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Nancy L. Messinger and E. Jay Holcomb

Abstract

Experiments were conducted during the summer and fall to evaluate the effects of various concentrations of chlormequat chloride, ancymidol, BAS 106, and SD8339 on the height and plant quality of potted Dianthus cultivars ‘Snowfire’, ‘Indian Carpet’, and ‘Persian Carpet’. The effects of the growth retardants on the height and number of vegetative shoots were extremely diverse. The greatest height reduction was from BAS 106 applied at 3.6 mg a.i. per plant. As a result of this treatment, ‘Snowfire’ height was reduced by 70.0%, ‘Persian Carpet’ by 42.7%, and ‘Indian Carpet’ by 67.3%; however, both BAS 106 and SD8339, applied at concentrations that significantly reduced plant height, resulted in severe foliar damage. Chlormequat chloride and ancymidol reduced the height of ‘Snowfire’ at all treatment levels. ‘Snowfire’ height was reduced by 16.4% with 3000 ppm of chlormequat chloride and 47.5% with 144 ppm of ancymidol. Initial phytotoxic damage on ‘Snowfire’ from chlormequat chloride and ancymidol was not evident at the time of harvest. Chlormequat chloride and ancymidol applied to ‘Persian Carpet’ and ‘Indian Carpet’ in amounts to reduce plant height significantly resulted in severe foliage damage. Chemical names used: 2-chloro-N,N,N-trimethylethanaminium chloride (chlormequat chloride); α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol); 5-(4-chlorophenyl)-3,4,5,9,10 pentaaza-tetracyclo-5,4,102,6,08,11-dodeca-3-9-diene (BAS 106); and N-(phenylmethyl)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (SD8339).

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Mack Thetford, Jeffrey G. Norcini, Barry Ballard, and James H. Aldrich

2, end of season height (39 cm), width (63 cm), and basal width (30 cm) were similar to year 1, but plant quality was poor, as in SRC ( Fig. 5 ). Indian woodoats. Also known as mountain oats and northern sea oats, and formerly Uniola latifolia

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R.J. Schnell, J.S. Brown, C.T. Olano, A.W. Meerow, R.J. Campbell, and D.N. Kuhn

Mango (Mangifera indica L.) germplasm can be classified by origin with the primary groups being cultivars selected from the centers of diversity for the species, India and Southeast Asia, and those selected in Florida and other tropical and subtropical locations. Accessions have also been classified by horticultural type: cultivars that produce monoembryonic seed vs. cultivars that produce polyembryonic seed. In this study we used 25 microsatellite loci to estimate genetic diversity among 203 unique mangos (M. indica), two M. griffithii Hook. f., and three M. odorata Griff. accessions maintained at the National Germplasm Repository and by Fairchild Tropical Botanic Garden in Miami, Fla. The 25 microsatellite loci had an average of 6.96 alleles per locus and an average polymorphism information content (PIC) value of 0.552 for the M. indica population. The total propagation error in the collection (i.e., plants that had been incorrectly labeled or grafted) was estimated to be 6.13%. When compared by origin, the Florida cultivars were more closely related to Indian than to Southeast Asian cultivars. Unbiased gene diversity (Hnb) of 0.600 and 0.582 was found for Indian and Southeast Asian cultivars, respectively, and both were higher than Hnb among Florida cultivars (0.538). When compared by horticultural type, Hnb was higher among the polyembryonic types (0.596) than in the monoembryonic types (0.571). Parentage analysis of the Florida cultivars was accomplished using a multistage process based on introduction dates of cultivars into Florida and selection dates of Florida cultivars. In total, 64 Florida cultivars were evaluated over four generations. Microsatellite marker evidence suggests that as few as four Indian cultivars, and the land race known as `Turpentine', were involved in the early cultivar selections. Florida may not represent a secondary center of diversity; however, the Florida group is a unique set of cultivars selected under similar conditions offering production stability in a wide range of environments.

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Raymond Schnell, J. Steven Brown, Cecile Olano, Alan Meerow, Richard Campbell, and David Kuhn

Mangifera indica L. germplasm can be classified by origin with the primary groups being cultivars selected from the centers of diversity for the species, India and Southeast Asia, and those selected in Florida and other tropical and subtropical locations. Accessions have also been classified by horticultural type: cultivars that produce monoembryonic seed vs. cultivars that produce polyembryonic seed. In this study, we used 25 microsatellite loci to estimate genetic diversity among 203 accessions. The 25 microsatellite loci had an average of 6.96 alleles per locus and an average PIC value of 0.552. The total propagation error in the collection, i.e., plants that had been incorrectly labeled or grafted, was estimated to be 6.13%. When compared by origin, the Florida cultivars were more closely related to Indian than to Southeast Asian cultivars. Unbiased gene diversity (Hnb) of 0.600 and 0.582 was found for Indian and Southeast Asian cultivars, respectively, and both were higher than Hnb among Florida cultivars (0.538). When compared by horticultural type, Hnb was higher among the polyembryonic types (0.596) than in the monoembryonic types (0.571). Parentage analysis of the Florida cultivars was accomplished using a multistage process based on introduction dates of cultivars into Florida and selection dates of Florida cultivars. Microsatellite marker evidence suggests that as few as four Indian cultivars, and the land race known as `Turpentine', were involved in the early cultivar selections. Florida may not represent a secondary center of diversity; however, the Florida group is a unique set of cultivars selected under similar conditions offering production stability in a wide range of environments.

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Craig S. Charron and Carl E. Sams

The U.S. Clean Air Act bans the use of methyl bromide after 2005. Consequently, the development of alternative methods for control of soilborne pathogens is imperative. One alternative is to exploit the pesticidal properties of Brassica L. species. Macerated leaves (10 g) from `Premium Crop' broccoli [B. oleracea L. (Botrytis Group)], `Charmant' cabbage [B. oleracea L. (Capitata Group)], `Michihili Jade Pagoda' Chinese cabbage [B. rapa L. (Pekinensis Group)], `Blue Scotch Curled' kale [B. oleracea L. (Acephala Group)], Indian mustard [B. juncea (L.) Czerniak, unknown cultivar] or `Florida Broadleaf' mustard [B. juncea (L.) Czerniak] were placed in 500-mL glass jars. Petri dishes with either Pythium ultimum Trow or Rhizoctonia solani Kühn plugs on potato-dextrose agar were placed over the jar mouths. Radial growth of both fungi was suppressed most by Indian mustard. Volatiles were collected by solid-phase microextraction (SPME) and analyzed by gas chromatography-mass spectrometry. Allyl isothiocyanate (AITC) comprised >90% of the volatiles measured from `Florida Broadleaf' mustard and Indian mustard whereas (Z)-3-hexenyl acetate was the predominant compound emitted by the other species. Isothiocyanates were not detected by SPME from `Premium Crop' broccoli and `Blue Scotch Curled' kale although glucosinolates were found in freeze-dried leaves of all species. When exposed to AITC standard, P. ultimum growth was partially suppressed by 1.1 μmol·L-1 (μmol AITC/headspace volume) and completely suppressed by 2.2 μmol·L-1 R. solani was partially suppressed by 1.1, 2.2, and 3.3 μmol·L-1 AITC. Use of Brassica species for control of fungal pathogens is promising; the presence of AITC in both lines of B. juncea suppressed P. ultimum and R. solani but some Brassicas were inhibitory even when isothiocyanates were not detected.

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Thomas L. Thompson and Thomas A. Doerge

Three field experiments using subsurface trickle irrigation with various rates of target soil water tension (SWT) and N rates were conducted in southern Arizona during 1990–93. The experiments were conducted with collard (Brassica oleracea L. Acephela Group cv. Vates), mustard [Brassica juncea (L.) Czerniak cv. Southern Giant], and spinach (Spinacea oleracea L. cv. Indian Summer). The interactive effects of water and N treatments on crop yield, N uptake, and unutilized fertilizer N were studied. In general, excessive irrigation (SWT <5.6 kPa) resulted in lower yield and N uptake and higher unutilized fertilizer N. Optimum SWTs were 9 kPa for collard, 8 kPa for spinach, and 6 to 10 kPa for mustard.

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Thomas S.C. Li and Douglas A. Wardle

The influence of seed treatments and planting depth on the percentage of seed emergence of Hippophae rhamnoides L. `Indian-Summer', H. tibetana Schlecht., H. neurocarpa Liu & He, H. salicifolia D. Don, and H. rhamnoides subsp. rhamnoides, sinensis, turkestanica, and mongolica were studied. Surface seeding had higher percentages of seed emergence and more rapid completion of emergence compared to a 1- or 2-cm (0.4- or 0.8-inch) seeding depth. Seeds soaked in water or potassium nitrate solution at room temperature emerged in higher percentages. Average plant height of the eight species and subspecies varied significantly at the end of first growing season.

Open access

Richard L. Fery and P. D. Dukes

Abstract

‘Kiawah’ (kee'-a-waw) southernpea [Vigna unguiculata] (L.) Walp.] has been released by ARS/USDA as a replacement for ‘Pinkeye Purple Hull,’ a widely grown commercial cultivar. ‘Kiawah’ is well adapted for production throughout the southeastern United States where it can be expected to produce excellent yields of high quality, pinkeye-type peas. The major attribute of ‘Kiawah’ is its high level of resistance of root knot, a major root disease of southernpea incited by several species of the root-knot nematode genus Meloidogyne. The new cultivar is named in honor of the friendly Kiawah Indian Tribe, which welcomed and helped the original English settlers of Charleston, S.C.

Open access

Benny J. Simpson, N. P. Maxwell, and E. L. McWilliams

Abstract

Texas silverleaf, cenizo, or purple sage [Leucophyllum frutescens (Berl.) l.M. Johnst.] is native to Texas in the Rio Grande Plains, southern Trans-Pecos and sparingly in the Edwards Plateau (1, 5, 7, 8). It is not a true sage (Salvia) but is in the same family (Scrophulariaceae) as penstemon, snapdragon, and Indian paintbrush. It is found in plant hardiness zones 10a, 9a, 9b, 8b, and 8a (6) as far north as London in Kimble County where it is most prevalent on south-facing slopes of caliche hills.

Open access

A. A. Boe, Winston C. Dunwell, and Thomas J. Bakken

Abstract

‘Latah’ and ‘Shoshone’ tomatoes (Lycopersicon esculentum Mill.), are 2 new cultivars of the “Sub-Arctic Type” (1). Both are “ultra-early” cultivars which ripen with the “Sub Arctics” and will produce ripe fruit in areas where standard “early” cultivars do not mature. “Ultra-early” cultivars are a new class of tomatoes which extend the range where tomatoes may be grown into short and cool growing season areas. Under warm conditions they are useful as a very early crop ripening 14—21 days before the standard “early” cultivars. ‘Latah’ is named for Latah County, Idaho, where it was selected. ‘Shoshone’ is named for an Indian tribe of Idaho.