Plant Pathology Commons^™

Downy Mildew Of Wheat, S C. Chambers

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

DOWNY MILDEW is caused by the fungus Sclerospora macrospora Sacc. and is almost solely confined to waterlogged areas in paddocks of heavy soil types.

Generally, the disease is most evident in crab-hole gimlet country.

Root Diseases In Wheat On Clover Ley : Factors Under Investigation. 4. Seed Bed Preparation, S C. Chambers

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

The occurrence of root rots in wheat crops in relation to seed bed preparation was studied in a series of field experiments.

Results suggest depth of cultivation has little effect upon the incidence of root diseases.

Ploughing of the seed bed reduced the amount of root rot compared with scarifying and also gave higher yields.

However, the increased yield appears to be mainly due to better control of weeds.

Frost Injury Of Wheat, S C. Chambers

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

Late spring frosts commonly reduce yields and affect the quality of grain in many wheat crops- especially throughout the southern, eastern and north-eastern districts.

The damage is usually localised on individual farms, but occasionally widespread damage occurs in the south of the State.

Farming Without Fallow, H M. Fisher

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

UNDER the more intensive cropping rotations common in the early development of the cereal areas of Western Australia bare fallowing was a basic technique in cereal production.

By ploughing the land in July or August and keeping it bare of vegetation for nine or ten months, either by grazing or cultivation, a substantial beneficial effect on the subsequent crop could be expected.

Root Diseases In Wheat On Clover Ley : Factors Under Investigation. 2. Relative Susceptibility Of Wheat And Barley, S C. Chambers

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

ROOT ROTS of wheat and barley are caused by several fungi, the most important in Western Australia being Fusarium spp., Helminthosporium sativum and Ophiobolus graminis.

Local surveys have shown that the incidence of each organism varies with district and also depends on other factors, such as seasonal conditions and cultural practices.

The relative susceptibility of wheat and barley to these fungi has never been studied in detail under local conditions, although many such investigations have been conducted overseas.

Root Diseases In Wheat On Clover Ley : Factors Under Investigation. 5. The Evaluation Of Fungicidal Treatments, S C. Chambers

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

The use of fungicides, either as seed or soil dressings, for the control of root rotting diseases of wheat, was examined in a series of field experiments.

Results suggest that seed dressings have no effect on the incidence of root rotting fungi in the mature crop.

When fungicides were applied to the soil, a reduction in the incidence of take-all was noted in one experiment, but the same treatments had toxic effects on plants in a second similar experiment.

Streak Mosaic Of Wheat In Nebraska And Its Control, R. Staples, W. B. Allington

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This bulletin reports the results of studies on the epidemiology of wheat streak mosaic under Nebraska conditions. Particular attention is given to the occurrence and certain characteristics of the mite vector of the virus, the relation of weather and other factors to some of its activities, a correlation of certain mite situations with epidemics of the disease, and recommendations for disease control.

The Differential Reaction Of Strains Within A Variety Of Wheat To Physiologic Forms Of Puccinia Graminis Tritici, T. A. Kiesselbach, George L. Peltier

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Black stem rust of wheat (Puccinia graminis tritici (Pers.) Erikss. & Henn.), which occurs in Nebraska and thruout most of the wheat producing regions of the world, is of a composite nature, in that it consists of a number of physiologic forms which can be determined by their action on different varieties of Triticum species, as shown by Stakman and Levine. The ordinary commercial variety of wheat may likewise be regarded as a mixture, in that it consists of numerous strains, which differ in some more or less important characteristics, as has been frequently indicated in the literature concerning …

A Study Of The Environmental Conditions Influencing The Development Of Stem Rust In The Absence Of An Alternate Host. Iv. Overwintering Of Urediniospores Of Puccinia Graminis Tritici. V. The Period Of Initial Infection Of Urediniospores Of Puccinia Graminis Tritici On Wheat. Vi. Influence Of Light On Infection And Subsequent Development Of Urediniospores Of Puccinia Graminis Tritici On Wheat, George L. Peltier

Nebraska Agricultural Experiment Station: Historical Research Bulletins

IV. In order to ascertain whether the urediniospores of Puccinia graminis tritici (Pers.) Erikss. and Henn. overwinter under the environmental conditions prevailing at Lincoln, Nebraska, a series of experiments was carried out extending over a period of 5 years. The results of this investigation are briefly presented. V. By the period of initial infection is meant the time required by a pathogen after it reaches a susceptible plant part to enter the tissues. To determine what the period of initial infection of urediniospores of Puccinia graminis tritici might be, experiments were undertaken during the season of 1923-24 using urediniospores of …

A Study Of The Environmental Conditions Influencing The Development Of Stem Rust In The Absence Of An Alternate Host. Iii. Further Studies Of The Viability Of Urediniospores Of Puccinia Graminis Tritici, George L. Peltier

Nebraska Agricultural Experiment Station: Historical Research Bulletins

1. The influence of relative humidity and temperature on the viability of the urediniospores of two Physiologic Forms of Puccinia graminis tritici has been determined. 2. The same general relation between the viability of the urediniospores and the relative humidity and temperature was found, namely, that the lower the temperature the longer the spores retained their viability at all relative humidities, while at any stated temperature the spores were viable the longest at the medium humidities. 3. Urediniospores of Physiologic Form XXI held at 49.0 per cent relative humidity and maintained at a temperature of 5° C. when tested for …

Bulletin 119 - Take-All Of Wheat And Similar Diseases Of Cereals, W. M. Carne, J. G.C. Campbell

Bulletins 1 - 2999

This important disease, known also as Footrot, Blackleg, and Whiteheads, affects wheat principally, but also occurs on barley, rye, and certain grasses. In a very few instances it has been known to attack oats, but this is so rare that oats may be regarded for practical purposes as free from attack. Of the grasses attacked the most important, from a farming point of view in Western Australia, are Bailey Grass (Hordeum murinum), Silver Grass (Festuca bromoides and F. myuros), and the so-called Spear grasses (Bromus spp.). These annual grasses are very common in the wheat belt.

A Study Of The Environmental Conditions Influencing The Development Of Stem Rust In The Absence Of An Alternate Host. Ii. Infection Studies With Puccinia Graminis Tritici Form Iii And Form Ix, George L. Peltier

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Stakman and Levine have shown that Puccinia graminis tritici (Pers.) Erikss. and Henn. consists of a number of biologic forms, which can be determined by their action on different varieties of Triticum species. To date 37 such biologic forms have been identified by them through the parasitic action on 12 differential hosts chosen from a large number of varieties of Triticum species. To determine whether these biologic forms remain constant in their behavior under various environmental conditions, a detailed study of the host-parasite relation was undertaken with 2 of these forms. At the same time an opportunity was afforded to …

A Study Of The Environmental Conditions Influencing The Development Of Stem Rust In The Absence Of An Alternate Host. I. The Viability Of The Urediniospores Of Puccinia Graminis Tritici Form Iii, George L. Peltier

Nebraska Agricultural Experiment Station: Historical Research Bulletins

No exact data are at hand regarding the influence of temperature and relative humidity on the viability of the urediniospores of stem rust under controlled conditions. 1. The influence of relative humidity on the viability of the urediniospores of Puccinia graminis tritici Form III is very pronounced and closely associated with temperature. 2. At high relative humidities, depending somewhat on the temperature, the percentage of germination is low and the period over which the spores are viable is very short. 3. The same relation exists at the low relative humidities except that it is not so pronounced and is more …