Agronomy and Crop Sciences Commons^™

Invertebrate Pests Of Endophyte-Infected And Endophyte Free Perennial Ryegrass Swards In Northern New Zealand, R A. Prestidge, R N. Watson, E R. Thom

IGC Proceedings (1977-2023)

Plots of endophyte-infected and endophyte-free perennial ryegrass (Lollum perenne) cv. Ellett and white clover (Trifolium repens) cv, Grasslands Pitau were established in autumn 1990 by direct drilling into pastures previously sprayed with glyphosate herbicide. Plots were rotationally grazed by dairy cows. Insect pests were sampled by soil coring and extraction, and plant pathogenic nematodes by root staining and examination. Ryegrass tiller density and the proportion of ryegrass in the swards were-significantly less in November, March and May on plots sown with endophyte-free ryegrass c_ompared with endophyte-infected ryegrass. Conversely, the propo!'tion __ of white clover was greater on endophyte-free …

Invertebrate Pests Associated With Italian Ryegrass In Northern New Zealand, R A. Prestidge, R N. Watson, E R. Thom

IGC Proceedings (1977-2023)

Damage threshold levels were established for adult Argentine stem weevil (Listronotus bonariensis (Kuschel)) feeding on Italian ryegrass (Lolium multiflorum Lam;) cv, Concord seedlings in a glasshouse pot trial. Population densities of 35-70/m1 reduced seedling survival by 34% and herbage yield after 28 days growth by 35%. A field trial was established In autumn 1991 by sowing Concord in early February, in late February and in March into areas previously treated with glyphosate herbicide, Insecticide application increased ryegrass tiller density by 36% from 2339/m' (April 1991) and herbage accumulation by 43% from 1.4 t DM/ha only up to the …

Screening For Biological Control Agents Of Root Pathogens Of Pasture Legumes, R A. Skipp, F S. Hay

IGC Proceedings (1977-2023)

Fungi isolated from roots of legumes from pasture soil were applied to seeds of red clover (Trifolium pratense L.) on water agar in Petri plates in a seedling screening test designed to detect antagonism to the fungal pathogens Fusarium solani, Trichrocadium basicola and a Pythium sp. Isolates of Triclroderma koningii, T. /ramatum, a binucleate Rhizoc1011ia sp. or an unidentified basidiomycete protected seedling roots from damage by one or more of the fungal pathogens. Fungi isolated from cysts of the plant-parasitic nematode Helerodera trifolii obtained from pasture soil were tested for their ability to infect eggs of H. trifolii …

Effects Of Three Viruses On Productivity Of Annual Pasture Legume Swards, R A. C Jones

IGC Proceedings (1977-2023)

The effects of 3 non-persistently aphid-transmitted viruses on the productivity of swards of annual pasture legumes were investigated in 1988-91. Virus-host combinations studied were alfalfa mosaic virus (AMV) in burr medic (Medicago polymorplia), cucumber mosaic virus (CMV) in subterranean clover (Trifo/i111n subterra11eum) and bean yellow mosaic virus (BYMV) in subterranean clover. Swards were mown to simulate grazing, grazed or left undefoliated. Herbage (dry weight) and seed production were decreased significantly by infection with all three virus-host combinations. However, the extent of losses vnried with extent of virus spread, cultivar, site and season. Decreased seed yield resulted from both fewer and …

Burial Of Surface-Applied Lime By Earthworms In South Australian Pastures, G H. Baker, P. M.L Williams, V J. Barrett, P J. Carter

IGC Proceedings (1977-2023)

The ability of earthworms, Aporrectodea trapewides, A. caliginosa, A. rosea (Lumbricidae) and Gemascolex walkeri (Megascolecidae), to bury surface-applied lime and offset soil acidity was investigated in 2 pastures in the Mount Lofty Ranges, South Australia, In one pasture, A. trapewides increased pH by 0.8 of a unit at 4-6 cm depth. A. caliginosa also increased soil pH compared with controls, but A. rosea and G. walkeri had no influence, A. trapewides is suggested as a valuable addition to acid pastures, if not already present,

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.

Twas Facilitates Gene-Scale Trait Genetic Dissection Through Gene Expression, Structural Variations, And Alternative Splicing In Soybean, Delin Li, Qi Wang, Yu Tian, Xiangguang Lyv, Hao Zhang, Huilong Hong, Huawei Gao, Yan-Fei Li, Chaosen Zhao, Jiajun Wang, Ruizhen Wang, Jinliang Yang, Bin Liu, Patrick S. Schnable, James C. Schnable, Ying-Hui Li, Li-Juan Qiu

Department of Agronomy and Horticulture: Faculty Publications

A genome-wide association study (GWAS) identifies trait-associated loci, but identifying the causal genes can be a bottleneck, due in part to slow decay of linkage disequilibrium (LD). A transcriptome-wide association study (TWAS) addresses this issue by identifying gene expression–phenotype associations or integrating gene expression quantitative trait loci with GWAS results. Here, we used self-pollinated soybean (Glycine max [L.] Merr.) as a model to evaluate the application of TWAS to the genetic dissection of traits in plant species with slow LD decay. We generated RNA sequencing data for a soybean diversity panel and identified the genetic expression regulation of 29 …

Significance Of Honeybee Pollination In Increasing Seed Yield Of Trifolium Alexandrinum (Fabales: Fabaceae) And Its Impact On Economic Sustainability Of Smallholder Farmers, Muhammad Shoaib Tufail, Gaye L. Krebs, Alison Southwell, John Piltz, Peter C. Wynn, David F. Cook

Grain and Other Field Crops Research Articles

A major limitation to producing high seed yields in berseem clover (Trifolium alexandrinum L.) is failure to set seed, predominantly due to lack of pollination. Despite the importance of berseem clover as a leading forage legume, the contribution of pollinators to seed set is scarce. In Pakistan, the honeybee population is declining mainly because of the extensive use of neonicotinoid pesticides and habitat fragmentation. This, combined with the region’s harsh environment and the use of inferior, locally bred genotypes, has resulted in low seed yields. Insufficient seed availability leads to limited forage supply, resulting in poor livestock nutrition, which …

Spot Form Net Blotch And Its Management In Barley, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Spot form net blotch (SFNB) has become increasingly more common in Western Australia (WA) due to the widespread cultivation of susceptible varieties, such as Spartacus CL and RGT Planet.

These crops generate large amounts of inoculum, which is carried between seasons on infected stubble. Crops grown onto or located close to infected stubble are at greatest risk of infection. The disease can be effectively managed using a combination of varietal selection, crop rotation, and fungicides.

Managing Frost Risk, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Frost occurs on clear nights in early spring when the air temperature drops to 2°C or less. Crop damage from frost may occur at any stage of development but is most damaging at or around flowering.

Frost is difficult to manage, and damage will be unavoidable in some seasons. Risk management options proven to reduce frost risk include paddock zoning, crop and variety selection, time of sowing, stubble management and managing inputs. The greatest gains result from in paddock choice/zoning, crop and variety choice, and manipulating the canopy.

Summer- And Fall-Planted Cover Crops Across Nebraska: Assessing Performance Using Aerial Imagery And Evaluating Short-Term Soil Impacts, Grace Emperatriz Pacheco Jiron

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Cover crops are widely recognized for improving soil health and promoting sustainability in agricultural systems. Despite the increasing use of monitoring tools like aerial imagery, their application in evaluating summer-planted cover crops in the Great Plains remains limited, hindering effective management strategies. Fall-planted cover crops provide long-term environmental benefits, including enhanced soil quality and erosion control; however, understanding their short-term effects on soil properties is crucial for encouraging adoption. This study assessed summer- and fall-planted cover crops across Nebraska, integrating aerial imagery and soil health analyses.

Over two years, fifteen summer-planted monocultures and five mixtures were evaluated for establishment, biomass …

Three-Horned Bedstraw, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity factsheets

Three-horned bedstraw (Galium tricornutum), otherwise known as bedstraw, rough bedstraw, rough fruit corn bedstraw, and corn cleavers, is an annual weed that poses a significant threat to Western Australia’s grains industry. It is a declared pest in Western Australia (WA). A weedy member of the Rubiaceae (madder family), it is closely related to cleavers (Galium aparine)

Bedstraw is a high priority eradication target for Western Australia.

Rabbit Control: Fumigation, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity factsheets

Fumigation for rabbit control involves the introduction of poisonous gas into a warren. It is one of the best control methods to use where low numbers of rabbits live in a few widely scattered warrens. The threat to non-target animals is minimal. This factsheet should be read in conjunction with registered product labels and directions for use. Check the Department of Health, Western Australia website (health.wa.gov.au) for public health requirements for the use of phosphine fumigation.

Fumigation may be used in areas where access is limited, such as fence lines, around trees, and on riverbanks, but it may be difficult …

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 …

Blackbird, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity factsheets

The introduced common blackbird (Turdus merula) is a pest in eastern Australia. It damages commercial fruit crops and may compete with native birds. The species is prohibited in Western Australia and individuals found here are destroyed.

The Western Australian Organism List (WAOL) contains information on the area(s) in which this pest is declared and the control and keeping categories to which it has been assigned in Western Australia (WA). For more information, see our website at dpird.wa.gov.au.

Foliar Application Of Vermitea On Wheat Against Salt Stress Under Hydroponic Condition, Basir Ahmed, Anser Ali, Muhammad Sarwar, Wajad Nazeer, Imdad Ullah

Journal of Bioresource Management

Salinity is one of the major issues that drastically reduce wheat production. In a hydroponic investigation, vermitea was employed to evaluate the impact of salinity on wheat. The vermitea is a by-product of the vermicomposting process that has both macro- and micronutrients. When these plants reached full maturity, they were harvested. The evaluation was based on their morphological characteristics, such as root/shoot dry weight, root/shoot ratio, plant height, root/shoot length, number of spikelets per spikelet, spike length, number of grains per spikelet, and biological yield per plant. The leaves relative water contents and other biochemical parameters including K+, Na+, chlorophyll …

Climate Smart Agriculture, J. David Aiken

Cornhusker Economics

There are several programs encouraging producers to reduce their carbon intensity, including United States Department of Agriculture climate-smart agriculture programs, the 2024 Nebraska Climate Action Plan, and the 2024 Nitrogen Reduction Incentive Act. The hope is that producers with lower carbon intensity (CI) scores will receive a premium for their products. Producers would be well advised to learn more about these programs, as reducing carbon intensity in agriculture seems to be an emerging agricultural policy trend that will be with us for some time to come.

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 …