bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors Affecting Cold Injury of Sugarbeat Seedlings1
Authors: Cary J. W. 
Published: July 2010

AbstractSugarbeet seedlings (Beta vulgaris L.) may be killed by Spring frost just as they emerge from the soil. Possible solutions to this problem were investigated under closely controlled laboratory and growth chamber conditions. The seedlings were germinated at different temperatures in contact with solutions containing both varying osmotic pressures and compounds known to promote cold‐hardiness in other plants. Following germination, the seedlings were frozen in blocks of ice at different minimum temperatures and the degree of injury was noted.The results indicated that two mechanisms were involved in seedling survival. One was related to the osmotic potential of the plant sap and the other to the amount of water in the sap that could be converted to ice without killing the seedlings. Seedling osmotic pressures could be increased through the solution in contact with the roots, while the tolerance for ice could be increased with cool temperatures during germination. These two factors had a strong positive interaction and could reduce the normal lethal temperature from −0.5 to −2.5 C. Growth regulators and other compounds that have been reported to increase cold‐hardiness in other plants were not effective.
Seed Appendages and Germination of Two Asiatic Bluestems1
Authors: Ahring R. M. , Eastin J. D. , Garrison C. S. 
Published: July 2010

AbstractEstablishment of several grass species is difficult because of seed dormancy. The objective of this research was to evaluate the inhibitory effects on germination of substances from the bracts (glumes, lemma, palea), which enclose the caryopses of two Asiatic bluestems, Bothriochloa ischaemum (L.) Keng var. ischaemum (‘M’ strain) and B. intermedia (R. Br.) A. Camus (‘T’ strain).Standard germination tests demonstrated that the germination capacity of caryopses of both strains freed of appendages by hand was significantly greater than that of the rough seed units. Ether‐soluble inhibitors were present in aqueous refluxed material from empty bracts of both strains. The heavy oily residue of this extract after ether evaporation significantly retarded seedling growth in both strains. Ether extracts from empty bracts subjected to a 72‐hour 65 to 70 C heat treatment did not inhibit germination of lettuce seed. Ether‐soluble inhibitors in the untreated bracts were heat liable and concentration‐dependent for inhibition effects.The inhibition of germination in fresh seed of both species was caused, at least in part, by substances within the bracts. Heat drying appeared to cause a degradation of these biologically active compounds(s). Thin‐layer chromatography showed that certain compound(s) were immediately or progressively lost with each increment of treatment duration. Appropriate drying of the rough seed units prior to planting would reduce the inhibitory effects of natural ether‐soluble components within the bracts and increase the probability of stand success.
Potassium Uptake by Cotton in Relation to Verticillium Wilt1
Authors: Hafez A. A. R. , Stout P. R. , DeVay J. E. 
Published: July 2010

AbstractIncreasing evidence of a close relationship between K‐nutrition of cotton plants (Gossypium hirsutum L.) and verticillium wilt (Verticillium dahliae Kelb) development was observed in certain K‐deficient soils in San Joaquin Valley, California. Therefore, a K uptake field experiment on verticillium‐infected K‐deficient soil with 270 kg K/ha fertilized and unfertilized plots were conducted on both (420 liter/ha) chloropicrin (trichloronitromethane) fumigated and non‐fumigated treatments. The uptake of fertilizer K was traced by the “reverse‐tagging” procedure in which the indigenous soil‐Rb was used as a tag for K. In this instance the fertilizer Rb/K ratio was about 0.01 of the Rb/K ratio of the labile K in the upper foot of the soil profile.Cotton plants grown on fumigated soil absorbed 62% of their leaf K from the fertilizer source versus 48% for the non‐fumigated soils. Also it was observed that in the unfertilized plots, fumigation induced shifts in Rb/K ratio in plant tissues, which is explained by the differences in the Rb/K ratios in the upper and lower soil horizons coupled with reduced uptake efficiencies when roots in the upper soil horizons are infected with verticillium wilt.K‐fertilization alone resulted in a significant decrease in verticillium wilt. In both fumigated and non‐fumigated plots, yields of cotton lint responded significantly to K‐fertilization. However, corrections of K deficiency symptoms of cotton leaves required a combination of soil fumigation with chloropicrin and K‐fertilization.
Time of N Application and Yields of Corn in Wet, Alluvial Soils1
Authors: Miller H. F. , Kavanaugh John , Thomas G. W. 
Published: July 2010

AbstractTime and rates of N application to corn (Zea mays L.) grown in wet alluvial soils in western Kentucky were studied in the years 1968 through 1972. Two soils representative of the wetter soils in the area were used, Stendal silt loam and Melvin silt loam. The objective of the study was to determine the N fertilization practices that would produce highest corn yields on such soils. The early experiments were concerned with Fall vs. Spring application of N as practiced in the Midwest, but Fall‐applied N at lower rates (90 or 112 kg/ha) gave no better yields than the check treatments and even at relatively high N rates (180 and 224 kg/ha) gave such a poor response that this was changed to a comparison between Spring and Summer side‐dress applications for the last 2 years. Side‐dress application of N was nearly as good as or better than N applied at planting at both locations, although increasing the N rate at planting tended to obscure this effect. The results show that Summer side‐dressing of N on corn grown in wet soils is an effective way of fertilizing corn. They also suggest that late N application on corn made severely N deficient by excessive rain is an excellent practice.
Ratoon Cropping of Sorghum: II. Effect of Daylength and Temperature on Tillering and Plant Development1
Authors: Escalada Rodolfo G. , Plucknett Donald L. 
Published: July 2010

AbstractTillerlng capacity and behavior determine the success or failure of ratoon cropping in grasses. This work was initiated to gain more understanding on the seasonal effects on tillering and ratoon cropping of sorghum [Sorghum bicolor (L.) Moench] in the high rainfall tropics by studying the effects of various daylengths and temperature regimes on plant growth and development and yields of ratoon crops.Sorghum plants were grown under two daylengths and four temperature regimes in controlled‐environment chambers. Temperatures and daylengths used simulated tropical winter and summer conditions similar to rainfed sugarcane (Saccharum officinarum L.) plantations of Hawaii where ratoon sorghum has been grown. It is contemplated that sorghum could be used as an alternate crop for sugarcane plantations phasing out of production and that ratooning the crop could be utilized as a management practice, thus reducing the high cost of production.An interaction between photoperiod and temperature was observed. With low temperature (23.9 C‐day/15.5 C‐night) and short day (10 hours), fewer tillers/plant were produced resulting in the development of fewer reproductive tillers. At the same low night and day temperatures, but with photoperiod increased from 10 to 14 hours, more tillers/plant, more reproductive tillers/plant, greater leaf area, more leaves, more numerous but shorter internodes, and longer panicles were produced. The check plants grown outside produced more reproductive tillers/plant than the various treatments. Increasing both the temperature (32.2 C‐day/23.9 C‐night) and daylength (14 hours) resulted in further increase in tiller number/plant, leaf area, and internode number. Higher temperature and shorter daylength tended to bring about early maturity.Low light intensity, short photoperiod, and low temperature, resulted in rosette form of foliage with very short internodes and reduced number of leaves. This condition led to low grain and stover yields.
Influence of Environment on Protein Content of Rice1
Authors: Gomez K. A. , De Datta S. K. 
Published: July 2010

AbstractRecognition of world‐wide protein malnutrition has focused greater emphasis on improving rice (Oryza sativa L.) protein content, either through breeding for high‐protein cultivars or through manipulation of environment and cultural practices. This study was undertaken to investigate the overall influence of environment on the protein content of rice, to identify cultural practices that can be used to increase protein content without sacrificing grain yield, and to examine the relationships between grain yield and protein content.Since 1968, the International Rice Research Institute has collected from rice field experiments voluminous data on grain yield and protein content on several of its promising rice cultivars. For this study, we examined data from 964 experimental plots of ‘IR8’ and 538 plots of ‘IR480‐5‐9.’ Protein content ranged from 4.8 to 12.1% in IR8 and 6.4 to 17.4% in IR480‐5‐9. Crop season, location, N fertilization, water management, and weed control were the major sources of variation in protein content. It was also found that grain yield and protein content can be increased simultaneously, but only up to a certain point (protein‐yield threshold) beyond which further increase in the protein content results in a decrease in grain yield. The protein‐yield threshold was higher for IR480‐5‐9 (10.3%) than for IR8 (8.5%). The existence of protein yield threshold in rice cultivars has significant implication in the improvement of protein content in rice grains, either through breeding or improved cultural practices.
N Behavior Under No‐Till vs. Conventional Corn Culture. I. First‐Year Results Using Unlabeled N Fertilizer1
Authors: Bandel V. A. , Dzienia Stanislaw , Stanford George , Legg J. O. 
Published: July 2010

AbstractThis study comparing corn yields from different rates of applied N under no‐tillage and conventional culture was prompted by numerous field observations in Maryland that no‐till corn, with low to moderate rates of N, often showed more pronounced N deficiency symptoms than did conventionally tilled corn. Little is known regarding the relative N requirements of untilled corn grown in cover‐crop residues as compared to conventional tillage. The purpose of this study was therefore, to determine whether tillage method affected optimal crop requirements for fertilizer N. First‐year effects of tillage method and fertilizer N applications (0, 45, 90, 135, and 180 kg/ha) on corn (Zea mays L.) yields, N uptake by the crop, mineral N accumulation in the soil, and total and potentially mineralizable soil N are reported. With suboptimal N rates, N deficiency symptoms were more severe throughout the season on untilled than on cultivated plots. However, the optimal level of applied N for grain and dry matter yields did not differ with tillage method. After grain harvest, the amount and distribution of residual mineral N in the root zone for a given rate of applied N were similar in tilled and untilled plots at two locations (Poplar Hill and Plant Research Farm). At the third site (Wye Institute), however, residual mineral soil N was higher with conventional than with no tillage. These differences were attributed to variation among sites in amounts of precipitation between planting and harvest, as it affected relative water infiltration in tilled and untilled plots. Total residual mineral N in the root zone tended to increase with N application rate. Between harvest (1973) and planting (1974), however, most of the residual mineral fertilizer N was removed by the cover crop or lost.Total soil organic N to a depth of 30 cm was unaffected by N rate or tillage method during one cropping season. At one rate, however, potentially mineralizable N was higher in untilled than in tilled plots. Studies are continuing on two of the sites, with l5N‐lepleted fertilizer, to determine relative changes with time in soil N status as influenced by tillage method.
Compatibility of Rhizobium japonicum with Chemical Seed Protectants1
Authors: Curley R. L. , Burton J. C. 
Published: July 2010

AbstractThe literature on the compatibility of Rhizobium sp. with seed protectant chemicals is controversial because of variation in methods and the lack of quantitative data. The present study was planned to develop a reliable quantitative method of measuring compatibility of Rhizobium japonicum with seed‐applied fungicides. The effect of four seed protectant chemicals on survival of R. japonicum on soybean (Glycine max L. Merr. cv. ‘Hark’) seed was studied in laboratory growth chamber experiments. The chemicals tested and levels used were tetramethyl‐thiuram‐disulfide (thiram), 0.6 g/kg seed; N‐trichloromethylthio‐4‐cyclohexene‐l,2‐dicarboximide (captan), 0.8 g/kg seed; 5,6‐Dihydro‐2‐methyl‐l,4‐oxathiin‐3‐carboxanilide (carboxin), 1.1 g/kg seed; and pentachloronitrobenzene (PCNB), 0.9 g/kg seed. Quantitative measurements for compatibility included plate counts for survival of R. japonicum on inoculated chemically treated seed and counts of taproot nodules on plants at 2 weeks age. R. japonicum were compatible with Thiram and Carboxin but not with PCNB and Captan. PCNB reduced Rhizobium survival on seed and decreased taproot nodulation. Captan was less toxic to rhizobia than was PCNB, but taproot nodulation of plants was greatly reduced by captan. Carboxin had little effect on viable rhizobia or taproot nodulation when seeds were planted within 4 hours of inoculation. Nodulation was poor when these seeds were planted 24 hours after inoculation despite the presence of what would normally be considered adequate viable rhizobia. Thiram had no adverse effect on viable rhizobia or taproot nodulation even when seeds were held 24 hours before planting. The results also indicate that compatibility must be measured quantitatively in relation to time and that nodulating ability of the surviving bacteria is the prime factor in determining compatibility.
Hydrocyanic Acid Potentials in Leaf Blade Tissue of Eleven Grain Sorghum Hybrids
Authors: Eck Harold V. 
Published: July 2010

AbstractHydrocyanic acid potentials (HCN‐p) of grain sorghums [Sorghum bicolor (L.) Moench] need not be considered in grain production but become important when fresh forage is fed to livestock. This study involved determination of seasonal leaf blade HCN‐p levels of 11 field‐grown grain sorghum hybrids, relationships between HCN‐p levels in growth chamber‐grown seedlings and older fieldgrown plants, and effects of N fertilization on seasonal leaf blade HCN‐p levels.Growth chamber plants were grown in vermiculite, subirrigated daily with nutrient solution. Plants were harvested and assayed for HCN‐p 10, 14, and 18 days after planting. In 1972, the 11 hybrids were field‐grown on N fertilized soil. In 1973, ‘DeKalb E‐59’ was grown on N fertilized and on N‐deficient soil. Field‐grown hybrids were assayed for HCN‐p weekly from 27 (1972) or 37 (1973) days after planting until physiological maturity. HCN‐p was determined potentiometrically on homogenized, β‐glucosidase hydrolized leaf blade tissue.Relationships between HCN‐p levels at sampling dates during the season and seasonal average HCN‐p levels indicated that, for purposes of ranking cultivars, approximately equal precision would be attained at any time from growing point differentiation through soft dough. The correlation between HCN‐p levels in 18‐day‐old growth‐chamber plants and seasonal average HCN‐p levels of field plants was significant at the 10% level (r = 0.56) but HCN‐p levels in 10‐ and 14‐day‐old plants were not significantly related to seasonal average HCN‐p levels of field plants. HCN‐p in leaf blade tissue was highly dependent on N availability. At a sustained adequate level of N, HCN‐p levels in sorghum leaf blade tissue declined from the seedling stage to about flag leaf and then remained fairly constant until they declined at the approach of maturity. HCN‐p levels exceeded the “threshold of danger” (200 ppm) until physiological maturity. On N‐deficient soil, leaf blade HCN‐p levels declined to a low level (<100 pm) at soft dough.
Nitrogen Accumulation and Translocation in Corn Genotypes Following Silking1
Authors: Beauchamp E. G. , Kannenberg L. W. , Hunter R. B. 
Published: July 2010

AbstractThe potential for improvement of N utilization in corn (Zea mays L.) can depend on the existence of genotypic differences. Accordingly studies were conducted to determine if N translocation from the leaves and stalk to the ear during the period immediately following silking depended on the genotype. In 1970, the N concentration of individual leaf blades, stalk, and developing ears of four inbreds was determined at the silking stage and 14 and 28 days after silking. In a similar experiment in 1971, using bulked leaf blade samples, three of the inbreds plus their F1 hybrids were analyzed for N at silking and 24 days after silking.In 1970, the apparent translocation of N from individual leaf blades differed considerably depending on the inbred Significant differences in N concentration in either the stalks or developing ears occurred among genotypes in 1970 and 1971. Appreciable differences were found in the apparent propensity of the inbreds to translocate N to the developing ear. In 1970, apparent N translocation during the 14 to 28 day period was greater than during the first 14 days following silking. The inbreds differed between years with respect to apparent N translocation suggesting a genotype ✕ environment interaction.The N accumulation rate following silking was substantially greater in one of the three F1 hybrids than in the parent inbreds. Thus there appears to be some potential for the screening and development of hybrids capable of accumulating a relatively large quantity of N or using N more efficiently through translocation from various plant parts.
Drying Rates of Frosted Maturing Maize1
Authors: Hicks D. R. , Geadelmann G. L. , Peterson R. H. 
Published: July 2010

AbstractFreezing air temperatures sometimes occur in early autumn before maize (Zea mays L.) grain is physiologically mature. A study was conducted to determine maize grain, cob, and ear moisture profiles following certain treatments to simulate plant conditions which exist after a subfreezing temperature occurrence.Ears with husks and shanks attached were removed from plants and placed in a controlled temperature chamber for 0, 4, or 8 hours at −7 C. Three husk treatmeats‐loosened, normal, or tied‐were imposed on ears subjected to the three cold treatments. Treated ears were taped onto plants in the normal ear position for field drying. Ears from these nine treatments and also ears from completely defoliated and control plants were sampled weekly from 19 Sept. to 23 Oct. 1974, to estimate drying rates of grain, cobs, and ears.Grain drying rates ranged from 0.83 to 1.16% moisture loss⁄day. Drying rates of grain following leaf blade defoliation or moderate to severe cold treatments were not statistically different from the drying rate of normally maturing maize grain. Husk condition did not statistically affect grain drying rates.Defoliation and cold treatments caused grain moisture levels to be 2 to 6 percentage points greater than that of grain from control plants when grain from control plants was in the 22 to 30% harvest range. Grain from these treatments required 4 to 9 additional days of field drying to reach the 22 to 30% moisture range.Defoliation and cold treatments had little effect on the drying rates of cobs and ears. However both cob and ear moisture levels were greater than those of the control throughout the sampling period. Loose husks caused faster cob and ear drying compared to normal or tied husks which had similar cob and ear drying rates.
Border Effects in a Long‐Term Fertility Experiment1
Authors: MacDonald G. E. , Peck N. H. 
Published: July 2010

AbstractThe concept of plot border effects in a fertility experiment is well known. However, the magnitude of the possible border effects is often unappreciated. Thus an experiment was designed to determine how much horizontal movement of soil across plot boundaries results from normal tillage operations. Horizontal movement of P and K was determined by soil tests at the completion of a 10‐year fertility experiment during which 9 applications of differential rates of broadcast concentrated superphosphate (CSP) and potassium chloride (KCl) had been applied. Soil tests revealed that soil P was depleted to a distance of 2.7 m in the high CSP residual plots and moved into the low residual CSP plots 1.8 m. Soil K was depleted to a distance of 2.7 m in the high KCl residual plots and moved into the low KCl residual plots 2.7 m. Normal tillage operations moved soil in both directions across plot boundaries. The high CSP or KCl plots were depleted of fertility to about the same distance that the low CSP or KCl plots increased in fertility. The effective length of plots was reduced from 15 to 10 m for CSP plots and 9 m for KCl plots in the direction of the tillage operations after a period of 10 years. Dimension of long‐term fertilizer plots should be adjusted according to the number of years the experiment will be continued.
An Evaluation of a Resistance Form of the Energy Balance to Estimate Evapotranspiration1
Authors: Heilman J. L. , Kanemasu E. T. 
Published: July 2010

AbstractEvapotranspiration (ET) models that use the air‐diffusion resistance to momentum (rD) have been unsatisfactory under certain conditions. A field study was conducted in soybean [Glycine max (L.) ‘Williams’] and sorghum [Sorghum bicolor (L.) ‘Pioneer 846’] to evaluate an ET model that uses the diffusion resistance to heat transport (rH) in the energy‐balance equation and to assess the effect of replacing the resistance for heat with that for momentum.Resistances were determined using wind speed and temperature profiles. Model estimates of latent‐heat flux (LE) were compared with lysimetric measurements of LE. When using rH, model estimates of LE were within 4% and 15% of lysimetric measurements for soybean and sorghum, respectively. When using rD, estimates of LE for soybean were 25% greater, but for sorghum only 10% greater than when using rH. Results indicated that the resistance form of the energy balance can be useful for estimating ET if the proper resistance is used. Significant errors may occur if the momentum resistance is used in the model instead of the resistance for heat.