THE USE OF SEQUENTIAL SAMPLING IN EMBRYO TESTS FOR LOOSE SMUT IN BARLEY SEED

1961 ◽  
Vol 41 (4) ◽  
pp. 772-779
Author(s):  
R. C. Russell ◽  
B. J. Sallans ◽  
H. B. Cannon
Keyword(s):  
Sampling Method ◽  
Sequential Sampling ◽  
Barley Seed ◽  
Double Sampling ◽  
Loose Smut ◽  
Considerable Saving ◽  
Ustilago Nuda

One hundred and forty lots of barley seed were subjected to an embryo test for the mycelium of Ustilago nuda (Jens.) Rostr. Ten samples of 100 embryos were examined from each lot. It was found that the use of sequential sampling, instead of single or double sampling, in making routine tests for loose smut in barley seed, would result in a considerable saving of time and effort as far as determining whether seed stocks contain more or less than the percentage of smut set as the limit of tolerance. However, if the growers require a more exact knowledge of the level of infection in their stocks of seed, it would be preferable to examine 1,000 embryos from each stock, using the single sampling method.

THE INFLUENCE OF AGING OF SEED ON THE DEVELOPMENT OF LOOSE SMUT IN BARLEY

1961 ◽  
Vol 39 (7) ◽  
pp. 1741-1746 ◽  
Author(s):  
R. C. Russell
Keyword(s):  
Close Correlation ◽  
Barley Seed ◽  
Loose Smut ◽  
Average Amount ◽  
Average Percentage ◽  
Ustilago Nuda ◽  
Time Required ◽  
Growing Crop ◽  
Aged Seeds

For several years after their production, 15 stocks of barley seed, infected with Ustilago nuda (Jens.) Rostr., produced approximately the same average percentage of smutted plants in growth tests as the average percentage of infected embryos found in the seed. As the seed became older, this was no longer true. Some samples produced less smut after six years, while others continued to produce similar amounts up to the ninth year, but eventually all samples produced decidedly lower percentages of smut. The average percentage of smutted plants in crops grown from these samples became less with each succeeding year after the sixth in nearly all instances. In the stocks of barley seed studied, the average amount of smut in the growing crop declined from about 14% initially to only 3.2% at the end of the 11-year period.The main reason for the decline in percentage infection was the successively larger proportions of infected seeds that failed to germinate as the seed became aged, as compared with the slower loss of viability in the healthy seeds. A close correlation was found between the length of time required for aged seeds to germinate and the percentage of such seeds carrying smut in their embryos.

A STUDY OF THE GERMINATION OF BARLEY SEED TREATED TO CONTROL LOOSE SMUT

1957 ◽  
Vol 37 (1) ◽  
pp. 59-68
Author(s):  
J. E. Machacek ◽  
H. A. H. Wallace
Keyword(s):  
Suppressive Effect ◽  
Barley Seed ◽  
Anaerobic Incubation ◽  
Loose Smut ◽  
Ustilago Nuda ◽  
Incubation Method

Tests of barley seed treated by the water-soak and the Spergon method to control loose smut (Ustilago nuda (Jens.) Rostr.) have shown that both treatments reduce germination, the Spergon treatment being the more injurious of the two. A part of the reduction may be due to an induced dormancy, but usually the ungerminated seeds are dead.Varieties of barley vary greatly in susceptibility to injury from treatment, but an equally great variation may occur among different lots of seed of the same variety. Susceptibility to the water-soak treatment is closely correlated with susceptibility to the Spergon treatment. Treatment with Ceresan M improves germination and there is a correlation between improvement by this treatment and reduction in germination caused by the water-soak or the Spergon treatment.Treatment of barley seed by the water-soak and Spergon methods destroys a part of the Alternaria contaminant usually present in such seed, but has less effect on it than Ceresan M. Treatment of the seed by the anaerobic-incubation method as used in this study had scarcely any suppressive effect on Alternaria.

PEST MANAGEMENT OF DOUGLAS-FIR TUSSOCK MOTH (LEPIDOPTERA: LYMANTRIIDAE): A SEQUENTIAL SAMPLING METHOD TO DETERMINE EGG MASS DENSITY

1984 ◽  
Vol 116 (7) ◽  
pp. 1041-1049 ◽  
Author(s):  
R. F. Shepherd ◽  
I. S. Otvos ◽  
R. J. Chorney
Keyword(s):  
Sampling Method ◽  
Mass Density ◽  
Sequential Sampling ◽  
Douglas Fir ◽  
Egg Mass ◽  
Tussock Moth ◽  
Incipient Stage ◽  
Orgyia Pseudotsugata ◽  
Detection Tool ◽  
Variability Data

AbstractA sequential egg-mass sample system for Douglas-fir tussock moth, Orgyia pseudotsugata McDunnough (Lepidoptera: Lymantriidae), was designed, based on visual scanning of the lower branches of Douglas-fir trees, Pseudotsuga menziesii (Mirb.) Franco. A branch was removed from each quadrant from the upper, middle and lower crown level, and from the lowest whorl of a total of 59 non-defoliated trees in 10 areas. No consistent trend in egg-mass density per branch could be found between crown levels and no level proved superior as a representative of the tree. Therefore, the lower whorl of branches was selected for survey purposes because of sampling efficiency. Sample stop lines were determined from egg-mass density and variability data collected on 55 sites and subsequent defoliation estimates were related to these densities. The system is designed as an early detection tool to be used only in non-defoliated stands at the incipient stage of an impending outbreak.

THE RELATIONSHIP BETWEEN KERNEL LOCATION, KERNEL SIZE AND THE INCIDENCE OF LOOSE SMUT IN BARLEY

1963 ◽  
Vol 43 (1) ◽  
pp. 88-93 ◽  
Author(s):  
Ahmet Demirlicakmak ◽  
M. L. Kaufmann
Keyword(s):  
Artificial Inoculation ◽  
Loose Smut ◽  
Kernel Size ◽  
Ustilago Nuda ◽  
The Relationship

The association between the incidence of loose smut (Ustilago nuda) and kernel location in 6-rowed barley was studied. With artificial inoculation, kernels from the upper portion of the spike yielded the highest incidence of loose smut. Central and lateral kernels yielded similar numbers of smutted plants.With naturally infected seeds, lateral kernels produced more smutted plants than central ones. The percentage of infected seeds from the upper, middle, and lower portions of the spike varied from sample to sample.Within individual samples of nine 6-rowed varieties of barley small seeds generally produced more infected plants than large or medium-sized seeds. Since lateral kernels are normally smaller than central kernels, these results supported previous findings that the former are more subject to loose smut infection than the latter.

Sign in / Sign up

Export Citation Format

Share Document