Life Sciences Commons^™

The Prairie Naturalist Volume 24, No.4 December 1992

The Prairie Naturalist

NEW VASCULAR PLANT RECORDS FOR NORTIl DAKOTA ▪ B. L. Heidel, A. J. Duxbury, W.T. Barker, and J. R. Challey

GROWTH OF BLUEGILLS AND YELLOW PERCH IN SOUTH DAKOTA WATERS ▪ D.w. Willis, J.P. Lott, C.S. Guy, and D.O. Lucchesi

SEASONAL VARIATION IN SAMPLING DATA FOR WALLEYE AND SAUGER COLLECTED WITH GILL NETS FROM LAKE SAKAKAWEA, NORTH DAKOTA ▪ S.W. Mero andD.W. Willis

OBSERVATIONS ON NESTING OF THE AMERICAN BITTERN IN NORTIlWEST MINNESOTA ▪ W D. Svedarsky

FOOD HABITS OF MOURNING DOVES IN EAST CENTRAL SOUTH DAKOTA ▪ J.T. Van't Hul and J.A. Jenks

DISTRIBUTION OF TIlE PYGMY SHREW IN …

Simulating Winter Wheat Shoot Apex Phenology , G. S. Mcmaster, Wallace Wilhelm, J. A. Morgan

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Simulation models are heuristic tools for integrating diverse processes and help to increase our understanding of complex processes and systems. Models that predict crop development can serve as decision-support tools in crop management. This paper describes a phenology simulation model for the winter wheat shoot apex and reports validation and sensitivity analysis results.

The complete developmental sequence of the winter wheat shoot apex is quantitatively outlined and correlated with commonly recognized phenological growth stages. The phyllochron is used to measure the thermal time between most phenological growth stages, thereby increasing the flexibility over the growing degree-day (GDD) and photothermal approaches. …

Low Pressure Center Pivot And Soil Management Effects On Runoff, L. N. Mielke, J. R. Gilley, Wallace Wilhelm

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The objective of this research was to determine the influence center-pivot sprinkler irrigation methods in combination with tillage practices for corn (Zea mays L.) have on surface runoff of irrigation and rainfall. A center pivot irrigation machine was redesigned to apply water by high-pressure-impact (HPI), low-pressure-impact (LPI), and low-pressure-spray (LPS) nozzles. The center-pivot was a standard 10-tower machine, 395 meters in length and 38.4 meters tower spacing. Three tillage systems were used -- till-plant (T), disk (D), and subtill (S) which was till-plant with subsoiling between rows with straight single shanks, 360 mm deep, after last cultivation. The soil …

Simulating Winter Wheat Spike Development And Growth, Gregory S. Mcmaster, Jack A. Morgan, Wallace Wilhelm

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Mechanistic crop simulation models can aid in integrating and directing research, and in improving farm management strategies. Information derived from recent research on spike development and growth of winter wheat (Triticum aestivum L.) was incorporated into a submodel, SPIKEGRO, and added to an existing model called SHOOTGRO. This manuscript discusses the SPIKEGRO submodel.

SPIKEGRO emphasizes the reproductive functioning of the shoot apex. The complete developmental sequence of the shoot apex is outlined and quantified. All developmental events and growth stages are predicted, most using the phyllochron approach. Spikelet and floret primordium initiation, growth, and abortion; ovule fertilization and growth; …

A Homolog Of Escherichia Coli Reca Protein In Plastids Of Higher Plants, H. Osman, P. Grandoni, Heriberto D. Cerutti, André Jagendorf

Center for Plant Science Innovation: Faculty and Staff Publications

Studies of chloroplast DNA variations, and several direct experimental observations, indicate the existence of recombination ability in algal and higher plant plastids. However, no studies have been done of the biochemical pathways involved. Using a part of a cyanobacterial recA gene as a probe in Southern blots, we have found homologous sequences in total DNA from Pisum sativum and Arabidopsis thaliana and in a cDNA library from Arabidopsis. A cDNA was cloned and sequenced, and its predicted amino acid sequence is 60.7% identical to that of the cyanobacterial RecA protein. This finding is consistent with our other results showing …

The Prairie Naturalist Volume 24, No.3 September 1992

The Prairie Naturalist

VESICULAR-ARBUSCULAR MYCORRHIZAE IN BLOWOUT PENSTEMON ▪ T. R. Flessner and J. Stubbendieck

STATUS OF HAPLOPAPPUS FREMONTII A. GRAY SSP. MONOCEPHALUS (A. NELSON) HALL [ASTERACEAE] IN COLORADO ▪ K.A. Schulz and R.B. Shaw

HABITAT CHANGES ABOVE AND BELOW WATER PROJECTS ON THE NORTH PLATTE AND SOUTH PLATTE RIVERS IN NEBRASKA ▪ P. M. McDonald and J.G. Sidle

INSECT FLORAL VISITORS TO FOUR SPECIES OF TALL-GRASS PRAIRIE COMPOSITE (ASTERACEAE: HELIANTHEAE) ▪ J. A. Dickinson and M. J. McKone

SUMMER BIRD USE OF KANSAS WINDBREAKS ▪ T.T. Cable, R.L. Schroeder, V. Brack, Jr., and P.S. Cook

RING-NECKED PHEASANTS AND FOOD PLOT SIZE (GALLIFORMES: …

Proceedings Of The Workshop Social Science Research And The Crsps, C. Milton Coughenour, John M. Yohe, Anne E. Ferguson, Jere L. Gilles, Jo Purcell

INTSORMIL Impacts and Bulletins

Contents

Executive Summary: A New Agenda for CRSP Social Science Research - C. Milton Coughenour . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Session 1

Developing a Strategic Research Agenda David G. Cummins, Chair

Framing a Strategic Research Agenda.-John Yohe ................ 3

Social Sciences and Collaborative Research: Toward an Agenda for the Social Sciences in Agriculture -Jere Lee Gilles ............... 7

Session 2

Technology Development and Sustaining Household Food Security Kathleen DeWalt, Chair

Technology Development and Household Food Security - …

Book Review: Genetically Engineered Organisms: Benefits And Risks, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

In the continuing debate on the introduction into the environment of genetically modified organisms, particularly those modified by recombinant DNA, there are few books suitably written for policymakers, the lay public and scientists in other fields. This book describes the current state of the science and art of genetic engineering, potential uses (particularly outside the laboratory), and the benefits that can be expected. It is particularly pertinent for examining potential risk and management of risk from the perspective of the United Kingdom.

Performance Of Green And Blanched Asparagus Cultivars In Nebraska [Abstract], Laurie Hodges, Roger Uhlinger, Ernesto Brovelli, Susan Cuppett, Anne Parkhurst

Department of Agronomy and Horticulture: Faculty Publications

Fourteen asparagus cultivars were established in 1988 in eastern Nebraska on a heavy silty clay soil to determine suitability for Nebraska production.

The Prairie Naturalist Volume 24. No.2 June 1992

The Prairie Naturalist

FIRST FLOWERING DATES AND FLOWERING PERIODS OF PRAIRIE PLANTS AT WOODWORTH. NORTH DAKOTA ▪ J. M. Callow, J A. Kanlrud, and K.F. Higgins

PROBABLE DISTRIBUTION OF THE WOODCHUCK IN NORTH CENTRAL KANSAS ▪ J.R. Choate and T. W. Haner

NEST AND NEST SITE CHARACTERISTICS OF SOME GROUND-NESTING NON-PASSERINE BIRDS OF NORTHERN GRASSLANDS ▪ H A. Kantrud and K.F. Higgins

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA ▪ R.N. Randall

COMPARISON OF SIZE STRUCfURE AND CATCH RATE FOR LARGEMOUTH BASS SAMPLES COLLECTED BY ELECTROFlSHING AND ANGLING ▪ DJ. Isaak, T.D. Hill, and D.W. Willis

MULE DEER HABITAT USE IN THE NORTH DAKOTA …

Response Of Central Plains Taligrass Prairies To Fire, Fertilizer, And Atrazine, Robert A. Masters, Kenneth P. Vogel, Robert B. Mitchell

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Tallgrass prairies are an important forage resource in the eastern Central Great Plains. The effect of spring burning, fertilization, and atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine- 2,4-diamine] on standing crop of selected herbaceous species and categories of vegetation was determined in 6 tallgrass prairie environments located near Lincoln and Virginia, Neb., from 1987 through 1989 and 1 site near Bloomfield, Neb., in 1987. The grasslands were in good to excellent condition at the time these studies were conducted. Portions of each site were burned in mid-to late spring, atrazine was applied at a rate of 2.2 kg a.i. ha^-1 in late April to …

Simulating Winter Wheat Production In Three Tillage Systems Using The Nitrogen Tillage Residue Management Model, B. Davidoff, Wallace Wilhelm, Joseph M. Skopp

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Crop production system analysis is necessary to identify tillage and residue management practices that affect crop production. The objective of this study was to evaluate the potential of using the Nitrogen Tillage Residue Management (NTRM) model to evaluate the influence of tillage practices on winter wheat (Triticum aestivum L.) yield. Modifications of the NTRM model were required to simulate winter wheat production. The model was calibrated using site-specific information obtained from a tillage-nitrogen rate experiment conducted at the High Plains Agricultural Laboratory near Sidney, NE, on an Alliance silt loam (fine silty, mixed, mesic Aridic Argiustoll). Model output was …

The Prairie Naturalist Volume 24, No.1 March 1992

The Prairie Naturalist

HABITAT CONSERVATION FOR NESTING LEAST TERNS AND PIPING PLOVERS ON THE PLATTE RIVER, NEBRASKA ▪ J. W. Ziewitz, J. G. Sidle, and J. J. Dinan

DIURNAL FLIGHT TIME OF WINTERING CANADA GEESE: CONSIDERATION OF REFUGES AND FLIGHT ENERGETICS ▪ J. E. Austin and D. D. Humburg

MYCOTOXIN OCCURRENCE IN WASTE FIELD CORN AND INGESTA OF WILD GEESE IN THE NORTHERN GREAT PLAINS ▪ K. F. Higgins, R. M. Barta, R. G. Neiger, G. E. Rottinghaus, and R. I. Sterry

NOTES

Cost of Nest Reuse by Western Kingbirds ▪ T. M. Bergin

A New Record for Falcate Spurge in the Midwest …

In Situ Ruminal Protein Degradation Of Switchgrass And Smooth Bromegrass, J. J. Mullahey, Steven S. Waller, K. J. Moore, Lowell E. Moser, Terry J. Klopfenstein

Department of Agronomy and Horticulture: Faculty Publications

Performance of livestock grazing warm-season, perennial grasses is generally greater than would be expected given their relatively low protein concentrations. Two experiments were conducted to assess ruminal escape protein using an in situ rumen technique for switchgrass (Panicum virgatum L.) and smooth bromegrass (Bromus inennis Leyss.). Whole-plant, leaf, and stem samples were harvested at specific stages of maturity in 1987. Duplicate samples of each grass were incubated for 12 h in situ. Escape protein values were expressed as concentration [grams escape protein per kilogram dry matter (DM) adjusted for acid detergent insoluble nitrogen (ADIN)] and as a percentage …

Registration Of N27 Sweetclover Germplasm, Herman J. Gorz, Francis A. Haskins, G. R. Manglitz, R. R. Smith, K. P. Vogel

Department of Agronomy and Horticulture: Faculty Publications

N27 Sweetclover [Melilotus officinalis (L.) Lam.] (Reg. no. GP-l, PI 552552) is a biennial, yellow-flowered, high-coumarin strain that was selected for large seed size and for resistance to the sweetclover aphid [,i>Therioaphis riehmi (Bornerj]. N27 was developed cooperatively by the USDA-ARS and the Nebraska Agricultural Research Division and was released in February 1991.

Registration Of N28 And N29 Sweetclover Germplasms, Herman J. Gorz, Francis A. Haskins, G. R. Manglitz, R. R. Smith, K. P. Vogel

Department of Agronomy and Horticulture: Faculty Publications

Two sweetclover [Melilotus officinalis (L.) Lam.] germplasms, N28 (Reg. no. GP-2, PI 552553) and N29 (Reg. no. GP-3, PI 552554), are improved biennial, yellow-flowered strains selected for low coumarin content (or, more accurately, for low content of o-hydroxycinnamic acid β-D-glucoside; [1]) and for resistance to the sweetclover aphid (Therioaphis riehmi Bomer). N28 and N29 were developed cooperatively by the USDA-ARS and the Nebraska Agricultural Research Division and were released in February 1991.

Proceedings Of The 19th Annual Meeting, Southern Soybean Disease Workers (February 19-20, 1992, St. Louis, Missouri), J. Allen Wrather, Patrick D. Colyer, Glenn R. Bowers Jr., Brian M. Anderson, Glenn G. Hammes

Southern Soybean Disease Workers: Conference Proceedings

Contents

Southern Soybean Disease Workers 1991-1992 officers

1991-1992 Program Committee

Graduate student competition

Interactions of Macrophomina phaseolina with two soybean cultivars under four irrigation regimes. SR Kendig and JC Rupe

Influence of soybean planting dates on the incidence and severity of Sudden Death Syndrome. SS Alghamdi, PT Gibson, and MA Shenaut

The interrelationship of Heterodera glycines and Fusarium solani in sudden death syndrome of soybean. KS McLean and GW Lawrence

Frogeye leaf spot of soybean: evaluation of cultivars and isolates. PF Pace, DB Weaver, and LD Ploper

Soybean cyst nematode race symposium

SCN race scheme: a historical perspective. JA Fox …

Soil Science Research Report - 1992

Soil Science Research Reports

Weather Data - 1992 .......... 1

Influence of Anhydrous Ammonia Band Spacing on Irrigated Corn Grain Yield and Band Persistence .......... 9

Variable Rate Nitrogen Fertilization with Furrow Irrigation - Milton Ruhter Farm .......... 17

Burlington Northern Nitrogen Management Study .......... 25

The Effects of a Urease Inhibitor on Volatile Ammonia Loss and Urea Hydrolysis on Irrigated, Ridge Till Com .......... 37

Nitrogen Fertilization of Smooth Brome .......... 43

Evaluation of Soil Testing for Nitrate-Nitrogen .......... 47

Horizontal Sampling to Assess Agrichemical Movement .......... 55

Water Movement in Soils and Porous Media .......... 57

A Natural Gradient Transport Study of …

Determination Of Root Biomasses Of Three Species Grown In A Mixture Using Stable Isotopes Of Carbon And Nitrogen, H. Wayne Polley, Hyrum B. Johnson, Herman S. Mayeux

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A method is evaluated that employs variation in stable C and N isotopes from fractionations in C and N acquisition and growth to predict root biomasses of three plant species in mixtures. Celtis laevigata Willd. (C₃), Prosopis glandulosa Torr. (C₃, legume) and Schizachyrium scoparium (Michx.) Nash (C₄), or Gossypium hirsutum L. (C₃), Glycine max (L.) Merr. (C₃ legume), and Sorghum bicolor (L.) Moench (C₄) were grown together in separate, three-species combinations.

Scs Water Surface Profile Model - Wsp2, William H. Merkel, Donald E. Woodward

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The Soil Conservation Service (SCS) has revised its mainframe water surface profile model WSP2 and is distributing it as a microcomputer program. WSP2 is used by SCS and others in flood plain management studies and project planning. The model uses the standard step method for computing one-dimensional steady flow profiles for channel and flood plain cross sections and computes backwater at bridges and culverts.

Unique features of WSP2 are described with respect to input data, calculation procedures, user manual, error checking, and output. The use of WSP2 with other SCS hydrologic software is described.

New Diets For Production Of House Flies And Stable Flies (Diptera: Muscidae) In The Laboratory, Jerome Hogsette

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A diet for rearing the house fly, Musca domestica (L.), was developed from feed constituents available on a year-round basis in Gainesville, FL. The diet, called the Gainesville House Fly Diet, performed as well or better than the Chemical Specialties Manufacturers' Association fly larval medium (CSMA) and can be mixed, bagged, and delivered by a local feed mill within 3 d. By adding pelleted peanut hulls 1:1 by volume, the house fly diet becomes suitable for rearing the stable fly, Stomoxys calcitrans (L.). Use of these diets and the economics involved are discussed further.

Comparative Toxicity Of Aqueous Solutions Of Boric Acid And Polybor 3 To House Flies (Diptera: Muscidae), Jerome Hogsette, Philip Koehler

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

LC₅₀s and LT₅₀s of boric acid and polybor formulated in water and 10% sucrose were determined for 3- to 5-d-old adult house flies, Musca domestica (L.), of mixed sex. Differences between boric acid and polybor toxicities were significant in 10% sucrose, but not in water. However, borates formulated in water had significantly lower LC₅₀S than those formulated in 10% sucrose. Rate of kill for formulations in water was fairly uniform over time, whereas mortality from sucrose formulations was not observed until 17 h after treatment. Reasons for differences in the manifestation of mortality and …

Spontaneous Tetraploid Melons, Perry E. Nugent, Dennis T. Ray

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Since 1968, three spontaneous 4x melons (Cucumis melo L.) plants were discovered in our field or greenhouse plantings. Two were found in the cultivar Planters Jumbo and one in the virescent marker C879-52. Each of these 4x plants had rounded cotyledons, shorter internodes, thicker stems and leaves, more hairs, and smaller fruits, with larger stem and blossom scars, than their 2x counterparts. Also, their flowers, pollen grains, stomates, and seeds were larger. The discovery of a 4x virescent plant in 1987 allows easier germplasm transfer between ploidy levels. Morphological characteristics of 2x and 4x melons will allow identification without …

Comparison Of Restriction Fragment Length Polymorphisms In Chloroplast Dna Of Five Leafy Spurge (Euphorbia Spp.) Accessions, Scott Nissen, Robert A. Masters, Donald Lee, Martha Rowe

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Chloroplast DNA (cpDNA) restriction fragment length polymorphisms (RFLPs) were analyzed to assess genetic variation and relatedness among selections of North American and Eurasian leafy spurge. Leafy spurge accessions from Nebraska, Montana, Russia, Italy, and Austria were evaluated. Total DNA was extracted from young leaves and digested with the restriction endonuclease, EcoRI. CpDNA fragment patterns were determined by Southern blot analysis using mung bean cpDNA probes. Colinearity between the mung bean and leafy spurge chloroplast genomes was indicated by the observation that common fragments were hybridized by adjacent probes. Minimum estimates of chloroplast genome size for the five leafy spurge …

Distribution, Habitats, And Taxonomy Of Ruppia Maritima L. And R. Occidentalis S. Watson In Nebraska, Robert B. Kaul

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Specimens of Ruppia from all eleven Nebraska counties in which it is known fall into two groups: R. occidentalis in alkaline Sandhills waters and R. maritima in saline waters of the Platte River Valley and Lancaster County. Ruppia occidentalis is distinguished by its more robust size; redspotted leaves and stems; terete, entire, obtuse leaves; 4-8(9) carpels; and by two elliptic white spots on its endocarp, among other characteristics. Ruppia maritima is more delicate and unspotted; the leaves are oblate in section, sub-apically denticulate, and acute-acuminate; the carpels are 3 or 4, and the endocarp spots are nearly circular. Both species …

Loop Rating Curves From Goodwin Creek, Roger A. Kuhnle, Andrew J. Bowie

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Two types of hysteresis loops have been observed on Goodwin Creek: those with a greater flow depth for a given discharge on the falling limb of the hydrograph (type 1) and those with a greater flow depth for a given discharge on the rising limb of the hydrograph (type 2). Causes of these 2 loop types are investigated in this paper.

Effects Of Weaning On Concentrations Of Inhibin In Follicular Fluid And Plasma Of Sows, W. E. Trout, J. H. Killen, R. K. Christenson, B. D. Schanbacher, J. J. Ford

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Changes in plasma and follicular fluid concentrations of inhibin were examined in sows after weaning at 28-32 days post partum. From 0 to 48 h after weaning, inhibin concentrations were 200-300times higher in follicular fluid from small ( < 4 mm) and medium-large( ≥4 mm) follicles than in ovarian venous plasma. Inhibin concentrations increased in follicular fluid from medium-large follicles at 24 and 48 h after weaning; concentrations in ovarian venous plasma were positively correlated with the number of medium-large follicles (r= 0·40)and with ovarian venous plasma concentrations of oestradiol (r= 0·61).Blood samples were collected for 30 days from sows (n=6) that exhibited oestrus within 5 days after weaning and from sows (n=5) that remained anoestrous for 11 days after weaning. Plasma inhibin concentrations rose in oestrous and anoestrous sows by 12 h and continued to rise for 60 h after weaning. Plasma inhibin concentrations rose further and were higher at 3·5-4·5days after weaning in oestrous sows than in sows that remained anoestrous. After oestrus, plasma inhibin concentrations declined. At weaning, plasma concentrations of follicle-stimulating hormone (FSH) were higher in sows that subsequently exhibited oestrus than in sows that remained anoestrous. After weaning, plasma concentrations of FSH declined in both groups, reached a nadir at 2·5days, and increased gradually in anoestrous sows; oestrous sows exhibited an FSH surge at oestrus. Plasma FSH returned to preweaning concentrations in both groups of sows at Days 7-8.The results demonstrated dynamic changes in plasma concentrations of FSH and inhibin in sows after weaning; an inverse relationship of these, with the exception during the preovulatory surge of FSH, typifies the porcine oestrous cycle.

Autoseparation Method For Harvesting House Fly (Diptera: Muscidae) Pupae Of Known Age, Jerome Hogsette

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Postfeeding larvae of Musca domestica (L.) were allowed to crawl from the larval rearing medium into sand-filled collection containers to pupate. By separating postfeeding larvae and pupae from the sand at predetermined intervals, the approximate time of pupation and the pupal age could be determined. More postfeeding larvae were collected in fine, wet sand than in coarse, dryer sand. Whether or not the sand was tightly packed into collection containers was unimportant, and fly mortality was not increased by the sand-collection method. Uses for the system and implications of the results are discussed.

Methyl Jasmonate Inhibition Of Root Growth And Induction Of A Leaf Protein Are Decreased In An Arabidopsis Thaliana Mutant, Paul E. Staswick, Wenpei Su, Stephen H. Howell

Department of Agronomy and Horticulture: Faculty Publications

Jasmonic acid and its methyl ester, methyl jasmonate (MeJA), are plant signaling molecules that affect plant growth and gene expression. Primary root growth of wild-type Arabidopsis thaliana seedlings was inhibited 50% when seedlings were grown on agar medium containing 0.1 μM MeJA. An ethyl methanesulfonate mutant (jar1) with decreased sensitivity to MeJA inhibition of root elongation was isolated and characterized. Genetic data indicated the trait was recessive and controlled by a single Mendelian factor. MeJA induced polypeptides were detected in Arabidopsis leaves by antiserum to a MeJA-inducible vegetative storage protein from soybean. The induction of these proteins by …

Field Reaction Of Landrace Components Of Red Mottled Common Bacterial Blight, James S. Beaver, James R. Steadman, Dermot P. Coyne

Department of Agronomy and Horticulture: Faculty Publications

Field reaction of 25 red mottled bean ( Phaseolus vulgaris L.) genotypes to common bacterial blight [Xanthomonas campestris pv. phaseoli (Smith) Dye] was evaluated in Puerto Rico over 2 years. The average disease severity (percent leaf area with symptoms) was similar over years. The determinate red mottled genotypes had almost twice as much disease as indeterminate genotypes. Eight of the indeterminate genotypes had significantly less disease than the mean of the field experiments. These genotypes may serve as useful sources of resistance to common bacterial blight. The size of the chlorotic zone around necrotic lesions varied between growing seasons, …