Plant Pathology Commons^™

Studies On The Relationship Of Polygalacturonase Inhibitors To Verticillium Wilt Resistance In Tomatoes, Robert Lee Sneed

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Early studies of the vascular wilts were directed toward understanding the wilting of susceptible varieties (19, 22, 23). Only in recent years have workers begun to study plant resistance to Fusarium and Verticillium wilts.

A Study Of The Development Of The Sexual Stage Of Rhytisma Punctatum (Pers.) Fries, Ching-Fei Chen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Speckled tar spot caused by Rhytisma punctatum (Persoon) Fries is often found on maples in many parts of the world (Holden, 1961; Koval', 1960; Saccardo, 1889). In Northern Utah it develops every year on leaves of Acer grandidentatum Nutt., and it is especially abundant at elevations above 6,000 feet, where often it is difficult to find even one uninfected leaf. The black speckled spots and the associated leaf coloring tend to add to the brilliance of the autumn colors normally found in the leaves of Bigtooth Maple.

Mechanical Transmission Of A Latent Virus From Apple To Herbaceous Plants, Ali Majid Jafri

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent work has shown that viruses are widely disseminated in commercial apple trees growing in this country (1, 14, 16, 17)—quite often one or more latent viruses are found in these plants. Usually latent viruses produce no symptoms, except in special indicator hosts. Latent viruses may cause severe injury when infected plants are grafted to a sensitive variety or rootstock. Actual damage caused by most of the apple viruses is not known but some of these definitely cause serious losses. Experimental plots at Utah State University were ruined by stem pitting virus infection. However, other latent viruses were also present …

Biochemical Changes During The Growth Of Fungi: Ii. Ergosterol And Fatty Acids In Penicillium Atrovenetum, David Gottlieb, James L. Van Etten

Department of Plant Pathology: Faculty Publications

Changes in the lipid constituents of Penicillium atrovenetum were studied during the growth and development of this fungus. The stages in development, as measured by the dry weight, were divided into four phases: lag, log, stationary, and death. The total fatty acids on a dry-weight basis increased from a minimum in the spores to a maximum near the end of the log phase of growth. The major fatty acids were palmitic, stearic, oleic, and linoleic. Myristic, pentadecanoic, palmitoleic, heptadecanoic, linolenic, arachidic, and heptadecenoic acids, together with two unidentified components, were also present in the fatty acid fraction. Compared to ungerminated …

Nodulation Of Legumes On New Light Land. 1. Survival Of Rhizobia On Inoculated Pelleted Seed Held For Varying Periods Before Sowing Into Dry Soil, O M. Goss, W. A. Shipton

Journal of the Department of Agriculture, Western Australia, Series 4

MOST of the light land areas being opened up in Western Australia are very sparsely populated with the rhizobial bacteria so essential for successful legume establishment.

Seed inoculation is therefore a necessity.

Farmers often have to resort to dry sowing because of the large acreages being planted or late opening rains.

Nodulation Of Legumes On New Light Land. 4. Rhizobial Strains For Pasture Establishment, O M. Goss, W. A. Shipton

Journal of the Department of Agriculture, Western Australia, Series 4

LEGUMES are the basis of improved pastures in Western Australia.

Successful establishment of these legumes depends on the presence in the soil of suitable bacteria which will invade the roots and develop nodules in which nitrogen fixation is carried out. The nitrogen compounds produced are utilised by the plants, making them independent of soil nitrogen.

At the end of the season, the decomposition of the plant residues improves soil fertility.

Root Growth Of Apple Trees, J E L Cripps

Journal of the Department of Agriculture, Western Australia, Series 4

IT will surprise even experienced growers to know that an apple tree in W.A. needs twice the quantity of roots the same tree would need in a more temperate climate such as England's.

Black Spot And Powdery Mildew Of Grapes, H L. Harvey

Journal of the Department of Agriculture, Western Australia, Series 4

BLACK spot (or anthracnose) and powdery mildew (or oidium) are diseases that occur commonly on grape vines in W.A.

Grease Spot Of Passion Fruit, R F. Doepel

Journal of the Department of Agriculture, Western Australia, Series 4

PROLONGED wet periods during the winter months favour serious development of the bacterial disease grease spot in passion vine plantations.

The Black Beetle, Clee Francis Howard Jenkins

Journal of the Department of Agriculture, Western Australia, Series 4

Since first reported in Western Australia 27 years ago, the black beetle has spread widely to become a well-known pest in metropolitan home lawns and public grassed areas.

THE black beetle (Heteronychus sanctae-helenae Blanchard) is a native of South Africa which seems to have first gained a footing in Australia in about 1930, for it was then recorded as a pest of maize in New South Wales. (Gurney 1934).

Apple Dieback In Western Australia, Frank Melville

Journal of the Department of Agriculture, Western Australia, Series 4

Dieback of apple trees has been a serious and persistent problem in Western Australian orchards for many years.

Field observations and trials suggest that it can be greatly reduced or avoided by spray thinning to control cropping, summer irrigation, light pruning, and avoidance of root damage by cultivation.

Nodulation Of Legumes On New Light Land. 2. Protection Of Rhizobia From The Toxic Action Of Superphosphate And Trace Elements, O M. Goss, W. A. Shipton

Journal of the Department of Agriculture, Western Australia, Series 4

VAST areas of new light land being developed in Western Australia are deficient in trace elements such as copper, zinc and molybdenum as well as in phosphorus.

These fertilisers are known to be damaging to the rhizobial bacteria inoculated on the seed unless they are protected by lime pelleting.

Nodulation Of Legumes On New Light Land. 3. The Effect Of Rogor Seed Treatment On Legume Nodulation, O M. Goss, W. A. Shipton

Journal of the Department of Agriculture, Western Australia, Series 4

SEED treatment with systemic insecticides is widely used for the control of insect pests. However, when seed inoculation is necessary for pasture establishment, seed treatment with insecticide is not advisable.

A field experiment conducted at Badgingarra Research Station in 1964 showed that the systemic insecticide Rogor was very damaging to the applied rhizobia even when the treated seed was held for a month before inoculation.

Sugar Beet Eelworm (Heterodera Schachtii Schmidt) On Cauliflowers And Its Control, O M. Goss

Journal of the Department of Agriculture, Western Australia, Series 4

SUGAR beet eelworm causes severe damage to summer-grown cauliflowers in some areas in Western Australia, particularly those areas of Spearwood, Balcatta and Osborne Park which border the swamps.

Root-Bound Shrubs, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

THE illustrated garden shrub (Cotoneaster) strangled itself with its own roots.

When purchased several years earlier it had been in the pot too long and the young roots, not being able to grow straight down had spiralled round and round in the pot.

Damage Caused By Hormone-Like Herbicides, G R W Meadly

Journal of the Department of Agriculture, Western Australia, Series 4

THE discovery of the selective action of herbicides such as 2,4-D and MCPA resulted in a rapid expansion in the use of these chemicals for agricultural purposes, particularly for the control of weeds in cereal crops.

Plant Diseases : Leaf Spot Of Celery, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

LEAF SPOT is the most serious disease of celery in Western Australia, and causes heavy losses in many crops during the cold wet months of June, July and August.

The disease is incited by the fungus Septoria apii Chester, and was first recorded in this State at Osborne Park in 1923.

Since then it has become a limiting factor in the production of marketable celery during the winter months.

Inoculation And Lime Pelleting Of Leguminous Seeds, O M. Goss, W. A. Shipton

Journal of the Department of Agriculture, Western Australia, Series 4

MOST of the extensive areas of new land being brought into cultivation in Western Australia are very sparsely populated with the rhizobial root nodule bacteria which are essential for successful legume pasture establishment.

These bacteria, therefore, must be introduced into the soil where, under favourable conditions, they will develop nodules on the roots (Fig. 1).

White Rust Of Gerberas, R F. Doepel

Journal of the Department of Agriculture, Western Australia, Series 4

WHITE rust has proved to be a most damaging fungal disease of Gerberas.

Frequent fungicidal sprays are recommended for susceptible varieties in late winter and spring.

Puccinellia : Outstanding Saltland Grass, C V. Malcolm, S. T. Smith

Journal of the Department of Agriculture, Western Australia, Series 4

"Puccinellia" is a tussocky perennial grass with an outstanding ability to survive salty and waterlogged conditions.

Considerable areas of saltland in Western Australia are suited to its growth.

Seed is now available commercially and in this article the conditions to which the grass is suited are described and establishment and management methods are suggested.

Slime Moulds [Replaced By Farmnote 114/77], Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

DURING autumn and spring, yellow or grey masses of slimy or powdery material suddenly appear on the blades of lawn grass and other low-growing plants and render them unsightly.

The organisms responsible are known as slime moulds.

Plant Nutrition In Western Australia, George Henry Burvill

Journal of the Department of Agriculture, Western Australia, Series 4

PLANT nutrition is of great practical importance in Western Australia.

Without a well developed fertiliser industry and research and experiments to guide farmers in appropriate fertiliser use the State's agriculture would be very restricted.

Clover Disease Of Sheep In Western Australia, A B. Beck, M. R. Gardiner

Journal of the Department of Agriculture, Western Australia, Series 4

DURING the past five years there has been a marked increase in the incidence of breeding abnormalities of sheep associated with the grazing of subterranean clover pastures.

This complex of diseases first became a major problem in Western Australia in the years following 1940 and eventually became known as "clover disease".

Root Knot Eelworm And Its Control, O M. Goss

Journal of the Department of Agriculture, Western Australia, Series 4

ROOT galling caused by root knot eelworm attack is very common in the lighter sandy soils of Western Australia.

This parasitic worm causes severe unthriftiness which may even result in the death of the plant, particularly during the summer months when the disease is most damaging.

Root knot eelworm has a wide host range.

Peach Leaf Curl, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

PEACH LEAF CURL is a common disease in Western Australia during the spring and early summer.

Control Of Bamboos, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Bamboos can be controlled by spraying with a solution containing 2,2-DPA.

Vegetable Seed Treatments, G C. Macnish

Journal of the Department of Agriculture, Western Australia, Series 4

Many common vegetable diseases can be carried over from one crop to the next by means of contaminated seed.

The use of such seed also results in contamination of the soil with the disease-causing organisms.

Prevention or control of seed-bome diseases can be achieved by the use of appropriate chemical or hot water treatments.

Density-Gradient Centrifugation: Non-Ideal Sedimentation And The Interaction Of Major And Minor Components, Myron K. Brakke, J. M. Daly

Department of Plant Pathology: Faculty Publications

A small amount of southern bean mosaic virus was contained in a narrow zone after density-gradient centrifugation, but in a much wider zone after centrifugation with a large amount of a second virus. Zone-spreading of a major component by non-ideal sedimentation in density-gradient centrifugation can cause zone spreading of a minor component that the major component overlaps.

Blossom-End Rot Of Tomatoes, G C. Macnish

Journal of the Department of Agriculture, Western Australia, Series 4

Complete control of this common physiological disorder of tomatoes cannot as yet be achieved, but a number of measures can be employed to reduce its incidence.

DURING the summer months many tomato specimens are received showing symptoms of blossom-end rot.

Many growers attribute this trouble to parasitic organisms and are anxious to prevent it spreading to the rest of their crop.

However as blossom-end rot is not a parasitic disease, it cannot be controlled by fungicidal or bactericidal sprays.

Brown Spot Of Passion Fruit, R F. Doepel

Journal of the Department of Agriculture, Western Australia, Series 4

Brown Spot is a serious fungal disease of passion fruit in this State.

Successful crop production is dependent on adequate disease control in the plantation.

BROWN SPOT is found in plantings throughout Western Australia. Severe outbreaks of the disease have occurred in most districts, including Serpentine, Manjimup, Nannup and Denmark.

Although isolated young plantings may remain healthy for two or three years, the disease eventually becomes established in the vines.