TY - CONF TI - Effects of harvest management on forage and grain production from wheat and triticale AU - Miller, G.L. AU - Joost, R.E. T2 - American Forage and Grassland Conference C2 - 1990/// C3 - Proceedings of American Forage and Grassland Conference DA - 1990/// PY - 1990/// SP - 339–343 ER - TY - CHAP TI - Relationship between polymerization and crystallization in microfibril biogenesis AU - Haigler, C.H. T2 - Biosynthesis and Biodegradation of Cellulose A2 - Haigler, C.H. A2 - Weimer, P PY - 1990/12// SP - 99–124 PB - Marcel Dekker SN - 0-8247-8387-5 ER - TY - JOUR TI - Flocculation series test yielding time-invariant critical coagulation concentrations of sodium illite AU - Hesterberg, D. AU - Page, A.L. T2 - Soil Science Society of America Journal AB - Abstract Critical coagulation concentrations (CCCs) of Na illite were measured using flocculation series tests. Results consistent with kinetic theories of coagulation showed the effect of coagulation/settling time on the CCC at various pH levels. A general flocculation series test procedure for reference and soil minerals is proposed. This test controls particle‐interaction dynamics and uses a long coagulation time to minimize the effects of variations in particle diffusion rates and solids concentrations, and to yield time‐invariant CCCs. After combining Na illite dispersions with a series of pH‐adjusted, concentrated NaClO 4 solutions, the mineral particles coagulated primarily by Brownian diffusion. To control the release of interlayer K from Na illite, an equilibrium K concentration of 0.1 mol m −3 was added to all suspensions. The CCCs were detected from turbidity measurements taken after various coagulation time intervals. Between 2 and 17 h, CCCs generally decreased with increasing particle‐interaction time; however, CCCs measured after 17 and 36 h were equivalent and time invariant. DA - 1990/// PY - 1990/// DO - 10.2136/sssaj1990.03615995005400030017x VL - 54 IS - 3 SP - 729-735 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0025692030&partnerID=MN8TOARS ER - TY - JOUR TI - Critical coagulation concentrations of sodium and potassium illite as affected by pH AU - Hesterberg, D. AU - Page, A.L. T2 - Soil Science Society of America Journal AB - Abstract The effects of saturating cation (Na or K) and pH on the critical coagulation concentrations (CCCs) of illite were measured. Flocculation series tests showed that between pH 6 and 11, the time‐invariant CCCs of Na illite increased from 6 to 58 mol Na m −3 ; release of interlayer K was controlled by adding 0.1 mol K m −3 to Na‐illite suspensions. The CCCs of K illite increased from 3 to 14 mol K m −3 over the pH range 6 to 10. The lower CCCs of K illite relative to Na illite were consistent with a higher surface affinity for K. Increasing CCC with increasing pH was explained by charge alterations on the edge surfaces due to surface‐specific proton interactions. A comparison of our Na‐illite CCCs to published Na‐kaolinite and Na‐montmorillonite CCCs revealed a greater pH dependence for Na‐illite and Na‐kaolinite CCCs. DA - 1990/// PY - 1990/// DO - 10.2136/sssaj1990.03615995005400030018x VL - 54 IS - 3 SP - 735-739 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0025593031&partnerID=MN8TOARS ER - TY - JOUR TI - THE VALUE OF GAMETOCLONAL VARIATION IN BREEDING FOR QUANTITATIVE TRAITS IN FLUE-CURED TOBACCO (NICOTIANA-TABACUM-L) AU - YUNG, CH AU - WERNSMAN, EA T2 - THEORETICAL AND APPLIED GENETICS DA - 1990/// PY - 1990/// DO - 10.1007/bf00210076 VL - 80 IS - 3 SP - 381-384 SN - 0040-5752 ER - TY - JOUR TI - Physioecological effects of cultural and pesticide management on no-till establishment of switchgrass and seed dormancy AU - Zarnstorff, M. E. T2 - Dissertation Abstracts International. B, Sciences and Engineering DA - 1990/// PY - 1990/// VL - 51 IS - 7 ER - TY - JOUR TI - SOYWEED - A SIMULATION-MODEL OF SOYBEAN AND COMMON COCKLEBUR GROWTH AND COMPETITION AU - WILKERSON, GG AU - JONES, JW AU - COBLE, HD AU - GUNSOLUS, JL T2 - AGRONOMY JOURNAL AB - Abstract The yield reduction caused by a particular weed species depends not only on weed density, but also on many other factors which affect both crop and weed growth through time. The objective of this study was to develop a simulation model of crop/weed competition which could be used to investigate the effects of environmental conditions on weed and crop growth. A previously developed soybean crop growth model was used to simulate the growth of soybean [ Glycine max (L.) Merr.]. A weed growth model was developed and coupled with the soybean model to describe growth of weed and soybean growing together and competing for resources. Published data from a field experiment were used to determine model parameters for common cocklebur ( Xanthium strumarium L.). In the combined soybean‐weed model, only competition for light and water are considered. Competition for light occurs within an “area of influence” around each weed. The size of this area depends on weed canopy diameter, which increases as a function of weed leaf area. Competition for water has been modeled by using a field average total leaf area (weeds and soybean) in the calculation of potential transpiration. The model developed from 1 yr of data fit data from another year reasonably well. The approach developed in this research is a practical way for modeling crop/weed competition which incorporates both the effect of environment on growth processes and the nonuniform effect of a weed on crop plants at different distances from the weed. DA - 1990/// PY - 1990/// DO - 10.2134/agronj1990.00021962008200050033x VL - 82 IS - 5 SP - 1003-1010 SN - 0002-1962 ER - TY - JOUR TI - MICROSPOROGENESIS IN PEANUT (ARACHIS-HYPOGAEA) AU - WILLCOX, MC AU - REED, SM AU - BURNS, JA AU - WYNNE, JC T2 - AMERICAN JOURNAL OF BOTANY AB - The stage of pollen development at the time of anther culture is an important factor in the production of haploids. The objectives of the current study were to develop a staining procedure for peanut (Arachis hypogaea L., ssp. hypogaea) microspores, to describe and document the stages of microsporogenesis in peanut, and to confirm a previous report concerning correlations of peanut floral bud shape with stage of microspore development. A staining procedure using propionic carmine provided adequate staining of pollen mother cells, microspores, and pollen. Pollen mother cells and microspores could easily be differentiated by their size and cell wall structure. Plants grown in a controlled environment were found to have highly synchronized microspore development, both within an anther and among anthers contained in the same bud. In addition, floral bud shape was confirmed as a reliable indicator of anther stage in peanuts. DA - 1990/10// PY - 1990/10// DO - 10.2307/2444586 VL - 77 IS - 10 SP - 1257-1259 SN - 0002-9122 ER - TY - JOUR TI - DIALLEL ANALYSIS OF COMPONENTS OF PARTIAL RESISTANCE TO SEPTORIA-NODORUM IN WHEAT AU - WILKINSON, CA AU - MURPHY, JP AU - RUFTY, RC T2 - PLANT DISEASE AB - A 5-parent full diallel and a 9-parent half diallel including adapted and exotic wheats of both winter and spring types were evaluated in the greenhouse for components of partial resistance to S. [Leptosphaeria] nodorum. F1 seedlings and parents were inoculated with a mixture of isolates of L. nodorum and evaluated for inheritance of incubation period and infection frequency. Significant general combining ability effects were found for incubation period and infection frequency. Significant specific combining ability effects were found for incubation period, but were observed in only 40% of the hybrid combinations in the full diallel and 16% of the hybrid combinations in the half diallel. Additive gene effects were most important in the inheritance of both components. Reciprocal and maternal effects were non-significant for both components of partial resistance measured by increasing incubation period and decreasing infection frequency. Another partially resistant parent (PAT 72-180) contributed to resistance through an increased incubation period only DA - 1990/1// PY - 1990/1// DO - 10.1094/PD-74-0047 VL - 74 IS - 1 SP - 47-50 SN - 0191-2917 ER - TY - JOUR TI - A comparison of preservation methods of Septoria nodorum isolates AU - Wilkinson, C. A. AU - Murphy, J. P. T2 - Cereal Research Communications DA - 1990/// PY - 1990/// VL - 18 IS - 1-2 SP - 33 ER - TY - JOUR TI - Influence of legume and rye mulches on no-till flue-cured tobacco, soil reception and dissipation of diphenamid, and weed suppression AU - Wiepke, T. T2 - Dissertation Abstracts International. B, Sciences and Engineering DA - 1990/// PY - 1990/// VL - 51 IS - 2 SP - 491 ER - TY - JOUR TI - Germplasm sources and breeding strategies for developing tobaccos with disease and pest resistance AU - Wernsman, E. A. T2 - Bulletin d'Information - CORESTA DA - 1990/// PY - 1990/// IS - 7 SP - 55 ER - TY - JOUR TI - SUBUNIT AND AMINO-ACID-COMPOSITION OF DIACYLGLYCEROL ACYLTRANSFERASE FROM GERMINATING SOYBEAN COTYLEDONS AU - KWANYUEN, P AU - WILSON, RF T2 - BIOCHIMICA ET BIOPHYSICA ACTA AB - The subunit and amino acid composition of the enzyme that catalyses triacylglycerol synthesis was determined for the first time from plant tissues. Diacylglycerol acyltransferase (acyl-CoA:1,2-diacylglycerol O-acyltransferase, EC 2.3.1.20) purified from germinating soybean (Glycine max L. Merr. cv. Dare) cotyledons, dissociated into three nonidentical subunits having apparent molecular masses of 40.8, 28.7, and 24.5 kDa. The respective subunits occurred in a 1:2:2 molar ratio in the native enzyme. Five peptides in that molar ratio were assumed to constitute a monomer having a putative molecular mass of 153.1 kDa. Based upon the apparent molecular mass of purified diacylglycerol acyltransferase after delipidation (1539 kDa), there was a high probability that the complete structure of the native enzyme from soybean contained ten identical monomers. The polarity index of each subunit was less than 21%, far below the 40% boundary reported for membrane bound proteins. Hydrophobic amino acids accounted for greater than 48% of the composition in each subunit. It was predicted from these data that the native enzyme contained 12,525 amino acid residues, and that the two smaller subunits were more deeply embedded in the membrane than the 40.8 kDa subunit. Attempts to reactivate the denatured or delipidated protein were not successful. DA - 1990/5/31/ PY - 1990/5/31/ DO - 10.1016/0167-4838(90)90227-7 VL - 1039 IS - 1 SP - 67-72 SN - 0006-3002 ER - TY - JOUR TI - REGISTRATION OF NC-BMR 42 AND NC-BMR 90 GERMPLASM LINES OF TOBACCO AU - RUFTY, RC AU - WERNSMAN, EA AU - MAIN, CE AU - GOODING, GV T2 - CROP SCIENCE AB - Crop ScienceVolume 30, Issue 1 cropsci1990.0011183X003000010071x p. 241-242 Registration of Germplasms Registration of NC-BMR 42 and NC-BMR 90 Germplasm Lines of Tobacco R. C. Rufty, Corresponding Author R. C. Rufty n/[email protected] Dep. of Crop ScienceCorresponding author.Search for more papers by this authorE. A. Wernsman, E. A. Wernsman Dep. of Crop ScienceSearch for more papers by this authorC. E. Main, C. E. Main Dep. of Crop ScienceSearch for more papers by this authorG. V. Gooding Jr., G. V. Gooding Jr. Dep. of Plant Pathology, North Carolina State University, Raleigh, NC, 27695Search for more papers by this author R. C. Rufty, Corresponding Author R. C. Rufty n/[email protected] Dep. of Crop ScienceCorresponding author.Search for more papers by this authorE. A. Wernsman, E. A. Wernsman Dep. of Crop ScienceSearch for more papers by this authorC. E. Main, C. E. Main Dep. of Crop ScienceSearch for more papers by this authorG. V. Gooding Jr., G. V. Gooding Jr. Dep. of Plant Pathology, North Carolina State University, Raleigh, NC, 27695Search for more papers by this author First published: 01 January 1990 https://doi.org/10.2135/cropsci1990.0011183X003000010071xCitations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume30, Issue1January–February 1990Pages 241-242 RelatedInformation DA - 1990/// PY - 1990/// DO - 10.2135/cropsci1990.0011183X003000010071x VL - 30 IS - 1 SP - 241-242 SN - 0011-183X ER - TY - JOUR TI - PHOSPHORUS STRESS EFFECTS ON ASSIMILATION OF NITRATE AU - RUFTY, TW AU - MACKOWN, CT AU - ISRAEL, DW T2 - PLANT PHYSIOLOGY AB - An experiment was conducted to investigate alterations in uptake and assimilation of NO(3) (-) by phosphorus-stressed plants. Young tobacco plants (Nicotiana tabacum [L.], cv NC 2326) growing in solution culture were deprived of an external phosphorus (P) supply for 12 days. On selected days, plants were exposed to (15)NO(3) (-) during the 12 hour light period to determine changes in NO(3) (-) assimilation as the P deficiency progressed. Decreased whole-plant growth was evident after 3 days of P deprivation and became more pronounced with time, but root growth was unaffected until after day 6. Uptake of (15)NO(3) (-) per gram root dry weight and translocation of absorbed (15)NO(3) (-) out of the root were noticeably restricted in -P plants by day 3, and effects on both increased in severity with time. Whole-plant reduction of (15)NO(3) (-) and (15)N incorporation into insoluble reduced-N in the shoot decreased after day 3. Although the P limitation was associated with a substantial accumulation of amino acids in the shoot, there was no indication of excessive accumulation of soluble reduced-(15)N in the shoot during the 12 hour (15)NO(3) (-) exposure periods. The results indicate that alterations in NO(3) (-) transport processes in the root system are the primary initial responses limiting synthesis of shoot protein in P-stressed plants. Elevated amino acid levels evidently are associated with enhanced degradation of protein rather than inhibition of concurrent protein synthesis. DA - 1990/9// PY - 1990/9// DO - 10.1104/pp.94.1.328 VL - 94 IS - 1 SP - 328-333 SN - 0032-0889 ER - TY - JOUR TI - Metabolism of metolachlor by a microsomal fraction isolated from grain sorghum (Sorghum bicolor) shoots AU - Moreland, D. E. AU - Corbin, F. T. AU - Novitzky, W. P. AU - Parker, C. E. AU - Tomer, K. B. T2 - Zeitschrift fur Naturforschung. C, Biosciences AB - A microsomal fraction isolated from the shoots of 3- to 4-day-old, dark-grown, grain sorghum (Sorghum bicolor cv. Funk G 522 DR) seedlings was characterized. The preparations had a cytochrome P-450 content that varied from approximately 90 to 150 pmol P-450/mg protein with cytochrome P-420 varying from 0 to 3% of the P-450 content. Type I difference spectra were formed with cinnamic acid and metolachlor, and a type II spectrum was formed with tetcyclacis. In short-term assays with [14C]metolachlor as substrate, the preparations produced a single time-dependent product that separated on silica gel TLC plates developed in benzene/acetone (2:1, v/v). RF values for metolachlor and the metabolite were approximately 0.70 and 0.48, respectively. The microsomal reaction required NADPH and oxygen, and was inhibited by carbon monoxide, with the inhibition being partially reversed by actinic light. Compounds known to inhibit the activity of cytochrome P-450 monooxygenases (piperonyl butoxide, tetcyclacis, and tridiphane) also prevented formation of the metabolite. Identity of the metabolite was confirmed by TLC and positive ion thermospray LC/MS to be 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-hydroxy-1-methylethyl)acetamide . Hence, the reaction catalyzed by the sorghum microsomes involved O-demethylation of the methoxypropyl side chain of metolachlor. DA - 1990/// PY - 1990/// DO - 10.1515/znc-1990-0544 VL - 45 IS - 5 SP - 558 ER - TY - JOUR TI - ALTERATIONS IN NITROGEN ASSIMILATION AND PARTITIONING IN NITROGEN STRESSED PLANTS AU - RUFTY, TW AU - MACKOWN, CT AU - VOLK, RJ T2 - PHYSIOLOGIA PLANTARUM AB - Although nutrient stress is known to alter partitioning between shoots and roots, the physiological basis for the phenomenon is unresolved. Experiments were conducted to examine assimilation of 15 NO 3 by N‐stressed plants and to determine whether apparent changes in assimilation in the root contributed to alterations in whole‐plant partitioning of reduced‐N. Tobacco plants ( Nicotiana tabacum L. cv. NC 2326) were exposed to a low concentration of NO 3 − in solution (80 μ M ) for 9 days to effect a N‐stress response. Exposure of plants to 1000 μ M 15 NO 3 − for 12 h on selected days revealed that roots of N‐stressed plants developed an increased capacity to absorb NO 3 − , and accumulation of reduced‐ 15 N in the root increased to an even greater extent. When plants were exposed to 80 or 1000 μ M 15 NO 3 − in steady‐state, 15 NO 3 − uptake over a 12 h period was noticeably restricted at the lower concentration, but a larger proportion of the absorbed 15 N still accumulated as reduced‐ 15 N in the root. The alteration in reduced‐ 15 N partitioning was maintained in N‐stressed plants during the subsequent 3‐day “chase” period when formation of insoluble reduced‐ 15 N in the root was quantitatively related to the disappearance of 15 NO 3 − and soluble reduced‐ 15 N. The results indicate that increased assimilation of absorbed NO 3 − , in the root may contribute significantly to the altered reduced‐N partitioning which occurs in N‐stressed plants. DA - 1990/5// PY - 1990/5// DO - 10.1111/j.1399-3054.1990.tb05870.x VL - 79 IS - 1 SP - 85-95 SN - 0031-9317 ER - TY - JOUR TI - ACCLIMATION OF BARLEY TO CHANGES IN LIGHT-INTENSITY - PHOTOSYNTHETIC ELECTRON-TRANSPORT ACTIVITY AND COMPONENTS AU - DELATORRE, WR AU - BURKEY, KO T2 - PHOTOSYNTHESIS RESEARCH DA - 1990/5// PY - 1990/5// DO - 10.1007/BF00032593 VL - 24 IS - 2 SP - 127-136 SN - 1573-5079 ER - TY - JOUR TI - ACCLIMATION OF BARLEY TO CHANGES IN LIGHT-INTENSITY - CHLOROPHYLL ORGANIZATION AU - DELATORRE, WR AU - BURKEY, KO T2 - PHOTOSYNTHESIS RESEARCH DA - 1990/5// PY - 1990/5// DO - 10.1007/BF00032592 VL - 24 IS - 2 SP - 117-125 SN - 1573-5079 ER - TY - JOUR TI - THE RESIDUAL EFFECT OF SEWAGE-SLUDGE ON HEAVY-METAL CONTENT OF TOBACCO AND PEANUT AU - KING, LD AU - HAJJAR, LM T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Abstract Sewage sludge normally would not be applied on land where peanut ( Arachis hypogaea L.) or tobacco ( Nicotiana tabacum L.) are being grown because of possible contamination of peanut with pathogens and increased Cd concentration in tobacco. These crops, however, might be grown in rotation with other crops to which sludge had been applied. The residual effect of sewage sludge on metal concentrations in tobacco and peanut was evaluated in a greenhouse pot experiment with a Typic Hapludult soil from a field that received aerobically digested municipal sewage sludge at 0, 9, 18, and 27 Mg ha − yr −1 for 3 yr. Cumulative amount of metals applied at the 27‐Mg rate were (kg ha −1 ) 1.8 Cd, 39 Cu, 48 Cr, 9 Ni, 30 Pb, and 84 Zn. Sulfuric acid or Ca(OH) 2 was used to effect three soil pH regimes: 5.2, 5.8, and 6.4 (median value within each regime). Tobacco (‘Speight G‐28’) was grown to flowering and peanut (NC 7) was grown to maturity. At the termination of the experiment, soils were extracted with diethylenetriaminepentaacetic acid (DTPA) and Mehlich 3 extractant (M3) for metal analysis. Tobacco dry weight (averaged over pH) increased from 66 g pot −1 with no sludge to 94 g pot −1 at the highest sludge rate. Peanut kernel yield (averaged over pH) was depressed at the highest rate (35 g pot −1 ) as compared to the lower rates (mean of 48 g pot −1 ). At low pH peanut top growth was depressed by sludge (probably a result of Zn toxicity) and no kernels were formed at the medium and high rates. Sludge rates and soil pH had little effect on concentration of Cr and Pb in tobacco or peanut. Concentration of Cd, Ni, and Zn in tobacco and in peanut top growth decreased as soil pH increased to 5.8 to 6.0 but no decrease was noted at higher pH. Sludge rate effect was significant at low pH but diminished as pH increased. Concentration of Cd, Ni, and Zn declined but Cu concentration increased with increasing height of leaf on the tobacco stalk. Results of stepwise multiple regression using linear and quadratic forms of cumulative sludge rate, soil pH, and DTPA‐extractable metals and pH × rate and pH × DTPA‐extractable metals interactions as independent variables and metal concentration in the lower tobacco leaves or in peanut tops as dependent variables suggested DTPA would predict tissue metal concentrations better than would M3. DA - 1990/// PY - 1990/// DO - 10.2134/jeq1990.00472425001900040018x VL - 19 IS - 4 SP - 738-748 SN - 1537-2537 ER - TY - CHAP TI - Plant analysis as an aid in fertilizing tobacco AU - Miner, G. S. AU - Tucker, M. R. T2 - Soil testing and plant analysis (3rd ed.) PY - 1990/// SP - 645 PB - Madison, Wis., USA : Soil Science Society of America Inc SN - 0891187936 ER - TY - JOUR TI - PHOSPHORUS MANAGEMENT FOR CONTINUOUS CORN-COWPEA PRODUCTION IN A BRAZILIAN AMAZON OXISOL AU - SMYTH, TJ AU - CRAVO, MS T2 - AGRONOMY JOURNAL AB - Abstract Although Oxisols occupy extensive areas in the Amazon, few studies have addressed their fertilizer P requirements for sustained, long‐term crop production. This field study was conducted to evaluate initial and long‐term responses to P rates and placement by corn ( Zea mays L.) and cowpea ( Vigna Unguiculata L.) when grown in annual rotation during five consecutive years in a Xanthic Hapludox (clayey, kaolinitic, isohyperthermic) near Manaus, Brazil. Effects on yields of sole broadcast P rates of 0, 22, 44, 88 and 176 kg ha −1 in split‐plot combination with subplot banded P rates of 0, 11, 22 and 44 kg ha −1 were evaluated over 11 total crops. Banded P at 11 kg ha −1 was applied to every crop and rates of 22 and 44 kg P ha −1 were only applied to the initial eight and four crops, respectively. Residual effect of broadcast P, as measured by both yields and Mehlich 1 soil P, were greater at high rates. Although cowpea yields were increased up to the highest band rate, no response in corn yields were observed beyond the rate of 22 kg P ha −1 . At equal amounts of applied P, banded P provided greater yields than broadcast P during the initial crops. Total corn and/or cowpea yields, after 11 crops, were similar for all broadcast and band combinations at equal amounts of total applied P. The absence of a cumulative yield difference among placement methods indicated that banded placement of 22 and 44 kg P ha −1 to corn and cowpea, respectively, would be the best method of applying P to sustain long‐term crop production under the manual tillage practices used in the region. DA - 1990/// PY - 1990/// DO - 10.2134/agronj1990.00021962008200020026x VL - 82 IS - 2 SP - 305-309 SN - 1435-0645 ER - TY - JOUR TI - GENOTYPE AND TOPPING STAGE IN RELATION TO MATURITY IN BURLEY TOBACCO AU - KELLEY, WT AU - BOWMAN, DT T2 - AGRONOMY JOURNAL AB - Abstract The danger of frost damage on burley tobacco ( Nicotiana tabacum L.) is an ever present risk to growers in western North Carolina. Therefore, a study was initiated to investigate the effects of topping stage and use of early and late‐flowering genotypes on maturity. Four genotypes (‘TN 86’, ‘VA 509’, m.s. Burley 21 ✕ L8, and ‘m.s. Ky 14 ✕ L8’) and three topping stages (early button, elongated button, and full flower) were examined at two locations (Laurel Springs and Waynesville, NC) in 1986 and 1987. Maturity was assessed by visually examining color of the tenth leaf from the bottom of the plant using a scale which is highly correlated with relative concentrations of chlorophylls and carotenoids and is based on the Munsell Color Charts for Plant Tissues. Data on color at harvest were analyzed. Late‐flowering cultivars, TN 86 and VA 509, were found to be paler in color at harvest. The paler color at harvest of the cultivars did not always translate into better quality tobacco in the cured leaf state. Choice of cultivar for short‐season environments should not necessarily be based on flowering date but on final quality of the cured leaf based on data collected over several seasons. DA - 1990/// PY - 1990/// DO - 10.2134/agronj1990.00021962008200060016x VL - 82 IS - 6 SP - 1107-1109 SN - 0002-1962 ER - TY - JOUR TI - Fumigation of tobacco plantbeds with dazomet AU - Miner, G. S. AU - Worsham, D. A. T2 - Tobacco International DA - 1990/// PY - 1990/// VL - 192 IS - 16 SP - 119 ER - TY - JOUR TI - CRITICAL PHOSPHORUS LEVELS FOR CORN AND COWPEA IN A BRAZILIAN AMAZON OXISOL AU - SMYTH, TJ AU - CRAVO, MS T2 - AGRONOMY JOURNAL AB - Abstract Phosphorus soil test interpretations in the Brazilian Amazon currently do not account for differences in P requirements among crops and lack information on the changes in available soil P per unit of applied fertilizer P. A long‐term P experiment in a Xanthic Hapludox near Manaus, Brazil was used to determine soil and leaf P critical levels for corn ( Zea mays L.) and cowpea ( Vigna unguiculata L.). A total of six corn crops were planted in annual rotation with five crops of cowpea during five consecutive years. Critical levels were established by a segmented linear regression, a linear plateau, of relative crop yields on soil test or leaf P concentrations for each crop species. Mehlich 1 (1:10) critical P levels were 6 and 8 mg kg −1 for corn and cowpea, respectively. Relationships between soil test P and crop yields were similar for fertilizer P placement as either broadcast and/or frequent bands. Fertilizer P required to raise the initial Mehlich 1 soil P to the critical levels were 41 and 60 kg P ha −1 for corn and cowpea, respectively. Higher amounts of P were extracted by Bray 1 than by Mehlich 1, but both extractants were effective in relating available soil P to yield and applied fertilizer P. Critical foliar P concentrations for corn and cowpea were 1.6 and 1.8 g kg −1 , respectively. Higher soil and leaf P critical levels for cowpea relative to corn were attributed to greater P requirements for plants depending on symbiotic N 2 fixation for their N supply. DA - 1990/// PY - 1990/// DO - 10.2134/agronj1990.00021962008200020027x VL - 82 IS - 2 SP - 309-312 SN - 1435-0645 ER - TY - JOUR TI - A colour scale for rapid measurement of relative pigment concentration in burley tobacco leaves AU - Kelley, W. T. AU - Danehower, D. A. AU - Bowman, D. T. T2 - Tobacco International DA - 1990/// PY - 1990/// VL - 192 IS - 5 SP - 35 ER - TY - JOUR TI - Rf4 from A619 maps distal to BNL13.05 on 8-S AU - Sisco, P. H. T2 - Maize Genetics Cooperation Newsletter DA - 1990/// PY - 1990/// IS - 64 SP - 97 ER - TY - JOUR TI - Information, expectations, and foreign exchange market efficiency AU - Pearce, D. K. AU - Kitchen, J. T2 - International financial markets and agricultural trade DA - 1990/// PY - 1990/// SP - 214 ER - TY - JOUR TI - INHERITANCE OF RESISTANCE TO ANGULAR LEAF-SPOT IN NICOTIANA-TABACUM-L CULTIVARS BURLEY-21 AND KENTUCKY-14 AU - WANNAMAKER, MJ AU - RUFTY, RC T2 - EUPHYTICA DA - 1990/4// PY - 1990/4// DO - 10.1007/BF00027225 VL - 46 IS - 3 SP - 253-258 SN - 1573-5060 ER - TY - JOUR TI - Field performance of nonclipped, clipped and intact-root flue-cured tobacco seedlings AU - Pfeiffer, I. AU - Smith, W. D. AU - Collins, W. K. AU - Peedin, G. F. AU - Miner, G. S. T2 - Tobacco International DA - 1990/// PY - 1990/// VL - 192 IS - 5 SP - 38 ER - TY - JOUR TI - FIELD DROUGHT TOLERANCE OF A SOYBEAN PLANT INTRODUCTION AU - SLOANE, RJ AU - PATTERSON, RP AU - CARTER, TE T2 - CROP SCIENCE AB - Rainfall is seldom sufficient to meet the evaporative and transpirational demands of a soybean crop [ Glycine max (L.) Merr.] in the southeastern USA. Development of new drought‐tolerant cultivars would thus seem an effective way in which to address the problem of moisture stress. Unfortunately, few drought‐tolerant genotypes have been identified for use as breeding stock. The objective of this study was to compare the relative droughtolerance of plant introduction PI 416937, a visually slow‐wilting accession, with that of ‘Forrest’, a popular cultivar of similar maturity. Leaf water potential (Ψw), solute potential (Ψs), and relative water content (RWC) these genotypes were measured under two levels of soil water adjustment (well‐watered and water‐stressed at early pod‐fill) during 2 yr in the field (on a Varina loamy sand, a clayey, kaolinitic, thermic Plinthic Paleudult). Although water stress reduced Ψw equally for both genotypes, PI 416937 maintained lower levels of Ψs and. higher levels of pressure potential and RWC than Forrest. A comparison of the relationship between RWC and Ψs for the two genotypes indicated that the PI may accumulate more solutes in leaf tissue under stress than Forrest. That is, at a normalized leaf pressure potential of zero, the Ψs of the PI was estimated to be 0.3 MPa lower than that of Forrest. Seed yields of Forrest and the unadapted PI were comparable under stress. However, stress reduced the yield of Forrest by more than half while reducing yield of the PI by only a third. The superior turgor maintenance and competitive yielding ability of the unadapted PI under stress indicated that the PI may be an important source of drought tolerance for breeding programs. DA - 1990/// PY - 1990/// DO - 10.2135/cropsci1990.0011183X003000010027x VL - 30 IS - 1 SP - 118-123 SN - 1435-0653 ER - TY - JOUR TI - Chromosome 1L AU - Sisco, P. H. T2 - Maize Genetics Cooperation Newsletter DA - 1990/// PY - 1990/// IS - 64 SP - 128 ER - TY - JOUR TI - Changes in ruminal and fecal particle weight distribution of steers fed coastal bermudagrass hay at four levels AU - Luginbuhl, J. M. AU - Pond, K. R. AU - Burns, J. C. T2 - Journal of Animal Science AB - Samples of digesta from the ruminal upper strata (RUS) and feces (F) were taken from four ruminally cannulated steers fed Coastal bermudagrass hay (78% NDF) in the long form to evaluate the effects of feeding level and time postfeeding on particle breakdown. The experimental design was a 4 x 4 Latin square with 18-d periods. Treatments based on previous intakes were set at 50, 70, 90 and 110% (3.1, 4.4, 5.5 and 6.7 kg/d, respectively) of feed consumed per animal and fed at 12-h intervals. Samples were taken at 2, 6 and 12h postfeeding and wet-sieved. Dry matter weight distribution of total recovered particles was used to partition RUS and F digesta among percentages of large (greater than 4.0 mm), medium (greater than 4.0 and less than or equal to 1.0 mm), small (less than 1.0 and greater than or eual to .125 mm) and fine (less than .125 and greater than or equal to .0027 mm) particles. With increasing feeding level, the percentage of medium RUS particles increased linearly (P less than .02), whereas the percentage of fine RUS particles decreased linearly (P less than .01). Increased time postfeeding resulted in a linear decrease in the percentage of large RUS particles (P less than .01), a linear increase in the percentage of small RUS particles (P less than .01) and in a quadratic increase in the percentage of fine RUS particles (P less than .01). Percentage of medium RUS particles remained unchanged. Increasing feeding level resulted in linear increases in mean RUS (P less than .01) and F (P less than .02) particle sizes. Percentages of RUS and F material passing through a 1.0-mm sieve averaged 52.8 and 88.8%, respectively. Animal-to-animal variation in proportions of RUS and mixed reticuloruminal particles was not entirely removed by rumination and was still reflected in the percentages of F particles. Factors such as particle entrapment in the fiber mat, reticular sedimentation, changes in specific gravity, swelling and hydration capacity, reticuloruminal motility and amount of digesta exiting per contraction appear to be more important than particle size reduction in the regulation of the passage of digesta from the reticulorumen. DA - 1990/// PY - 1990/// DO - 10.2527/1990.6892864x VL - 68 IS - 9 SP - 2864 ER - TY - JOUR TI - A morphological appraisal of wild species in section Arachis of peanuts AU - Stalker, H. T. T2 - Peanut Science AB - Abstract The cultivated peanut, Arachis hypogaea L., is a member of section Arachis nom. nud. along with its tetraploid progenitor, A. monticola Krap. et Rig., four validly described diploid species, eight diploid species whose names have never been validly published, and a large collection of taxa discovered since 1975. Systematic relationships and possible species circumscriptors are assessed in section Arachis by means of numerical taxonomy. Seventy-three accessions were grown in the field and three randomly selected specimens of each accession were evaluated. Numerical techniques in the form of cluster and principal components analyses were used on 56 characters, including 20 reproductive, 30 vegetative, and six created variables. Most variation was observed for leaflet size and shape, followed by branching habits and flower size. Although grouping of accessions did not always conform to expectations based on published species descriptions, general relationships among taxa are evident from the analyses. A total of 20 to 25 species will likely exist in section Arachis based on the observed variability. DA - 1990/// PY - 1990/// DO - 10.3146/i0095-3679-17-2-17 VL - 17 IS - 2 SP - 117 ER - TY - JOUR TI - RECURRENT SELFED PROGENY SELECTION FOR YIELD IN SOYBEAN USING GENETIC MALE-STERILITY AU - BURTON, JW AU - KOINANGE, EMK AU - BRIM, CA T2 - CROP SCIENCE AB - The value of recurrent S 1 line selection using genetic male sterility to achieve intercrosses has been questioned because of reduced seed set on male‐sterile S 1 progenies, which can affect the precision of yield measurements. Recurrent S 1 progeny selection for yield was practiced in two soybean [ Glycine max (L.) Merr.] populations (designated II and III) that segregate for genetic male sterility. Recombination of selected lines was accomplished through insect pollination, and yield evaluations of S 1 families disregarded the occurrence of male‐sterile plants in the plots. This study determined (i) rates of progress from four cycles of selection on seed yield in both populations and (ii) effects of selection for yield on other agronomic traits. Yield of Population II increased 76.6 ± 23.8 kg ha ‒1 cycle ‒1 ( b ± SE), for a 2.1% yr ‒1 increase; plant height increased 5.9% and lodging decreased 8.9% over the four cycles. Selection in Population III did not produce a significant (P > 0.05) linear increase in seed yield (only 37.7 ± 55.7 kg ha ‒ 1 cycle ‒ 1 ) and there were no significant (P > 0.05) changes in other traits. The success of selection for yield in Population II but not in Population III was most likely due to differences in genetic variability and heritability between the two. Because yield improvement was significant in Population II, it was concluded that segregation of male sterility in the S 1 families was not a serious impediment to the evaluation of their relative yield potentials. Thus, genetic male sterility proved to be a useful tool for recurrent yield selection because of the ease with which selected lines are intermated. DA - 1990/// PY - 1990/// DO - 10.2135/cropsci1990.0011183X003000060013x VL - 30 IS - 6 SP - 1222-1226 SN - 0011-183X ER - TY - JOUR TI - MOVEMENT OF RHIZOBIA BETWEEN ALFALFA PLANTS AU - CHAMBLEE, DS AU - WARREN, RD T2 - AGRONOMY JOURNAL AB - Abstract Evidence on the rapidity of movement of rhizobia in the soil is inconclusive. Successful inoculation of most of the legume plants in a field would result in subsequent inoculation of the remaining plants if substantial movement of legume bacteria occurred. The objective of this study was to determine the distance rhizobia move in the soil between inoculated and noninoculated alfalfa ( Medicago sativa L.) plants during the seeding year. Three field experiments were conducted in North Carolina. Experiments 1 and 2 were established on a Norfolk sandy loam (fine‐loamy, siliceous thermic Typic Paleudult) and Exp. 3 on an Appling sandy loam (kaolinitic thermic Typic Hapludult). Alternating rows of inoculated and noninoculated alfalfa (subplots) were seeded at spacings of 15,30 and 60 cm (whole plots) in four replications. Periodic measurements of nodulation, color, height of top growth and N concentration of top growth and roots were made. Results indicated that the lateral movement of rhizobia in an 11‐month period was largely limited to a distance of 15 cm. There was evidence that substantial N was obtained by noninoculated alfalfa rows from adjacent inoculated (15‐cm spacing) rows by sloughing and/or excretion. DA - 1990/// PY - 1990/// DO - 10.2134/agronj1990.00021962008200020021x VL - 82 IS - 2 SP - 283-286 SN - 1435-0645 ER - TY - JOUR TI - LONG-TERM SWINE LAGOON EFFLUENT APPLICATIONS ON COASTAL BERMUDAGRASS .1. YIELD, QUALITY, AND ELEMENT REMOVAL AU - BURNS, JC AU - KING, LD AU - WESTERMAN, PW T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Abstract Swine ( Sus scrofa domesticus ) confinement systems that use anaerobic lagoons for waste collection in the humid regions require effluent removal during the year. Land area adjacent to the hog facility frequently becomes the site for continuous effluent distribution. The objective of this experiment was to determine the effect of long‐term application of swine lagoon effluent to ‘Coastal’ bermudagrass [ Cynodon dactylon (L.) Pers.] on dry matter yield, stand persistence, and nutrient concentration and removal. Effluent loading rates of low (L), medium (M), and high (H) approximating 335, 670, and 1340 kg of N ha −1 yr −1 , respectively, were evaluated for 11 yr beginning in 1973 through 1983. The experiment was a randomized complete block with three replicates. Dry matter yields in Year 11 were altered by effluent loading rates with greater production from the M (19.0 Mg ha −1 ) or H (19.6 Mg ha −1 ) compared with the L (13.1 Mg ha −1 ). Although fluxes in stands occurred, they recovered completely as indicated by these yields. Higher concentrations of N, P, K, Mg, Cl, and Zn were present in forage in 1983 compared with 1973. Calcium was unchanged and Cu, Fe, and Na were less. In vitro dry matter disappearance of the forage was similar among loading rates (0.634) in 1983 and greater than in 1973 (0.553). Concentrations of NO 3 ‐N were higher in 1978 (1.14 g kg −1 ) compared with 1973 (0.87 g kg −1 ), but highest concentrations occurred in 1983 (1.57 g kg −1 ). By 1983, NO 3 ‐N concentrations of forages from the H loading rate approached or exceeded the toxic threshold in all summer harvests. Only the H loading (1340 kg ha −1 ) caused unstable stands and eventually produced forage that had NO 3 ‐N concentrations potentially toxic if fed as the sole ration to ruminants. Further, it resulted in disproportionally greater quantities of elements—especially N, P, K, Cl, and Na—that remained in the soil environment to become potential soil and soil‐water pollutants. DA - 1990/// PY - 1990/// DO - 10.2134/jeq1990.00472425001900040019x VL - 19 IS - 4 SP - 749-756 SN - 0047-2425 ER - TY - JOUR TI - DIALLEL ANALYSIS OF RESISTANCE TO ANTHRACNOSE STALK ROT IN MAIZE INBREDS AU - CALLAWAY, MB AU - SMITH, ME AU - COFFMAN, WR T2 - CROP SCIENCE AB - Anthraenose stalk rot (ASR), caused by Colletotrichum graminicola (Ces.) Wils., has become an important disease of maize ( Zea mays L.) in recent years. The purposes of this study were to evaluate general and specific combining ability effects for ASR resistance in a group of maize inbreds adapted to the northeastern USA, and to evaluate two commonly used ASR rating methods. Eight maize inbreds were crossed in a fixed effects diallel mating design and parents and crosses were grown at locations in New York, Delaware, and Pennsylvania. The two methods of rating for ASR resistance were: (i) total number of internodes infected, and (ii) number internodes greater than 75% infected. The inbreds LB31B, RD5264, and RD6501 had highly significant negative general combining ability effects for ASR ratings, indicating that these lines would be good choices as parents where ASR resistance is desired. The inbreds RD5215, RD5217, RD5529, B59Ht, and B37 had significant, positive general combining ability effects. Specific combining ability was important for certain combinations of lines. Results for the two rating methods were practically identical. Only one of the two rating methods need be used in a given year. The evaluation methods should be alternated at yearly intervals to minimize the possibility of preferential selection for a particular mechanism of resistance. DA - 1990/// PY - 1990/// DO - 10.2135/cropsci1990.0011183X003000020018x VL - 30 IS - 2 SP - 335-337 SN - 0011-183X ER - TY - JOUR TI - ALUMINUM TOLERANCE IN SOYBEAN .1. GENOTYPIC CORRELATION AND REPEATABILITY OF SOLUTION CULTURE AND GREENHOUSE SCREENING METHODS AU - CAMPBELL, KAG AU - CARTER, TE T2 - CROP SCIENCE AB - Breeding for Al tolerance in soybean [ Glycine max (L.) Merr.], has been hindered by confusion regarding screening methodology. This study was undertaken to determine the relationship between greenhouse and solution culture screening methods, using 12 diverse soybean genotypes. Greenhouse media consisted of a Goldsboro sandy loam (fine‐loamy, siliceous, thermic Aquic Paledult) at 19% Al saturation and the same soil amended with Al 2 (SO 4 ) 3 to 55% Al saturation. Solution‐culture media consisted of 0 or 11 μ M Al 2 (SO 4 ) 3 added to 200 μ M CaSO 4 solutions. Traits measured were shoot dry weight in greenhouse pots and radical elongation rate in solution culture. Aluminum tolerance was detected with both screening methods; however, unlike previous studies, agreement between methods was good ( r G = 0.81), indicating that the solution‐culture screen does have some utility in plant breeding. The solution‐culture screen had a higher repeatability (0.78, based on six replications, compared with 0.54 for the greenhouse), further substantiating its utility. Two factors were critical in establishing the relationship between the two screens: (i) expression of Al tolerance as a percentage of the control and (ii) abundant replication in the greenhouse. Reliance on growth in Al alone as a measure of tolerance led to poor agreement between methods in our study and is not recommended for breeding purposes, except where the genetic population is very uniform morphologically. Earlier published studies of Al tolerance in the greenhouse may have suffered from inadequate replication. DA - 1990/// PY - 1990/// DO - 10.2135/cropsci1990.0011183X003000050019x VL - 30 IS - 5 SP - 1049-1054 SN - 0011-183X ER - TY - JOUR TI - The effectiveness of early generation testing as applied to a recurrent selection program in peanut AU - Halward, T. M. AU - Wynne, J. C. AU - Monteverde-Penso, E. J. T2 - Peanut Science AB - Abstract The effectiveness of early generation testing for yield improvement in peanut (Arachis hypogaea L.) was evaluated in an attempt to increase the efficiency of an on-going recurrent selection program by reducing the time required for evaluation and selection. The objectives of the study were to (1) determine if the number of years required per cycle of selection could be reduced; and (2) estimate the amount of genetic variability remaining in the population for yield and four agronomic traits after four cycles of recurrent selection. Sixty-eight random-mated crosses, among the 40 highest yielding lines from the cycle 3 population, were evaluated for yield and agronomic traits in 1985 (S0:1), 1986 (S0:2), and 1987 (S0:3). The results were compared to determine if early generation performance accurately predicts the performance of cross bulks in later generations. No significant correlations were found for yield of entries in the S0:3 and S0:2 or in the S0:3 and S0:1; however, there was a significant correlation between yield of entries in the S0:2 and S0:1 generations. No correlations were found between yield and any of the agronomic traits measured in the S0:3; however, significant correlations were found in the S0:2 between yield and most traits measured. Significant correlations were also found for entries in the S0:3 and S0:2 generations for each agronomic trait measured except number of seed per 20 pods. Early generation testings appears to be useful for selection of certain agronomic traits, but of limited value when selecting for yield. A decrease in genetic variation for yield in the population from the S0:1 to the S0:3 generation was observed; however, the number of crosses equal to or exceeding the yield of the check cultivar increased in later generations. All agronomic traits measured, except number of seed per 20 pods, showed significant genetic variation remaining in the population in both the S0:2 and S0:3 generations. The greater the genetic variation remaining in the population for a given trait, the more likely it is that further improvement of that trait will be realized with additional cycles of selection. DA - 1990/// PY - 1990/// DO - 10.3146/i0095-3679-17-1-14 VL - 17 IS - 1 SP - 44 ER - TY - JOUR TI - STATISTICAL PROCEDURES FOR ASSESSMENT OF RESISTANCE IN A MULTIPLE FOLIAR DISEASE COMPLEX OF PEANUT AU - ANDERSON, WF AU - BEUTE, MK AU - WYNNE, JC AU - WONGKAEW, S T2 - PHYTOPATHOLOGY AB - Early leaf spot caused by Cercospora arachidicola, late leaf spot caused by Cercosporidium personatum, and rust caused by Puccinia arachidis are the three most important foliar fungal diseases of peanut (Arachis hypogaea) worldwide. A 10-parent diallel cross was performed using peanut lines susceptible and resistant to the three major foliar fungi. The objective was to investigate the interrelationship of the multiple disease complex with host genes for resistance. Parents and F 1 hybrid progeny were planted in the field in Thailand in 1985 (...) DA - 1990/12// PY - 1990/12// DO - 10.1094/Phyto-80-1451 VL - 80 IS - 12 SP - 1451-1459 SN - 1943-7684 ER - TY - JOUR TI - READILY MEASURABLE SOIL PROPERTIES THAT AFFECT THE PHOSPHORUS-FERTILIZER REQUIREMENT OF ULTISOLS AU - COX, FR AU - ESPEJO, R T2 - COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS AB - Abstract Phosphorus fertilizer recommendations could be improved mark‐edly if, in addition to the extractable P concentration, some estimate of the P buffering capacity were considered. Measuring the P buffering capacity or its estimate from clay content or surface area, however, is too time consuming for most soil testing laboratories. Soil samples from the southeastern USA and western Spain were analyzed for several properties that either are or could be measured readily. These properties were cation exchange capacity (CEC), sample density (SD), humic matter (HM), and a color index (CHL). Topsoil samples with HM > 20 g/L were eliminated from the set. The P buffering capacity was estimated with a sorption index. This index correlated well with clay content, so clay content was used for comparison with CEC, SD, and CHL. Of these parameters, clay content was best correlated with CHL (r2 = 0.81). Since CHL can be determined very quickly under routine laboratory conditions, it could be utilized for refining the P soil test interpretation and improving subsequent fertilizer P recommendations. DA - 1990/// PY - 1990/// DO - 10.1080/00103629009368360 VL - 21 IS - 17-18 SP - 2079-2088 SN - 0010-3624 ER - TY - JOUR TI - ISOZYMATIC VARIATION IN GUATEMALAN RACES OF MAIZE AU - BRETTING, PK AU - GOODMAN, MM AU - STUBER, CW T2 - AMERICAN JOURNAL OF BOTANY AB - Isozymatic data taken from 67 Guatemalan collections of maize were subjected to numerical taxonomic analyses to elucidate systematic relationships among the 19 maize races and subraces described for Guatemala by Wellhausen et al. As with Bolivian and Mexican races, isozymatic variation in Guatemalan maize was strongly associated with altitude. Guatemalan lowland races were in general isozymatically distinct from races of higher elevations. Two middle elevation Guatemalan races proved difficult to place taxonomically. As a group, Guatemalan highland races were isozymatically more diverse than races from lower elevations, and were rather weakly differentiated from Mexican highland races. Notably, variational patterns evident from phenetic analyses of isozyme data were generally congruent with those apparent in phylogenetic analyses. The data reported here, and in earlier studies, suggested that divergent combinations of isozymatic, karyotypic, and morphological features have evolved in local maize races from Mexico, Guatemala, and Bolivia, perhaps as the result of the different selective regimens indigenous cultivators have imposed on different regional phylogenetic lineages. DA - 1990/2// PY - 1990/2// DO - 10.2307/2444643 VL - 77 IS - 2 SP - 211-225 SN - 0002-9122 ER - TY - JOUR TI - Expectations of the graduate student AU - Bubeck, D. M. T2 - Journal of Agronomic Education DA - 1990/// PY - 1990/// VL - 19 IS - 2 SP - 215 ER - TY - JOUR TI - Assessment of a diallel cross for multiple foliar pest resistance in peanut AU - Anderson, W. F. AU - Patanothai, A. AU - Wynne, J. C. AU - Gibbons, R. W. T2 - Oleagineux (Paris) DA - 1990/// PY - 1990/// VL - 45 IS - 8-9 SP - 373 ER - TY - JOUR TI - A note on the effect of soil reaction and zinc concentration on peanut tissue zinc AU - Cox, F. R. T2 - Peanut Science AB - Abstract Zinc uptake by peanuts (Arachis hypogaea L.) is affected by both soil pH and extractable Zn concentration, but the combined effect of these two factors is not well defined. An experiment with lime rates was conducted using NC7 peanuts that showed an exponential decrease in leaf Zn as the soil pH increased from 4.3 to 6.1. The decrease was very rapid when the soil was more acid, and less rapid as acidity decreased. Plant Zn was also shown to increase quadratically with increasing soil Zn with a data set from Georgia. These two relationships were combined, assuming no interaction exists, to be able to predict peanut tissue Zn as a function of both soil pH and extractable Zn with either the Mehlich-1 or Mehlich-3 solutions. Equations are presented that conform closely with currently assumed values of critical deficient and toxic concentrations in the tissue and soil for peanuts. These should be especially helpful in predicting potential toxicities over a range of pH and soil Zn levels. DA - 1990/// PY - 1990/// DO - 10.3146/i0095-3679-17-1-6 VL - 17 IS - 1 SP - 15 ER - TY - JOUR TI - TREND ANALYSIS TO IMPROVE EFFICIENCY OF AGRONOMIC TRIALS IN FLUE-CURED TOBACCO AU - BOWMAN, DT T2 - AGRONOMY JOURNAL AB - Abstract The desire to improve statistical evaluation efficiency in flue‐cured tobacco ( Nicotiana tabacum L.) cultivar trials and the inconvenience of restricted entry numbers in incomplete block designs prompted an investigation into a statistical procedure known as the trend analysis. The objective was to determine relative efficiency of the trend procedure compared to the randomized, complete block design by examining error variances from both analyses of variance. Eleven traits on all entries of the North Carolina Official Flue‐Cured Tobacco Variety Trials were examined at five environments. Relative efficiency of trend compared to the randomized, complete block design ranged from 97 to 161% for traits and environments. Only one trait, number of ground suckers, showed no improvement in precision (101%) from trend analysis while quality indicators ($/kg and grade index) showed the greatest improvement (126 and 124%) when averaged for all environments. The data revealed that blocking may be effective for one trait and not another. DA - 1990/// PY - 1990/// DO - 10.2134/agronj1990.00021962008200030011x VL - 82 IS - 3 SP - 499-501 SN - 0002-1962 ER - TY - JOUR TI - Mendelian and non-Mendelian inheritance of three isozymes in peanut (Arachis hypogaea L.) AU - Grieshammer, U. AU - Wynne, J. C. T2 - Peanut Science AB - Abstract Because of the importance of peanut (Arachis hypogaea L.) as an oil, food, and feed source worldwide and the contributions of breeding and genetics to yield and quality improvement, it is desirable to understand the genetic structure of the plant. Isozymes have been used to gain an understanding of the genetic structure of several plant species. However, we found no literature on the inheritance of isozymes in peanut. The F1 and F2 seed of several crosses between cultivars and plant introduction lines of three botantical types of peanut were used to investigate the inheritance of three isozymes by horizontal starch gel electrophoresis: phosphohexose isomerase (PHI), isocitrate dehydrogenase (IDH), and glutamate oxaloacetate transaminase (GOT). Each of the three enzymes displayed two different banding patterns, the difference being the presence vs. the absence of either one (IDH) or two (PHI, GOT) bands. Chi-square analysis for goodness of fit of the observed F2 segregation ratios to ratios expected from genetic models indicated that the polymorphisms for both PHI and IDH are controlled by single genes. Two loci, Phi-1 and Idh-1, respectively, are proposed. Sixty-five of 71 F1 progeny monitored for GOT showed the banding pattern of the male parent. The F2 progeny segregated into the two parental types, but the ratios did not fit a simple genetic model. Possible explanations for the observed paternal inheritance of GOT include biparental transmission of plastids, prezygotic RNA synthesis and genomic imprinting. DA - 1990/// PY - 1990/// DO - 10.3146/i0095-3679-17-2-13 VL - 17 IS - 2 SP - 101 ER - TY - JOUR TI - Isozyme variability in mature seeds of U.S. peanut cultivars and collections AU - Grieshammer, U. AU - Wynne, J. C. T2 - Peanut Science AB - Abstract The mature seeds of 61 U. S. peanut (Arachis hypogaea L.) cultivars, one breeding and six exotic peanut lines representing three botanical types were surveyed for 25 enzyme systems using horizontal starch gel electrophoresis. The genotypes assayed showed no variation for most of the enzymes. For catalase and malate dehydrogenase, variability was present but not reproducibly within genotypes. Only three enzymes—glutamate oxaloacetate transaminase (GOT), isocitrate dehydrogenase (IDH), and phosphohexose isomerase (PHI)—were consistently polymorphic. Each of the three enzymes displayed two different banding patterns. With three exceptions, the distribution of the zymograms for GOT and PHI reflected the taxonomic relatedness of Spanish and Valencia botanical type peanuts which are members of the subspecies A. hypogaea L. ssp. fastigiata Waldron when compared with Virginia botanical varieties which belong to the subspecies hypogaea. IDH showed only one banding pattern for the Spanish- and valencia-type peanuts (one exception), whereas the virginia-type cultivars varied for this enzyme reflecting the narrow genetic base of most Spanish cultivars and the broader germplasm base used for the development of Virginia cultivars. The limited amount of variability appears to restrict the applicability of isozymes as genetic markers in the cultivated peanut. DA - 1990/// PY - 1990/// DO - 10.3146/i0095-3679-17-2-7 VL - 17 IS - 2 SP - 72 ER - TY - JOUR TI - GENETIC AND GERM PLASM STOCKS WORTH CONSERVING AU - GOODMAN, MM T2 - JOURNAL OF HEREDITY AB - The relative costs and benefits of genetic stock collections and germ plasm collections are discussed. The status of national and international collections is compared with the needs of plant breeders and geneticists. There is an international need for germ plasm systems that emphasize the use and employment of materials rather than acquisition and storage. For base collections to function, they must provide for regeneration, characterization, documentation, and evaluation of their materials. The quality of a germ plasm system should be judged on the basis of the quality of the materials available to scientists. Adequate quantities of high-quality seed that are of known provenience, spanning the range of known genetic diversity, promptly delivered, and well described constitute the minimum that should be expected. All too often such minimal requirements are not met. DA - 1990/// PY - 1990/// DO - 10.1093/oxfordjournals.jhered.a110919 VL - 81 IS - 1 SP - 11-16 SN - 1465-7333 ER - TY - JOUR TI - Estimating leaf ripening rates of flue-cured tobacco cultivars AU - Bowman, D. T. AU - Tart, A. G. AU - Stocks, G. R. T2 - Tobacco International DA - 1990/// PY - 1990/// VL - 192 IS - 19 SP - 30 ER - TY - JOUR TI - CHANGES DURING EARLY SOYBEAN SEED AND AXES DETERIORATION .1. SEED QUALITY AND MITOCHONDRIAL RESPIRATION AU - FERGUSON, JM AU - TEKRONY, DM AU - EGLI, DB T2 - CROP SCIENCE AB - Understanding the cause of soybean [ Glycine max (L.) Merr.] seed deterioration during storage will assist in the development of accurate laboratory tests to evaluate seed vigor. This study was designed to investigate the changes that occur in mitochondria! respiration during the early stages of soybean seed deterioration. High‐quality seed lots of ‘Desoto’ and ‘Union’ soybean were stored at 25 °C and 115 g kg ‐1 seed moisture. Seed quality (germination and vigor) and conductivity of leachate from embryonic axes were measured at monthly intervals during storage. Mitochondrial State 3 (ST 3) respiration rates and respiratory control ratios (RCR) were measured from excised axes of samples after 24 h of imbibition. Germination remained high for seeds of both cultivars throughout storage; however, seed vigor (as measured by accelerated aging) declined significantly after 7 and 10 months for Union and Desoto, respectively. Conductivity of the leachate from excised axes for both cultivars increased early during storage prior to detectable changes in whole seed vigor. State 3 respiration rates of mitochondria from axes decreased throughout storage and RCR values declined after 2 months for Union and after 4 months for Desoto. Decreases in ST 3 respiration rates and RCR in both cultivars preceded measurable declines in whole‐seed vigor and correlated with increases in the conductivity of axes leachate. DA - 1990/// PY - 1990/// DO - 10.2135/cropsci1990.0011183X003000010038x VL - 30 IS - 1 SP - 175-179 SN - 0011-183X ER - TY - JOUR TI - Regulation of spinach leaf sucrose-phosphate synthase by multisite phosphorylation AU - Huber, S. C. AU - Huber, J. L. A. T2 - Current Topics in Plant Biochemistry and Physiology DA - 1990/// PY - 1990/// VL - 9 SP - 329 ER - TY - JOUR TI - RAPID EXTRACTION AND HIGH-SPEED LIQUID-CHROMATOGRAPHY OF NICOTIANA-TABACUM LEAF PIGMENTS AU - DANEHOWER, DA AU - KELLEY, WT T2 - JOURNAL OF CHROMATOGRAPHY DA - 1990/3/2/ PY - 1990/3/2/ DO - 10.1016/s0021-9673(01)89609-6 VL - 502 IS - 2 SP - 431-436 SN - 0021-9673 ER - TY - JOUR TI - NITROGEN AND PHOSPHORUS NUTRITIONAL INTERACTIONS IN A CO2 ENRICHED ENVIRONMENT AU - ISRAEL, DW AU - RUFTY, TW AU - CURE, JD T2 - JOURNAL OF PLANT NUTRITION AB - Abstract Nonnodulated soybean plants (Glycine max. [L.] Merr. ‘Lee') were supplied with nutrient solutions containing growth limiting concentrations of N or P to examine effects on N‐ and P‐uptake efficiencies (mg nutrient accumulated/gdw root) and utilization efficiencies in dry matter production (gdw2/mg nutrient). Nutritional treatments were imposed in aerial environments containing either 350 or 700 μL/L atmospheric CO2 to determine whether the nutrient interactions were modified when growth rates were altered. Nutrient‐stress treatments decreased growth and N‐ and P‐uptake and utilization efficiencies at 27 days after transplanting (DAT) and seed yield at maturity (98 DAT). Atmospheric CO2 enrichment increased growth and N‐ and P‐utilization efficiencies at 27 DAT and seed yield in all nutritional treatments and did not affect N‐ and P‐uptake efficiencies at 27 DAT. Parameter responses to nutrient stress at 27 DAT were not altered by atmospheric CO2 enrichment and vice versa. Nutrient‐stress treatments lowered the relative seed yield response to atmospheric CO2 enrichment. Decreased total‐N uptake by P‐stressed plants was associated with both decreased root growth and N‐uptake efficiency of the roots. Nitrogen‐utilization efficiency was also decreased by P‐stress. This response was associated with decreased plant growth as total‐N uptake and plant growth were decreased to the same extent by P stress resulting in unaltered tissue N concentrations. In contrast, decreased total P‐uptake by N‐stressed plants was associated with a restriction in root growth as P‐uptake efficiency of the roots was unaltered. This response was coupled with an increased root‐to‐shoot dry weight ratio; thus shoot and whole‐plant growth were decreased to a much greater extent than total‐P uptake which resulted in elevated P concentrations in the tissue. Therefore, P‐utilization efficiency was markedly reduced by N stress. DA - 1990/// PY - 1990/// DO - 10.1080/01904169009364163 VL - 13 IS - 11 SP - 1419-1433 SN - 0190-4167 ER - TY - JOUR TI - ACTIVATION OF SUCROSE-PHOSPHATE SYNTHASE FROM DARKENED SPINACH LEAVES BY AN ENDOGENOUS PROTEIN PHOSPHATASE AU - HUBER, SC AU - HUBER, JL T2 - ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS AB - Sucrose-phosphate synthase (SPS; EC 2.4.1.14) extracted from darkened spinach (Spinacia oleracea L.) leaves has a low activation state, defined as the ratio of activity measured with limiting substrates (plus the inhibitor Pi) to activity with saturating substrates (maximum velocity). Preincubation at 25 degrees C of desalted crude extracts from darkened leaves resulted in a time-dependent increase in activation state that was inhibited by Pi [IC50 (concentration causing 50% inhibition) approximately 3 mM], molybdate, okadaic acid (IC50 approximately 25 nM) and vanadate, but was stimulated by fluoride. The "spontaneous activation" of SPS in vitro was enhanced slightly by exogenous MgCl2 (up to 5 mM) and exhibited a pH optimum of 7.0 to 7.5. Radioactive phosphate incorporated into SPS during labeling of excised leaves with [32P]Pi in the dark was lost with time when extracts were incubated at 25 degrees C. This loss in radiolabel was substantially reduced by vanadate. These results provide direct evidence for action of an endogenous protein phosphatase(s) using SPS as substrate. The spontaneous activation achieved in vitro could be reversed by subsequent addition of 1 mM Mg.ATP; the activation/inactivation achieved in vitro was similar in magnitude to the dark-light regulation observed in vivo. Moreover, feeding okadaic acid to excised leaves in the dark blocked subsequent light activation of SPS without affecting photosynthetic rate. These results are consistent with the notion that SPS contains phosphorylation site(s) that reduce enzyme activation state and that dephosphorylation of these residue(s) is the mechanism of light activation. Regulation of the protein phosphatase by Pi may be of physiological significance. DA - 1990/11/1/ PY - 1990/11/1/ DO - 10.1016/0003-9861(90)90138-O VL - 282 IS - 2 SP - 421-426 SN - 0003-9861 ER - TY - JOUR TI - CHANGES DURING EARLY SOYBEAN SEED AND AXES DETERIORATION .2. LIPIDS AU - FERGUSON, JM AU - TEKRONY, DM AU - EGLI, DB T2 - CROP SCIENCE AB - Peroxidative changes in seed lipids are thought to be a major cause of seed deterioration during storage. This study was conducted to determine the fatty‐acid composition of soybean [ Glycine max (L.) Merr.] seeds, axes, and mitochondria during the early stages of deterioration. High‐quality seed lots of ‘Union’ and ‘Desoto’ soybean were stored at 25 °C and 115 g kg ‐ 1 seed moisture for 10 and 12 months, respectively. Seeds were sampled at frequent intervals and the fatty‐acid composition of storage and membrane lipids from seeds, axes, and mitochondria were determined. There were no detectable changes in the fatty‐acid composition of storage lipids from whole seeds or axes during the storage period for either seed lot, despite the substantial decline in seed vigor. There was a slight decrease in the percentage of unsaturated fatty acids in the membrane lipids of excised axes from Desoto seeds. The percentage of unsaturated fatty acids in the mitochondria from excised axes declined early during storage. The double‐bond index (DBI) of lipids from mitochondria of the Union axes fell from 1.76 at the beginning of storage to 1.60 after 10 months. Similar declines of 1.79 to 1.70 after 1 yr in storage were seen for the Desoto axes. Mitochondria! respiration and DBI were highly correlated for both seed lots. These data suggest that the decreases in mitochondrial respiration during storage may be associated with peroxidative changes in mitochondrial lipids and that these changes occurred prior to loss in seed vigor. DA - 1990/// PY - 1990/// DO - 10.2135/cropsci1990.0011183X003000010039x VL - 30 IS - 1 SP - 179-182 SN - 0011-183X ER - TY - JOUR TI - TRACHEARY-ELEMENT DIFFERENTIATION IN SUSPENSION-CULTURED CELLS OF ZINNIA REQUIRES UPTAKE OF EXTRACELLULAR CA-2+ - EXPERIMENTS WITH CALCIUM-CHANNEL BLOCKERS AND CALMODULIN INHIBITORS AU - ROBERTS, AW AU - HAIGLER, CH T2 - PLANTA DA - 1990/3// PY - 1990/3// DO - 10.1007/bf02411447 VL - 180 IS - 4 SP - 502-509 SN - 1432-2048 ER -