooksey and Susan Frawley, from St. Johns County re ­ceived first place awards in the Horticulture Demonstratio n event. Leigh Ann and Susan, along with Dickie Bockoras, Todd Dailey, Mark Pacheco and Heather Dailey (t he Marion County team) will compete at the Nationa l Junior Horticulture Association Convention, at Niagara Falls, New York.

(McDonald)

C. 2nd Annual Advanced Master Gardener Training

Approximately 100 time and sk ills working Gainesville on August 4 Master Gardener Course.

Florida Master Gardeners who volunteer their at their county extension office arrived in to at tend the Second Annual Advanced Florida

Representatives from the 13 participating counties, Brevard, Broward , Dade, Hillsborough, Lake, Leon, Orange, Osceola, Palm Beach, Pas co , Pinell as, Polk and Volusia, enj oycd the two-day pro gr am which included hands-on insect identification, spray equipment demonstra ­tion, tour of both the Soils Lab and a look at the Plant Disease Clin­ic. Also they made a trip to the IFAS Horticultural Unit, where turf grass problems were discussed. Th e training session ended with Master Gardeners attending either a session on vegetable identification, or a program on lan dscape design.

The h ighlight of the event was the dinner. Dr. K.R. Tefertiller, Vice President for Agricultural Affairs spoke on the importance of a successful volunteer program and how the Florida Master Gardener