Sugar Beet Fields Research Articles

Abundance and Activity of Starlings in Winter in Northern Utah

Starlings (Sturnus vulgaris) were first observed in Utah in the winter of 1939 (Lockerbie, 1939). It was 10 years before they reached sufficient numbers to become a nuisance to feedlot operators and fruit growers. During the 1950's Starlings in Utah increased tremendously. By 1960 feedlot operators in 16 counties were complaining of damage during winter feeding operations, and in Washington County in the southern part of the state the County Agricultural Agent reported that Starlings were the major agricultural problem. Starlings in Utah are now concentrating in winter flocks estimated to be as large as 100,000, and complaints of damage are increasing. Starlings will probably continue to increase in Utah during the 1960's, causing increased economic loss to the state's feedlot and orchard industry. Thus some control action appears justifiable. Previous studies of agricultural pests have demonstrated that effective control is not possible until the ecology of the species is known. Information regarding distribution, abundance, and movements during winter would indicate whether a stable winter population or a mobile, nomadic population is responsible for the loss to ranchers. The study area was near Tremonton, Box Elder County, northern Utah. The area is at 4500-feet altitude and is flat except for the meandering Bear and Malad rivers. The region is covered largely by grain and sugar beet fields. Many cattle feedlots and silage pits are scattered over the area, and flocks of sheep are present in some fields at certain times of the year. The climate is semiarid with cold winters and hot summers. Average annual precipitation is about 13 inches, and the annual mean temperature is 560F. Snow rarely remains on the ground for more than a few days after a storm. Spring is the wettest season of the year; nearly 40 per cent of the average annual precipitation falls in March, April, and May.

The Photosynthesis and Transpiration of Crops

SummaryWhen a leaf absorbs radiant energy, only a small fraction is stored chemically in photosynthesis. In sunlight, this fraction is at most one-fifth of the energy in the visible spectrum, decreasing with increasing light intensity because of the finite resistance to the diffusion of carbon dioxide through the leaf to the chloroplasts. Energy absorbed but not stored in photosynthesis is dissipated by transpiration and convection.The potential or maximum photosynthesis of a crop canopy can be estimated from a set of six parameters describing the photosynthesis-light curve of single leaves, the arrangement of leaves in the canopy, and radiation climate. Comparing estimates of potential photosynthesis with measurements of carbon dioxide exchange over a field of sugar beet, the estimated rate of respiration was 2 gm carbohydrate per m2 leaf area per day, equivalent to 44 per cent of gross photosynthesis over the whole growing season. Over the season, the foliage lost 34 per cent of incident radiation by transmission to the soil.The potential rate of transpiration can be found from Penman's formula assuming values of external (aerodynamic) and internal (mainly stomatal) resistance for the canopy as a whole. In south-east England, the energy for potential transpiration is almost equal to net heat H in summer and is therefore about half the energy of incoming solar radiation. For a real crop of grass subject to moisture stress, transpiration was less than the potential rate at about 0·8 H on average and 0·3 H in very dry weather.During the summer, cumulative photosynthesis increases linearly with cumulative transpiration to give a production ratio (gross photosynthesis/transpiration) of 1/100 in the Thames Valley and 1/200 in the Sacramento Valley. The production ratio is expected to change with crop type as well as with climate.

Kidney and Marrow Fat as Indicators of White-Tailed Deer Condition

Comparisons of kidney fat indices and fat content of femur marrow from 34 female whitetailed deer (Odocoileus virginianus) showed that kidney fat is not a reliable indicator of physical condition during mobilization of femur marrow fat. A method involving the complementary use of the two measurements is suggested as a means of assessing physical condition over its entire range. This paper shows the relationship of kidney fat indices to the fat content of femur marrow in female white-tailed deer and presents a method for the complementary use of the two measurements in assessing physical condition. Riney (1955) studied various methods of evaluating the condition of red deer (Cervus elaphus) in New Zealand and concluded that weight of kidney fat expressed as a percentage of kidney weight is a valid index of total body fat over the entire range of physical condition. This method was applied to 66 female white-tailed deer collected in Manitoba from December, 1962, through April, 1963. The indices thus obtained decreased regularly over the winter until the second week of March when the poorest deer had indices as low as 8. But during the next month only 1 of 15 deer collected had an index below 8 although their general appearance indicated that several of the 15 were in poorer condition than any of those collected previously. Since Harris (1945) and Cheatum (1949) found that marrow fat is the last fat reserve to be mobilized in deer, I obtained the percentage of fat in femur marrow from 34 of the 66 deer to determine whether or not further deterioration in condition had escaped detection by the kidney fat index method. MATERIALS AND METHODS Kidney fat weights were obtained using a method described by Riney (1955) and an index for each animal was calculated using the fat from both kidneys in order to minimize variation. The percentage of fat in the central 2 inches of femur marrow 397 cent water. Of the dry matter about 75 percent is sucrose, and the balance includes salts of sodium and potassium plus nitrogenous compounds. In Table 1 the nutritional values of the sugar beet root and field corn are compared (Morrison, F. B. 1956. Feeds and feeding: A handbook for the student and stockman. 22nd ed. The Morrison Publishing Company, Ithaca, New York. vi+ 1165pp.). In recent years Canada geese have gradually been educated to feed on agricultural crops on the refuge and have thus developed a taste for sugar beets. From a nutritional standpoint, sugar beet roots and crowns rate considerably lower than field corn, but, at least during the dry season, they provide an important source of succulent browse. Received for publication March 26, 1964. This content downloaded from 157.55.39.249 on Wed, 03 Aug 2016 05:23:52 UTC All use subject to http://about.jstor.org/terms 398 Journal of Wildlife Management, Vol. 29, No. 2, April 1965

Spread of Yellows Virus by Myzus persicae in Sugar Beet Crops

WINGLESS Myzus persicae were reared on sugar beet plants (provided by Dr. G. E. Russell, Plant Breeding Institute, Cambridge) infected with sugar beet yellows virus (SBYV), sugar beet mild yellows virus (SBMYV)1, or both viruses. Eight widely separated plants in a 7¼-acre field of sugar beet each received three adult and six young aphids from these cultures on May 31, 1962, and nearby plants were examined for aphids and virus symptoms at weekly intervals thereafter.

Studies on the vicissitude of Pellicularia filamentosa in soil. Part II

From the results of the previous experiment on the crown rot of sugar beet in Hokkaido, it was pointed out that Rhizoctonia solani in the soil of sugar beet field becomes active in two different seasons of a year, i.e., usually May to June and July to August. The reason of the fluctuation of the fungus activity in soil was considered by the senior author to be due to alternation of different strains of R. solani in the soil depending on the advance of season.In the present experiment, the range of Rhizoctonia strains in a particular soil of flax field, and their comparative characteristics were studied.Isolations of the causal Rhizoctonia were made from May to August in the flax growing plots of the University Farm in Sapporo. More than 150 isolates were obtained from affected flax tissues and also about 100 cultures were isolated from the soil by means of the flax trap technique. All of them could be divided according to their cultural characters into two apparent groups: one called “spring strain” was isolated from the soil and damped-off seedlings in May and June; the other, “summer strain”, was obtained in July and August from the soil and lesions on the stems of flax at the post-flowering stage.Comparative studies were carried out with several isolates each of the two strains. The effect of temperature on the growth and pathogenicity of both strains is quite different: the temperature which induces the fastest mycelial growth of the spring strain on PDA (Table 3) or through soil-tubes (Fig. 1) is generally lower than that in the summer strain. The spring strain causes severe damping- off at low temperature such as 13°and 18°C (Figs. 2, 3).The results of pathogenicity trials on the flax of different ages (Tables 4, 5, 6) proved that the pathogenicity of strains is specialized by the age of the host plant: isolates of the spring strain are pathogenic only to young seedlings and can not attack mature plants, while those of the summer strain are slightly pathogenic on seedlings, but readily invade mature stems of flax in the post-flowering stage.The results of isolation experiments from the soil which was artificially inoculated with both strains showed that all of the isolates caught by the flax trap from the soil incubated at low temperature (5°to 18°C: average 13°C) and of those isolated from infected host plants which were grown under the same condition, were found to belong to the spring strain; when the soil was kept at higher temperature (12°to 28°C: average 20°C) both strains were obtained from the soil and host plants (Tables 7, 8).The cultural characters of all isolates of each strain are quite uniform, but there are remarkable differences between the two strains. The spring strain is identified as Pellicularia filamentosa from its morphological character as well as from the perfect stage formed on the flax stem and the surface of soil particles in the experimental plots during the isolation experiments in May and June. Because of the lack of perfect stage and of a few differences in its vegetative characters from the original description, the summer strain cannot be clearly identified as Pellicularia praticola. On this account the authors propose the name Rhizoctonia solani, the classic complex species, to cover the both strains.

The flux of CO2 over a field of sugar beet

The flux of CO₂ over a field of sugar beet

Ecophysiological significance of the height gradient of the equivalent evaporation power of the atmosphere

The term “equivalent evaporation power” is suggested to denote the evaporation power of the atmosphere measured as the relative evaporation from an evaporimeter which resembles to a great extent the physical conditions occurring during transpiration of a plant leaf (e.g. the Piche evaporimeter). The height dependence of equivalent evaporation power at heights between 5 and 500 cm. in an “open area”, in a field of sugar beet, maize, in a mature deciduous wood, in its small circular rejuvenation clearing and on a great clearing was investigated. The higher the absolute values of evaporation the lower the height gradient which is obviously observed to decrease progressively with height in all cases (Figs. 1 and 2). The stands decrease the average equivalent evaporation power in the height interval exceeding their height. Differences between the relative values of equivalent evaporation power of atmospheric environment surrounding different leaves of one plant are frequently considerably higher than those between ecoclimatically completely distinct localities (e.g. between a forest stand and a clearing). A statistically significant positive correlation was found to exist between the gravimetrically determined all-day total of transpiration of seedlings ofFagus silvatica L. andAcer platanoides L., freely exposed in small lysimeters for the entire vegetation season and between the all-day total of equivalent evaporation power. For the number of days n=95 the mean correlation coefficient r was +0·58±3.0·031 for the beech and +0·56±3.0·046 for the maple. The regression coefficient, which is linearly proportional to the leaf area, was low and provides evidence for the biological regulation of transpiration. It was shown by simultaneous measurements of transpiration (gravimetrically) of leaves ofSyringa vulgaris L. (n=95) and of equivalent evaporation power at the height of 10, 50 and 150 cm. above the ground in an “open area” that the height gradient of equivalent evaporation power of the atmosphere under natural conditions affects the intensity of transpiration at different heights (Fig. 3). The observed facts are undoubtedly to be associated with the formation of the xerophytic or mesophytic character of leaves located at different levels of the same plant, and thus withZalensky’s law.

The carbon‐dioxide flux over a field of sugar beet

AbstractThe difference of CO2 concentration at two heights above a sugar beet crop was measured with a sensitive infra‐red gas analyser. The ratio of evaporation to humidity gradient and of total heat flux to wet‐bulb temperature gradient gave a transport number for calculating CO2 flux, assumed proportional to CO2 gradient and wind speed. In August and September 1958 there was often a constant upward flux at night (mean 0·05 mg cm−2 hr−1) attributed to respiration by plants and soil micro‐organisms; but during daylight, photosynthesis gave a downward flux varying with solar radiation and reaching a maximum of 0·4 mg cm−2 hr−1. From 31 July to 11 September the net downward flux of atmospheric CO2 was 158 ± 29 mg cm−2 compared with an uptake of 217 ± 38 mg cm−2 estimated from dry matter increase of sampled plants. During October there was a net upward flux of 4·9 mg cm−2 day−1 attributed to a striking increase in amount of CO2 produced in the soil.

Cucumber mosaic in seed fields of sugar beet in the Salt River Valley of Arizona

Cucumber mosaic in seed fields of sugar beet in the Salt River Valley of Arizona

Evidence of nonspecific transmission of California aster-yellows virus by leafhoppers

does not appear. First page follows. Introduction It may be necessary to define two terms before proceeding with this paper. Specificity is the transmission of a particular virus by one or two closely related species of vectors. “When a virus can be transmitted only by one or two closely related insects and cannot be transmitted artificially (except by grafting) the insect transmission is considered obligatory” (Leach, 1940).3 Formerly it was assumed that a specific relation existed between each plant virus and its aphid vector. Among the viruses transmitted by aphids, specificity is now regarded as exceptional rather than common. In the opinion of (Smith (1937)), a rather strong point in favor of a specific relationship between leafhopper and virus lies in the fact that certain plant viruses can be transmitted by only one species. Heretofore it has been assumed that the aster-yellows virus could be disseminated only by the aster leafhopper, Macrosteles divisus (Uhl.) = [Cicadula sexnotota (Foll.)], and by no other means except grafting and budding of the plant. According to (Kunkel (1926)), the intimate and specific relation existing between the aster-yellows virus and its insect vector is important evidence that the causative entity is biological rather than chemical. (Leach (1940)) emphasizes the biological, obligatory, and highly specific transmission of viruses by leafhoppers. There may be some viruses which can be transmitted by only one species of leafhopper. During the past thirty years many species of leafhoppers collected in sugar-beet fields were tested by the author for the transmission of the curlytop virus, but up to the present time no other vector is known except the beet leafhopper, Eutettix tenellus (Baker). According to (DeLong (1942)), the North American fauna of leafhoppers, north of Mexico, consists of 2,000 species belonging to about 150 genera. No other species of the genus Eutettix has been tested up to the present time. It is naturally assumed that closely related species in the same genus should be tested; on the other hand, species in genera belonging to different subfamilies may be vectors. The sugar beet is an introduced plant, and it may be possible that if leafhoppers are collected on native host plants of the virus, other vectors may be discovered. As will be discussed with aster yellows in this paper, host plants highly susceptible to the virus should be used instead of the sugar beet. Herewith is presented evidence that the transmission of the aster-yellows virus by six species of phlepsid leafhoppers is not specific. The characters, distribution, and food plants of these six vectors are discussed in a companion paper (DeLong and Severin, 1945). It is evident in the following review of literature that the prevailing concept has in general favored specificity.

History of the Fenland*

WITHIN historic times, the English fenland stretched over the greater part of the area to the west and south of the Wash, extending as far north as Lincoln and as far south as Huntingdon and Cambridge. On the seaward side, the surface deposits are semi-marine silts, laid down, and afterwards occupied, during the Romano-British period. On the landward side, the upper layers are peat produced by discharge of the flood waters of the Rivers Witham, Welland, Nene and Ouse into the extensive shallow basin of the fens. The fen peats are alkaline and therefore support a vegetation of the true 'fen' type. Very little of the original vegetation of the peat fen remains, however, since the whole area has been drained and brought under extensive cultivation. Its present characteristics are the black peaty soil, uniform flatness and deep ditches full of reeds (Phragmites communis) which separate fields of cereals, potatoes and sugar beet.

Sugar Beet Field Labor under the AAA

Sugar Beet Field Labor under the AAA

Field observations on the beet leafhopper, Eutettix tenellus, in California

Abstract does not appear. First page follows. During 1918-1932 field investigations were carried on to determine where the beet leafhopper spends the winter and to locate the natural breeding areas in this state. Trips were taken to Death Valley, Mojave Desert, Imperial Valley, and the Tulare Lake and Bakersfieid sections of the San Joaquin Valley—areas from which Ball(2) believed the beet leafhopper migrated into sugar-beet fields—and also to the middle and northern sections of the San Joaquin Valley, to the Sacramento Valley, Santa Clara, and Salinas valleys, and to all other important sugar-beet districts in California. After a general survey of this enormous territory, it soon became evident that it would require many years of field work to map the natural breeding areas of this insect, and hence the work was limited to the San Joaquin, Sacramento, Santa Clara, and Salinas valleys and to several small valleys. No foothill investigation has been carried on in Death Valley, Antelope Valley, Mojave Desert, and Imperial Valley. Such results as were obtained in these districts have been published in previous papers.(28), (30), (40) The host plants of the beet leafhopper on the uncultivated plains and foothills, in the cultivated areas, and the original native host plants, the spring and summer dispersals and migrations, natural barriers, causes of fluctuation in population, and natural enemies were also observed during the investigations. Distribution of Beet Leafhopper The beet leafhopper is a native species and has been taken in western North America from Canada into Mexico. Davis(11) found the northern limit of the leafhopper was Cache Creek, British Columbia, 140 miles north of the international boundary. Carter(10) used the climograph as a means of comparing climates with respect to precipitation and temperatures in determining the probable limits of the range of the beet leafhopper; these studies were supplemented with surveys of the distribution of the insect. He considers that the presence of the leafhopper in British Columbia is due to a northward migration. Carter(9) published the results of the Canadian survey conducted by H. L. Seamans and states that the leafhopper was not found in the province of Alberta, although the results of the survey were not conclusive. Davis(11) found that the leafhopper was generally distributed in western Washington and Oregon.

Population of Eutettix Tenella Baker and the Osmotic Concentrations of Its Host Plants

Eutettix tenella Baker is a leafhopper (family Cicadellidae) found in the intermountain and coast regions of the western United States. Among other plants, it breeds on a number of the Chenopodiaceae. In some years the insect leaves its desert habitat and flies in enormous numbers into sugar-beet fields. The year I925, however, was not marked by such migrations in the intermountain region of the West, and an opportunity was thus afforded for continuous observations on the behavior of the insect in its desert breeding ground. METHOD