Earing Stage Research Articles

Applicability of Different Indices to Evaluate Nutrient Status of Winter Wheat in the Organic System

ABSTRACT Nitrogen (N), phosphorus (P), and potassium (K) nutrient status of two winter wheat cultivars (Kobra and Juma) in the organic crop production system was compared with integrated and conventional systems. This research was conducted between 1998 and 2000 at the Experimental Station in Osiny (Lublin province, Poland) on a grey-brown podzolic soil. To determine N, P, and K contents shoot samples of wheat were taken at the shooting and earing growth stages. Measurements of chlorophyll content were performed with a chlorophyll meter (SPAD) to estimate N nutrient status. Four different methods [Nitrogen Nutrient Index (NNI), Soil Plant Analysis Development (SPAD), Diagnostic Recommendation Integrated System (DRIS), and Sufficiency Range (SR)] of nutrient status evaluation were compared. Nitrogen (N) and potassium (K) nutrient status of wheat cultivated in the organic system was lower compared with the other farming systems. Assuring sufficient supply of nitrogen to cereals under the conditions of organic farming is particularly difficult in early growth stages. In the integrated and conventional systems wheat was sufficiently supplied with NPK. Kobra cv. proved to be more adapted to the organic system. Results indicate that classical nutrient status indices are of lesser use for organic farming.

A statistical model providing comprehensive predictions for the mRNA differential display

Differential display (DD) or arbitrarily primed fingerprinting serves to identify differentially expressed genes, but these techniques cannot determine how many of the theoretically available genes have been uncovered. Previous mathematical models are unsatisfying as they are not suitable to analyze experimental data. In the present study, we provide a statistical model based on the redundancy of cDNA fragments amplified during DD experiments. This model is applicable to any DD and predicts (1) the total number of genes expressed in a sample cell type or tissue, (2) the number of differentially expressed genes, (3) the coverage obtained with any given number of primer combinations. In a DD experiment comparing two developmental stages of the post natal rat inner ear, we estimated the total number of differentially expressed genes accessible by DD to be 445, and the number of primer combinations required to uncover 90% of these to be 127. The algorithms were implemented in Matlab (The Mathworks, Inc., Natick, MA) environment and are available at www.physiologie.uni-freiburg.de/download.html ellen.reisinger@physiologie.uni-freiburg.de.

Role ofCoccinella septempunctata(L.) in management of cereal aphid,Sitobion avenae(Fab.) in subtropical wheat crop ecosystem

The alates of Sitobion avenae started settling on wheat during first week of January (standard week 1) simultaneously with the activity of its predator, Coccinella septempunctata . However, the population density of this predator at this stage was very less. From standard week 5, the aphid population started increasing steadily and colonies of alates and apterous aphids were seen on leaves and stem. Middle of February to the start of March was the most favourable period for multiplication of this pest. The maximum population of cereal aphid was observed during standard week 10 (second week of March), when wheat ( Triticum aestivum ) crop was in earing stage and the temperature was between 8.5 and 23.1° C along with a relative humidity of 45.7 to 88.3 per cent. The aphid started declining gradually during following weeks, finally disappearing by second week of April (standard week 15). Its predator, C. septempunctata was observed feeding on aphid colonies during standard week 4, which increased steadily ti...

Constraining the time available to graze reinforces heifers’ preference for sward of high quality despite low availability

We studied, over 1 month (mid-June to mid-July), the effects of a restriction of available daily grazing time on the diet choices of heifers between a vegetative sward (VS) and a reproductive sward (RS) evolving from the earing to the flowering stage. The aim was to mimic a situation of extensively exploited pastures where resource quality varies against availability (height). The VS was either tall (13.5 cm) or short (7.5 cm), and was crossed with the available daily grazing time (24 h versus 5 h per day) to form four treatments. Twenty 18-month-old Charolais heifers were divided into four groups of five, with each group allocated to one treatment throughout the experiment. The effects of the constraints (VS height and available grazing time) varied with RS maturity. At the earing stage, the heifers, as expected, increased their proportion of grazing time spent on RS as access time and/or VS height decreased. However, at the flowering stage heifers maintained their grazing time on VS as VS height decreased, and reduced the time spent on RS more than on VS as grazing time was restricted, more so as VS was shorter. Thus, they accentuated their preference for VS as available time decreased. To examine these choices in terms of trade-off between diet quality and total daily energy intake, we estimated total intake and diet digestibility. The VS height constraint affected neither total intake nor diet digestibility. The time constraint caused both total intake and diet quality to decline, and intake seemed to be more markedly affected than diet digestibility. When the available grazing time was limited, heifers, by spending more than 0.60 of this time grazing VS, probably ate less than they would have done by grazing longer on RS, which provided higher intake rates. This marked preference for grazing VS of high quality indicates that heifers prioritised quality over intake when faced with the proposed trade-off.

Herpes simplex virus type 1-mediated transfer of neurotrophin-3 stimulates survival of chicken auditory sensory neurons

Neurotrophin-3 (NT-3) is one of the most potent stimulators for survival of auditory sensory neurons. Viral transfer of neurotrophins into auditory neurons may offer a route to provide a permanent supply of the growth factor and guarantee their long-term survival. Herpes simplex virus type 1 (HSV-1)-based vectors have demonstrated their effectiveness to transfer genes into peripheral sensory neurons. In the present report, we have produced a HSV-1-based amplicon vector expressing NT-3. This vector efficiently infects isolated auditory neurons and stimulates their survival during distinct developmental stages of the inner ear. Therefore, this vector may present a unique entry point to develop therapies preventing or treating hearing impairment caused by the degeneration of auditory neurons.

Coefficient réel d'utilisation du 15N urée pulvérisé sur des couverts de blé à floraison

The efficiency of recovery of N urea by plants or true recovery coefficient of N urea [TRC(N urea) %] was determined after fertilization of wheat via the leaves. A chemical preparation containing 15N urea (0.55 %) was sprayed on crops of two varieties at flowering. Two concentrations were given: 20 and 40 kg N urea. ha −1. The crops were previously fertilized (NH4NO 3) at optimum or at sub optimum doses at 1-cm ear stage. Leaf damage due to urea spray remained in a low range. At flowering, the tips of the leaves already exhibited necroses (10 % of the total leaf area). These necrotic area proportions doubled at the largest urea dose 72 h after the spray. A hypothesis involving leaf urea metabolism is proposed. The true recovery coefficients of N urea [TRC(N urea) %] were determined 6 h after spraying whole plants. They were found to be between 50 and 72 %, N urea being localized mainly in the ears and the leaves, and only slightly in the roots. The coefficients increased to 80–90 % at maturity. Thus, N urea assimilation was rapid and efficient. Eighty-six percent of the absorbed N urea was recovered in the seeds. The seed TRC(N urea) values were between 65 and 81 %. The high and constant values of the TRC(N urea) values described above contrasted with the low and variable data found in the literature. A metabolic compartmentation between N urea and the remobilized N from the other plant organs is proposed.

The effect of humic acids on the availability of phosphorus fertilizers in alkaline soils

Abstract. The effect of humic acids on transformation of phosphorus fertilizer was studied in an alkaline soil. Soil P was fractionated following 4 and 15 days incubation after humic acids were applied with phosphorus fertilizer to the soil. The availability of phosphate in the soil and total phosphorus in plants were determined at earing stage and at maturity in a pot experiment, and wheat yield was examined in a field trial. Addition of humic acids to soil with P fertilizer significantly increased the amount of water soluble phosphate, strongly retarded the formation of occluded phosphate and increased P uptake and yield by 25%.

Ear Developmental Stage Used for Timing Supplemental Nitrogen Application to Spring Wheat

Nitrogen fertilization at sowing is not always optimal or sufficient for stable yield and quality formation of wbeat (Triticum aestivum L.). Precise timing of supplementary N application for wheat requires detailed knowledge of the physiology of the reproductive phase. Our objective was to compare developmental stages of the wheat ear, for timing supplemental N application to ensure stable wheat yield and quality. The experiments were carried out at two locations in 1989 and 1990, with four spring wheat cultivars. Soil types were sandy loam (Mollie Cryoborolls). Foliar N (20 kg ha−1) as an aqueous solution of urea (144 g L−1) was applied at f our stages of ear development. A greenhouse experiment was designed to clarify the effect of N on the formation of spikelet and floret numbers in the apex during reproductive period. Maximum effect of supplementary N was achieved at the double‐ridge stage, and at the stage when the stigmatic branches of the carpel had formed. At these developmental stages, supplementary N increased the number of grains per ear and grains per square meter. Nitrogen added at pollination mainly increased the kernel weight and bread‐making quality (rated according to protein concentration in the flour, wet gluten content, Zeleny sedimentation value, farinograph water absorption, dough stability, and Panasonic loaf volume). Timing N application to apical development may provide a useful method for the producer to stabilize wheat grain yield and protein concentration.

Effect of Apical-timed Urea Spraying on Yield Components and Quality Properties of Spring Wheat (Triticum aestivumL.) in Greenhouse Experiments

Abstract The effect of foliar urea spraying on yield components and quality properties of four spring wheat varieties was studied at the University of Helsinki, Department of Crop Husbandry, in greenhouse trials during the autumn of 1988 and the winter of 1989. Nitrogen was applied four different developmental stages of the wheat ear. Foliar urea spraying had different effects on the examined wheat genotypes. Only yield components of a new Finnish variety, ‘Heta’, seemed to benefit from nitrogen application. Foliar spraying of urea increased the protein content and the amount of wet gluten in all varieties. The falling number of ‘Heta’ and ‘Kadett’ improved.

Interactions

Fifteen wheat cultivars differing in genetic origin but with almost the same growing season were investigated. Plants were grown in pots under greenhouse conditions. The investigations included the main stem only while the secondary stems were removed. The plant material to be analyzed was collected at earing, milk‐waxy, and full maturity stages. The concentrations of N, P, K, Ca, and Mg, were analyzed in 4 leaves (each separately). The results show that highly significant differences in nutrient concentration were obtained between the cultivars. Variation in elemental ranges depended on stage of plant development, leaf age, and the particular element under consideration.

Effect of the meteorological factors on the incidence of paddy stem-borer (Tryporyza Incertulas Walker) and its zonal apportionment

Paddy stem-borer (Tryporyza Incertulas Walker) infestation is very much influenced by meteorological factors. The effect of various weather elements on its incidence is endeavoured in present statistical analysis. It is found that less moisture content in the atmosphere in the elongation stage and a minimum temperature lower than 23 deg. C and sunshine hours more than 8 hours in flowering stage are favourable for increased larval activity in the earing stage of summer paddy crop at Bhubaneshwar. Northeast region of India are prone to heavy attack in summer and winter crops earing stage. Similar studies for other stations are necessary to draw general conclusion about threshold values of meteorological parameters to be used in forewarning of the infestation of stem-borer in paddy.

The influence of nutrition on the response of wheat to above-optimal temperature

Wheat plants (Triticum aestivum L. cv. Gabo) were grown at two temperatures (18/13 and 24/19�C, Day/night), either with full nutrient availability or deprived of nutrients after floral initiation or after anthesis, in order to identify possible interactions between nutrient availability and response to a temperature higher than the optimum for grain dry weight accumulation. Nutrient deprivation reduced levels of nitrogen, potassium and calcium in the vegetative organs of the plant at anthesis and maturity, and levels of nitrogen and calcium, but not potassium, in the grain. Differences in the distribution of nitrogen, potassium and calcium can be explained on the basis of their phloem mobility. An interaction was observed between nutrition and temperature in the time from seedling emergence to anthesis, the number of tillers at anthesis and the number of heads per plant at maturity. Within the main culm ear, high temperature and low nutrition reduced grain number. High temperature, but not low nutrition, reduced individual grain weights. However, there were no interactions between nutrition and temperature in regulating these responses. Therefore, although nutrition may be an important factor when considering the effect of temperature on tillering, there is no evidence from this study that nutritional status will mask the effects of temperature on the later stages of ear and grain development.

The effects of temperature and fertilizer nitrogen on the spring growth of tall fescue and cocksfoot

AbstractA detailed study of the spring growth curves of two forage grasses, tall fescue and cocksfoot, over three successive years showed a large variability of growth over the vegetative phase. This variability was evident at levels of fertilizer N which were considered to be non‐limiting (60 kg N ha‐1 in autumn plus 120 kg N ha‐1 in February).At this level of N there was a relationship between yield in the vegetative phase and accumulated temperatures from the last cut in the autumn which was described by a regression common to the three years. The slope of this regression represents the potential growth of a variety. At a lower level of N a separate regression was needed in each year to relate growth to accumulated temperature.Variation in spring growth was not related to accumulated net radiation. Growth in the reproductive phase was related to accumulated temperature and accumulated net radiation from the 10‐cm ear stage.

Gnotobiotic cultures of rice plants up to ear stage in the absence of combined nitrogen source but in the presence of free living nitrogen fixing bacteriaAzotobacter vinelandii andRhodopseudomonas capsulata

An all glass tight growth chamber, entirely sterilizable, has been constructed to carry out axenic and gnotobiotic cultures of rice plants (Oryza sativa L.). When grown in liquid medium and in the absence of combined nitrogen but in the presence of the diazotrophsAzotobacter vinelandii andRhodopseudomonas capsulata, rice plants exhibited a complete biological cycle from germination up to ear stage, during a period of time similar to the one encountered in french paddy soil of Camargue. In one experiment, mannitol was given to rice culture medium together withAzotobacter vinelandii andRhodopseudomonas capsulata. In another experiment, mannitol was not given together with Rhodopseudomonas, and still positive nitrogen gain was obtained, although it was less than culture with mannitol. When15N labeled cells of Rhodopseudomonas were added in rice culture medium,15N was partly transferred to rice plant. Among the nitrogen substances excreted from the bacteria in the rhizosphere medium, large organic molecules were shown to be the most abundant in our experimental conditions. Moreover, the concentration of free ammonia or aminoacids present in the rice rhizosphere were always compatible with a bacterial nitrogenase activity.

The combined effect of soil salinity and CCC on dry matter accumulation and yield of wheat plants

The rise in soil salinity level tended to decrease shoot dry weight, and, grain yield per plant and, to some extent, weight of I grain. This effect was usually more pronounced in the presence of CCC. On the other hand, the shoot dry weight was increased by CCC in salinity absence but the reverse at 0.8 % salinization degree. The grain yield per plant was raised by CCC in the presence or absence of salinity, particularly in the latter case. The dry matter accumulation in the shoot system (at earing stage) rather than grain yield tended to be much more affected, whether regarding the negative response to salinity or the positive one to CCC.

Proliferation gradients in the inner ear of the monkey (Macaca mulatta) embryo.

Radioautographic studies were conducted on early developmental stages of the inner ear in monkey (Macaca mulatta) embryos ranging in age from stage 11 to stage 20 (25 to 39 days' gestation) and labeled for one hour with [3H] thymidine. The most active period of proliferation occurred at stage 13, at which time all regions of the otocyst, including the endolymphatic duct, were heavily labeled. In subsequent stages the dorsal portion of the endolymphatic duct failed to incorporate label, whereas proliferation continued in the ventral portion of the duct near its communication with the medial wall of the otocyst. The duct thus appeared to grow upward as a result of cell division from below. Mitotic activity continued in the remainder of the otocyst although there was a progressive temporal decrease in the labeling index. Spatial gradients also occurred, with dorsal and lateral regions less active than ventral and medial ones. As the otocyst differentiated, the cells in various areas became attenuated. These flattened cells were still capable of undergoing cell division, as indicated by the presence of labeled nuclei in all regions of the utricle, saccule, semicircular ducts, and cochlear duct.

DYNAMICS OF BARLEY FLAVONOID AND PRODUCTIVITY UNDER UF-A RADIATION

The effect of increased UV-A radiation during the ontogeny of barley plants of the Vladimir variety in the vegetation experiment was studied. Changes in the content of malonic dialdehyde, flavonoids and grain yield were revealed. UV-A radiation as compared to UV-B radiation, has lower quantum energy and can have both positive and negative effects on plant regulatory and photosynthetic processes. One of the most damaging effects of increased levels of UV-A radiation is oxidative stress, which causes lipid peroxidation of biological membranes. The existence of a plant cell in such conditions is possible only thanks to a system of antioxidant defense mechanisms. The accumulation of phenolic compounds under the action of UV radiation is a universal mechanism of protection against photodamage, which was formed in the early stages of the evolution of photoautotrophic organisms. Flavonoids are localized in the epidermis of plant tissues and act as an internal filter. The content of flavonoids is determined by the genotype and due to ontogenetic patterns. Plants were grown in a greenhouse, in vessels containing 4.5 kg of air-dry soil. The repetition is threefold (3 vessels in each variant). Sowing density - 13 plants in each vessel. As a source of UV-A radiation used lamps Black Light BLUE company Philips. Plants were irradiated for 5 hours a day from 10 to 15 hours at 13, 25, 34, 43 and 52 stages of organogenesis. The magnitude of the daily biologically effective dose of UV-A radiation was 60.7 kJ / m2. The solar part of the UV spectrum in the vegetation experiment was absent in the greenhouse. The nature of changes in the content of flavonoids under the action of UV-A irradiation during the growing season of plants with the dynamics of the oxidative process has been established. The first maximum was observed during the vegetative growth period, the second - at the earing stage. The data obtained indicate that flavonoids have ontogenetic conditionality and perform photoprotective functions. The increase in their content under the action of UV-A radiation is accompanied by an increase in resistance to photodamage, which is confirmed by the formation of grain yield.

Studies on the Chiling Injury in Wheat plants : VI. On the frost injury at the earing stage in wheat plants.

1. In 1964 there ocurred a wheat plant sterile phenomenon at high sterile rate of 70% at Narabara area in Nagano prefecture. 2. The frost-damaged wheat plants were, as compared with normal ones, characterized by such outward appearances as shortness in culm-height, withered leaf apex, yellowish spikes, non-flowering, dead ovaries, abnormal pollen, etc. 3. Based upon the fact-finding survey results, it was inferred that such sterile phenomenon was caused by the death of ovaries and abnomal pollen due to the attack by low temperature of -0.5°C in shelter temperarature at the earing stage. 4. The exactness of the above inference was evidenced by tests using a refrigerator, and it was also clarified that the causes for the occurrence of chilling injury and frost injury at the earing stage were just the same in essence, but different merely in the disparity between them in the degrees of temperatures at the earing stage.

Genetical studies on ear-type affecting kernel shape in naked barley : I. Comparison of young ear developments among naked barley varieties

Ears and awns of barley vary in length. TAKEZAKI(10) made an extensive study on the characteristics of awns and ears in relation to their lengths. Short awns were associated with short or medium ars ; medium-long and long awns with long ears. He classified cultivated barley into eight different types, Ds, Dm1, Ms, Mm2, Mm1, Ml, . Lm2 and Ll, based on average awn length (i. e. s-5cm, m-8cm, m-10cm and l-15cm) and on average ear length (i. e. D-5cm, M-8cm, and L-11cm). Main varieties cultivated in Tokai-Kinki district were restricted to Mm1 and Dm1 types. However, these varieties were different in width of the lateral kernel rows. The ear width varide in the upper, central and lower parts of a spike. In this study, morphological observations of the ear development were made at different stage I to X were made by microscopic tests following INAMURA's method(5) and the ears from the ear stage X to the heading stage by the use of magniging glass. The results of these observations which have been presented in tables and figures of the text are summerized as follows: 1)Using three varieties bilonging to the same ear type (Mm1) and one belonging to a different ear type (Dm1), measurements of the ear width of young ears were made at defferent locations on a spike (upper middle and lower parts) both in main and lateral kernel rows. Also the number of spikelets per ear and the internode length of spikelets were measured. Authors studied these characteristics of young ears in relation to the widths of young ears and other characters. 2)The developmental difference between Mm1 and Dm1 appeared during the period between March 20 and ripeness. The varietal difference sithin Mm1 also appeared during the same period.

The Role of Granulated Insecticides for Control of Sweet Corn Pests in New Jersey1

In order to determine the role of granulated insecticides in the sweet corn insect-control program in New Jersey, experiments were conducted during the 1954-57 seasons. Of the materials used, 2½% heptachlor on attaclay and 1% parathion on tobacco were the most efficient, giving excellent control of European corn borer ( Pyrausta nubilalis (Hbn.)), corn ear worm ( Heliothis zea (Boddie)), and fall army worm ( Laphygma frugiperda (J. E. Smith)), on corn in the whorl stage. Sprays or dusts are still necessary when the plants are in the ear stage, but as a supplement the applications of granulated insecticides can be of great value to the New Jersey sweet corn growers.