Effects of seed size and seed weight on seedling establishment, vigour and tolerance of Argentine canola (Brassica napus) to flea beetles, Phyllotreta spp.

2008 ◽  
Vol 88 (1) ◽  
pp. 207-217 ◽  
Author(s):  
R. H. Elliott ◽  
C. Franke ◽  
G. F. W. Rakow
Keyword(s):  
Brassica Napus ◽  
Seed Size ◽  
Seedling Establishment ◽  
Seed Weight ◽  
Flea Beetle ◽  
Shoot Biomass ◽  
Seedling Vigour ◽  
Flea Beetles ◽  
Shoot Weight ◽  
Beetle Damage

A 3-yr study was conducted on four Brassica napus L. cultivars to determine the effects of seed size and seed weight on the performance and tolerance of canola seedlings to feeding damage by flea beetles, Phyllotreta spp. (Coleoptera: Chrysom elidae). Seed lots of a doubled haploid cultivar Cyclone, hybrid cultivar AC H102 and two open-pollinated cultivars Profit and AC Elect were sieved to obtain small, medium, large and very large seeds (1.4–1.6, 1.6–1.8, 1.8–2.0 and 2.0–2.2 mm diameter, respectively). Under controlled environmental conditions, leaf area, shoot weight and biomass of seedlings from large and very large seeds were 1.3–2.0 times greater than those of seedlings from small seeds. Under field conditions without insecticides, seedlings from small seeds of each cultivar had the highest flea beetle damage, poorest establishment, and lowest shoot weight, biomass and yield. Compared with small seeds, large seeds improved seedling establishment, shoot weight, biomass and yield by 1.1, 1.6–2.0, 3.0–3.5 and 1.5 times, respectively. Results indicated that seedlings from large seeds are more vigorous and tolerant to flea beetle damage than seedlings from medium or small seeds. Seedling vigour and tolerance was due to a higher initial shoot biomass and higher growth rate when flea beetle damage was severe. When damage exceeded 50%, large heavy seeds had the best stand establishment, best shoot growth and highest yield in each cultivar. Key words: Canola, flea beetles, seed size, seed weight, seedling vigour, tolerance

Effects of seed size and seed weight on seedling establishment, seedling vigour and tolerance of summer turnip rape (Brassica rapa) to flea beetles, Phyllotreta spp.

2007 ◽  
Vol 87 (2) ◽  
pp. 385-393 ◽  
Author(s):  
R. H. Elliott ◽  
L. W. Mann ◽  
O. O. Olfert
Keyword(s):  
Seed Size ◽  
Brassica Rapa ◽  
Seedling Establishment ◽  
Seed Weight ◽  
Flea Beetle ◽  
Dry Weight ◽  
Seedling Vigour ◽  
Shoot Dry Weight ◽  
Flea Beetles ◽  
Beetle Damage

A 3-yr study was conducted on three synthetic Brassica rapa L. cultivars to determine the effects of seed size and seed weight on seedling establishment, seedling growth and susceptibility to feeding damage by flea beetles, Phyllotreta spp. (Coleoptera: Chrysomelidae). Seed lots of AC Boreal, Fairview and Hysyn 110 were sieved to obtain small, medium and large seeds (1.4–1.6, 1.6–1.8 and 1.8–2.0 mm, respectively). In the laboratory, seedlings grown from large seeds had the largest cotyledons, highest shoot dry weight and highest biomass. Shoot weights increased as seed size increased. Sized seeds of the three cultivars were grown in the field without insecticides in 1998–2000. Seedlings of small seeds had the highest flea beetle damage and poorest seedling establishment. Shoot dry weight and biomass 14–35 d after planting increased as seed size and seed weight increased. Compared with small seeds, large seeds improved shoot dry weight, biomass and seed yield by 13–43, 25–57 and 12%, respectively. Results indicated that seedlings of medium and large seeds are more vigorous and tolerant to flea beetle damage than seedlings of small seeds. Tolerance was due to a higher initial seedling weight rather than higher relative growth rate. Shoot dry weights, biomass and yield of the three cultivars were more strongly correlated with 1000-seed weight than with seed diameter. Key words: Canola, flea beetles, seed size, seedling vigour, tolerance, seed weight

Influence of seed size in canola, Brassica napus L. and mustard, Sinapis alba L., on seedling resistance against flea beetles, Phyllotreta cruciferae (Goeze)

1991 ◽  
Vol 71 (2) ◽  
pp. 397-404 ◽  
Author(s):  
R. P. Bodnaryk ◽  
R. J. Lamb
Keyword(s):  
Brassica Napus ◽  
Seed Size ◽  
Seedling Survival ◽  
Flea Beetle ◽  
Sinapis Alba ◽  
Brassica Napus L ◽  
Seedling Resistance ◽  
Phyllotreta Cruciferae ◽  
Flea Beetles ◽  
Sinapis Alba L

Seedlings of Brassica napus L. 'Westar' or Sinapis alba L. 'Ochre' grown from seeds of various size were offered to flea beetles, Phyllotreta cruciferae (Goeze) in feeding tests for damage assessment. The proportion of cotyledon area damaged in both species was highest for seedlings grown from small seeds in choice and no-choice feeding tests. The proportion of seedlings killed by flea beetle feeding was also highest in seedlings from small seeds, an effect that was especially pronounced at high beetle densities (10/seedling) where 100% of seedlings from small seeds of B. napus were killed compared to 28.3% of seedlings from big seeds. For S. alba, at 20 beetles/seedling, 45.4% of seedlings from small seeds were killed compared to only 9.1% of seedlings from big seeds. Seedlings grown from big seeds of S. alba tolerated low levels of damage caused by flea beetle feeding or by scissors. No evidence for tolerance was obtained for seedlings from small seeds of S. alba or for seedlings from big or small seeds of B. napus. "Big seeds" appears to be a desirable trait that enhances crucifer seedling resistance to flea beetle attack and results in increased seedling survival. Key words: Brassica napus 'Westar', Sinapis alba 'Ochre', Phyllotreta cruciferae, flea beetle, seed size, resistance

When is fall feeding by flea beetles (Phyllotreta spp., Coleoptera: Chrysomelidae) on canola (Brassica napus L.) a problem?

2012 ◽  
Vol 92 (1) ◽  
pp. 97-107
Author(s):  
Juliana J. Soroka ◽  
Larry F. Grenkow
Keyword(s):  
Brassica Napus ◽  
Field Experiments ◽  
Flea Beetle ◽  
Brassica Napus L ◽  
Late Season ◽  
The Third ◽  
Flea Beetles ◽  
Seeding Date ◽  
Seed Yields

Soroka, J. J. and L. F. Grenkow. 2012. When is fall feeding by flea beetles ( Phyllotreta spp., Coleoptera: Chrysomelidae) on canola ( Brassica napus L.) a problem? Can. J. Plant Sci. 92: 97–107. Two cultivars of Brassica napus canola were seeded in mid-May and early June in three field experiments in each of 3 yr near Saskatoon, Saskatchewan, to determine the effects of late-season flea beetle feeding on seed yields. In the first experiment, canola was sprayed with insecticide late in the summer to eliminate naturally-infesting flea beetles. In the second, 1×1×1.5 m screen cages were placed over early- and late-seeded canola at flowering and infested with flea beetles as canola matured. In the third investigation, sleeve cages were placed over individual plants and infested with 100 flea beetles. Flea beetles had no detrimental effects on early-seeded canola in any experiment, but did affect seed yields of late-seeded plots in some trials. Over two cultivars in 1 year, late-seeded plants in cube cages infested with about 350 flea beetles per plant when lower pods were turning from translucent to green in colour reduced yield by 241 kg ha−1 over control yields. Seed weights in these late-seeded plots were decreased from 2.68 g per 1000 seeds in uninfested cages to 2.44 g per 1000 seeds in infested cages. Populations of 100 flea beetles per plant in sleeve cages had no effect on harvest parameters in any seeding date or year.

A SELECTION OF OILSEED RAPE, BRASSICA RAPA L., WITH RESISTANCE TO FLEA BEETLES, PHYLLOTRETA CRUCIFERAE (GOEZE) (COLEOPTERA: CHRYSOMELIDAE)

1993 ◽  
Vol 125 (4) ◽  
pp. 703-713 ◽  
Author(s):  
R.J. Lamb ◽  
P. Palaniswamy ◽  
K.A. Pivnick ◽  
M.A.H. Smith
Keyword(s):  
Brassica Rapa ◽  
Flea Beetle ◽  
Phyllotreta Cruciferae ◽  
Flea Beetles ◽  
Cotyledon Stage ◽  
Small Seed ◽  
Incomplete Resistance ◽  
Beetle Damage ◽  
Field Plots ◽  
Selection Of

AbstractFive cycles of single-plant and progeny-row selection in lines derived from Brassica rapa L. "Tobin" were used to identify plants with incomplete resistance to flea beetles, Phyllotreta cruciferae (Goeze). This line, called C8711, had higher survival, grew larger, and yielded more seed than Tobin when the two lines were compared in field plots at Glenlea, Manitoba, unprotected by insecticide. C8711 without insecticide yielded more seed than Tobin treated with a lindane seed dressing, but less than Tobin treated with carbofuran granules. With carbofuran, which prevents most flea beetle damage, the yield of C8711 was 35% higher than for Tobin. At Saskatoon, Saskatchewan, the differences between C8711 and Tobin were not statistically significant, although the trends were similar to those at Glenlea. C8711 was late maturing, produced small seed, and was not of canola quality. The resistance in C8711 is attributed to a low level of antixenosis, rapid growth at the cotyledon stage, and tolerance to damage during the first 3–4 weeks of growth.

OBSERVATIONS ON DISTRIBUTION, SEASONAL LIFE HISTORY, AND ABUNDANCE OF FLEA BEETLES (COLEOPTERA: CHRYSOMELIDAE) THAT INFEST RAPE CROPS IN MANITOBA

1979 ◽  
Vol 111 (12) ◽  
pp. 1345-1353 ◽  
Author(s):  
H. G. Wylie
Keyword(s):  
Life History ◽  
Brassica Napus ◽  
Relative Abundance ◽  
Flea Beetle ◽  
Phyllotreta Cruciferae ◽  
Main Species ◽  
Phyllotreta Striolata ◽  
Flea Beetles ◽  
History Of

AbstractPhyllotreta cruciferae (Goeze) was usually the most abundant flea beetle on crops of Argentine rape, Brassica napus L., in Manitoba, followed in order by Phyllotreta striolata (F.) and Psylliodes punctulata Melsh. These three species and small numbers of Phyllotreta bipustulata (F.) were present on volunteer rape in the spring. A few specimens of a fifth rape-eating species, Phyllotreta robusta Lee, were trapped in April after hibernating. The three main species were recorded in all 16 localities in which samples of flea beetles on rape crops and/or volunteer rape were collected. Details of seasonal life history of each species are presented, as well as data on the abundance of the three main species throughout the year on rape crops, in overwintering habitats and on volunteer rape in spring. The relative abundance of P. cruciferae, P. striolata, and Ps. punctulata in different rape-growing areas of Manitoba is discussed.

WOUND-INDUCED ANTIXENOTIC RESISTANCE TO FLEA BEETLES, PHYLLOTRETA CRUCIFERAE (GOEZE) (COLEOPTERA: CHRYSOMELIDAE), IN CRUCIFERS

1993 ◽  
Vol 125 (5) ◽  
pp. 903-912 ◽  
Author(s):  
P. Palaniswamy ◽  
R.J. Lamb
Keyword(s):  
Laboratory Experiments ◽  
Flea Beetle ◽  
Sinapis Alba ◽  
Plastic Film ◽  
Feeding Damage ◽  
Similar Extent ◽  
Mechanical Wounding ◽  
Phyllotreta Cruciferae ◽  
Flea Beetles ◽  
Beetle Damage

AbstractLaboratory experiments were conducted to determine the effect of wounding the cotyledons of Sinapis alba L. cv. Ochre, Brassica napus L. cv. Westar, B. rapa L. cv. Tobin, and C8711, a selection from Tobin, on subsequent feeding damage by the flea beetle, Phyllotreta cruciferae (Goeze). Cotyledons of 7-day-old seedlings were wounded either by puncturing them with needles (mechanical wounding) or by exposing them to flea beetles. One, 2, or 9 days following wounding, the wounded and unwounded seedlings were exposed to flea beetles and the feeding damage was estimated as a measure of antixenosis. Mechanical wounding of one of the cotyledons with 96 needle punctures induced a significant reduction in the damage of the unwounded cotyledons of S. alba, 1 or 2 days following wounding. True leaves of the wounded seedlings also showed consistently less damage than unwounded controls, 9 days following wounding. In S. alba, all three levels of mechanical wounding (i.e. 6, 24, or 96 punctures per cotyledon) reduced subsequent flea beetle damage to a similar extent. Wrapping a cotyledon of S. alba with a plastic film produced an effect similar to wounding it with needles. As with mechanical wounding, flea beetle wounding also reduced subsequent flea beetle damage in S. alba. Other plant species (B. napus and B. rapa) tested showed no measurable induced effects on subsequent feeding damage.

Seed weight, emergence and seedling vigour of four tetraploid crested wheatgrass populations

2003 ◽  
Vol 83 (1) ◽  
pp. 69-70 ◽  
Author(s):  
A. Mellish and B. Coulman
Keyword(s):  
Key Words ◽  
Seed Size ◽  
Seed Weight ◽  
Seedling Emergence ◽  
Seedling Vigour ◽  
Crested Wheatgrass

This study compared the seed weight, and seedling emergence vigor of four tetraploid crested wheatgrass populations. S9240H, a population selected for seed size, had larger seeds than the cultivars Kirk and CD-II. Heavy seeds had greater emergence and heavier seedlings than light seeds, but there were no differences in these characters among the four populations. Key words: Crested wheatgrass, seed size, seedling vigour

HAIRS PROTECT PODS OF MUSTARD (BRASSICA HIRTA ’GISILBA’) FROM FLEA BEETLE FEEDING DAMAGE

1980 ◽  
Vol 60 (4) ◽  
pp. 1439-1440 ◽  
Author(s):  
R. J. LAMB
Keyword(s):  
Flea Beetle ◽  
Feeding Damage ◽  
Brassica Hirta ◽  
Flea Beetles ◽  
Beetle Damage

Pods of the mustard Brassica hirta ’Gisilba’, which have stiff hairs, showed no significant flea beetle damage, while adjacent rapeseed plots showed heavy pod damage. Removal of hairs from mustard pods caused an increase in feeding damage by the flea beetles. Breeding for pod hairiness in rapeseed may reduce pod damage caused by this pest to an insignificant level.

ASSESSING THE SUSCEPTIBILITY OF CRUCIFER SEEDLINGS TO FLEA BEETLE (Phyllotreta spp.) DAMAGE

1988 ◽  
Vol 68 (1) ◽  
pp. 85-93 ◽  
Author(s):  
R. J. LAMB
Keyword(s):  
Field Study ◽  
Block Design ◽  
Flea Beetle ◽  
Pest Resistance ◽  
Phyllotreta Cruciferae ◽  
Phyllotreta Striolata ◽  
Flea Beetles ◽  
Randomized Complete Block Design ◽  
Beetle Damage

A 5-yr field study to develop a method for assessing the susceptibility of crucifer seedlings to damage by the flea beetles Phyllotreta cruciferae (Goeze) and Phyllotreta striolata (F.) is described. The recommended method consisted of five replicate 5-m rows per cultivar in a randomized complete-block design. Each test was sown three times at weekly intervals, to assure that at least one test received an appropriate level of flea beetle damage. Each test was assessed 4–5 wk after seeding by counting the number of surviving seedlings in each row and by weighing the dried aboveground portion of 10 randomly selected seedlings, although the latter discriminated fewer lines. The damage caused by flea beetles varied spatially, but this source of variation was minor and did not compromise the tests. This method proved adequate for discriminating among crucifer species and agronomically similar cultivars, some of which showed consistent, significant differences in their responses to flea beettle damage.Key words: Crucifer, rapeseed, flea beetle, pest resistance

scholarly journals Seed size and its influence on germination, seedling growth and biomass in Saraca asoca (Roxb). De Wilde, critically endangered tree species of Western ghats, India

2016 ◽  
Vol 8 (3) ◽  
pp. 1599-1602
Author(s):  
A. B. Mirgal ◽  
Rajesh P. Gunaga ◽  
C.B. Salunkhe
Keyword(s):  
Seed Size ◽  
Large Scale ◽  
Shoot Biomass ◽  
Leaf Biomass ◽  
Plantation Forest ◽  
Seed Length ◽  
Endangered Tree ◽  
Seedling Vigour ◽  
Endangered Tree Species ◽  
Saraca Asoca

Saraca asoca (Roxb). De Wilde is one of the high traded medicinal plant species of India. There is a huge demand for bark of this species both in domestic and international markets. There is a demand for quality planting materials for large scale plantation. Forest department and farmers have already initiated captive plantation of this species. Several factors affect the seedling quality in nursery. Seed grading is one among them. The present study aims at understand the influence of seed size on seed germination and seedling vigour in S. asoca. Association study showed that seed length was positively correlated with seed weight (r= 0.887), seed width (r=0.697) and thickness (r=0.621). Therefore, seed length was used to categorize seedlot into small (< 30.0 mm), medium (30.1-40.0 mm) and large (> 40.1 mm) seeds. Result showed that larger seeds produced maximum germination (86.7%) as compared to smaller seeds (45.0%). Moreover, larger seeds attained higher collar diameter (3.34 mm) and dry biomass viz., leaf biomass (0.91 g), shoot biomass (0.31 g), root biomass (0.95 g) and entire seedling biomass (2.17 g) as compared to smaller seeds. Seedlings raised from medium seeds were at par with larger seeds in most of the traits. Therefore, it is suggested to use seedlot having > 30 mm length, preferably larger seeds (> 40 mm) in the nursery for better establishment of quality seedlings.

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