Effects of fungicides and insecticides applied to spring barley sown on different dates in 1976-79

Factorial experiments in 1976–1979 investigated the effects of sowing date, fungicides (ethirimol seed treatments and tridemorph sprays) and insecticides (phorate applied to the soil, and menazon or dimethoate sprays) on powdery mildew, aphids, barley yellow dwarf virus (BYDV) and grain yield of spring barley (cv. Julia in 1976 and 1977; cv. Wing in 1978 and 1979). Late sowing usually increased the severity of powdery mildew, numbers of aphids and incidence of BYDV and generally decreased yield. Responses to pesticides were commonly greater on the late-sown than on the early-sown barley. Response to fungicides are principally attributed to the control of powdery mildew (Erysiphe graminis f. sp. hordei; the target species) but responses to insecticides cannot be attributed to virus control and seem unlikely to be due solely to control of aphids, whose numbers were relatively small. There were some effects of fungicides on aphids and insecticides on mildew, but they were inconsistent and too small to affect crop protection strategies.     

Interspecific dominance amongst three species of coarse fish in Slapton Ley, Devon

Marked changes in the relative numbers of roach Rutilus rulilus (L.), rudd Scardinius erylhroplhalmus (L.) and perch Perca fIuviatilis L. , in Slapton Ley, Devon, have been observed over the period 1967–1978. Historically, the lake had been dominated by rudd and perch; significant numbers of roach were not thought to be present until 1967. From then onwards the roach population exhibited a considerable expansion, apparently replacing the rudd, which had virtually disappeared by 1974. In 1975 extensive mortalities of roach were caused by the pseudophyllidean cestode Ligula intestinalis L. During 1976 and 1977 larger number of rudd, belonging to the 1975 and 1976 year classes, were present, suggesting that the roach mortalities might be giving the rudd a chance to recover. However, very few rudd were present during 1978, possibly because lower incidences of ligulosis during 1976–1978 had allowed the roach to recover from the main outbreak of the disease in 1975, and to replace the rudd for the second time. Evidence from trap catches indicated that the perch population had shown a consistent decline between 1970 and 1977. The major phase of this decrease occurred between 1971 and 1973, when the roach population was increasing the most rapidly. Comparisons were made with changes in fish populations in other localities. The major reason for the changes observed was thought to be a competitive relationship between the plankton feeding younger stages, with roach being the dominant species, although other factors may also have been involved.     

Studies of the cereal cyst-nematode, Heterodera avenae under continuous cereals, 1974–1978. I. Plant growth and nematode multiplication

Population changes of Heterodera avenae and crop growth in a sandy loam soil were studied from 1974 until 1978; the nematode decreased plant growth but failed in two of the years to multiply on susceptible hosts. Spring oats were the most heavily invaded cereal and produced the smallest shoots. Second-stage juveniles invaded cereal roots in decreasing numbers: spring oats > autumn oats > spring barley > spring wheat > autumn barley > autumn wheat. Numbers of females developing on the different cultivars were in a similar order. Most females developed on roots in 1976 despite poor crop growth in the severe drought. Numbers of H. avenae in soil treated with oxamyl (Vydate) at 8.8 kg/ha a. i. were less in all years except 1975. In the dry winter and spring of 1975/76 nematode multiplication was prevented in soil treated with oxamyl before drilling in the autumn. In all years large numbers of females were produced on the roots of all cultivars but in 1975 and 1978 nematode populations declined because few females survived to form cysts containing eggs and their fecundity was reduced. Numbers of cysts after harvest were not affected by formalin (38% formaldehyde) applied as a drench at 3000 litres/ha in 1977 but fecundity doubled in treated soil, and nematode multiplication increased from 3.8 × in untreated plots to 18.6 ×. When the plots were irrigated in 1978 numbers of cysts and fecundity increased in formalin treated soil resulting in an increase in multiplication from 0.3 × to 14.6 ×. Fungal parasites attacking H. avenae females and eggs are considered responsible for the poor multiplication of the nematode.     

Effects of chemical treatments for mildew control at different times on the growth and yield of spring barley

Experiments in 1973 and 1974 tested the effects of ethirimol seed treatment and the timing of single sprays of ethirimol or tridemorph, on mildew control and the growth and yield of spring barley. These treatments were compared with selected combinations of two treatments designed to give longer protection. In 1973, combinations of seed treatment and spray, or two sprays, did not yield better than the best component treatment applied alone or the most effective single spray of tridemorph applied on 1 June. In 1974, mildew developed usually early and yields were increased by applying ethirimol to the seed plus a tridemorph spray or two tridemorph sprays. However, barley sprayed once with tridemorph on 20 May, the expected best date, yielded more than barley receiving a seed treatment of ethirimol plus a tridemorph spray applied on either 3 or 12 June. Sprays of captafol and tridemorph, applied as separate treatments, successively to the same plots on three occasions, gave the best yields in both years. Treatments most affected ear number but they did have some effect on all components of yield. In 1974 there was a significant relationship between ear number and the variance of the number of grains per ear.     

A summary of the prevalence of Parelaphostrongylus tenuis in a captive wapiti population.

A total of 87 brains from harvested and collected wapiti and red deer (Cervus spp.) were examined grossly and microscopically between 1973 and 1977 in a 2104 ha. preserve. Prevalence of infection significantly increased from 26.6% of the sample in 1973 to 64.3% in 1975 (P less than .05). A decline to 47.7% in 1977 (P greater than .05) was not significant. However, the number of clinical cases was significantly higher in 1976-1977 (P less than .02) than previously reported in 1973-1975.     

Plant Remains From Phillips Spring,A Multi Component Site In The Western Ozark Highland Of Missouri

Abstract

Phillips Spring (23Hi216) is a multicomponent archaeological site associated with an active artesian spring on a terrace of the Pomme de Terre river in western Missouri. Preservation of both carbonized and uncarbonized plant remains is excellent and remains of plants representing 32 taxa, including 24 potential food plant, occur atthe site as well as eight taxa of wood charcoal. In addition, there are remains of squash (Cucurbita pepo) and bottle gourd (Lagenaria siceraria) dating 4260 B.P., 40008.), 1999 B.P., and squash dating 2293 B.P. When combined with data from a Woodland storage pit at nearby Boney Spring (squash dated at 1920 B.P.) and Blackwell Cave (bottle gourd at 730 B.P.), it appears that these cultigens were being grown in the western Missouri Ozarks for much of the last 4000 years. Phillips Spring is a multicomponent (Late Archaic and Middle Woodland) site situatedon a terrace of the Pomme de Terre River in Hickory County, Missouri. Discovered in 1973, the site was subsequently excavated during four field seasons: 1974, 1976, 1977 and 1978. The 1974 excavations defined four cultural horizons including three Late Archaic and a Woodland component (Chomko 1976) and produced numerous well preservedplant remains. The presence of squash (Cucurbita pepo) in the earliest component, later associated with a date of3927 B. P., prompted additional testing of the site in 1976 and full scale excavation in 1977 and 1978 (Kay 1978, Robinson 1978). Results of the 1974 excavations have been previously discussed (Chomko 1978, Chomko and Crawford 1978) and the present paper discusses the plant remains from the 1976 and more extensive 1977 excavations. While the 1978 material, presently awaiting analysis, will undoubtedly increase both our knowledge of activity patterns at the site and our sample size of specific types of features and biotic remains, it will probably not add substantially to the extensive list of plant taxa which have been recovered from the spring.     

Chemical evolution and the origin of life

This bibliography is the seventeenth annual supplement to the comprehensive bibliography on the same subject which was published in Space Life Sci. 2(1970), 225-295; 3(1972), 293-304; 4(1973), 309-329 and in Origins of Life 5(1974), 505-527; 6(1975), 285-300; 7(1976), 75-85; 8(1977), 59-66; 9(1978), 67-74; 10(1980), 69-87; 10(1980), 379-404; 11(1981), 273-288; 12(1982), 93-118; 13(1983), 61-80; 15(1984), 55-69; 17(1987), 171-184; 17(1987), 185-206.     

The macrobenthos of the river IJssel

Summary This survey of the macrobenthos of the River IJssel, a branch of the River Rhine, was conducted in 1973, 1975, 1976 and 1977. The water quality was poor in 1973 and 1976 and relatively good in 1975 and 1977.The numbers of macroinvertebrate species and numbers of individuals in the stone samples taken from the jetties were lowest in 1976 and highest in 1977.The species composition of the Tubificidae showed a marked difference in various types of substratum at one locality.Decrease of water quality since a study of LAUTERBORN (1918) is reflected by impoverishment of the fauna; for instance, insects have disappeared to a large extent.     

An investigation into inter-plot interactions, in experiments with mildew on barley, using balanced designs

Serial designs, balanced for effects of neighbours, were used in 1975–1977 to investigate interactions between plots of spring barley given different treatments for the control of powdery mildew (Erysiphe graminis DC. f. sp. hordei Mérat). Differences in amounts of disease, between similarly treated plots, could be related largely to the treatments applied to the neighbouring plots and to wind directions. Amounts of disease in plots were usually increased if the upwind neighbour was untreated but untreated plots themselves were also affected by neighbours, having least disease where the upwind neighbour was sprayed early. Differences in mildew due to treatment were reflected in grain yield. Yields also provided evidence of interactions between plots. Interference, as well as altering the average response to treatments, can also contribute to variability in experiment results and lead to substantial losses in efficiency. The yields in 1975 and 1976 provided strong evidence of profiles of fertility. In the analyses, adjustment by covariates, employed to allow for these profiles, gave substantial net gains in accuracy.     

Interactions between phytoplankton and zooplankton in a fertilized lake

The limnology of an oligotrophic lake, Langvatn, situated in Trøndelag county in Central Norway, has been studied for five years (1974–1978). In two years, 1975 and 1976, the lake was fertilized with a general fertilizer to change feeding conditions for the zooplankton. Mean phytoplankton biomass in the epilimnion and primary production for the years (1974–1978) were 417, 618, 1370, 607 and 779 mg m⁻³ and 10.6, 22.2, 49.0, 26.8 and 17.7 g C m⁻² yr⁻¹, respectively. Cladocerans were the dominant herbivore group in 1974 and 1975 and Rotifera in the next three years. The main difference in the interaction between phytoplankton and zooplankton occurred when cladoceran dominance gave way to rotifer dominance. Heavy phytoplankton grazing by cladocerans in 1974 and 1975 stabilized the biomass and maintained it at a low level, which also resulted in a relatively low primary production. The rotifer-dominated community during the years 1976–1978 did not possess the ability to maintain a stable level of algal biomass. Primary production was also relatively high during these years.     

Spot-distribution in Maniola jurtina (Lepidoptera) on small islands in southern Sweden

The Meadow Brown Butterfly, Maniola jurtina L., which is polymorphic for spotting on hind wings, was studied for five years on four small (0.15–1.0 km²) islands off the south coast of Sweden. Samples of females and males were unimodal for 0 and 2 spots, respectively. Spot-distributions remained unaltered in 1973–1974 but changed significantly in 1975 only to be restored again in 1976 and 1977. The change in 1975 was assumed to be associated with an unusually dry and warm summer and the results are discussed in terms of natural selection.     

Water chemistry changes during artificial aeration of spruce Knob Lake,West Virginia

The water mass below 3.5 m in Spruce Knob Lake was artificially aerated with a modified full lift aerator during two consecutive summers (1974 and 1975) of an investigation that began in July of 1973 and ended in September, 1975. Artificial aeration increased water temperature below 3.5 m without causing destratification. Several chemical parameters were significantly affected by artificial aeration, especially from July to autumnal overturn in 1974 and 1975. Below 3.5 m, total inorganic carbon, total alkalinity, nitrite, soluble reactive phosphorus, and total phosphorus, were lower during aeration than in the summer of no aeration (1973). Although artificial aeration lowered soluble reactive and total phosphorus, there was no significant impact on the phosphorus budget of the impoundment. In 1975, continuous aeration from vernal overturn to autumnal overturn resulted in higher nitrate concentrations below 3.5 m than in the preceeding summers. Lower pH values encountered through the whole water column in 1975 followed a brief isothermal interruption of summer stratification in early June. There was no direct effect of artificial aeration on either temperature or water chemistry parameters in the epilimnion. Significantly lower chlorophyll concentrations observed in 1975 were related to destratification in June. Primary production was unaffected by aeration.     

Effect of sodium fertiliser on water status and yield of sugar beet

Effects of sodium fertiliser on growth, water status and yield of sugar beet crops were measured in 1974 and 1975. Sodium increased leaf area index early in the growing period, the water content of the leaves and the final yields of root dry matter and sugar in both years. In 1974, it increased leaf relative water content and diffusive conductance under conditions of moderate soil moisture deficit in August but had no effect in June or September when soil moisture deficits were low. There was also no effect in June 1975 but later, when there was a severe drought, sodium decreased leaf water potential. Further evidence of an interaction between sodium and soil moisture on leaf water status was obtained from a reappraisal of results of field experiments made between 1965 and 1976. Sodium increased sugar yield through at least two different physiological mechanisms; it improved interception of radiation by the crop by increasing leaf area early in the season and it improved the efficiency of leaves under conditions of moderate water stress.     

Effects of pesticide treatments on the yield of swedes

The effects of insecticide and fungicide applications to swedes (Brassica napus var. napobrassica) were examined at 15 sites in England from 1974 to 1978. Several different pesticide combinations were applied including carbofuran granules at drilling (63 mg a. i./m of row), demeton-S-methyl sprays (0·24 kg a. i./ha) and fluotrimazole sprays (0·18 kg a. i./ha). The best treatments, which varied in different years, gave significantly higher yields than no treatment in 12 out of a total of 15 trials, with varying levels of damage attributable to cabbage root fly (Delia brassicae), aphids (Myzus persicae) and powdery mildew (Erysiphe cruciferarum) in each of the 4 years. In 10 of 12 trials, plots receiving a complete insecticide and fungicide programme yielded on average 40% (range 21–61%) more than untreated plots, mainly through control of root fly and aphids in 1975 and of aphids and mildew in 1976. Aphid damage to swedes was exceptionally severe in both years. Granular formulations of aldicarb, carbofuran, chlorfenvinphos or fonofos used alone to prevent cabbage root fly damage gave significant yield benefits in only 8 of the 15 trials, with least effect in 1977 and 1978 when growing conditions for swedes were good and damage relatively light.     

西藏哺乳类名录

十九世纪30-40年代,曾一度旅居尼泊尔的霍奇森(Hodgson),通过各种渠道获得一批西藏标本。本世纪初,沙俄军官科兹洛夫(1901)率“探险队”入藏考察;沃尔顿(Walton,1903,1904)随英军到藏南收集动物标本;沃拉斯顿(Wollaston,1921)以及路德洛(Ludlow,1932,1934,1938,1946-1947)等,相继在藏南(包括珠穆朗玛峰地区)、藏东南和藏西北等地区调查采集。     

The effect of nutrient addition on the phytoplankton community of an oligotrophic lake

This investigation was performed during a 5-yr period (1974–1978) in the oligotrophic Lake Langvatn, Central Norway. In 1975 and 1976 the lake was enriched with a commercial fertilizer, In 1975 increase in phytoplankton biomass was first recorded more than three weeks after the fertilization started, despite a near fivefold increase in the primary production after fertilizer application. The mean seasonal biomass increased from c. 3500 mg wet weight m⁻² in 1974 to 4400 mg in 1975. In 1976 the biomass increased to near 9600 mg ⁻² and the seasonal primary production to 49.0 g C m⁻² (22.2 g C in 1975), despite a reduction in the nutrients added. Chrysophytes constituted the largest share of the seasonal algal biomass in all years, but in fertilization periods cryptophytes dominated in 1975 and diatoms, chlorophytes and cryptophytes in 1976. The highest biomass turnover rate was recorded during a period of cryptophyte dominance. The different biomass and production development in the fertilization years may be explained by a change in the consumer level.     

Projections of Graduates from Canadian Medical Schools, 1970-81

This paper sets forth the projections made by the various Canadian medical schools of first-year undergraduate enrolment through 1977-78. Non-Canadian enrolment and student attrition are discussed and some assumptions are made concerning their levels up to 1981. In conclusion, a set of projections on Canadian and landed immigrant graduates from Canadian medical schools during the period 1970-1981 is offered. The national projections are broken down by medical school and province.The results of this paper indicate that Canadian medical schools will graduate 1019 Canadians and landed immigrants in 1970, 1052 in 1971, 1064 in 1972, 1113 in 1973, 1250 in 1974, 1342 in 1975, 1377 in 1976 and 1480 in 1981.     

武汉东湖浮游动物数量和生物量变动的研究

本文报道了东湖Ⅰ、Ⅱ站1974—1975,1979—1980四个周年浮游动物种类组成和现存量的调查结果。束湖浮游动物的种类在减少,Ⅰ、Ⅱ站间种类组成的差别亦在缩小。浮游动物现存量的总趋势为逐渐增加。年数量变动曲线一般有夏季和秋季两个高峰,秋季高峰比夏季高峰更为突出。浮游动物总数的消长完全受原生动物数量的支配。年生物量的变动曲线不甚规则,不同的年份,Ⅰ、Ⅱ站均有所不同,以冬、春两季的生物量较高。四年年平均生物量统计结果:Ⅰ站原生动物占浮游动物总量的18.93%,轮虫占25.25%,枝角类占46.02%,桡足类占9.80%;Ⅱ站原生动物占总量的13.92%,轮虫占15.24%,枝角类占58.93%,桡足类占11.91%。本文还对影响浮游动物现存量变动的生态因子进行了讨论。       

Mildew reinfection in adjacent and separated plots of sprayed barley

In latin square experiments in 1973 and 1974, reinfection of sprayed barley, by mildew (Erysiphe graminis f.sp. hordei) was decreased by widely spacing the plots. In 1974, when yields differed between plots which were either contiguous or separated, the results suggested different times to spray for best yield increase.     

Production of presumptive humoral haematopoietic regulators in canine cyclic haematopoiesis

Abstract. Conditioned media (CM) were prepared according to previously published techniques from the bone marrow of dogs with cyclic haematopoiesis (CH). CM prepared from day 9 marrows inhibited mouse bone marrow CFU-s proliferation rate while CM from day 10 marrows were stimulatory and also contained an erythroid stimulating factor which appeared to be erythropoietin. In addition a highly significant trend from CM containing CFU-s inhibitory materials to media with CFU-s stimulatory activity was observed through cycles day 1 to 8. These studies further support the concept that CH is due to a defect in factors controlling stem cell proliferation and suggest that a major event occurs in CH dog marrow on days 9 and/or 10 of the cycle. Bone marrow transplantation studies (Dale & Graw, 1974; Weiden et al., 1974; Jones et al., 1975b) have indicated that canine cyclic haematopoiesis (CH) is probably due to a disorder in the multipotential stem cells. Morphological evidence (Scott et al., 1973) and the almost synchronous cycling of CFU-e, CFU-c and diffusion chamber progenitor cells (DCPC) (DUM et al., 1977, 1978a, b) lend support to such a theory. However, efforts to identify the mechanisms controlliig multipotential stem cell proliferation in dogs have been handicapped by the lack of suitable techniques to study these cells in the canine. Recently, Wright and co-workers (Wright & Lord, 1978, 1979; Wright et al., 1979; Lord et al., 1979), on the basis of previous observations (Frindel et al., 1976; Frindel & Guigon, 1977), described the preparation of species non-specific, bone marrow conditioned media (CM) which are capable of influencing the proliferation rate of murine colony forming units-spleen (CFU-s). The studies now reported were designed to determine if CM prepared from canine CH marrow would influence the proliferation rate of murine bone marrow CFU-s. The results indicate that a major event, possibly related to the in vivo control of stem cell proliferation in dogs with CH, occurs on days 9–10 of the cycle; day 1 being the first day when the peripheral blood neutrophil count falls below-1600 mm³.