Plant Pathology Commons^™

Effect Of The K Fertilization On The N-Mineralization In A Grassland Soil And On The N-Uptake By Italian Ryegrass, I Campino

IGC Proceedings (1977-2023)

In a pot experiment with a hydromorph grassland soil enriched with organic matter containing tagged N and sown with Italian ryegrass N-mineralization and uptake with increasmg K fertilization were investigated. The N-mineralization and the mtnficatlon were promoted with increasing K fertilization. Because the K content of the plant was high enough to guarantee a healthy growth, the higher N uptake, a��d especi��lly the m��reased uptake of mineralized N from the + added organic matter, was attnbuted to the higher content of mmeral N m the sod and to a synergic interaction between K and NO3

Effect Of Invertebrates On Nitrogen Fixation In Temperate Pastures, K W. Steele, R N. Watson, P M. Bonish, R A. Littler, G W. Yeates

IGC Proceedings (1977-2023)

Annual nitrogen fixation in New Zealand pastures is well below its potential. The research reported is part of a programme directed towards identifying limitations to nitrogen fixation by the Trifolium repens-Rhizobium trifolii symbiosis. Sixteen field trials were conducted with tretments designed to provide selective control of various invertebrate pests of Trifolium repens. Measurements included herbage production, botanical composition, nitrogen fixation and root dissections. Application of pesticides significantly increased legume production, the number of nodules/g of Trifolium repens root and nitrogen fixation. Total N uptake in pasture herbage was increased by up to 118 kg N/ha/yr. The increase in nitrogen fixation …

Study Of Nitrogen Transfer From Alfalfa To Associated Timothy Under Field Conditions, M A. Faris, T C. Ta

IGC Proceedings (1977-2023)

In a forage cropping system (legume-grass), some of the nitrogen (N) which is fixed symbiotically by legumes is used by the associated grass. However, very few measurements of such transfer have been conducted under field conditions. The objective of this work was to estimate N transfer from alfalfa to associated timothy under field conditions, by using the 15N dilution technique. There was no significant difference in total N (T-N) content in timothy grown alone or in mixture at cut one. However, the effects of associated alfalfa became apparent at cuts two and three where T-N% increased by 15 to 38% …

The Fate Of Fertilizer Nitrogen Applied To Grass Sward In Japan- Influence Of Sward Age And Season Of The Year, T Kimura, K Kurashima

IGC Proceedings (1977-2023)

The seasonal uEtake of fertilizer nitrogen (N) and the annual fertilizer-N balance in cut orchard grass swards were studied by using the field SN-tracer method under humid temperate condition in Japan. 1) Fertilizer-N applied in early spring (for the first cut) and early summer (for the third cut) was readily absorbed by grass, but N applied in autumn (for the fifth cut) was slowly absorbed, the fact is considered to reflect on the efficiency of fertilizer-N. Much more fertilizer-N was recovered in grass (the total of top and root) of the first and third cut than in grass of the …

Maintenance Of Lolium Perenne L. In Mixture, K Sato, R Meguro, T Nomoto, M Nashiki

IGC Proceedings (1977-2023)

Lolium perenne L. (PRG) is one of the promising species in the northern Japan. However, this species is utilized less widely due to short persistency. The study was conducted to clarify the proper conditions for maintenance of this species in the context of defoliation treatments. The grasslands mixed with Dactylis glomerata L. (OG), Festuca arundinacea Schreb. (TF), Poa pratensis L. (KBG) and PRG were established and botanical composition of this mixture were measured in terms of Summed Dominance Ratio (SDR) under grazing (3 Japanese Black Cattle per ha) and cutting (3 times a year) conditions. PRG were maintained well …

Growth Analysis In The Regrowth Of Italian Ryegrass As Affected By Fertilization Level, K Watanabe, Y Sato, H Shirakawa, S Abe

IGC Proceedings (1977-2023)

Growth analysis was conducted to clarify the process of the regrowth, and the relation between LAI and plant height, percentage light penetration, CGR or NAR in the 2nd crops of Italian ryegrass (Lolium multiflorum) given 3 rates of fertilizer (20kg N + 10kg P205 + 17.5kg K20 ha-1, twice and 4 times). For the analysis, cubic regrassion curves were used, as they were fitted significantly by the changes of plant height, LAI, percentage light penetration and dry weight of whole plant with the regrowth. CGR (dt/dw) was obtained by the differentiation of cubic regression equation in the dry weight (w); …

Conditions For Raising The Yield Of Orchardgrass, S Kawashima

IGC Proceedings (1977-2023)

Up to the present, studies have been done on cutting height and plant length at the time of cutting. Concern with planting density, on the other hand, has been slight, with the result that reports which consider all three factors are almost non existent. Our field experiment considered these three aspects to determine the conditions for raising the yield of orchardgrass. Our perspective in the research was ecological.

The following points were recognized:

1) Long plants at cutting time are preferable to short ones.

2) Planting density should be high rather than low.

3) Cutting height must be low.

Cold Acclimation Of Alfalfa Cells In Suspension Culture, S Shibata

IGC Proceedings (1977-2023)

Effects of 2,4-D and kinetin on the growth of cells derived from alfalfa and their capacity to induce cold acclimation were investigated for the breeding of the cold hardy alfalfa using suspension culture. The yield was the highest in the modified Schnek and Hildebrandt medium containing 1 ppm 2,4-D and 0.5 ppm kinetin. Cells proliferated 12-fold in this medium at 26°C in the dark in ten days. Cells ceased growing during the cold acclimation and the pH in the medium kept unchanged. The cold hardiness of cells incubated at 1 °C in the dark increased during the first 20 days …

Grass Species Selection For Meadows Establishment, J V. Chlevickas, S J. Mikutenas

IGC Proceedings (1977-2023)

Observations have shown that due to better moisture supply perennial grasses grown on bog soils produce higher yields as compared with grass species grown on mineral soils. Nevertheless, at higher levels of N fertilization a number of grasses show poor winter hardiness, therefore, most of productive meadows must be reseeded, which requires high inputs and leads to significant yield losses in the year of reseeding. Furthermore, soil loosening causes peat mineralization, which is quite undesirable. In 1977-1980, at the Radviliskis Experimental Station a series of trials was carried out with the aim to determine grass species most suitable for meadows …

Effects Of High Temperature Stress On Growth And Digestible Dry Matter Content Of Timothy Cultivars, M Furuya, T Masutani, S Tsutsui

IGC Proceedings (1977-2023)

As part of a study on the adaptability of timothy cultivars to environmental conditions, the effects of high temperature stress on growth and digestible dry matter content were examined using the following cultivars: Kunpii (extremely early maturing), Senpoku (early), Nosappu (early), Erecta R. v. P. (medium), and Hokushu (late). Three levels of temperature treatment employed in this study were 23/18 (Tl), 31/26 (TI), and 31/31°C (T3) (day/night) for 10 days. High temperature treatment for 10 days resulted in an obvious decrease in dry weight and RGR at TI, which might be mainly caused by the decrease in NAR. These values …

Relationship Between Productivity And Canopy Structure During Reproductive Growth Stage In Dactylis Glomerata, Festuca Pratensis And F. Arundinacea, S Sagiyama, A Kusutani, N Takahashi, K Gotoh

IGC Proceedings (1977-2023)

The relationship between productivity and canopy structure during reproductive growth stage was examined in swards of three temperate grass species, Dactylis glomerata, Festuca pratensis and F. arundinacea. The relationship between extinction coefficient(K) and culm length depended on species, and the relation was positive in short-culmed species but negative in Jong-cul med one. The relationship between productivity and K during this stage was also inconsistent among three species. The relation was negative in D. glomerata, but positive in F. pratensis. And there was no clear relation in F. arundinacea. These relations were discussed in terms of the arrangement of leaves …

Physiological Characteristics Of Green Needlegrass (Stipa Viridula Trin.), Edward F. Redentre, Timothy E. Fulbright

IGC Proceedings (1977-2023)

Green needlegrass is commonly used in range seedings in the northern Great Plains in the United States (U.S.). Because of its potential as a revegetation species a series of experiments were conducted to determine 1) germination requirements; 2) capacity of seedlings for emergence and root growth following dehydration; and 3) influence of planting depth, seed source and temperature on seedling emergence and morphology. A variety of sources of green needle grass seed were used in growth chamber experiments following standard procedures. The results indicated that optimum temperatures for green needlegrass germination were 20°C (constant) and 20-15°C (16 hour-8 hour alteration) …

Relationship Between Soil Physics And Grass Roots Elongation, T Sugiura, H Kobatashi

IGC Proceedings (1977-2023)

Differences in soil strength and pore configuration between natural structure soil and compacted structure soil composed of volcanic ash soil and brown forest soil were compared, and their effects on the elongation of grass roots were examined. It was found that the soil strength and pore configuration of natural and compacted soils differed despite equal bulk density. Soil strength of natural soil was greater than that of compacted soil because the structure of natural soil was stable. On the other hand, compacted soil had continuous pores. Root growth in these soils of different structures was not hampered by soil containing …

Physiology Of Regrowth In Sorghum Bicolor Moench: Studies On The Sequential Action Of Hormones And Reserves, H Oizumi, Y Takasaki, H Nojima, Y Isono

IGC Proceedings (1977-2023)

As a hypothesis on the mechanism of the regrowth of sorghum plants, the sequential action of phytohormones and reserves was proposed.By application of cytokinin and sucrose to sorghum plants it was clarified that cytokinin was essential as a trigger for the growth of the lateral buds after cutting and the supply of sucrose to the buds was indispensable for the growth of buds afterwards. The cytokinin level of the stubble of sorghum plants was highest on the 1st day after cutting (Nojima et al., 1985) and that of buds was the highest on the second day after cutting. The detached …

Regulating Grass And Clover Growth With Mefludide, R J. Haggar, S P. Isaac

IGC Proceedings (1977-2023)

A three-year study on the use of mefluidide, a plant growth regulator, for suppressing seed-head production in a range of grass is reported. The first stage, involving the evaluation of a range of does and timings on up to nine grass species, indicated the potential of mefluidide applied at 150 g ha-1 in early spring to prevent the normal decline in herbage quality associated with flowering and to transfer growth from spring to mid-summer, albeit at a loss of some 30% in total dry-matter production. A supplementary investigation showed that white clover was reasonably tolerant to mefluidide treatment although a …

Photosynthetic Recovery And Regrowth Of Aeschynomene Americana And Hemarthria Altissima Swards After Defoliation, K A. Albrecht, K J. Boote

IGC Proceedings (1977-2023)

An experiment was desined to study regrowth characteristics of aeshynomene (Aeschynomene americana) and hemarthria (Hemarthria altissima) swards after defoliation. Leaf area index (LAI), light interception, and canopy carbon exchange rate (CER) were measured over an eight week period of regrowth in aeschynomene and hemarthria swards cut to 9 or 18 cm. Virtually all leaves were removed by cutting aeschynomene to either height. Regrowth and recovery of photosynthetic activity commenced rapidly in the 18 cm treatment because of leaf and branch growth from remaining axillart buds. Cutting at 9 cm resulted in delayed regrowth and photosynthetic recovery. …

Nonstructural Carbohydrate Storage And Snow Endurance In Winter Annual Forage Crops, Y Tamura

IGC Proceedings (1977-2023)

An experiment was carried out to clarify the relationships of growth characteristics and nonstructural carbohydrate (NSC) storages in relation to snow endurance in winter annual forage crops. Twenty one varieties of oats, barley and rye differing in snow endurance were sown in the fall of 1982 in the experimental field at Hokuriku Natl. Agri. Expt. Stn. Dry matter weights and concentrations and compositions of NSC were measured before snow fall. Dry matter weight of roots was in the same order as snow endurance among the three species while no significant differences were observed in those of tops among them. Roots …

Preliminary Study On The Effect Of Spraying Myricyl Alchohol (1-Hydroxyriacontane, N-Triacontanol) Upon Chinese Wildrye, Wang Yulin, Luo Xinyi, Chai Feng0jiu

IGC Proceedings (1977-2023)

The objective of this experiment was to determine the effect of different concentration, amount and spraying times of the plant growth hormone on Chinese Wildrye production, with the orthogonal comparison. It has been found by the orthogonal analysis that fresh yield per mu mas increased by 11.92%, 12.95%; 17.34%, 7.5%; 11.11%, 13.17%; in the treatment of solution concentration of 0.1 ppm, 0.05ppm; spraying times of 1, 2; solution amount of 10 kg, 20 kg per mu, as compared with that control trial (225.3 kg per mu of fresh yield), respectively. The treatment of concentration of 0.05 ppm, spraying times of …

Nutritio-Physiological Evaluation Of Drought Resistance Of Warm Season Forage Crops, S Ogata, H Saneoka, K Matsumoto

IGC Proceedings (1977-2023)

This study was conducted to evaluate the mechanisms of drought resistence of several warm season forage crops . Plants were grown both in field and greenhouse and subjected to sequences to water stress. During experiment, dry matter yield, leaf water potential('V), stomata[ resistance(rs), apparent photosynthesis (P0), transpiration rate(T), root distribution in stressed soil and nutrient uptake were measured. Ratio of dry matter yield of each plant on non-irrigated field to that of the maximum growth obtained by the most suitable watering were higher as follows: Dallisgrass > Rhodesgrass=Bahiagrass >Sorghum> Corn> African millet> Job's tears. 'V of all plants was decreased by …

Transpiration Intensity Of Alfalfa And Its Effect In Yield, Xu Ling-Ren, Lin Bai-He, Wang Jian-Guang

IGC Proceedings (1977-2023)

We observed that the alfalfa appears diurnal fluctuation of transpiration very clearly by in its flower initial stage. They always appear two transpiration peaks in the morning and afternoon, respectively. In the fruiting stage as well as in flowering stage, the diurnal fluctation of alfalfa was lesser with smaller transpiration retes. Both of the diurnal fluctuations in the two stages are strongly affected by the leaf temperature. In the flower initial stage, from 5:30 to 9:30 a.m., the transpiration rate increases with the increase of leaf temperature. After 9:30, while the transpiration drops down rapidly, till afternoon 16:30 p.m. the …

Improved Efficiency Of Plant Regeneration From Smooth Bromegrass (Bromus Inermis) Suspension Culture, T H. Chen, J Marowitch

IGC Proceedings (1977-2023)

Smooth bromegrass, Bromus inermis Leyss, is the most important forage grass in Canada. Breeding for improvements such as higher yield and faster regrowth has made little progress, mainly due to the polyploidy and cross-pollination which are characteristic of this grass. The application of tissue culture methods to bromegrass improvement holds promise only if an efficient procedure for plant regeneration is found. Various basal culture media and auxins were tested for their effects on callus induction, growth of suspension cultures and plant regeneration. None of the tested auxins gave better in vitro growth than 2,4-D. Eriksson's medium with 2,4-D as the …

Effects Of Mefluidide On Vegetative Growth And Root Production Of Forage Sorhum, A G. Matches, A Martinez, C R. Richardson

IGC Proceedings (1977-2023)

Forage sorghums (Sorghum bicolor) provide high-quality pasture during the summer, but because of their rapid rate of growth quickly become mature and unacceptable for grazing. Maintaining their growth in a more juvenile stage could be expected to improve forage quality and utilization by livestock. Our objectives were to determine the effects of the plant growth regulator meflidide (N-[2,4-dimethy-5-[[(trifluoromethyl) sulfony]amino]phenyl] acetamide) on vegetative growth and root production of a hybrid forage sorghum. In two greenhouse experiments different rates of mefluidide (0, 0.035, 0.07, 0.14 and 0.28 kg/ha) were applied to 'Dekalb ST6+ ' hybrid forage sorghums and plant responses …

Effects Of Flooding On The Metabolism Of Red Clover (Trifolium Pratense) And Bromegrass (Bromus Inermis), Seppo Pulli, Jaana Vaisanen

IGC Proceedings (1977-2023)

Two months old red clover and bromegrass stands were tested for flooding behaviour. Experimental design simulated the environmental conditions of summer, early and late autumn. Stands with normal watering and in anoxia had daylength and temperature conditions of+ 18°C/16 h, + l0°C/12 h and +4°C/8 h during the first, second and third week. Plants were analyzed at the end of each period. In anoxia the peak of ADH-activity of both species was reached at + l0°C/12 h representing the most hermful conditions predominantly for red clover survival. During the hardening period ( +4°C/8 h) the ADH-activity of roots of both …

Mechanisum Of Aluminum Tolerance In Sericea Lespedeza, R E. Joost, C S. Hoveland

IGC Proceedings (1977-2023)

Sericea lespedeza (Lespedeza cuneata) is a warm-season perennial legume tolerant of aluminum (Al) in acid soils. This study was designed to ascertain the mechanism of Al-tolerance in sericea lespedeza. The mechanism of Al-tolerance in sericea was investigated through tissue analysis, rhizosphere pH measurement, and examination of Al distribution using energy dispersive spectrophotometry (EDS) in conjunction with scanning electron microscopy (SEM). Sericea was found to exclude Al from its herbage three times better alfalfa (Medicago sativa), but seedlings reduced pH in their rhizosphere. EDS scans of root tissue embedded in scid soil indicated that Al was accumulated in or …

Patterns Of Tillering And Tiller Bud Development Of Some Temperate Herbage Grasses Under Different Light Intensities, M Ito, Y Tsubota, S Nakayama

IGC Proceedings (1977-2023)

The tiller and tiller bud development in young seedlings of orchardgrass (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), timothy (Phleum pratense L.) and reed canarygrass (Phalaris arundinacea L.)were studied anatom­ically. Regular appearance of successive leaves on main shoot and emerged primary tillers were observed in grasses grown under both normal (30,000 lux) and reduced (6,000 lux) light intensities. The leaves expanding simultaneously on different shoots developed analogously. These growth habits in tillering and leaf production were well supported by Katayama's concept on tillering systems in cereals such as rice plant, wheat and barley. The visible synchronization in appearance of …

Effect Of Vernalization And Stem Elongation On Production Physiology Of Lolium Perenne, B Deinum

IGC Proceedings (1977-2023)

In order to study the production potential of vernalized, leafy grass, vernalized cultivars of Lolium perenne were grown at different photoperiods and compared with non-vernalized plants. After vernalization stem elongation was greatly accelerated by long days and occurred later in later-heading cultivars. Late cultivars hardly showed any stem elongation in short days, if at all. Total dry-matter production (herbage above 5 cm + stubble + roots) of stemmy and leafy vernalized grass was much higher than that of non-vernalized grass. The stemmy crops allocated much dry matter in herbage and little in stubble, roots and tillers, whereas the leafy …

Branching Geometry And Effective Leaf Area Of Spreading Herbs, The Crabgrass And The Korean Lawn, G S. Kim, N K. Chang

IGC Proceedings (1977-2023)

An attempt was made to study the terminal branching patterns, and maximizing effective spreading stems and leaf surface area of herbs such as crabgrass, Digitaria sanguinalis and Korean lawn, Zoysia japonica. Two dimensional positions of the end-points of the branches could be calculated using branching angle and relative ratio of the branch lenghts. The branching angles and the relative ratio of the branch lenghts were well fitted to analyze effects on the whole canopy structures of herbaceous individuals and communities. The branching pattern and leaf cluster for maximum effective leaf area, and maximum interception and absorption of sunlight were interpreted …

The Regulation Of Winter Growth Of Temperate Pasture Grasses, D R. Kemp

IGC Proceedings (1977-2023)

Temperate pasture grass growth rates are lowest in winter and limit the number of stock that can be carried through the year on many farms. Field studies of the regulation of pasture growth in winter showed that the earlier a grass intiates reproductive development the greater is the mean pasture growth rate through winter. A 5 to 10 fold variation in winter growth rates between a range of genera and ecotypes was simply related to the time of onset of reproductive development. Prospects for improving winter pasture growth by selecting for early flowering outlined.

Italian Ryegrass Response To Allelopathic Effects Of Stubble-Residues From Several Tropical Grasses, Y Takahashi, S Uozumi, S Ono, Y Yoden

IGC Proceedings (1977-2023)

The laboratory experiments with aqueous extracts of 11 tropical grass stubble-residues allowed an examination of the allelopathic effects of the extracts on seed germination and early growth of Italian ryegrass (Lolium multiflorum, cv. Minamiwase, Abbr. as IRG). Germination of IRG was generally found to be reduced with an increase in concentration of the residue extracts. Extracts of African millet (Eleusine coracana), Guinea grass (Panicum maximum, strain GR-171) and setaria (Setaria anceps, cv. Nandi and Kazungula) were very inhibitory to the germination of IRG at a high concentration (4g dried stubble/lOOml) ; whereas …

Relationship Between Germination Tests And Field Emergence Of Perennial Warm-Season Forage Grasses, F H. Hsu, C J. Nelson

IGC Proceedings (1977-2023)

Perennial warm-season forage grasses can be valuable components of forage systems to improve animal performance in summer, but they are difficult to get established. Therefore, two germination tests and two field experiments were conducted to determine relationships between seed germination and field emergence. Chilled and unchilled seed of big bluestem (Andropogon gerardi Vitman), caucasian bluestem ( Bothriochloa caocasica (Prin.) C. E. Hubb.), indiangrass ( Sorghastrum nutans (L.) Nash.), and switchgrass (Panicum virgatum L.) were germinated at different temperatures. Unchilled seed were planted in the field near Columbia, MO., at approximately 2-week intervals from early April to late June in …