bluuebunny/crossref_metadata_2025 huggingface dataset:
Simple, Inexpensive Solid State Liquid Level Detection and Control1
Authors: Spomer L. Art
Published: July 2010

Liquid level detection and control is commonly used in agronomic and soil science research. Various mechanical, electromechanical, and solid state systems have been devised for this purpose. Of these, the solid state systems are the most versatile and reliable but also the most expensive to purchase or complex to construct. The function and construction of a very simple, inexpensive, sensitive, and versatile solid state liquid level detection and control system is described here. The detection circuit consists of an integrated circuit plus two capacitors and a simple bielectrode probe. Indicator, alarm, and control functions are available with the inclusion of as few as one to three additional components.
Seed and Oil Characteristics of Nitrogen Fertilized Meadowfoam1
Authors: Crane J. M. , Calhoun W. , Ayres T. A.
Published: July 2010

Meadowfoam (Limnanthes alba Benth.) is a potential new oilseed crop. However, effects of fertilization on oil content and fatty acid composition have received limited attention. This 3‐year field study was designed to determine the effects of ammonium sulfate and ammonium nitrate used at two rates, 50 and 100 kg/ha, on meadowfoam seed protein content, oil content, and oil fatty acid composition. The plots were located on a silt loam soil (fine silty, mixed mesic Aquultic Argixeroll) near Corvallis, Oregon. Seed protein content increased as much as 29% over the control as N levels increased whereas seed oil content decreased with each increase of N. For any given N level, ammonium sulfate caused greater response thn ammonium nitrate for all characters measured. The C20 monoene (cis‐5‐eiocosenic acid) of the meadowfoam oil was reduced by the application of N in 1974 and 1975, but not 1977. Application of N increased the C22 diene content (cis‐5‐cis 13 docosadienoic acid) in all 3 years. These results demonstrate that fatty acid composition of meadowfoam oil can be altered by applying N, but that the total oil content of the seed is reduced.
Herbicidal Enhancement of Dallisgrass Establishment1
Authors: Evers G. W.
Published: July 2010

Dallisgrass (Paspalum dilatatum Poir.), a desirable subtropical pasture grass, is difficult to establish because of its slow germination and seedling growth compared to annual weeds. Herbicides were evaluated for weed control and phytotoxicity to dallisgrass planted on a prapared seedbed each spring for 3 years by determining seedling density and forage production. All herbicides were applied in 154 liters of water/ha with a CO2 pressurized sprayer. Herbicides used were dicamba [3,6‐dichloro‐O‐anisic acid], paraquat [l,l′‐dimethyl‐4,4′‐bipyridinium ion], tebuthiuron [N‐(5‐(l,l‐dimethylethyl)‐l, 3,4‐thiadiazol‐2‐yl)‐N,N′‐dimethylurea], diuron [3‐(3,4‐dichlorophenyl)‐l,l‐dimethylurea], simarine [2‐chloro‐4,6‐bis (ethylamino)‐s‐triazine], bromacil [5‐bromo‐3‐sec‐butyl‐6‐methyluracil], glyphosate [N‐(phosphonomethyl)glycine], hexazinone [3‐cyclohexyl‐6‐(dimethylamino)‐l‐methyl‐l,3,5‐triazine‐2,4(1H,3H)‐dione], and metribuzin [4‐amino‐6‐tert‐(‐butyl‐3‐(methylthio)‐as‐triazn‐5(4H‐one].

Dallisgrass production was increased 3, 30, and 8 fold for 1977, 1978, and 1979 respectively, by the best herbicide treatments. The most effective treatments were 1.1 kg/ha tebuthiuron; 0.6, 0.8, and 1.1 kg/ha metribuzin; and 2.2 kg/ha diuron. Lower rates of diuron failed to provide effective weed control. Tebuthiuron applied at 2.2 and 4.4 kg/ha resulted in some phytotoxicity to dallisgrass seedlings. Simazine increased seedling density and yield 2 out of 3 years when applied at 2.2 kg/ha but was ineffective at 1.1 kg/ha. The other herbicides failed to significantly increase seedling density or forage production.
Treatment of Heterogeneity of Variances in Hydrocyanic Acid Data1
Authors: Gray Elmer , Hurt Valina K. , Duckworth Diana L.
Published: July 2010

Homogeneity of variance is a basic assumption of the analysis of variance. Hydrocyanic acid potential (HCN‐p) of samples of sorghum (Sorghum bicolor (L.) Moench) plants may vary from nil to the maximum produced by the genotype‐treatment combination, resulting in heterogeneous variances. The purpose of the present study was to further elucidate heterogeneity of variance in HCN‐p data and to employ appropriate treatment of the heterogeneity.

‘Greenleaf’ and ‘Piper’ sudangrass (Sorghum sudanese (Piper) Stapf.) and ‘Suhi‐l’, a sorghum ✕ sudangrass hybrid were subjected to five N treatments: (a) no N applied, (b) 67.2 kg/ha at planting, (c) 33.6 kg/ha at planting and 33.6 kg/ha after second harvest, (d) 134.4 kg/ha at planting, and (e) 33.6 kg/ha at planting and 33.6 kg/ha after first, second, and third harvests. When the plants reached a height of 75 cm, they were cut at a height of 20 cm, resulting in four harvests. The cultivar, N, and harvest treatments were analyzed for heterogeneity of variances.

For the natural data the treatment means and variances were positively associated and the variances for several treatment comparisons were heterogeneous. Transforming the natural data to common logarithms failed to eliminate the evidence of heterogeneity of variances. Since the data did not meet the assumption of homogeneity of variance, an approximate test of equality of means based upon the assumption of heterogeneity of variance was recommended for the HCN‐p data.

Heterogeneity of variances decreases the accuracy of statistical comparisons of means. Since HCN‐p is converted to highly toxic hydrocyanic acid by ruminant animals, accuracy of statistical decisions is critical. Researchers should examine HCN‐p data for evidence of heterogeneity of variances and, if present, employ the approximate test which includes provisions for heterogeneity of variances.
Seasonal Dry Matter Yield and Digestibility of Seven Grass Species, Alfalfa, and Cicer Milkvetch in Eastern Montana1
Authors: White Larry M. , Wight J. Ross
Published: July 2010

In the past, seed and total dry matter (DM) yield have been two of the main criteria for forage plant selection and improvement. However, we have little information on seasonal digestibility, one of the most important criteria, of major forage species in the northern Great Plains. Our objective was to determine differences in seasonal digestibility and DM yield of seven grass species, three (‘Rambler’, ‘Drylander’, and ‘Orenberg’) alfalfas (Medicago sativa L. subsp. × varia (Martyn) Arcangeli), and ‘Lutana’ cicer milkvetch (Astragalus cicer L.) the first and second year after establishment. Forage species were seeded in 1974 in 50‐cm rows on a Williams loam soil (fine‐loamy mixed, Typic Argiborolls) near Sidney, Montana, which has an average annual precipitation of 35 cm. Dry matter yield and in vitro digestibility converted to in vivo digestibility were determined seven times hi 1975 and 11 times in 1976 at progressive growth stages. ‘Mayak’ Russian wildrye (Elymus junceus Fisch.) and ‘Prairieland’ Altai wildrye (Elymus angustus Trin.) produced the lowest peak DM the first year after seeding; however, they were among the species that produced the most DM the second year. The three alfalfas and ‘Luna’ pubescent wheatgrass [Agropyron trichophorum (Link) Richt.] produced the most peak DM the first year after seeding; however, by the second year, they were among those species that produced the least. Digestibility at a given stage of development also differed greatly among species. The second year, forage of Prairieland Altai wildrye and Lutana cicer milkvetch during the fall and early winter were 8 to 10 percentage units more digestible than ‘Nordan’ crested wheatgrass [Agropyron desertorum (Fisch.) Schult.]. ‘Regar’ meadow bromegrass (Bromus biebersteinii Roem. and Schult.), a selection of reed canarygrass (Phalaris arundinacea L.), and ‘Lodorm’ green needlegrass (Stipa viridula Trin.) were also studied. Evaluating DM yield of a forage species at a given stage of plant development, such as anthesis, does not adequately reflect its potential. Species are best evaluated for DM production at some given level of digestibility, based on animal requirements.
Controlled Cooling of Onion Umbels by Periodic Sprinkling1
Authors: Wright J. L. , Stevens J. L. , Brown M. J.
Published: July 2010

Low onion (Allium cepa L.) seed yields frequently occur without obvious reasons, particularly with hybrid varieties. Solutions to the problem need to be found to insure seed for bulb onion production. Water and temperature stress in the umbel may be factors during hot, dry, sunny weather. We investigated the relationship of umbel temperature to ambient and umbel conditions and the effects of periodic wetting of the umbels. Onions were grown in a field experiment at Kimberly, Idaho on Portneuf silt loam soil (Durixerollic Calciorthids; coarse‐silty, mixed, mesic) using commercial practices except that periodic sprinkling was provided with a rotating‐head sprinkler irrigation system when temperatures exceeded certain levels. Sprinkling for five min reduced floret temperatures as much as 15 C below ambient. The florets remained cool for 20 to 40 min, depending on umbel maturity, wind speed, and air temperature and humidity. Nearly mature umbels were hotter and required more sprinkling to keep cool. Five min of sprinkling every 20 to 30 min usually provided adequate cooling. A specially‐designed temperature sensor was found to successfully simulate the behavior of an onion floret during wetting and drying, permitting direct control of the initiation, duration, and frequency of sprinkling. Excessive temperatures did not occur during the experiment, so seed yields were similar on sprinkled and unsprinkled plots. while we have shown that periodic sprinkling will provide umbel cooling and minimize undesirable effects on pollination, similar studies need to be conducted in hotter, major seed producing areas to establish economic benefits.
Atrazine Persistence in a Corn‐Soybean Doublecropping System1
Authors: Brecke B. J. , Currey W. L. , Teem D. H.
Published: July 2010

In areas with a relatively long growing season, a doublecropping system of soybeans (Glycine max (L.) Merr.) planted after corn (Zea mays L.) harvested for silage or grain is gaining acceptance. One problem which has arisen involves the potential injury to the soybean crop from atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine] residue remaining in the soil after the corn is harevsted. Field studies were conducted during 1977 on an Arrendondo fine sand (Grossarenic Paleudult) at Gainesville, Florida and during 1978 and 1979 on a Tifton fine sandy loam (Plinthic Paleudult) at Jay, Florida to determine the persistence of atrazine in such a doublecropping system. Soybeans were no‐till planted at various intervals (4 to 19 weeks) after atrazine (0 to 4.48 kg/ha) was applied preemergence to corn.

Soybean yields were not significantly affected by 1.12 or 2.24 kg/ha atrazine when the interval between corn herbicide application and soybean planting was 8 weeks. An Interval of 10 weeks was required before 4.48 kg/ha atrazine had no significant affect on soybean yield. The yield loss observed with shorter planting intervals appeared to be the result of a reduction in soybean stand. These results indicate that under conditions of warm temperatures, relatively high rainfall amounts, and sandy soils soybeans can be safely planted after corn harvested for silage or grain (approximately 14 and 20 weeks, respectively, after atrazine application) when rates of atrazine normally recommended for annual weed control in corn (1.12 to 4.48 kg/ha) are used.
Effects of Nitrogen and Sulfur Fertilizers on Sulfur Content of Tall Fescue and Phalaris1
Authors: Burmester C. H. , Adams Fred , Haaland R. L.
Published: July 2010

In an experiment to determine the effect of N and S fertilizer rates on yield and S uptake by cool‐season forage grasses, two cultivars of tall fescue (Festuca arundinacea Schreb.) and one of phalaris (Phalaris aquatica L.) were grown in greenhouse and field experiments on a Cahaba fine sandy loam (Typic Hapludult) at comparable fertility levels. Fertilizer rates in the greenhouse were 38, 75, 125, 175 ppm N and O, 5, 10, 20 ppm S. Nitrogen rates in the field were 85, 170, 280, 390 kg/ha; and S rates were 0, 11, 22, 44 kg/ha. Organic‐S content of foliage was about equal in greenhouse and field experiments; it progressively increased with higher N rates but not with S rates. Inorganic‐S content was much higher in the green. house experiment,. particularly with phalaris; it progressively decreased with N rates and increased with S rates. Phalaris accumulated potentially toxic levels (to ruminants) of sulfate in the greenhouse but not in the field. Greenhouse‐grown plants accumulated much higher levels of S than did field‐grown plants, probably because the field soil was able to retain only a portion of the fertilizer sulfate within the rooting zone of the soil profile.
The Reproductive Efficiency of Cultivated Peanuts. IV. The Influence of Photoperiod on the Flowering, Pegging, and Fruiting of Spanish‐Type Peanuts1
Authors: Emery D. A. , Sherman M. E. , Vickers J. W.
Published: July 2010

The time of flowering and pegging during the early development of the peanut plant are heritable and correlated This research was designed to determine the effects of photoperiod on the periodicity of flowering and subsequent peg growth within specific portions of the life cycle of the peanut plant. A Spanish‐type peanut, Arachis hypogaea L., C2 (PI 262000), was used in the investigations.

Plants exposed to long‐day treatments (light interrupted 15‐hour dark period) in growth chambers of the North Carolina State University Phytotron Unit, produced 1.84 times more flowers per plant than those grown in 9 hour photoperiods. Plants in short‐day treatments reached flowering peaks earlier than those in long‐day chambers and produced 134.4 shellable fruit per plant in contrast to 34.1 fruit per plant for long‐day treatments.

The reproductive efficiency, relative to other plant traits, was also enhanced by growing the plants in short‐day photoperiods. Twenty‐seven percent of the flowers on plants grown under short days produced shellable fruit resulting in 106.5 g of seed per plant. Only 3.8% of the flowers on plants in long‐day chambers produced shellable fruit resulting in 12.1 g of seed per plant. The proportion of seed weight to plant top weight was 59.6% in short‐day regimes compared to 3.0% in long‐day regimes.

The peanut, unlike other plants, has three distinct steps in the reproductive process. These are the flowers, the peg, and the fruit. To measure the responses of the plants in each of these reproductive steps to changes in photoperiod, seven different sequences of photoperiods were applied to the plants over three 36‐day growth periods. The stage most sensitive to changes in photoperiod was found to be that period when the plant was between 36 and 72 days of age. Substituting short days for long days during this growth caused increased numbers of pegs, increased peg growth, increased fruit numbers, increased fruit weight, increased seed weight, and increased seed weight per plant weight. Plant weight was decreased by the same substitution.

The dramatic changes in flowering periodicity and increased rates of growth for reproductive traits when plants are exposed to shortday growth periods will serve as selection criteria in segregating populations of crosses between Spanish and Virginia‐type peanuts. The latter are large‐seeded and later maturing than lines used in this study.
Some Characteristics of Plinthite Inhibiting Plant Growth1
Authors: Perkins H. F. , Kaihulla Egbert
Published: July 2010

Plant roots do not readily penetrate soil horizons containing plinthite. This study was conducted to determine some chemical and physical characteristics of plinthite which appear inhibitory to normal plant growth. Field and laboratory studies indicate that bulk density of plinthite is higher than non‐plinthic material surrounding nodular plinthite bodies. Bulk density of non‐plinthic material associated with nodular plinthite bodies is comparable to soil without plinthite. Samples from the Ap, B22tpl, and C horizons of a Tifton soil (fine‐loamy, silicious, thermic family of Plinthic Paleudults) were collected and placed in containers to simulate field arrangement of soil horizons and a test crop of grain sorghum (Sorghum bicolor L.) was grown under different treatments of CaCO3 and CaSO4. Aluminum toxicity was overcome by adding CaCO3. Soluble Al was reduced by CaCO3 but not by CaSO4. The addition of CaSO4 had less effect on yield, Ca uptake, and suppression of Al uptake by sorghum plants than CaCO8. There was no major root growth in the plinthic layer except when soluble Al was removed by CaCO3 addition.
Air and Soil Temperature Effects on Elongation of Adventitious Roots in Blue Grama Seedlings1
Authors: Wilson A. M.
Published: July 2010

Blue grama [Bouteloua gracilis (Willd. ex H.B.K.) Lag ex Griffiths] is difficult to establish on disturbed sites of the Central Great Plains because environmental conditions are seldom favorable for development of adventitious roots. Therefore, a study was conducted to determine the effects of air temperature, soil temperature, and total green leaf blade length on adventitious root development. Seeds were planted in the greenhouse (25 to 30 C) in tubes filled with moist soil (Aridic Argiustoll). Seedlings were subirrigated to maintain favorable soil moisture in the seminal root zone and a dry soil surface, thus preventing the initiation of adventitious roots. At 28 days, seedlings were surface irrigated and the initiation and extension of adventitious roots was evaluated in a 4‐day test at three air temperatures and seven soil temperatures in a plant growth chamber.

Air temperatures of 20 and 30 C produced average root elongation rates of 2.4 and 2.0 cm/day, respectively. In contrast, average rates of elongation increased more than 2‐fold as soil temperature increased from 20 to 30 C. Consistent differences in number of roots, rate of root elongation, and root weight per unit length resulted in a 2.5‐fold difference among accessions in total weight of adventitious roots/seedling. Growth maxima in relation to number of roots, rate of root elongation, total weight of roots, and leaf growth occurred at soil temperatures of 19.3, 31.8, 30.6, and 33.6 C, respectively. Regression coefficients indicated positive effects of total leaf blade length on number of roots, rate of root elongation, and root weight per unit length.

The results suggest that planting of blue grama should be delayed in the spring until soil temperatures warm to about 15 C. Differences among accessions and individual seedlings in rate of adventitious root growth suggest opportunities for selection and breeding. The capacity for high rates of elongation might increase the establishment of blue grama seedlings when environmental conditions for adventitious root development are marginal.
Influence of NH3 Conservation from Dairy Manure on the Yield of Corn1
Authors: Klausner S. D. , Guest R. W.
Published: July 2010

Dairy manure contains an appreciable amount of NH3‐N, and if left exposed on the soil surface, it is easily lost by ammonia volatilization. Two methods of row applied liquid manure were made on corn (Zea mays L.) during the early stages of the growing season to identify the yield response to NH3 conservation. From 1975 to 1977, the manure treatments consisted of a control, topdressing, and soil injection as a side‐dress application. The control received side‐dressed fertilizer N at 0 and 112 kg/ha. In 1978, rates of side‐dressed fertilizer N (0, 56, 112, and 224 kg/ha) were superimposed on the control and topdressed manure treatments to further quantify the fertilizer N equivalent of the two methods of manure application. The soil was a Minoa fine sandy loam (Aquic Duptric Eutrochrept, coarse loamy, mixed, mesic).

The use of manure significantly increased yield in comparison to no manure. There was a positive response to NH3 conservation in 2 out of 4 years. Atypical weather patterns in 1975 and 1976 erased the influence of the method of manure application. Grain and silage yields were significantly increased in 1977 by 1.60 and 1.88 metric tons/ha, respectively for injected vs. top‐dressed manure. Yields from manure injected plots were equivalent to the control receiving 112 kg/ha of fertilizer N. The greatest response to NH3 conservation occurred in 1978. The yield advantages of injection vs. topdressing was 1.92 and 2.82 metric tons/ha for grain and silage, respectively. The data showed that in terms of yield, a 40 metric tons/ha application of manure had a fertilizer N equivalent of 30 and 90 kg N/ha (0.78 kg N/metric ton and 2.3 kg N/metric ton) for top‐dressed and injected manure, respectively.
Potassium Response of Cotton on Some Inceptisols and Oxisols of Nothern Nigeria1
Authors: Lombin G. , Mustafa S.
Published: July 2010

Consequent upon the shift from the traditional bush fallowing system of agriculture to more intensive continuous cultivation, plant‐available soil K which was hitherto considered adequate in the West African savannah zone is now becoming a major yield limiting factor. Information is urgently needed on the K fertilization requirements of the promising crop varieties and on the suitable diagnostic parameters for evaluating these requirements. The objectives of the present study were to: 1) approximate the optimal K fertilization level for cotton (Gossypium hirsutum L.), 2) evaluate the yield predictive abilities of four K availability indices, and 3) estimate the critical values of these indices under the tropical savannah conditions.

Four rates of K (0, 25, 50, and 75 kg ha−1) were tested in a 3‐year field study conducted on three Oxisols (Typic or Tropeptic Haplustox, fine, gaolinite, isohyperthermic) and two Inceptisols (Oxic and Typic Ustropept, fine, mixed, isohyperthermic). Seedcotton yields were measured all 3 years while soil and index leaf samples were taken from the third year's trials for laboratory chemical analysis. The relationships between seedcotton yield and soil exchangeable K, (Ca + Mg)/K ratio, rates of applied K, and leaf percent K were measured using multiple regression techniques involving quadratic polynomials.

Significant yield responses (only at first level of applied K) were obtained on the Oxisols (all of which are derived from sandstones and had topsoil exchangeable K values of ≤ 0.10 meq/100g). Marginal responses obtained on the Inceptisols are, however, indicative of imminent deficiency. Percent K in index leaf best predicted yield (R2 = 0.86***; yield = 3099.2 + 6031.6 % K — 1543.3 % K2) and so provides the best measure of K availability for cotton followed by rates of applied K (R2 = 0.812*; Yield = 1302.3 + 56.96 app. K — 0.54 (app. K2). Their estimated critical values (values associated with the highest predicted seedcotton yields) were 1.84% K and 50 kg/ha K, respectively for a highest yield range of 2,400 to 2,700 kg ha−l. These results may be limited by the relatively few observations used but they are sufficiently close to published values for crops of similar nutrient requirements to justify proposing them as a guide for the savannah areas of Nigeria and similar soils elsewhere.
Relationship between Crop Temperature and the Physiological and Phenological Development of Differentially Irrigated Corn1
Authors: Gardner B. R. , Blad B. L. , Maurer R. E. , Watts D. G.
Published: July 2010

Quantitative data relating crop temperature under different water stress conditions to the phenological and physiological development of corn (Zea mays L.) over a growing season are lacking. This study was motivated by the need to obtain quantitative information which can be beneficially utilized by those involved in predicting crop yields and to assist those who assess the economic impact of drought on crop production.

Infrared canopy temperatures and physiological and phenological measurements were made on differentially irrigated corn throughout the 1978 growing season. Irrigation treatments were designed to evaluate the effects of moisture stress on these measurements. The soil type in the experiment area is Valentine fine sand (Typic Ustipsamment).

The effect of moisture stress on vegetative growth was demonstrated by an average height difference of 50 cm between fully irrigated and nonirrigated plants.

There was a tendency for plants which had been subjected to moisture stress during the grain filling stage to mature faster than plants fully irrigated during that period.

Yield reductions were greatest when stress occurred during the pollination or grain filling periods. Canopy temperature increases between the onset of tasseling and the end of grain fill were related to reduced yields.

Five crop temperature indices were tested for their relationship to phenological stage of growth. Three were highly correlated, one had a low correlation, and one was not correlated with phenological development.
Tall Wheatgrass and Russian Wildrye Growth on Natrustoll Horizons Treated with Phosphate and Calcium Amendments1
Authors: Bowman R. A. , McGinnies W. J.
Published: July 2010

The central Great Plains of Colorado and Wyoming contain over 500,000 ha of saltgrass [Distichlis stricta (Torr.) Rydb.] meadows. In many places these meadows are subirrigated by a shallow, nonsaline water table. Rehabilitation of these meadows with palatable, salt‐tolerant species would greatly increase the grazing capacity. We conducted a greenhouse study to evaluate the effects of three levels of phosphate (P) and two levels of Ca on herbage growth and on the root development of tall wheatgrass [Agropyron elongatum (Host) Beauv.] and Russian wildrye (Elymus junceus Fisch.) when grown in a mixed horizon and in a simulated profile of Typic Natrustoll soils. Both species showed significant increases in herbage production with P and substantial increases in P uptake. Calcium treatments and P ✕ Ca interactions were significant only in the second and third herbage harvests and in roots of tall wheatgrass. Tall wheatgrass absorbed considerable quantities of Na* (>1%), while Russian wildrye absorbed appreciably less, which suggests an exclusion mechanism for Na* by Russian wildrye. No direct enhancement effect was noted in plant vigor due to fertility‐salinity interactions. In the mixed horizon treatment, which simulates plowing to a depth that would mix saline C horizon material with the A and B horizons, tall wheatgrass responded to both P and Ca, and Russian wildrye responded to P. One should avoid plowing into the saline C horizon, but if this cannot be avoided, applications of P and Ca fertilizer may help ameliorate the effects of the salinity. In the simulated horizon treatment, which simulates cultural practices that do not mix the C horizon with the A and B horizons, the addition of P and Ca was neither necessary nor beneficial.
Cultural Methods to Increase Sucrose and Energy Yields of Sugarcane1
Authors: Gascho G. J. , Shih S. F.
Published: July 2010

Sugarcane (Saccarum spp.) is widely grown in the tropics and sub‐tropics for sucrose production. The higher sugar yield make sugarcane an attractive candidate as a feedstock for producing ethanol for fuel. To increase yields of either sucrose or ethanol, information is needed on the effects of row spacing and chemical ripening.

Sugarcane (cv. CP 65‐357) was grown at narrow interrow spacings on Pahokee muck (Lithic Medisaprist) and Riviera sand (Arenic Glossaqualf) in Florida to determine the effect of high plant populations on yields of biomass, cane, sucrose, total sugars, and ethanol. A narrow interrow spacing of 0.5 m resulted in increased yields in comparison to the standard commercial spacing of 1.5 m. Differences in yields between row spacings tended to be larger in ratoons than in the plant crop (first growth). Increased yields were mainly due to an increased stalk population at the 0.5 m row spacing for all crops. Stalk population differences were large early, decreased with time, but still remained significantly different at harvest. Rapid canopy cover which reduced weed competition was an advantage of narrow interrows. An intermediate spacing of 1.0 m resulted in only slightly higher yields than the 1.5 m spacing on sand. Applications of glyphosine [N,N‐bis(phosphonomethyl) glycine] increased potential yields of sucrose, total sugars, and ethanol. The photosynthetic efficiency for the narrow rows was 1.5 to 1.6% of total short wave radiation; for the standard rows, 0.9 to 1.0% and for commercial cane in Florida during the period 1977–1978,0.7%. Fresh biomass, dry biomass, fresh stalks, sucrose, total sugar and fiber yields averaged 182, 53, 149, 21.2, 25.2 and 25.0 metric tons ha‐1 year‐1 over five harvests with a 0.5 m inter‐row spacing. If only the stalks were processed, the potential ethanol yield would have averaged about 10,000 liters ha‐1 year‐1. The dry matter (trash and bagasse) for burning to fire the ethanol plant averaged 25 metric tons ha‐1 year‐1. Such high yields make sugarcane a potential energy source in areas suitable for its growth.
Water Management and Nitrogen Fertilization of Ratoon Crop Rice1
Authors: Mengel D. B. , Wilson F. E.
Published: July 2010

Ratoon cropping of rice (Oryza sativa L.) offers the opportunity to obtain an additional grain crop with minimal input on land which may otherwise not be utilized during that period of time.

Field experiments were conducted for 3 years to determine the effect of two water management systems and N fertilization on the yield and milling quality of ratoon crop rice. The experiments were conducted on a Crowley silt loam (Typic Albaqualf) soil.

Applying a shallow (5 to 8 cm) continuous flood immediately after harvest of the planted crop was superior to a series of short‐term floodings to provide adequate moisture for regrowth, followed by a continuous flood when the ratoon tillers were 10 to 15 cm tall (approximately 4 weeks after planting). Grain yield averaged 68% higher where the immediate flood was applied. Under both water management regimes a significant increase in plant height and grain yield was observed when N fertilizer was applied. No significant effects of water management or N on grain milling quality were observed.
Effect of Leaf Area, Incident Radiation, and Moisture Stress on Reflectance of Near Infrared Radiation from a Corn Canopy1
Authors: Dale R. F. , Schreeringa K. L. , Hodges H. F. , Housley T. L.
Published: July 2010

Plant moisture stress is a major limiting factor in crop production. Remote sensing of moisture stress in crops would allow definition of the environmental conditions causing stress and timely use of management practices to avoid it. The reflectance of solar radiation, however, may be more affected by plant cover and meteorological factors than by moisture stress. The objectives of this research were to monitor continuously incident near infrared radiation (IR ↓) and reflectance (IR ↑ ) from corn (Zea mays L.) and to relate the reflectance ratio (IR ↑ /IR ↓ ) to green leaf area index (LAI), IR ↓ , and moisture stress indices. The experiment was conducted at West Lafayette, Indiana on a Typic Argiaquoll (Chalmers silt loam) in 1973 and 1974 and on dune sand in 1975 and 1976. Under non‐moisture stress (ns) conditions, LAI was used in a function (FLAI) to identify the ratio of green plant cover (RGPC). Linear regressions showed that as FLAI or RGPC increased from 0 to 1, (IR ↑ /IR ↓ )‐ increased an average of 9%. For each cal cm‐2 hr‐1 increase in IR ↓, (IR ↑ / IR ↓ )ns decreased an average of 0.6% for every hour ending at 0900 to 1800 EST. Differences (DIFR) between measured IR ↑ /IR ↓ and that predicted with the ns regressions for each hour were regressed on a characteristic soil moisture potential (Ψsm) for the dune sand and on a ratio of calculated actual to potential evapotranspiration (ET/ PET) for the Typic Argiaquoll. Correlations of DIFR on Ψsm or ET/ PET were low. Differences in reflectance first appeared to increase with increasing moisture stress, and then decreased with further increase in moisture stress, as leaf rolling reduced the RGPC. These findings suggest one reason for different IR reflectance‐plant moisture stress results reported in the literature, and clearly show that without accurate measures of LAI (or RGPC) and IR ↓ plant moisture stress cannot be detected with measurements of IR ↑
Insect Control on Seedling Alfalfa by Cultivars and Soil and Foliar Insecticides1
Authors: Kehr W. R. , Manglitz G. R. , Ogden R. L.
Published: July 2010

Control of insects on seedling alfalfa (Medicago sativa L.) is often desirable for stand establishment and forage production. The objective of these studies was to determine the use of cultivars and soil and foliar insecticides in controlling insects on seedling alfalfa. Three field studies were conducted on the use of preplant soil application of carbofuran (2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl methylcarbamate) in spring seedings on a Typic Arguidoll soil. The studies also included foliar application of carbofuran alone and in combination with soil application, and cultivars that varied, in resistance to insect species. Insecticide was applied at 1.1 kg a.i./ha.

Neither soil nor foliar insecticide application increased forage yield, protein and carotene concentration of seedling alfalfa. Potato leafhopper [Empoasca fabae (Harris)], pea aphid [Acyrthosiphon pisum (Harris)], spotted alfalfa aphid [Therioaphis maculata (Buckton)], and plant bugs [Lygus lineolaris (Beauv.)] and [Adelphocoris lineolatus (Goeze)] were controlled by carbofuran.

The pea aphid resistance of ‘Arc,’ ‘Baker,’ and ‘Perry’ and spotted alfalfa aphid resistance of Baker were effective in controlling aphid populations. ‘Buffalo,’ susceptible to potato leafhopper, pea aphid, and spotted alfalfa aphid, was lower than Arc, Baker, and Perry in forage yield, protein and carotene concentrations.

No residual effects of soil insecticide application prior to seeding were apparent on insect numbers in the second and third cuttings.
Effect of a Nitrification Inhibitor on the K, Ca, and Mg Composition of Winter Wheat Forage1
Authors: Mathers A. C. , Stewart B. A. , Grunes D. L.
Published: July 2010

Winter wheat (Triticum aestivum L.) is an important forage for cattle in much of the Southern Great Plains. However, death losses in wheat pastures due to grass tetany of nursing and pregnant older cattle, and frothy bloat of younger cattle, often occur. Forages from fields moderately or heavily fertilized with N are generally more hazardous than forages from unfertilized fields. As regards grass tetany, high rates of N fertilization are particularly hazardous when soil K is high. The objective of the present study was to determine the effect of the nitrification inhibitor nitrapyrin (N‐serve) on the relative uptake of K, Ca, and Mg by winter wheat growing in pots in the greenhouse. When nitrapyrin was added, the plants took up less NO−3‐N because nitrapyrin inhibited nitrification of the added NH+4. The plants also had lower concentrations of K, Ca, and Mg. However, the depression effect was greater for the divalent cations Ca and Mg, than for the monovalent cation K, so the K/(Ca + Mg) ratio was increased. Therefore, when nitrapyrin was added, the forage was more likely to cause grass tetany. Nitrapyrin also decreased plant organic acid concentrations and this probably decreased Mg and Ca uptake. The concentration of K was higher and Mg and Ca was lower during periods of rapid growth. Therefore, the forage was more likely to cause tetany during these periods. Nitrapyrin was effective in delaying nitrification, and this could be useful for supplying N to wheat later in the growing season. However, other steps might have to be taken to avoid an increased incidence of grass tetany.
Seed‐borne Fungi, Quality, and Yield of Soybeans Treated with Benomyl Fungicide by Various Application Methods1
Authors: Jeffers D. L. , Schmitthenner A. F. , Reichard D. L.
Published: July 2010

Soybeans [Glycine max (L.) Merr.] are often damaged by the seedborne fungi Phomopsis sp., Diaporthe phaseolorum (Cke. and Ell.) Sacc. var. sojae (Lehman) Wehm. and D. phaseolorum var. caulivora Athow and Caldwell which inhibit germination and sometimes cause moldy seed. These fungi can be controlled with benomyl (methyl 1‐[(butylamino)carbonyl]‐1H‐benzimidazol‐2‐ylcarbamate) fungicide when applied at the R4‐R5 stage in relatively large, illegal, quantities, >1.1 kg/ha (a.i.), and in large volumes of spray solution, >230 liters/ha. The purpose of this research was to determine if Phomopsis and Diaporthe seed contamination and seed rot can be effectively controlled with legal rates of benomyl applied by aircraft or ground equipment at reduced volumes.

Aircraft application of benomyl at 0.56 kg/ha resulted in no overall improvement in seed germination, and on only 4 of 14 farms were there significant reductions in Phomopsis and Diaporthe seed contamination following benomyl application, but these were not large enough to be economical.

Ground application was with a backpack mistblower, a tractor‐mounted Myers Downdraft sprayer, a high‐clearance powered unit using hydraulic broadcast application with flat‐fan nozzles, and the high‐clearance unit with a special boom using a directed hydraulic spray.

Phomopsis + Diaporthe seed contamination in the controls ranged from 34 to 94% and germination, 10 to 71%. Benomyl decreased Phomopsis + Diaporthe seed contamination 20 to 67% and increased germination 16 to 61%. Incidence of these fungi in seed decreased and germination percentage increased with increasing spray volume where hydraulic flat‐fan nozzles were used, but not with the other methods. With equal volumes (230 liters/ha) the mistblower and downdraft sprayer were superior to the hydraulic flat‐fan broadcast method, and equal to a directed hydraulic spray for controlling Phomopsis and Diaporthe. Improvement in germination was sufficient to warrant application of benomyl with ground equipment.
Soil Coring Method for Sites with Restricted Access1
Authors: Foale M. A. , Upchurch D. R.
Published: July 2010

A hand method of rapidly collecting soil cores to 2 m depth is described. The components of the system are adaptable and modified from previously published accounts. The system fills a gap in coring technology between shallow hand corers and large machine‐mounted coring rigs.

Tests have shown that this system will be of great use where site and administrative factors prevent the use of a large coring rig.
Nitrogen Management for Irrigated Annual Ryegrass in Southwestern United States1
Authors: Ehlig C. F. , Hagemann R. W.
Published: July 2010

Annual ryegrass (Lolium multiflorum Lamb.) is becoming an important winter and spring pasture crop in the irrigated southwestern USA. A field study was conducted to determine the optimum N fertilization rates for producing maximum dry matter yields within tolerable NO−3‐N concentrations for livestock and to develop a diagnostic test using plant and/or soil NO−3‐N concentrations for recommending rates and frequency of N applications to ryegrass pastures. The cv. ‘Ucivex’ was seeded in an Imperial silty clay [fine, montmorillonitic (calcareous), hyperthermic Vertic Torrifluvents] in October, first harvested in December, and cut about monthly thereafter. In seven treatments, NH4NO3 was applied at seasonal rates of 0, 224, 448, 676, 896, and 1,120 kg N/ha, in five equal applications, or 90 kg N/ ha preplant plus 112 kg N/ha after each harvest.

Seasonal dry matter yield (Y) was related to N application rate (X) by the equation Y = 2.37 + 0.0272X + 0.0000118X2 (r = 0.999). Hay nitrate concentration increased with N application rate and was excessive, for animal tolerance, with single N applications above 112 kg/ha for the second test. Protein, ash, and fiber content of the hay increased, N‐free extract and total digestible nutrients decreased, and fat was unaffected by increase in N application rate. Soil nitrate concentrations of 10 to 20 ppm in the upper 60 cm ensured near maximal yields at next cutting without excessive hay nitrate concentrations. A hay content of 2,000 to 3,000 ppm NO−3‐N was not adequate for satisfactory yield at the next cutting without additional N application. Multiple N applications at 112 kg/ha at about monthly intervals were recommended.
Yield of Indeterminate Soybeans in Response to Multiple Periods of Soil‐Water Stress During Reproduction1
Authors: Snyder R. L. , Carlson R. E. , Shaw R. H.
Published: July 2010

Yield potential of soybeans [Glycine max (L.) Merr.], which are grown under nonlimiting soil‐moisture conditions, has been greatly improved through breeding and management practices in recent years. Much improvement, however, is still needed in the development of high yielding soybeans grown under suboptimal soil‐moisture conditions. To better understand limiting soil‐water effects on yield, four indeterminate soybean cultivars were grown in restricted rooting mediums of Nicollet Loam soil (fine‐loamy, mixed, mesic Aquic Hapludolls) in the field, and single and multiple periods of soil‐moisture stress were induced during the reproductive stage by withholding hand watering at appropriate times and covering the plots during periods of rainfall.

Seed yield reductions for all soil‐water treatments and cultivars varied from 2% (NS) to 27% (α = 0.01). Two of the cultivars, ‘Ottilie 7270’ and ‘Beeson’, were less affected by soil‐water stress (12% yield loss) than the other cultivars (18% yield loss), ‘Hodgson’ and ‘Corsoy’, averaged over stress treatments. Soil‐water stress during the first of three stress periods reduced yield by 12% (α = 0.01). A second and third period of soil‐water stress reduced yield additionally 5% (NS) and 4% (NS), respectively. Treatments receiving soil‐water stress for the first time during period 2 or period 3 had 11% (α = 0.01) or 12% (α = 0.01) yield reductions, respectively. The plants subjected to three periods of soil‐water stress produced fewer but heavier seeds than plants stressed only during the third period. The response of yield components, nodes/plant, pods/node, seeds/pods, and weight per seed, varied extensively between cultivars and treatments. The magnitude of individual decrements in these parameters was dependent on the timing of soil‐water treatments and the state of development of the soybeans.

Under the conditions of this experiment, all the cultivars exhibited similar yield response to single periods of stress. Preconditioning soybeans for later stress resulted in less yield reduction than if the plants were unconditioned. Seed yields of later maturing cultivars, Ottilie 7270 and Beeson, were greater and were less affected by multiple stress during reproductive growth than the cvs. Corsoy and Hodgson. Soil‐water stress imposed on plants early in their reproductive periods appeared to change dry matter partitioning by increasing their harvest index, and this was most notable with the later maturing cultivars.
Effect of Calcium Sulfate on Iron and Zinc Uptake in Sorghum1
Authors: Bowman R. A. , Olsen S. R.
Published: July 2010

In a recent report, Olsen and Watanabe found significant increases in uptake of Fe and Zn in sorghum (Sorghum bicolor L. Moench. var. RS‐610) due to calcium sulfate treatments in four of six soils. Our research extended this sulfate × micronutrient interaction study to evaluate the possible ameliorative effect of sulfate on Fe and Zn as influenced by P and CaCO3 levels. A greenhouse factorial experiment was designed using two levels of P, sulfate, and CaCO3 in a Nunn loam soil (fine, montmorillonitic mesic Aridic Argiustoll) with sorghum as the test plant. Plants were grown for 60 days, and then sectioned into top leaves, bottom leaves, and stems. Data collected included dry matter, and P, Fe, and Zn concentrations in the various parts.

Dry matter yields and P concentrations were increased with added P treatments. Phosphorus with added CaCO3 resulted in the lowest Fe and Zn concentrations in the top leaves while P with added sulfate resulted in the highest. These treatment effects were generally reversed in the bottom leaves. Phosphorus, and Fe and Zn, showed different mobility relationships. Total Fe uptake was increased 20% and Zn uptake also tended to increase with added sulfate. Apparently, the top leaves were supplied with Fe through internal transfer of Fe from bottom to top leaves, and external transfer (soil), while the Zn transfer was largely through internal transfer processes.
First Crop Seed Yield of Selected Cool‐Season Grasses as Influenced by Weed Control1
Authors: Morrow L. A. , Canode C. L.
Published: July 2010

Perennial grass grown for seed is an important part of the economy of Pacific Northwest agriculture, both as a crop and as an integral part of the rotation practices for control of soil erosion. Annual weeds are often difficult to control and extremely damaging to grass seedlings in the year of stand establishment. A 3‐year field study was conducted on a Palouse soil (fine‐silty, mixed, mesic pachic Ultic Haploxerolls) to determine the influence of control of witchgrass (Panicum capillare L.) and annual broadleaf weeds in the year of establishment on first seed crop yield of ‘Sherman’ big bluegrass (Poa ampla Merv.), ‘Whitmar’ bluebunch wheatgrass [Agropyron inerme (Scribn. and Smith) Rydb.], ‘Durar’ hard fescue [Festuca ovina var. duriuscula (L.) Koch.], ‘Pennlawn’ red fescue (Festuca rubra L.), and ‘Manchar’ smooth brome (Bromus inermis Leyss.). Bromoxynil (3,5‐dibromo‐4‐hydroxybenzonitrile) was applied to these grasses at 0.56, 1.12, or 1.68 kg/ha at the single leaf stage and MSMA (monosodium methanearsonate) was applied at 3.36, 4.48, 5.60, or 6.72 kg/ha when perennial grasses had five tillers and witchgrass was at the four‐ to eight‐tiller stage of development. Bromoxynil applied at 0.56 kg/ha controlled annual broadleaf weeds and, except for red fescue, there was no effect from increased bromoxynil rates on first crop seed yields. Pennlawn red fescue yield was increased with 1.68 kg/ha bromoxynil. Applications of MSMA generally increased grass seed yields because witchgrass was controlled. Except for smooth brome, control of witchgrass and annual broadleaf weeds aided grass seedling establishment and increased first crop seed yield. Apparently, the larger‐seeded grasses such as smooth brome have the ability to establish rapidly and to effectively compete with annual weeds.