Agricultural Science Commons^™

Results Regarding The Accelerated Production Of Complete Generations Of Lolium Perenne L. And Dactylis Glomerata L. Under Artificial Climate, Joachim Buhring, Karin Neubert

IGC Proceedings (1977-2023)

Studies were performed on Lolium perenne L. and Dactylis glomerata L. for accelerated pro­duction of plant generations. Flowering of Lolium perenne - was induced in single-leaf seedlings by 65-day vemalization at + 4.5 °C, short-day conditions, and low intensity of illumination (30 microeinsteins • m-2 • s- 1 ). In Dactylis glomerata, flowering was achieved within 100 days by vernalization at low to medium temperatures, short-day conditions, and high intensity of illumination (440 micro­einsteins • m-2 • s- 1). Accordingly, by means of refrigerators for producing low temperatures during vernalization and with artificial light, one generation of Lolium perenne can …

Evaluation Of Quality Factors In Warm Season Forages, Warren G. Monson, Gkenn W. Burton, Wayne W. Hanna

IGC Proceedings (1977-2023)

Improved forage quality is a feasible objective. Coastcross-1 bermudagrass, Cynodon dactylon (L.) Pers., selected for high dry matter digest­ibility, has consistently enhanced the perform­ance of the animals consuming it. Variation in quality factors of other species, particularly Paspalum notatum var. Saurae Parodi and Pennisetum americanum (L.) K. Schum., makes it possible to improve digestibility. Pearl millet varieties with improved animal­production potential have been developed and released for farmer use. The varieties have been selected for higher digestibility and short stature, with reduced stem fractions. The assessment of the digestion of fresh forage permits evaluation of the effects of other factors, …

Intra-Specific Variation In Rates Of Dark Respiration And Of Photosynthesis At Low Positive Temperatures In Festuca Rubra L., William S. Stewart, John H. Ollerenshaw

IGC Proceedings (1977-2023)

Low temperature is a primary limiting factor to the growth of grass in the uplands of Britain. Types better able to grow at low temperature are required for the extension of the growing season. Higher rates of dark respiration are considered to be an adaptation to growth at low temperature. An ecotype of Festuca ruhra L. from a cold environment is shown to have higher rates of dark respiration, photosynthesis, and growth at low temperature than one from a warmer habitat. Observation of this kind may form the basis of a laboratory test for rapidly selecting ecotypes able to grow …

The Inheritance Of Sodium Content In The Dry Matter Of Dactylis Glomerata L., Jaroslav Nasinec, Vaclav Mika

IGC Proceedings (1977-2023)

Experiments were carried out about the indi­vidual composition of the variety 'Milona', its parental varieties 'Aberystwyth Sl43' and 'Welta', and random-selection cross progenies which took part in the formation of the popu­lation of 'Milona'. It was stated that the inter­mediary character of the Na content of 'Milo­na' is not due to a medium or nearly medium Na content of the individual plants, but is expressed by the number of single plants whose Na content exceeds the limit of 0.015 % in the third cut. 'Aberystwyth S 143' and some proge­nies in which A-S 143 was used as mother plant, are …

An Approach To Evaluate A Large Number Of Mixtures Under Grazing, Warwick Harris

IGC Proceedings (1977-2023)

A technique is described to evaluate under grazing the large number of mixtures of grass and legume possible with the increasing num­bers of herbage cultivars. Measurements were made under sheep grazing with and without applied nitrogen of the component species yields of 15 grass and legume monocultures and their 54 grass-legume mixtures. Data from the final grazing of the establish­ment year were examined for interactions be­tween the competing grasses and legumes using regression analysis. The coITelation between cultivar yield and suppressive effect on associ­ates in mixture was strongly negative. Interac­tions between yield and associate effects ob­served were related to seasonal …

Preliminary Selection Of Rye Grass Plants For Mg Accumulating Ability, D.W A. Lane, C A. Lamp

IGC Proceedings (1977-2023)

The selection of clones of perennial ryegrass (Lolium perenne) containing a higher than nor­mal concentration of magnesium in the foliage was seen as one approach to assisting the alle­viation of magnesium deficiency (hypomagnes­aemia) in grazing ruminants. Selection of such material has an unusual feature in that the levels of magnesium concerned are luxury to the rye­grass plant. Twelve commercial cultivars from England, Wales, New Zealand, and Australia were compared in an initial pot experiment. Although no exploitable variation in the magne­sium level of these cultivars was found, further screening uncovered a stable 25 % difference between clones from …

Improving Water Use Efficiency Of Smooth Bromegrass By Selecting For Regrowth, D F. Gross, J G. Ross

IGC Proceedings (1977-2023)

A cultivar of the cool-season grass species smooth bromegrass (Bromus inermis Leyss.), designed to be more efficient in water use for summer pasture, was selected from a source nursery of 37,000 plants grown under near opti­mum moisture and fertility. From this nursery 69 genotypes superior for regrowth were placed in the greenhouse and tested for regrowth, net carbon dioxide exchange (NCE) rates, and other characteristics relevant to regrowth. On the basis of performance 32 genotypes were selected and vegetatively reproduced for inclusion in a field test, again under optimum conditions of moisture and fertility. Two harvests were made in …

The Breeding Of Tetraploid Alsike Clover (Trifolium Hybridum L.) For Mowing And Grazing, Vladimir Malashenko, Svetlana Cheprasova, Antonina Fadeeva

IGC Proceedings (1977-2023)

An account is given of the long-range im­portance that should be attributed to the use of No. 701 tetraploid alsike clover as an early ­maturity, fast-growing, high-yield competitive leguminous plant for irrigated pastures and arable forage cultivation.

Leguminous plants are of very great im­portance to forage production at large. They actually constitute a major source for nitrogen supply. This underlines their decisive role in grassland farming as a device by which to get to grips with the nitrogen deficit. Pasture pro­ductivity can best be improved by proper arrangement of plant associations with forage crop partners of the legume family which …

Performance Of Diallel Crosses Of Alfalfa (Medicago Sativa L.) Among Single Crosses At Different Levels Of Inbreeding: Protein And Saponin Content In The Leaves, P Rotili, L Zannone

IGC Proceedings (1977-2023)

In an alfalfa breeding study conducted under conditions of high competition between plants, combining ability for protein and saponin content was evaluated from diallel crosses among single crosses at the levels of inbreeding S , S2 , S3 , and S4 . For protein content general combining ability (GCA) and specific combin­ing ability (SGA) were never significant. For saponin content GCA was highly significant at S S3 , and S4 levels of inbreeding. The best entry was a single cross of the S2 level.

Predicting Forage Intake By Laboratory Methods, D J. Minson

IGC Proceedings (1977-2023)

It was shown that large varietal differences in voluntary intake occur even· when there were no differences in dry matter digestibility and level of pepsin soluble dry matter. To over­come this problem when comparing different methods of predicting intake the use of multiple regressions was proposed in which dry matter digestibility was always one of the two independ­ent variables. Using this method leaf % was shown to be the best predictor of intake (r = 0.87) closely followed by physical attrib­utes of the feed. It was concluded that more time should be spent studying the physical factors in pastures that …

Possibilities Of Improving The Feeding Value Of Alfalfa By Breeding, R Steuckardt, I Bocsa

IGC Proceedings (1977-2023)

1. The character "in vitro digestibility" repre­sents a complex factor. It is fixed by genetic constitution. Certain correiations were found to exist between the digestibility coefficients (DC) established in the individual cuts, as well as between the DC found in the two years of alfalfa use tested.

2. The in vitro digestibility shows sufficient variability, thus offering an adequate range for a selection programme to improve the feeding value of alfalfa. With such pro­grammes it is, however, necessary at the same time to maintain or even to further improve matter production. The effect of characters correlating with digestibility (po­sitive correlation) …

Productivity Cultivated Native And Foreign Alfalfa Varieties On Two Soil Types In Yugoslavia, Dragoljub Bosnijak, Mirko Stjepanovic

IGC Proceedings (1977-2023)

The following findings were recorded from a four-year series of experiments (1971 to 1974) conducted in the central-northern region of Yugoslavia, with the view to comparing culti­vated native and foreign alfalfa varieties in two locations: The differences between the varieties were significant in either location. 'Os-Z.b.' (a new native selection) and the native variety 'Osjecka 66' gave very high yields. 'Synalfa' (H) and 'Magali' (F), two foreign varieties, were of above-average productivity at Osijek, while two other varieties from abroad, 'Florida' (I) and 'Du Puits' (F), performed well at Nasice. 'Amim' (FRG) and 'Neuga' (GDR) gave high yields of crude …

Breeding A Bloat-Safe Alfalfa (Medicago Sativa L.) Cultivar, B P. Goplen, R E. Howarth

IGC Proceedings (1977-2023)

The soluble protein fraction, which comprises both fraction 1 and fraction 2 proteins, is the major surfactant (of herbage origin) responsible for frothy bloat in ruminants grazing alfalfa pastures. However, variation in soluble protein content of the pasture herbage does not account for the wide variation in the incidence and severity of bloat. Variation in cell rupture and other surfactants may also contribute to the unpredictable nature of pasture bloat. The foam volume measurement is not a suitable technique for development of a bloat-safe alfalfa cultivar because it is not correlated with either soluble protein or the occurrence of bloat. …

The Development Of Grazable Alfalfa Varieties Suitable For The Conditions In The Nonchernozem Zone Of The Rsfsr, Yuri Piskovatski, Yuri Nenarokov, Galina Stepanova

IGC Proceedings (1977-2023)

An alfalfa collection was studied consisting of samples of breeding varieties from home and abroad as well as some wild species. Samples being of interest for breeding alfalfa varieties for grazing were chosen. On the basis of inter­specific and intraspecific hybridization and selection, the high-yielding hybrids B 49, B 98 and others were obtained, being highly pro­ductive and well suited for grazing.

Preliminary Data On Breeding Of Lucerne For Tolerance Of Frequent Cutting, I Bocsa, J Buglos

IGC Proceedings (1977-2023)

We carried out preliminary studies to material­ize a new objective of luceme breeding: the development of a variety tolerant of frequent cutting. We found considerable differences between varieties and strains in tolerance of frequent cutting or cutting performed always in an early phenophase. With normal utilization taken for 100 per cent, the height of frequently cut plants was only 76 per cent on the average of several thousand plants. Frequently cut treatments of close-spaced varieties produced 54-74 per cent of their own normally utilized controls. On the basis of our preliminary studies we have introduced a selection made under "stress" …

Results Of Interspecific And Intergeneric Hybridization Of Lolium L. And Festuca L., N Netzband, G Wacker

IGC Proceedings (1977-2023)

Interspecific and intergeneric hybridization of Festuca pratensis (2n= 14) x Festuca arundina­cea (2n=42), Lolium multiflorum (2n= 14) x Festuca arundinacea (2n=42), and Festuca pratensis (2n = 28) x Lolium multiflorum (2n = 28) has been performed since 1971. From the largely sterile F1 (2n= 28) of the crosses with Festuca arundinacea partly fertile progenies with 2n = 56 chromosomes were obtained after colchicine treatment of seedling plants in their two- to three-leaf stage. For testing plant fertility - fertility being expressed by the number of plants that emerged per defined seed quantity - pollen staining is rather unsuitable an approach …

Hybrid Effect And Fertility In The F 1 Generation Of Interspecific And Intergeneric Hybrids Of Lolium And Festuca, Kurt Grober, Fritz Matzk, Martin Zacharias

IGC Proceedings (1977-2023)

Interspecific and intergeneric hybrids between species of Lolium and Festuca have been studied during three years with respect to fertility and vegetative growth (hybrid effect). Differences in both characters have been found to exist not only between F1 hybrids from several cross combinations but also between the hybrids from one and the same cross combinations. The material examined contains a number of cross combinations showing a relatively high hybrid effect for vegetative growth.

Variability In Panicum Maximum Jacq. And Some Results Of The Selection, V Sidak, Esoeranza Segui, C Perez

IGC Proceedings (1977-2023)

The results of the first-year evaluation of 192 0.lones of Panicum maximum Jacq. are presented. The clones were collected in different regions of Cuba or introduced from foreign countries (71 % and 29 %, respectively). The evaluation was carried out without fertilization nor water supply, each clone being represented per one row and each row divided into three sections, each one representing a particular treatment:(1) annual cutting; (2) cutting frequency of 6 weeks in the dry season and 4 weeks in the wet season; (3) cutting frequency of 8 weeks in the dry season and 6 weeks in the wet …

Within-Varieties Variability In Differently Adapted Types Of Lolium Perenne, Salvatore Ceccarelli, Franco Lorenzetti

IGC Proceedings (1977-2023)

The within-variety variances were estimated at Perugia (Central Italy) for heading time, flag leaf length and width, and length of the tallest stem in 22 varieties of Lolium perenne. The 22 varieties, grouped on the basis of their country of origin, were characterized by dif­ferent levels of variability; the variances esti­mated in varieties from Holland, Denmark, France, and Germany w·ere always higher than those of the Italian varieties, the differences being significant in 11 out of 1'6 cases. The highest variability observed in non­adapted types suggests the opportunity of re­considering the validity of the rules for which certified seed can …

Testing And Selection For Frost Tolerance Within Populations Of Lolium Perenne L. And Dactylis Glomerata L., Arlid Larsen

IGC Proceedings (1977-2023)

Plants from one Lolium perenne variety and two varieties of Dactylis glomerata were tested for frost tolerance as replicated clones. Direc- • tional selection within populations was applied for one generation. Responses were obtained in both species, most efficient in high direction. Here realized heritability was 0.6 and 0.5 for L. perenne and the D. glomerata variety 'Unke', respectively. The variety 'Hattfjelldal' showed only small responses.