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Effects Of Fungicide Seed Treatments On Germination And Establishment Of Sainfoin And Other Legumes, Nan Zhi Biao, Liu Zhao Hui, R A. Skipp

IGC Proceedings (1977-2023)

Treatment of seed with thiram or thiophanate methyl at a rate of 3 g ai/kg seed increased germination of crownvetch (Coro11illa varia L.), milkvetch (Astragalus ads11rge11s Pall.), sainfoin (011obrycl1is viciifolia Scop.) and yellow sweet clover (Melilotus officinalis (L.) Lam.) in laboratory tests. The magnitude of the increases varied with fungicide and species. The greatest increase in germination relativ!) to that of untreated seed was 115% for sainfoin dusted with thiophanate methyl. Thiophanate methyl increased field emergence of sainfoin at 4 and 8 weeks after sowing by 41% and 55% respectively, and at 8 weeks increased the dry weights of shoots …

Pastures In Crop Rotations Enhance Earthworm Populations In Southern Australia, John C. Buckerfield

IGC Proceedings (1977-2023)

The effects of crop rotations on earthworm populations in seasonally dry arable lands was assessed on long-term field trials at 2 sites with an annual rainfall of 450-500 mm, In cropping and sheep-grazing areas of southern Australia. Earthworm densities were substantially higher in rotations of cereals with a volunteer-pasture phase than under continuous cropping with cereals and grain legumes. The degree and frequency of soil disturbance associated with cropping has been shown to influence earthworm numbers: trial plots In which crops were sown with minimal cultivation, in alternate years, supported earthworm populations 2-3 times higher than those conventionally cultivated and …

Costs And Benefits Of Controlling Grasshoppers On Rangeland, E W. Huddleston, R Sanderson, L A. Torell, J H. Davis, J G. Watts

IGC Proceedings (1977-2023)

Ultra low volume (ULV) aerial application of malathion at 0.58 I/ha is the common method of rangeland grasshopper control in the USA. Aircraft often are unavailable or too expensive for treating small infestations; therefore, air-assist ground equipment was adjusted 10 apply the ULV rate from a small truck. In winds of 2.2 m/sec or greater, control with the ground equipment was equivalent to that expected from aircraft. The low spray volume, low sprayer cost and use of a small truck have increased the benefit/cost ratio. Using results from this research and site-specific estimates of control costs and forage value, the …

The Rodent Pests Of Pasture And Their Control In China, Xixian Hou, Weihui Dong, Yanlin Zhou

IGC Proceedings (1977-2023)

Rodent damage is increasingly recognised as a major problem for grasslands of China rodents damage up to an estimated 33 million ha each year, There are two reasons for rodent damage in grassland: one is overgrazing, which causes degeneration of grassland and provides good habitats for rodents; another is the ecological characteristics of rodents. A rodent control programme has been followed for years in China, and includes: (1) studies on the ecology of major rodent pests in pasture, (2) prediction of population, (3) setting up control indexes paying attention to economic benefits, (4) tightening up grassland management and developing integrated …

Stylo Host Heterogeneity For Anthracnose Management, S Chakraborty, A N. Petitt, R M. Boland, S Low Choy, D F. Cameron, J A.G Irwin, R D. Davis

IGC Proceedings (1977-2023)

Small plots of 3 different mixtures of Stylosallllles. scabra genotypes were established within background paddocks of either pure cv. Seca, or a mixture of 6 S. scabra genotypes including Seca, to study anthracnose development in the three mixtures under exogenous inoculum pressures arising from the two backgrounds. There was no difference in disease severity between the background paddocks after the first year. In the small plots, severity of nearest neighbours significantly influenced anthracnose severity on the partially resistant accession 55860 in the first year; this effect disappeared as the disease became more widespread throughout the plot in later years. Replacing …

Increased Resistance To Sclerotinia Crown And Stem Rot Of Alfalfa Through Recurrent Selection Of Surviving Plants In Inoculated Field Plots, M Kanbe, F Fujimoto, S Inami

IGC Proceedings (1977-2023)

ABSTRACT Breeding alfalfa (Medicago saliva L.) for resistance to Sclerotinia crown and stem rot (SCR; causal agent Sclerotitivia trifoliorum Eriks.), which is a serious disease in Japan, was started in 1983. Increased resistance to this disease has been examined after repeated selected of surviving plants from artificially inoculated field plots to the 5th generation. The strains selected for SCR resistance showed higher resistance than Tachiwakaba, which was the main breeding material. The effectiveness of selection judged by the survival rate of progenies was low in the early selection generations but high in the later ones, It is considered that …

Biological Control Of Alfalfa Aphids In Japan Using Coccinella Septempunctata Brucki, Keiichi Takashi

IGC Proceedings (1977-2023)

The oviposition, predation, and survival abilities of Coccinella septempuncrara bmcki Mulsanl (lady beetle), a natural enemy of alfalfa aphids (Acyrtllosyphon kondoi Shinji), increased as temperatures rose in laboratory tests. The second-instar larvae were released into cages in alfalfa (Medicago saliva L.) fields in spring 1991. One month later, alfalfa plants in the control cages without larvae showed much lower yield; however, no damage was observed in cages in which larvae had been released. There is a strong probability that alfalfa aphids can be controlled by the timely release of lady beetle larvae in the field.

Estimating The Size Of Retained Canola Seed, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

The size of canola seed (or number of seeds per kilogram) is essential in calculating the seeding rate for the crop. The rate needs to be high enough to get good establishment and protect against pests, diseases, or other seeding issues.

To work out the seeding rate, the seed size or number of seeds per kilogram. This can be easily calculated by farmers who retained seed.

Insect Pests And Their Management In Oats, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Field pests

Damage from invertebrate pests is generally not a major factor for oat crops, however there is a zero tolerance to live pests in export hay.

Significant damage can occur if pest populations build up. Planning rotations to minimise pest carryover, timely sowing, adequate crop nutrition, and good control of weed and root diseases will assist in reducing the likelihood of crop damage by insect pests. Check crops regularly throughout their growth for field insects.

• Control redlegged earth mite and lucerne flea during the seedling stage if necessary.

• Aphids should be checked for and controlled from flag …

Development Of Intensive Grassland Systems: From Science To Practice, D G. Mccall, G W. Sheath

IGC Proceedings (1977-2023)

Level of nnimal production from grassland is determined by the amount of pasture grown, pasture utilisation and animal conversion efficiency. The key components affecting production are pasture growth and animal conversion efficiency. These arc mainly influenced by environment, genetics and through inputs to maintain soil fertility or animal health. Systems development aims to link pasture growth and animal conversion through efficient strategies for pasture utilisation. The means of influencing pasture utilisation is through adjustments to animal feed demand, feed supply or grazing management. Stock policies that adjust the pattern and level of feed demand are of greatest significance in developing …

The Ecology Of Grazing Management, R K. Heitschmidt

IGC Proceedings (1977-2023)

The broad objective of this paper is to review the fundamental principles of grazing management as a means of assessing the inherent value of intensive and extensive grazing systems. Conceptual analyses of intensive and extensive grazing systems reveal that the fundamental differences between intensive and extensive grazing systems are related to differences in non-grazing rather than grazing tactics. Intensive grazing systems employ a wide array of non-grazing tactics in an attempt to overcome the inherent ecological constraints that limit secondary (i.e., livestock) productivity in extensively grazed systems. Moreover, analyses of the ecological or true efficiency of various agricultural production systems …

An Analysis Of The Dry Matter Intake And Rate Of Live-Weight Gain Of Growing Cattle Fed Forage Diets, J G. Buchanan-Smith

IGC Proceedings (1977-2023)

The intake and rate of live-weight gain of 500 growing steer calves fed experimental forage diets in 7 trials were compared with corresponding values predicted using the Na1ional Research Council (NRC) model (1984). The cattle were predominantly weaned calves and most of the experimental diets were alfalfa-grass silage, either unsupplemented or supplemented with various protein sources, but some diets were based on maize silage or maize grain. The feeding period evaluated in this study ranged between the first 84 and 147 days when protein accretion rate in the cattle would be relatively high. Dry matter intakes were overpredicted by the …

Management Of Extensive Pastures For Dairy Youngstock, G.E J. Fisher, D J. Roberts

IGC Proceedings (1977-2023)

The effects of low input systems on the ground cover of species and yield and chemical composition of herbage cul from extensive lowland swards was studied over 3 years. The live-weight gain of dairy heifer replacements offered grazed or conserved forage from these pastures was also assessed, The swards were sown with a mixture of grasses, wildflowers and herbs and received no inorganic fertilizers, Applications of slurry in January and February increased herbage yield by 43%, but reduced the cover of flowers and herbs. Using a 2- cut conservation system improved yield of metabolisable energy/ha in herbage by 33%, and …

Intensive Grazing Of Alfalfa By Beef Steers, M Rasnake, W R. Burris, G D. Lacefield, J Randolph, N Gay, L Davis

IGC Proceedings (1977-2023)

In the temperate region of North America, high temperature and moisture deficit cause low forage growth during the summer of most years, making it difficult to grow beef (Bos taurus), calves through summer grazing. Alfalfa (Medicago sativa), offers some potential to provide high dry matter production during summer if an effective system of grazing can be developed. The objective of this study was to test a system of intensive grazing of beef steers on alfalfa to maximise live-weight gains/ha and maintain plant population. Alfalfa was no-till seeded into a 6.5 ha field in autumn 1988 after …

Variance Across Years In Growth Of Cattle On Annual Pastures In A Mediterranean Climate, K D. Greathead, J Zorrilla Rios

IGC Proceedings (1977-2023)

Annual pastures were continuously grazed by new drafts of yearling cattle each year for 4 years at 2 sites. The variability of weight gained across years at any date was not different between sites. The level of rainfall in April, but strongly influenced weight gained by the cattle in any year. Variances in weight change were small up to April, they increased rapidly from April to late July and were not different after July (P<0.05).

Modification Of The Botanical Composition Of Perennial And Annual Temperate Pastures By Strategic Grazing Practices, D R. Kemp, P M. Dowling

IGC Proceedings (1977-2023)

Where livestock production depends upon pastures, management is more difficult in environments where rainfall varies considerably from season to season and year to year. Flexible grazing practices are needed to optimise species composition and pasture productivity. Results presented in this paper show that pasture composition can be improved within climatic constraints, by grazing practices within seasons, In temperate annual pastures, long rests in winter (similar to a long rotation during that season) increased annual legume content in early spring from 20 to 50%. Annual grass content was unchanged. In perennial (phalaris) pastures, the dominant legume can change over years from …

Development Of Grass-Clover Pasture Systems For Autumn-Calving Beef Cows. I. Forage Production, G D. Mooso, D G. Morrison, J I. Feazel, D R. Morris

IGC Proceedings (1977-2023)

Four 8-ha areas of bermudagrass-based (Cynodon dactylon (L.) Pers.) grazing systems were sodseeded and received annual N fertiliser as follows: I) clover (Trifolium sp.)+81 kg Nnm, 2) annual ryegrass (Lolium multiflorum Lam)+clover +81 kg N/ha, 3) ryegrass+clover+l39 kg N/ ha, and 4) ryegrass+139 kg N/ha. Monthly forage accumulation was estimated for 3 years by clipping samples from 2 exclosures/pasture. Environmental conditions had a significant effect on total annual forage dry matter (DM) production. Systems 3 and 4 produced more (P<0.05) forage DM than Systems 1 and 2 (11.0 v. 10,3 Mg/ha). System I produced more (P<0.l) forage DM than 2 (10.6 ll, 9.8 Mg/ha). Systems 3 and 4 were similar, producing I 1.0 Mg/ha. Monthly forage accumulation was lowest in winter (December to February) and highest in spring and summer (March to August). The results of this study demonstrate that at a low N level, there was no benefii from including ryegrass in the system and al a moderate N level, there was no benefit from including clover.

Development Of Grass-Clover Grazing Systems For Autumn-Calving Beef Cows. Ii. Cow-Calf Production And Economic Analysis, D G. Morrison, J I. Feazel, G D. Mooso

IGC Proceedings (1977-2023)

Four 8-ha areas of bermudagrass-based (Cynodon dactylon (L.) Pers.) grazing systems were sod seeded and received annual N fertiliser as follows: I) clover (Trifolium sp.)+81 kg/ha, 2) annual rye grass (Lolium multiflorum Lsm.)+clover +81 kg/ha, 3) ryegrass+clover+139 kg/ha, and 4) ryegrass+l39 kg/ha. Each system was stocked year-round with 20 (2,5/lla) cows each with crossbred suckling calf. Cow and calf performance data for 3 of 4 years are included. Year affected (P<0.01) cow and calf live weight, Cows in System 2 were 25-50 kg lower in live weight in autumn and winter than cows in other systems. From February to July, cow daily live-weight gains were 0.11 kg higher (P<0.01) for Systems 2 and 3, Cow live weight in July was affected by N level (Systems 1,2<3,4; P<0,01), Year by system interactions (P<0.05) occurred for cow live weight in February, April and July because of live weight increasing over years in Systems 3 and 4 but not in Systems 1 and 2. Calf daily live-weight gain February to weaning (July) was higher (P<0.01) for System 2 v. 1 (0.06 kg), Syuem 3 v. 4 (0.07 kg), and Systems 3, 4 v. 1, 2 (0.07 kg), Estimated net returns favoured Systems 3 and 4 over Systems 1 and 2.

Improved Grazing Systems For Lamb Production On Appalachian Hill Farms, R L. Reid, J R. Puoli, G A. Jung, D P. Belesky

IGC Proceedings (1977-2023)

Improved grazing methods were tested to increase lamb outputs per ha from Appalachian hill farms. Components of a grazing system were cool-season grass [tall fescue (Festuca arundinacea Schreb.), Grasslands Matua prairie grass (Brom us willdenowii Kunth)J or grass­legume [Kentucky bluegrass (Poa pratensis L.)•red clover (Trifolium pralense L.)] pastures in spring and early autumn, warm-season grass [switchgrass (Panicum virgatum L.)] in summer, and brassicas in late autumn and early winter. Matua was highly productive in cool weather but was subject to fungal infection and grazing ewes had low Mg status in spring. Rotationally grazed switchgrass maintained high numbers …

Use Of Brassica Forage Crops To Extend The Grazing Season In The North-East Usa, G A. Jung, H W. Harpster, M G. Lambert, K T. Leath, R A. Byers

IGC Proceedings (1977-2023)

Forage turnip (Brassica rapa L,) can be made available for animal utilisation in late summer or In late autumn-early winter, when cool­season grass pastures have a low animal carrying capacity. field trials were conducted to identify and quantify factors that influence turnip yield in December or January and to determine whether these factors affect turnip cultivars similarly. Different levels of production in late autumn-winter were attributed to summer drought, foliar diseases, freezing temperatures and rate of leaf senescence. In all instances, the effects of these factors varied with turnip cultivar. However, cultivar ranking generally was the same whether mean …

Interactions Of Rotational And Continuous Grazing With Stocking Rate On Warm And Cool-Season Pastures, David I. Bransby

IGC Proceedings (1977-2023)

With more intense commercialisation of electric fencing many production and economic advantages have been claimed for rotational grazing compared with continuous grazing. However, very little research data are available from the south-eastern USA to verify these claims, Therefore, the objective of this study was to evaluate animal performance under conditions of continuous and IO-paddock rotational grazing on cool- and warm-season pastures commonly used in this region. Three 2-year grazing experiments were conducted, one each on a mixed rye-annual ryegrass (Secale cereale-Lolium multiflorum) pasture, Coastal bermudagrass ( Cynodon hybrid) and Pensacola bahiagrass (Paspalum notatum). In each experiment continuous …

Integrating Pasture Technology Research With Farm Management, R T. Cowan, T M. Davison, K F. Lowe, G K. Reason, G D. Chopping

IGC Proceedings (1977-2023)

An applied research programme which involved farmers in a continuum of trials measuring pasture, soil and milk responses to the application of nitrogen fertiliser to tropical grasses is described. Pasture responses were consistent across farms, grass species and, within limits, rainfall zones and soil types. Soil pH declined by 0.03 lo 0.2 units each year. Additional milk production ranged from 4 to 14 I/kg nitrogen, the response being greater at lower levels of application. Results from farm and research station experiments were consistent. The high adoption rate, reaching 68% in 6 years, was ' attributed to the integration of farm …

Hay Supplementation And Stocking Rate Effects On Live Weight Gain Of Steers Grazing Rye And Ryegrass, Susan E. Sladden, David I. Bransby

IGC Proceedings (1977-2023)

The objective of this study was to evaluate continuous ad lib. supplementation of hay as a means of compensating for the uneven growth distribution of rye (Secale cereale) and ryegrass pastures (Lolium multiflorum) grazed by steers in the south-eastern USA. Pastures were continuously grazed by 230 to 270 kg steers at stocking rates of 2.5, 3.1, 4.1 and 4.9 head/ha with and without hay supplementation for 2 grazing seasons. On average, average daily live-weight gain (ADO) at the highest stocking rate (4.9 steers/ha) was 0.47 kg higher (P<0.01) when hay supplement was provided. Although not significant, in both years ADO tended to be higher for h_ay supplementation even at low stocking rates .

Improved Pasture Species, Fertilizer And Pasture Use To Increase The Productivity Of Wool Sheep In South-Western Victoria, G R. Saul, D Jowett, T Morgan, P Noble, D Borg

IGC Proceedings (1977-2023)

Pastures were upgraded by sowing perennial grasses and subterranean clover (Trifolium subterranum) and applying fertiliser to paddocks on S farms in the wool sheep region of south-western Victoria. Upgraded pastures were stocked at higher rates to ensure utilisation of feed grown. In the third year after sowing, wool production was increased by 56% (35 v. SS kg/ha), and ewe live weights by 4% (49.4 v. 51.4 kg) from upgraded pastures compared with untreated pastures. The results demonstrate the considerable potential to increase output from sheep farms in the region by upgrading pastures. Poor persistence of sown perennial grasses may …

System Research: Preliminary Results From A Farmlet Comparison Between A Biological And Conventional Sheep And Beef System, A D. Mackay, D I. Gray, I M. Brookes, P J. Budding, B Devantier

IGC Proceedings (1977-2023)

Initial findings of a farm let study comparing biological (agrochemical­ free) and conventional sheep and beef production are presented and discussed. Little difference was found in sheep production between the two systems in 1991-92, despite large differences in the level of internal parasitism, particularly in young sheep. In contrast! growth rates of rising 1 year steers and heifers on the conventional unit were superior to those of the biological farmlet throughout spring and summer of the first year. While a reduction in the use of anthelmintic drench would have little impact on the productivity of sheep systems, the productivity of …

A Management System For The Planning, Implementation, And Monitoring And Evaluation Of Farmlet Trials, D I. Gray, A D. Mackay, P J. Budding, I M. Brookes

IGC Proceedings (1977-2023)

A management system used to operate the farmlet component of a farm· systems research programme investigating biological sheep and beef production is described and the advantages and disadvantages of this approach are discussed,

Economics Of Milk Production From Perennial Ryegrass Cultivars With Different Seasonal Growth Patterns, I M. Brookes, A F. Mcrae, D I. Gray, N Cameron

IGC Proceedings (1977-2023)

Cutting trials at 4 sites throughout New Zealand over 2 years with perennial ryegrass (Lolium perenne L) cultivars showed that Bmbassy (B) produeed similar annual dry matter (DM) yields to Supernui (S) and Yatsyn (Y). However, B grew 10% more DM in January-August, but 5% less DM in September-December. The economic value of these diffecent patterns of growth for milk production was assessed using a computer model. The model constrained pasture covers within specified limits by removing excess feed for conservation and adding additional feed as supplements during periods of deficit. Stocking rates needed to maintain the system in equilibrium …

Effect Of Sward Surgace Height On Herbage Intake, Grazing Behavior And Productivity Of Ewes Lambing In June (Winter) Or August (Spring), S T. Morris, W J. Parker, H T. Blair, S N. Mccutcheon

IGC Proceedings (1977-2023)

Herbage organic mailer intakes (OMI) were measured, using chromic oxide capsules, during the last 4 weeks of pregnancy in ewes due to lamb in June (winter) or August (spring). OM! (averaged across lambing date groups) were 1.4±0.1, 1.8±0.1, 1.8±0.1 and 2.0±0.1 kg OM/ewe/day (mcan±s.e.m. P<0.05) in ewes maintained at sward surface heights (SSH) of 20, 40, 60 and 80 mm respectively. There were no differences in OM! between June- and August-lambing ewes from pregnancy day 122 to day 125 (Pl22-Pl25), but between Pl35 and 139 June-lambing ewes had lower OMI than August-lambing ewes (1.5±0.1 v. 1.7±0.1 kg OM/ewe/day (P<0.05)). Live-weight gain of ewes was lowest on the 20 mm sward and highest on the 80 mm sward (157±34 v. 315±31 g/day, P<0.05). SSH had no effect on lamb birth weight. Preliminary data presented here suggest that, at the same SSH, June-lambing pregnant ewes can achieve OMI similar to those of August-Jambers.

Seasonal Herbage Intake Of Once-Bred Heifers, A A. Khadem, S T. Morris, W J. Parker, R W. Purchas, S N. Mccutcheon

IGC Proceedings (1977-2023)

Once-bred heifer (ODH) beef production systems, which are new to New Zealand, involve mating heifers at 15 months of age to cnlve as 2-year-olds and then slaughtering the heifers (at less than 30 months of age) as prime beef. Never-pregnant, pregnant and lactating Hereford x Friesian heifers were used in 4 experiments. There were no significant differences between pregnant (days 260-270 of pregnancy) and never-pregnant heifers in their herbage organic matter intake (OMI), ingestive behaviour or daily live-weight gain (LWG) when a restricted pasture allowance of 7 kg DM/head/day was offered. Heifers at days 50-60 of lactation and never-pregnant heifers …

A Response Of Angora-Type Goats To Increases Of Legume And Chicory Content In Mixed Pastures, D R. Stevens, M J. Casey, G S. Baxter, K B. Miller

IGC Proceedings (1977-2023)

Live-weight gain of angora-type year-old wethcr goats in the spring and summer of 2 years was compared with the total legume and chicory content of 9 different grass, legume, chicory ( Cichorium intybus) mixtures. These pastures were grown in a cool moist temperate climate on fertile silt loam soil. The goats were held on a self• contained rotationally grazed system on each pasture type, leaving a post-grazing residual height of 10 cm. The live-weight gain of the goats responded quadratically to increasing legume and chicory content in both spring and summer. Live-weight gain was optimised when approximately 40% of …