SCREENING FOR IMPROVED STAND ESTABLISHMENT IN RUSSIAN WILD RYEGRASS

1980 ◽  
Vol 60 (4) ◽  
pp. 1171-1177 ◽  
Author(s):  
K. H. ASAY ◽  
D. A. JOHNSON

Laboratory and field trials were conducted to determine the extent of the genetic variation among 134 Russian wild ryegrass (Elymus junceus Fisch.) progeny lines for characters related to stand establishment under semiarid conditions. Progenies were evaluated in the laboratory for seedling emergence and subsequent vigor using a 7.6-cm planting depth, seedling emergence under controlled soil moisture stress, and seedling recovery after exposure to drought. Significant genetic variation was detected for emergence, seedling vigor, and stand establishment in the field and for all measurements made in the laboratory except seedling recovery after drought. The genetic variance comprised from 50 to 60% of the total phenotypic variance in most instances. Emergence and subsequent seedling vigor from a 7.6 cm planting depth were the most closely related to data collected in the field (r = 0.17–0.33**). Results from the other laboratory trials were not significantly correlated with field performance.

1984 ◽  
Vol 64 (1) ◽  
pp. 131-138 ◽  
Author(s):  
J. D. BERDAHL ◽  
R. E. BARKER

Seedling emergence of 30 open-pollinated progeny lines of Russian wild ryegrass (Psathyrostachys juncea (Fisch.) Nevski. Syn: Elymus junceus Fisch.) ranging in seed weight from 2.1 to 4.5 mg/seed was evaluated in laboratory and greenhouse tests and compared to stand establishment capability in the field. Increases in emergence percentage and coleoptile length associated with increased seed weight diminished when seed weights of parents increased beyond 3.0 mg/seed. Emergence in two field environments was correlated with emergence from a 5-cm planting depth in the greenhouse (r = 0.70** and 0.71** for field tests 1 and 2, respectively) and with coleoptile length (r = 0.51** and 0.64**), but not with emergence under laboratory-induced drought stress of −1.1 MPa matric potential (r = −0.05 and 0.13). Experimental error was high for measurements of forage yields in the establishment year (CV = 38% and 36% for field tests 1 and 2, respectively), and resources required to obtain reliable yields would limit testing to a small number of entries. Preliminary screening of a Russian wild ryegrass population for improved seedling vigor could be accomplished by first eliminating plants with small seed size by visual assessment of seed samples. This could then be followed by selection for increased coleoptile length among progeny lines from those plants with medium or large seed.Key words: Russian wild ryegrass, seedling vigor, stand establishment, seed weight, coleoptile length


1980 ◽  
Vol 60 (2) ◽  
pp. 547-554 ◽  
Author(s):  
R. J. McLAUGHLIN ◽  
B. R. CHRISTIE

Physiological studies had indicated that low mid-summer yields of alfalfa (Medicago sativa L.) can be attributed to high temperature. A program was initiated to study genetic variation for response to high temperatures. Two thousand genotypes were grown from seed in the growth room at 20/15 °C, harvested twice, then grown at 30/25 °C for two more harvests. A great deal of variation among genotypes was found to exist for response to temperature. Genotypes that were found to yield well at higher temperatures tended to be early-maturing with few stems per plant. Genotypes that yielded well at low temperatures tended to be later in maturity and to have a large number of stems. Based upon dry matter yields, 300 genotypes were selected to represent differences in responses, namely: 100 had high yields at high temperature only; 100, high at low temperature only; and 100, high at both temperatures. These selections were transplanted to the field for subsequent field trials to substantiate growth room findings. Little or no relationship was found between growth room performance and field performance. This lack of association was due in part to winter injury experienced the first year. In addition, temperatures experienced in the field were much lower than those used indoors.


Agriculture ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 201 ◽  
Author(s):  
A. Damalas ◽  
D. Koutroubas ◽  
Fotiadis

Seed priming has been used to advance germination and stand in several crops, but relevant research on faba bean (Vicia faba L.) is scarce. Laboratory and field trials were carried out for two years to study the effect of hydro-priming on faba bean germination and field performance in spring sowing. In laboratory trials, the effects of hydro-priming for 0, 8, 16, 24, 36, and 48 h on final germination percentage, germination speed, Timson’s germination index, mean germination time, mean daily germination, synchronization index, and seedling vigor index were studied. All hydro-priming treatments improved germination parameters of faba bean seeds, except for final germination percentage and mean daily germination compared with non-primed seeds. Averaged over priming duration treatments, hydro-priming improved germination speed by 16.2%, germination synchrony by 20.7%, and seedling vigor index by 13.4%. All hydro-priming durations improved germination synchrony, while hydro-priming for 8, 16, and 24 h provided the highest values of germination speed (2.56, 2.58, and 2.37 seeds day−1, respectively). Hydro-priming for 8 and 16 h provided the lowest values of mean germination time (5.81 and 5.96 days, respectively). In field trials, hydro-priming periods of 0, 8, 16, and 24 h were compared. On average, seed hydro-priming did not affect significantly seedling emergence 14 days after sowing in the first year, but significantly improved seedling emergence by 34.4% in the second year. No significant effect of seed hydro-priming was noted in the number of plants at 28 and 35 days after sowing. Seed priming for 8 h resulted in higher fresh weight at anthesis by 22.3% and 8.6% in the first and the second year, respectively, than the non-primed control. Similarly, seed priming for 8 h provided higher seed yield by 12.0% in the first year and by 5.9% in the second year compared with non-primed control. Overall, seed hydro-priming accelerated faba bean germination and seedling emergence, but the magnitude of the response was associated with the environment and was more evident under limited soil moisture after sowing, whereas the beneficial effect of priming was masked when rainfall followed sowing. Similarly, the beneficial effect of priming on seed yield was more pronounced with limited soil moisture after anthesis.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 663g-663
Author(s):  
Vincent A. Fritz ◽  
James B. Hebel

Germination and stand establishment of shrunken-2 sweet corn is a major production-related problem, particularly during early spring in the upper Midwest U.S. Several potential physical and physiological factors have been identified as contributors to poor stand establishment. Poor pericarp integrity and high sucrose levels may lead to non-uniform moisturization and imbibitional injury. Studies were conducted to determine if the use of “controlled moisturization” preplant treatments reduced imbibitional injury and improved germination and seedling vigor. Both laboratory and field results will be discussed.


Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum


1967 ◽  
Vol 57 (2) ◽  
pp. 271-278 ◽  
Author(s):  
Margaret E. Richardson ◽  
D. J. W. Rose

An account is given of the history of chemical control Phthorimaea operculella (Zell.) in potato fields in Rhodesia since the introduction of DDt prior to 1952. The failure of DDT and endrin, in routine spraying, to control field infestations is reproted, and some evidence that this is due to insecticide resistance is given. The results of critical field trials made in 1961, 1964 and 1965 to evaluate a range of insecticides for control of P. operculella and for their effects on populations of Macrosiphum euphorbiae (Thos.) are presented, together with the results of some laboratory tests. Good control of P. operculella in the field was obtained with sprays of azinphos-methyl at the rate of 0.5 lb active ingredient in 20 gal. water per acre, and two new compounds, methidathion and chlorfenvinphos, showed promise for the future.


2007 ◽  
Vol 37 (3) ◽  
pp. 515-522 ◽  
Author(s):  
Tore Skrøppa ◽  
Ketil Kohmann ◽  
Øystein Johnsen ◽  
Arne Steffenrem ◽  
Øyvind M. Edvardsen

We present results from early tests and field trials of offspring from two Norway spruce ( Picea abies (L.) Karst.) seed orchards containing clones that have been transferred from high altitudes to sea level and from northern to southern latitudes. Seedlings from seeds produced in the low-altitude seed orchard developed frost hardiness later at the end of the growth season, flushed later in field trials, and grew taller than seedlings from seeds produced in natural stands. They had the lowest mortality rate and the lowest frequency of injuries in the field trials. Similar results were observed in seedlings from seeds produced in the southern seed orchard. We found no adverse effects of the changed growth rhythm. Seedlings from two seed crops in the southern orchard, produced in years with a warm and a cold summer, had different annual growth rhythms. The results are explained mainly by the effects of the climatic conditions during the reproductive phase. Seed crops from different years in the same seed orchard may produce seedlings that perform as if they were from different provenances. It is argued that the effects of the climatic conditions during seed production must contribute to the variation among provenances of Norway spruce.


2003 ◽  
Vol 83 (3) ◽  
pp. 519-524 ◽  
Author(s):  
A. G. Xue

The efficacy of seed treatments with bioagent ACM941 (a strain of Clonostachys rosea), its formulated products GB116 and ACM941-Pro, and common fungicides for the control of pea root rot complex were examined in six field trials in western Canada from 1996 to 2000. The effects on seedling emergence, root rot severity, and yield varied among years. In trials 1 and 2 (1996–1997), none of the treatments significantly reduced root rot severity or increased yield. ACM941 + Thiram 75WP was the most effective treatment, increasing emergence by 17.4% and was significantly better than that of the untreated controls. In trials 3 and 4 (1997–1998), Apron FL alone and ACM941 + Apron FL were significantly better than the untreated control, increasing emergence by 6.2 and 7.7%, and yield by 10.8 and 11.5%, respectively. In trials 5 and 6 (1999–2000), AC M 941 and GB116 were equally the most effective treatments, increasing emergence by 11.5 and 12.2%, and yield by 8.2 and 6.3%, respectively. These effects were significantly greater than that of the untreated control, but not significantly different from those of Apron FL or Vitaflo-280. ACM941-Pro was developed and tested in 2000 only, and it increased emergence by 17.1% and reduced root rot severity by 29.6%. Key words: Bioagent, Clonostachys rosea, field pea, Pisum sativum, pea root rot complex (PRRC), seed treatment, fungicide


2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Ridwan Kusuma ◽  
Nyimas Sa’diyah ◽  
Yayuk Nurmiaty

Soybean consumption here in Indonesia continues to increase each year that is notaccompanied by an increase in soybean production. One way to increase soybeanproduction by using improved varieties. The purpose of this study were (1) Estimating thevalue of the diversity of phenotypes soy F6 generations from crosses between Wilis x Mlg2521,(2) Estimating the heritability estimates soybean F6 generations from crosses Wilis x Mlg2521,(3) Know the numbers expectation of F6 generation crosses Wilis x Mlg2521. The researchwas conducted from March 2014 until June 2014 at the Land Lab Lampung StatePolytechnic and observations made in Laboratory of Seed and Plant Breeding, University ofLampung. Soybean seeds used were F6 generation zuriat from Wilis x Mlg2521, Wilis andMlg2521. The treatment laid out in a randomized block design, 2 replications. The resultsshowed that (1) The diversity of phenotypes population F6 for characters date of flowering,harvesting age, plant height, number of productive branches, total number of pods plant,weight of 100 grains, grain weight plant and number of seeds plant including all the broadcriteria, (2) The value of heritability estimates the population F6 for characters date offlowering, harvesting age, plant height, number of productive branches, total number ofpods plant, weight of 100 grains, grain weight per plant and number of seeds plantbelonging to the high criteria, (3) Number expectations of the population F6 is 7-64-1-8 and7-64-1-3.Keywords: heritability, phenotypic variance, soybean


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