Impact of insects and fungi on doublegee (Emex australis) in the Western Australian wheatbelt

1998 ◽  
Vol 49 (5) ◽  
pp. 767 ◽  
Author(s):  
John K. Scott ◽  
Roger G. Shivas
Keyword(s):  
Biological Control ◽  
Seed Production ◽  
Western Australia ◽  
Seed Quality ◽  
Dry Weight ◽  
High Density ◽  
Exclusion Experiment ◽  
Emex Australis ◽  
Study Sites ◽  
Western Australian

Biotic influences on doublegee(Emex australis Steinheil) seed production wereinvestigated as a precursor to the introduction of new insect biologicalcontrol agents for this weed, and to investigate the cause of doublegeedecline in the northern and central wheatbelt of Western Australia since 1990.The symptoms of the decline are doublegee plants of reduced size withdistorted leaves, collapsed stems, and smaller achenes(the spiny seed-bearing fruit) that crumble when mature.Three sites were investigated in 1992 by surveys for insects and fungi, andinsect and fungus exclusion experiments.Emex stem blight (Phomopsis emicis R. G. Shivas) waspresent at the 3 study sites. The Watheroo site had comparatively high levelsof dock aphids (Brachycaudus rumexicolens Patch) ondoublegee plants, the Badgingarra site had a comparatively high density ofdock sawfly (Lophyrotoma analis Costa) on doublegee, andvery few insects were present on doublegee at the Wongan Hills site. Viruseswere not detected in samples of plants showing the effects of decline.The exclusion experiment showed a significant effect of removing insects andfungi on achene dry weight at the Watheroo site. There was no treatment effectat the Badgingarra and Wongan Hills sites. The biology of the fungus and theaphid lead to the conclusion that the primary cause of doublegee decline isthe dock aphid. This indicates that biological control againstE. australis might be achieved by using insects thatindirectly affect seed quality.

The European Rabbit in South-Western Australia. I. Study Sites and Population Dynamics.

1985 ◽  
Vol 12 (2) ◽  
pp. 183 ◽  
Author(s):  
DR King ◽  
SH Wheeler
Keyword(s):  
Biological Control ◽  
Western Australia ◽  
Biological Control Agent ◽  
Control Agent ◽  
European Rabbit ◽  
Breeding Period ◽  
South West ◽  
Study Sites ◽  
Breeding Seasons ◽  
Winter Rain

Descriptions are given of 2 study sites in the south-west of Western Australia, on which rabbit numbers were monitored. Breeding seasons began in March or April, with the onset of winter rain, and rabbit numbers peaked in October-December, followed by a fall over the non-breeding period in summer. Winter epizootics of myxomatosis, which were spread by Spilopsyllus cuniculi, caused severe declines in rabbit numbers at both sites. Summer epizootics at one site before the introduction of the flea as a biological control agent, and rabbit mortality during these, was lower than in the winter epizootics.

scholarly journals Effect of Nodal Position of Fruits on Seed Quality of Okra (Abelmoschus esculentus L. Moench)

2020 ◽  
pp. 50-54
Author(s):  
Sunil Kumar ◽  
Satbir Singh Jakhar ◽  
Anil Kumar Malik ◽  
Sangeet Kumar
Keyword(s):  
Seed Production ◽  
Seedling Establishment ◽  
Seed Quality ◽  
Dry Weight ◽  
Field Studies ◽  
Abelmoschus Esculentus ◽  
Laboratory Studies ◽  
Seedling Length ◽  
Nodal Position

The present study was carried out in the field and laboratory of the Department of Seed Science and Technology, CCS Haryana Agricultural University, Hisar, Haryana during 2018-2019 to know the effect of nodal position of fruits on seed quality of okra. The parameters recorded during laboratory studies were i.e. germination, seedling length, seedling dry weight, vigour indices-1 & 2 and field studies were i.e. field emergence index, seedling establishment. The results indicated that the best nodal position of fruits for quality seed production was middle nodes (6th to 10th) as compared to lower nodes (1st to 5th) and upper nodes (11th to 15th) and the control.

scholarly journals Effect of botanicals and insecticides seed treatment and containers on seed longevity of black gram under natural ageing conditions

2015 ◽  
Vol 7 (1) ◽  
pp. 328-334 ◽  
Author(s):  
N. Amruta ◽  
G. Sarika ◽  
Umesha Umesha ◽  
J. B. Maruthi ◽  
G. V. Basavaraju
Keyword(s):  
Seed Production ◽  
Seed Treatment ◽  
Seed Quality ◽  
Seed Viability ◽  
Dry Weight ◽  
Management Approach ◽  
Black Gram ◽  
Ambient Conditions ◽  
Emamectin Benzoate ◽  
Production Programme

Good storage is the basic requirement in seed production programme as maintenance of high seed viability and vigour from harvest to planting is of utmost importance in a seed production programme. Therefore, inexpensive, simple and practicable technology to prolong the shelf life of seeds under ambient condition is immensely needed. Hence, an experiment was carried out to study the effect of seed treatment with neem oil, nimbicidin, emamectin benzoate 5 SG, deltamethrin 2.8 EC, novuluron EC on black gram seed quality under ambient conditions. The seeds without any seed treatment were included as control. The treated and untreated seeds were stored in cloth bag and polylined cloth bag. The results revealed that, botanicals and emamectin benzoate seed treatments were significantly superior in controlling the storage insect and maintaining higher seed quality up to 10 months of storage when compared to control. Among the chemicals, the emamectin benzoate 5 SG @ 40 mg kg-1 of seed found better by recording significantly higher germination percentage (80.28), vigour index I (2124) and dry weight of seedlings (43.14 mg) and lower electrical conductivity (0.939 dSm-1) and seed damage (0.00 %) compared to control (78.78%, 2012, 38.90 mg, 0.942 dSm-1, respectively) at the end of 10th month of storage. The emamectin benzoate 5 SG and nimbicidintreated seeds stored in polylined cloth bags were considered as effective seed storage management approach in blackgram.

Factors Limiting the Recruitment of Eucalyptus salmonophloia in Remnant Woodlands .I. Pattern of Flowering, Seed Production and Seed Fall

1994 ◽  
Vol 42 (5) ◽  
pp. 531 ◽  
Author(s):  
CJ Yates ◽  
RJ Hobbs ◽  
RW Bell
Keyword(s):  
Seed Production ◽  
Western Australia ◽  
Seed Viability ◽  
Fragmented Landscape ◽  
Viable Seed ◽  
Seed Fall ◽  
Individual Trees ◽  
Western Australian ◽  
Remnant Population ◽  
Conservation Of Biodiversity

Woodlands dominated by Eucalyptus salmonophloia F. Muell. occur throughout the fragmented landscape of the Western Australian wheatbelt. In most of these remnant woodlands, there is no regeneration of E. salmonophloia and this has become a concern for the conservation of biodiversity in the region. This study examined seed production, seed viability and pattern of seed fall in four remnant populations of E. salmonophloia in the central wheatbelt of Western Australia, to determine whether these factors are limiting recruitment. Surveys of flowering, seed production and seed fall were conducted over a two-year-period which included three potential flowering seasons. Individual trees flowered once over this period and the intensity of flowering and the proportion of flowers which set seed varied greatly between remnants. Seed from up to two consecutive flowering seasons was stored in the canopy, thus, E. salmonophloia formed substantial canopy seed stores. Seeds were released from this store throughout the year and seed fall showed only a weak winter decline. The viability of seeds released from the canopy store in each remnant population was high. These results indicate that the availability of viable seed is unlikely to be responsible for the lack of E. salmonophloia recruitment in remnant woodlands.

Resource Allocation to Asexual Gemma Production and Sexual Reproduction in South-Western Australian Pygmy and Micro Stilt-Form Species of Sundew (Drosera spp, Droseraceae)

1992 ◽  
Vol 40 (3) ◽  
pp. 353 ◽  
Author(s):  
PS Karlsson ◽  
JS Pate
Keyword(s):  
Resource Allocation ◽  
Sexual Reproduction ◽  
Seed Production ◽  
Asexual Reproduction ◽  
Western Australia ◽  
Dry Matter ◽  
Late Season ◽  
Plant Resource ◽  
Total Plant ◽  
Western Australian

Proportional allocations of current total dry matter (DM), N and P to early season asexual gemma production and late-season flowering and seed production were compared for eight pygmy rosette form and three micro stilt-form perennial pygmy sundews (Drosera spp.) in native habitat in south-western Australia. Mean allocations to gemmae for the smaller rosette species were 22% for DM, 60% for N and 38% for P versus 8, 20 and 23% (DM, N, P) respectively for the micro stilt forms. Allocations to mature fully formed seeds were extremely low, 1-8, 4.0 and 5.4% (DM, N, P) for the rosette forms, 0.7, 3-0 and 2.3% respectively for the micro stilt forms. The above values reflect the heavy bias towards gemma production, (8-52 propagules per plant per season across the 11 species) as opposed to that for seed (0-8 fully formed seeds per plant per season). Comparable information for the annual nongemmiferous pygmy sundew D. glanduligera showed end of season allocation of 66, 37 and 29% (DM, N, P) of total plant resource to inflorescences minus seeds, and additional amounts equivalent to 30, 59 and 69% to the 60 seeds produced per plant of this species in the study season. A detailed phenology of resource allocation across a full season of growth in second, third and fourth season plants of the rosette perennial D. closterostigma showed net seasonal losses in the total vegetative resource of N and of P in older plants attributable to apparent over commitment to asexual reproduction during the season of study.

Radopholus nativus (Nematoda: Pratylenchidae), a potential economic pest of wheat in Western Australia

Nematology ◽  
2001 ◽  
Vol 3 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Sean Kelly ◽  
Ian Riley
Keyword(s):  
Western Australia ◽  
Large Population ◽  
Dry Weight ◽  
Economic Loss ◽  
Economic Damage ◽  
Population Densities ◽  
Poor Growth ◽  
Diagnostic Samples ◽  
Lower Population ◽  
Western Australian

AbstractLarge population densities (more than 100 000 per g dry weight of roots) of Radopholus nativus apparently caused economic damage to wheat near Wyalkatchem, Western Australia. Plants in large areas of poor growth were colonised by R. nativus, whereas in areas of better growth Pratylenchus neglectus occurred at lower population densities. The boundary between the areas was distinct. In the same year (1998), a further nine wheat samples were found to be infested with R. nativus through examination of 300 diagnostic samples submitted by Western Australian growers. Mixed Radopholus/Pratylenchus populations occurred in six of those samples. Populations of R. nativus were widely dispersed throughout the cropping areas of the State. It is concluded that R. nativus has the potential under certain conditions and/or crop rotations to reach high population density and cause economic loss.

Seed production in cluster clover (Trifolium glomeratum L.). 2 Effect of sowing time and sowing rate on flowering time, abortion, seed size, and hardseededness

1998 ◽  
Vol 49 (6) ◽  
pp. 965 ◽  
Author(s):  
F. P. Smith ◽  
P. S. Cocks ◽  
M. A. Ewing
Keyword(s):  
Flowering Time ◽  
Seed Production ◽  
Seed Size ◽  
Western Australia ◽  
Seed Quality ◽  
Seed Mass ◽  
Above Ground Biomass ◽  
Sowing Time ◽  
Growing Seasons ◽  
Small Seed

An ecotype of cluster clover (Trifolium glomeratum L.) common to the wheatbelt of Western Australia was sown in pure undefoliated swards at rates in the range 2-256 kg/ha, on 2 dates to give growing seasons 13 and 18 weeks in length. Irrigation was phased out at the time of flowering of late-sown plots. The treatments generated a scale of seed production in cluster clover from 148 kg/ha (43 000 seeds/m2) to 1640 kg/ha (389 000 seeds/m2). Delayed sowing was more important in reducing seed production than was increasing sowing rate. By comparison with the early-sown plots, the late-sown plots had less above-ground biomass at flowering (2053 v. 2728 kg/ha); 48-66% fewer inflorescences per m2; a shorter vegetative phase (9 days); fewer seeds per inflorescence (26 v. 31); and lesser seed mass (337 µg v. 436 µg). There was little effect of the treatments on hardseededness except that hardseededness after 1 season in the field was higher in seeds from late-sown swards at high sowing rate (58%) than from late-sown swards at low sowing rate or early-sown swards (40%). Neither sowing rate nor sowing time influenced the within season pattern of hardseed breakdown. The results indicate that cluster clover is capable of massive seed production, and that even under highly stressed conditions seed production is maximised by a high reproductive allocation and small seed size. Despite conditions which reduced seed production by up to 90%, cluster clover is able to maintain its seed quality. Relatively few inviable seeds are produced and hardseededness is either unaffected or enhanced.

scholarly journals Hybridisation between populations of Enoggera nassaui in New Zealand

2011 ◽  
Vol 64 ◽  
pp. 44-48
Author(s):  
T.M. Withers ◽  
L.D. Phillips ◽  
T.E.M. Bates ◽  
R.J. Ganley
Keyword(s):  
Biological Control ◽  
New Zealand ◽  
Sequence Analysis ◽  
Cytochrome Oxidase ◽  
Western Australia ◽  
Egg Parasitoid ◽  
Cytochrome Oxidase I ◽  
Original Population ◽  
Tortoise Beetle ◽  
Western Australian

The eucalyptus tortoise beetle (Paropsis charybdis) egg parasitoid Enoggera nassaui is distributed throughout New Zealand The original population released in New Zealand was from Western Australia and was later augmented with two strains from Tasmania (Florentine Valley and Evandale) Analysis of E nassaui in 2001 showed a predominance of the Western Australian strain with only one Florentine Valley individual being detected In the present study collections of E nassaui specimens from P charybdis eggs made during spring 2010 were subjected to cytochrome oxidase I (COI) sequence analysis The majority of individuals from Poronui Station (Taupo) were either the Tasmanian Florentine Valley strain or hybrids between the original Western Australian and Tasmanian strains It is uncertain whether this outcome will improve the biological control of Paropsis charybdis in New Zealand

scholarly journals Evaluation of arugula cultivars and seed production in the organic system

2019 ◽  
Vol 41 (4) ◽  
pp. 423-430
Author(s):  
Patricia Augusto da Silva ◽  
Sakae Kinjo ◽  
Marcia Provinzano Braga Xavier de Melo ◽  
Fernando César Sala
Keyword(s):  
Seed Production ◽  
Seed Quality ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Organic Production ◽  
High Yield ◽  
Organic System ◽  
Weight Yield ◽  
Seed Health ◽  
Number Of Leaves

Abstract: The production of arugula (Eruca sativa Mill.) in Brazil uses seeds produced in the conventional system, without availability of organic seeds. The aim of this research was to indicate the cultivars of arugula with best performance for commercial production and to evaluate seed production viability, as well as seed quality of these cultivars in the organic production system. Eight cultivars were evaluated in a protected environment for agronomic characteristics in two periods and for seed production. The parameters evaluated were plant height, number of leaves, shoot fresh and dry weight, yield, iron and vitamin C contents. For seed production, time for flowering, number of branches per plant, silique length, number of siliquae per plant, number of seeds per silique, yield, one thousand seed weight, first count of germination, germination and seed health. After storage, first germination count, germination, seedling emergence, emergence speed index and seed health were evaluated. “Astro” and “Giovana” performed well in the organic system. Organic arugula seeds can be produced with high yield and good seed quality in a protected environment, and the cultivars Astro and LG Maia are suitable for this purpose.

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