scholarly journals Contribution of Awns to Seed Yield and Seed Shattering in Siberian Wildrye Grown under Irrigated and Rainfed Environments

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2219
Author(s):  
Fabrice Ntakirutimana ◽  
Yiyang Wan ◽  
Wenhui Liu ◽  
Wengang Xie
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Grass Species ◽  
Forage Grass ◽  
Forage Production ◽  
Abscission Layer ◽  
Seed Shattering ◽  
Growing Conditions ◽  
Arid Grasslands ◽  
The Impact

The seed yield of grass species is greatly dependent on inflorescence morphological traits, starting with spikelets per inflorescence and seeds per spikelet, to kernel size, and then to awns. Previous studies have attempted to estimate the contribution of these traits on the harvested yield of major cereal crops, but little information can be accessed on the influence of awns on seed yield of forage grass species. Siberian wildrye (Elymus sibiricus L.) is a widely important perennial forage grass used to increase forage production in arid and semi-arid grasslands. The grass has long inflorescences with long awns developed at the tip end of the lemmas in the florets. In order to evaluate the effect of awns on Siberian wildrye seed production, awn excision analyses from 10 accessions were performed at flowering stage under irrigated and rainfed regimes. Overall, awn excision reduced thousand-seed weight and seed size under both irrigated and rainfed regimes, which decreased final seed yield per plant. De-awned plants produced significantly more seeds per inflorescence, but spikelets per inflorescence was not influenced by awn excision in either condition. Moreover, histological analyses showed a high degradation of the abscission layer in the awned plants than de-awned ones, and awn excision evidently improved average seed breaking tensile strength (BTS), and thus decreased the degree of seed shattering. In conclusion, the observed significant impact of awn excision on different yield-related traits mirrored the impact of awns on the performance of Siberian wildrye under diverse growing conditions. These results provide useful information for plant breeders, seed producers, and researchers to efficiently improve seed production in Siberian wildrye.

scholarly journals Paclobutrazol Improves Sesame Yield by Increasing Dry Matter Accumulation and Reducing Seed Shattering Under Rainfed Conditions

2021 ◽  
Author(s):  
Muhammad Zeeshan Mehmood ◽  
Ghulam Qadir ◽  
Obaid Afzal ◽  
Atta Mohi Ud Din ◽  
Muhammad Ali Raza ◽  
...  
Keyword(s):  
Leaf Area ◽  
Seed Production ◽  
Seed Yield ◽  
Dry Matter ◽  
Biomass Accumulation ◽  
Total Biomass ◽  
Dry Matter Accumulation ◽  
Seed Shattering ◽  
Rainfed Conditions ◽  
Leaf Greenness

AbstractSeveral biotic and abiotic stresses significantly decrease the biomass accumulation and seed yield of sesame crops under rainfed areas. However, plant growth regulators (such as Paclobutrazol) can improve the total dry matter and seed production of the sesame crop. The effects of the paclobutrazol application on dry matter accumulation and seed yield had not been studied before in sesame under rainfed conditions. Therefore, a two-year field study during 2018 and 2019 was conducted with key objectives to assess the impacts of paclobutrazol on leaf greenness, leaf area, total dry matter production and partitioning, seed shattering, and seed yield of sesame. Two sesame cultivars (TS-5 and TS-3) were treated with four paclobutrazol concentrations (P0 = Control, P1 = 100 mg L−1, P2 = 200 mg L−1, P3 = 300 mg L−1). The experiment was executed in RCBD-factorial design with three replications. Compared with P0, treatment P3 improved the leaf greenness of sesame by 17%, 38%, and 60% at 45, 85, and 125 days after sowing, respectively. However, P3 treatment decreased the leaf area of sesame by 14% and 20% at 45 and 85 days after sowing than P0, respectively. Compared with P0, treatment P3 increased the leaf area by 46% at 125 days after sowing. On average, treatment P3 also improved the total biomass production by 21% and partitioning in roots, stems, leaves, capsules, and seeds by 23%, 19%, 23%, 22%, and 40%, respectively, in the whole growing seasons as compared to P0. Moreover, under P3 treatment, sesame attained the highest seed yield and lowest seed shattering by 27% and 30%, respectively, compared to P0. This study indicated that by applying the paclobutrazol concentration at the rate of 300 mg L−1 in sesame, the leaf greenness, leaf areas, biomass accumulation, partitioning, seed yield, and shatter resistance could be improved. Thus, the optimum paclobutrazol level could enhance the dry matter accumulation and seed production capacity of sesame by decreasing shattering losses under rainfed conditions.

Residue management increases seed yield of three turfgrass species on the Canadian prairies

2002 ◽  
Vol 82 (4) ◽  
pp. 687-692 ◽  
Author(s):  
B. D. Gossen ◽  
J. J. Soroka ◽  
H. G. Najda
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Poa Pratensis ◽  
Creeping Bentgrass ◽  
Kentucky Bluegrass ◽  
Residue Management ◽  
Row Spacing ◽  
Seeding Rate ◽  
Canadian Prairies ◽  
The Impact

Little information is available on the management of turfgrass species for seed production in the Canadian prairies. The objective of these studies was to assess the impact of residue management and row spacing on seed yield under irrigation. A factorial experiment was seeded at Saskatoon, SK, in 1993 to assess the impact of burning or scalping (very close mowing with residue removal) vs. mowing, and 20- vs. 40-cm row spacing on seed yield of Kentucky bluegrass (KBG) (Poa pratensis), creeping red fescue (CRF) (Festuca rubra subsp. rubra) and creeping bentgrass (CBG) (Agrostis palustris). Also, a residue management trial on KBG was seeded at Brooks, AB, in 1993. At Saskatoon, yield was higher at 20-cm spacing across all three species in 1994, but spacing had no impact on winter survival, stand density, tiller growth or yield in subsequent years. Burning and scalping consistently resulted in earlier spring green-up, a higher proportion of fertile tillers, and higher seed yield than mowing. Even with residue management, yield declined after one harvest in CBG and CRF, and after two harvests in KBG. At Brooks, residue management had a similar impact on yield of KBG. A second trial at Brooks examined the impact of row spacing (20, 40, 60 cm) and seeding rate (0.5 to 6 kg seed ha-1) on KBG. Seed yield was highest at 40-cm spacings in 1994, at 60 cm in 1995, and at 40 to 60 cm in 1996. Seeding rate did not have a consistent effect on yield. We conclude that a combination of residue management and 20- to 40-cm spacings provide the highest, most consistent seed yields for these turfgrass species in this region. Key words: Burning, clipping, turfgrass, seed production, row spacing, Poa, Festuca, Agrostis

Effect of grazing intensity and number of grazings on herbage production and seed yields of Trifolium subterraneum, Medicago murex, and Ornithopus compressus

1994 ◽  
Vol 34 (2) ◽  
pp. 181 ◽  
Author(s):  
DJ Conlan ◽  
BS Dear ◽  
NE Coombes
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Grazing Intensity ◽  
Trifolium Subterraneum ◽  
Grazing Pressure ◽  
Early Spring ◽  
Pasture Legumes ◽  
Heavy Grazing ◽  
Ornithopus Compressus ◽  
The Impact

The impact of grazing intensity and number of grazings was assessed on the growth and seed production of 5 annual pasture legumes [Trifoliunz subterraneum var. subterraneum cv. Karridale, var. brachycalycinum cv. Clare, var. yanninicum cv. Trikkala; Medicago murex (murex medic) cv. Zodiac; Ornithopus compressus L. (yellow serradella) cv. Avila]. There were 7 grazing treatments: an ungrazed control; and 2 grazing intensities (light and heavy), each for 3 periods of grazing (winter, winter-early spring, winter-late spring). Tethered sheep in small experimental plots were used to provide controlled herbage removal across all cultivars through winter and winter-spring grazing. This grazing system resulted in significantly different levels of herbage being present in the light and heavy grazing treatments following each grazing period. Grazing had variable effects on seed production: <35% increase for Trikkala, and no significant effect for Karridale. Both cultivars continued growth and seed production late in the season after grazing pressure was removed on 8 November. Seed yield of Clare was reduced by 46-49% by heavy grazing treatments. Seed yield of murex medic was not significantly affected by grazing, while that of serradella was reduced by 30-55% by grazing late in the season. The seed yield responses show that cultivar and species responses to grazing may be highly variable. Under favourable spring conditions, Trikkala, Karridale, and murex medic can be grazed heavily until late in the season without adversely affecting seed yield, whilst Clare and Avila cannot.

scholarly journals Self-Fertilization, Inbreeding, and Yield in Alfalfa Seed Production

2021 ◽  
Vol 12 ◽  
Author(s):  
Molly E. Dieterich Mabin ◽  
Johanne Brunet ◽  
Heathcliffe Riday ◽  
Lauren Lehmann
Keyword(s):  
Pacific Northwest ◽  
Seed Production ◽  
Inbreeding Depression ◽  
Seed Yield ◽  
Seed Set ◽  
Central Valley ◽  
Selfing Rate ◽  
Alfalfa Seed ◽  
The Impact ◽  
Number Of Seeds

Selfing (self-pollination) is the ultimate form of inbreeding, or mating among close relatives. Selfing can create yield loss when inbreeding depression, defined as a lower survival and reproduction of inbred relative to outbred progeny, is present. To determine the impact of selfing in alfalfa (Medicago sativa L.), we quantified the selfing rate of 32 alfalfa seed production fields located in three regions, namely, the Pacific Northwest (PNW), the Central Valley of California (CEV), and the Imperial Valley of California (IMP). Selfing rates (the proportion of selfed seeds) varied between 5.3 and 30% with an average of 12.2% over the 32 seed production fields. In both the parents and their progeny, we observed an excess of heterozygotes relative to Hardy–Weinberg expectations. We detected notable levels of inbreeding in parents (0.231 ± 0.007 parental inbreeding coefficient) and progeny (0.229 ± 0.005). There were a 15% decrease in the number of seeds per stem (seed set) and a 13% decline in the number of seeds per pod in selfed relative to outcrossed stems, but negligible inbreeding depression for pods per raceme and seed weight. The number of racemes on selfed stems increased significantly in fields with greater selfing rates, supporting the presence of geitonogamous or among flower selfing. Despite the significant level of inbreeding depression, seed set did not decrease in fields with higher selfing rates, where the greater number of racemes on the selfed stems increased the seed set. The effects of the field selfing rate on the seed yield metrics were mostly indirect with direct effects of the number of racemes per stem. Available data indicate that the majority of selfing in alfalfa is pollinator-mediated, and thus, eliminating selfing in alfalfa seed production would require the selection of self-incompatible varieties, which, by eliminating inbreeding depression, would provide a 15% potential increase in seed yield and an increase in future hay yield.

scholarly journals The impact of the period of sowing and fertilization on morphological characteristics and seed yield of garden poppy (Papaver somniferum L.)

2016 ◽  
Vol 107 (1) ◽  
pp. 219
Author(s):  
Simon OGRAJŠEK ◽  
Darja KOCJAN AČKO ◽  
Damijana KASTELEC
Keyword(s):  
Crop Yield ◽  
Seed Yield ◽  
Field Experiments ◽  
Morphological Characteristics ◽  
Papaver Somniferum ◽  
Statistical Dependence ◽  
Average Height ◽  
Poppy Seed ◽  
Growing Conditions ◽  
The Impact

Garden poppy (<em>Papaver somniferum </em>L.) is a traditional crop that had already been cultivated in Slovenia in the past for the production of seed and oil. During its re-introduction in present time, numerous agro-technical dilemmas have been raised for the processes from sowing to harvesting and have to be studied in our present growing conditions. On the fields of the Ograjšek farm in Cerklje ob Krki two field experiments in complete randomized design had been sown in 2013 and 2014 to establish the influence of the sowing date and fertilization on morphological properties and crop yield of garden poppy seed of the Austrian variety 'Zeno 2002'. Results have shown that the average yield of seed in both trials (1643 kg/ha) is more than one time higher than the average crop yield recorded globally (700 kg/ha), proving how suitable growing conditions in the area of eastern Dolenjska are for the cultivation of poppy. Analysis of crop yield per plot showed there is no statistically significant interaction between the considered factors. The yield of poppy seed in the spring sowing term was 1742±77 kg/ha and in the autumn sowing was 1545±122 kg/ha. The difference is not statistically significant (<em>p </em>= 0.1845). Recorded yield per plant was higher for the autumn term but that was not transferred to the total crop yield due to poor overwintering and consequentially lower plant density at the time of harvest. Both sowing dates have confirmed that exposure to light and duration of growing period had an important impact on plants height – average height of plants sown in autumn was 139±1 cm, which is more than 60 cm higher than the average height of the plants sown in spring (p = 0.0000). A strong statistical dependence of the yield of seed per capsule on diameter of the capsule was proved (<em>p </em>= 0.0000). It can be concluded that when the capsule diameter increases by 10 mm, the seed yield increases for 2.1 g to 2.3 g with 95 % confidence. Dependence of the average seed yield on the number of lateral shoots per plant also proved to be statistically significant (<em>p </em>= 0.0000). Linear model was used for the comparison of the four lines showed that the lines representing poppy sown in autumn and spring are statistically different for the control and for the ENTEC; the slope was higher for the poppy sown in autumn. These trials have given the first practical advice for production of garden poppy in Slovenia and should be continued for further useful results.

Effect of fertilizer on seed yield of alfalfa under irrigation in Saskatchewan

2004 ◽  
Vol 84 (4) ◽  
pp. 1105-1108 ◽  
Author(s):  
B. D. Gossen ◽  
H. Ukrainetz ◽  
J. J. Soroka
Keyword(s):  
Soil Fertility ◽  
Seed Production ◽  
Seed Yield ◽  
Sandy Loam ◽  
Soil Surface ◽  
Soil Testing ◽  
Clay Loam ◽  
Initial Soil ◽  
The Impact ◽  
Commercial Field

The impact of fertilizers containing macro- and micro-nutrients on seed production of alfalfa under irrigation in Saskatchewan was assessed. Trials were conducted on a Sutherland clay loam at Saskatoon, SK, from 1986 to 1991, and in a commercial field on Asquith sandy loam near Outlook, SK, from 1990 to 1993. Nutrients (primarily combinations of P, K, S) were applied at establishment (in-row with seed, side-banded, or broadcast and incorporated prior to seeding), and/or broadcast on the soil surface each year. Seed yield at both sites was excellent for the region, and application of fertilizer had little or no impact on yield. At sites with adequate initial soil fertility, as indicated by soil testing, alfalfa may not require added fertilizer to maintain high levels of seed production. Key words: Medicago sativa, lucerne

Phytophagous arthropods and silvertop levels associated with post-harvest residue treatments in three turfgrass species grown for seed

2005 ◽  
Vol 85 (1) ◽  
pp. 213-224 ◽  
Author(s):  
J. J. Soroka ◽  
B. D. Gossen
Keyword(s):  
Seed Production ◽  
Poa Pratensis ◽  
Creeping Bentgrass ◽  
Kentucky Bluegrass ◽  
Residue Management ◽  
Grass Species ◽  
Festuca Rubra ◽  
Agrostis Palustris ◽  
Red Fescue ◽  
The Impact

Silvertop, which is characterized by whitish, completely sterile seed heads produced on green tillers, is a common symptom in many perennial grasses. A 3-yr study of creeping bentgrass (Agrostis palustris), Kentucky bluegrass (Poa pratensis) and creeping red fescue (Festuca rubra subsp. rubra) grown for seed production was conducted at Saskatoon, Saskatchewan, to investigate the cause(s) of silvertop, the impact of residue management strategies on silvertop incidence, and the impact of silvertop on seed yield. Three residue management practices were applied in the fall of the first harvest year and again the next fall, as follows: (i) burned after harvest; (ii) clipped to 1–2 cm in height and the residue removed; or (iii) mowed to 20 cm and the residue retained. Arthropods in each plot were collected weekly from May until July by sweep sampling, counted, and identified to family level or lower, and the incidence of seed heads with and without silvertop were assessed. The majority of arthropods were thrips, leafhoppers, plant bugs, mites, or grass-dwelling flies. Grass species and residue treatment strongly affected the number of reproductive tillers and levels of silvertop. Levels of silvertop were lowest in creeping bentgrass in all 3 yr of the study, while they were similar for Kentucky bluegrass and creeping red fescue. Mown plots had fewer reproductive tillers, fewer heathy seed heads, and higher levels of silvertop than burned or clipped plots. However, arthropod species composition was generally similar across grass species and residue treatments. This indicates that a specific arthropod taxon may not be a critical factor in silvertop expression. The relationship between the number and composition of arthropods found and incidence of silvertop is discussed. Key words: Festuca rubra subsp. rubra, Poa pratensis, Agrostis palustris, seed production, arthropods, silvertop

CarduusThistle Seed Destruction byRhinocyllus conicus

Weed Science ◽  
1978 ◽  
Vol 26 (3) ◽  
pp. 264-269 ◽  
Author(s):  
W. W. Surles ◽  
L. T. Kok
Keyword(s):  
Seed Production ◽  
Seed Viability ◽  
Fold Increase ◽  
Larval Feeding ◽  
Carduus Acanthoides ◽  
Rhinocyllus Conicus ◽  
Growing Conditions ◽  
Total Seed ◽  
The Impact ◽  
Heavy Infestation

The impact of a weevil(Rhinocyllus conicusFroel.) (Coleoptera: Curculionidae) onCarduusthistles in Virginia was evaluated in terms of seed reduction and viability during 1973 and 1974. Musk thistle(Carduus nutansL.) seed production from terminal and first lateral heads was reduced by 10% in 1973 and 75% in 1974 due to larval feeding ofR. conicus.The greater seed reduction in 1974 was caused by heavy infestation (45% in 1973, 70% in 1974); there was a five-fold increase in the number of weevil pupation chambers per head over the previous year. Total seed production per plant decreased by 35 to 36% in both years despite increased plant vigor due to better growing conditions in 1974. Larval feeding reduced viability of mature musk thistle seeds. Although individual heads of plumeless thistle(Carduus acanthoidesL.) were frequently destroyed by larval feeding, seed production from early heads of this thistle decreased by only 5% in 1973 and 4% in 1974 due to low rates of infestation (9% in 1973, 5% in 1974). Total seed reduction per plant for each of the two years was less than 0.2%. Infested heads of plumeless thistle did not produce sufficient seeds for evaluation of the weevil's impact on seed viability.

scholarly journals Stem Smut (Ustilago hypodytes) on Intermediate Wheatgrass in Canada

Plant Disease ◽  
2001 ◽  
Vol 85 (1) ◽  
pp. 96-96 ◽  
Author(s):  
K. F. Chang ◽  
R. J. Howard ◽  
B. D. Gossen ◽  
S. F. Hwang
Keyword(s):  
New York ◽  
Seed Production ◽  
Seed Yield ◽  
Disease Incidence ◽  
Flag Leaf ◽  
The United States ◽  
Grass Species ◽  
Smut Fungi ◽  
Intermediate Wheatgrass ◽  
The North

Intermediate wheatgrass (Thinopyrum intermedium [Host] Barkworth & D.R. Dewey) (syn. Agropyron intermedium [Host] Beauv.) is becoming an important forage grass species in Alberta, Canada. Severe losses in seed yield due to stem smut (Ustilago hypodytes [Schlecht.] Fr.) were noted in a 70-acre field near Warner, AB, in 1999. The crop had been established in 1993 and harvested for seed each year. Smut symptoms (5% incidence) were noted initially in 1997. Incidence, determined by counting the number of symptomatic stems, increased to 10% in 1998 and 50% in 1999. The symptoms usually appeared in the first week of June. Brown sori developed on infected stems, especially between the uppermost node and the leaf below the flag leaf, and gradually became black during the period of seed filling, which is characteristic of stem smut (1). Teliospores were smooth, spherical to oval, light to dark brown, and 4.5 to 5.0 × 5.0 to 6.8 μm in dimension, which is also consistent with previous descriptions of U. hypodytes. Infected stems occasionally flowered, but did not set seed, so seed yield losses were proportional to disease incidence. Plants infected with stem smut were often stunted. Tissues in the smutty stem often became sunken and stems became twisted and thinner than normal due to the propagation of sori in the stem over time. Stem smut has been reported on crested wheatgrass and slender wheatgrass in other parts of Canada (2) and on T. intermedium in the United States (3). This is the first report of stem smut affecting commercial grass seed production in Alberta, Canada. This disease could also have a significant impact on the seed production of intermediate wheatgrass elsewhere. References: (1) G. W. Fischer. 1953. Manual of the North American Smut Fungi. Ronald Press, New York. (2) B. D. Gossen and D. Regnier. Can. Plant Dis. Surv. 71:88–89, 1991. (3) J. F. Karn and J. M. Krupinsky. Phytopathology 73:1152–1155, 1983.

Seed production of Lotus tenuis (Fabaceae), a forage legume: effects of row spacing, seeding date, and plant defoliation

2010 ◽  
Vol 61 (12) ◽  
pp. 1027 ◽  
Author(s):  
O. R. Vignolio ◽  
G. S. Cambareri ◽  
N. O. Maceira
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Row Spacing ◽  
Seed Shattering ◽  
Lotus Tenuis ◽  
Seeding Date ◽  
Vegetative Biomass ◽  
Beginning Of Flowering ◽  
Seed Crops ◽  
Pod Dehiscence

Indeterminate flowering, pod dehiscence, and seed shattering are some the most important factors that limit seed yield in some Lotus species. The objective of this study was to determine strategies to maximise Lotus tenuis seed yield by evaluating: (i) the effects of row spacing (17.5 and 35.0 cm) and seeding date (autumn 2007, autumn 2008, and spring 2008) on vegetative biomass and reproductive components, and (ii) plant defoliation at the beginning of flowering to make the time of seed ripening more uniform. Plant density was held constant at 20 plants/m2. The beginning of flowering was later in plants seeded in spring than in those seeded in autumn. Defoliation retarded peak flowering through destruction of reproductive organs. Vegetative and reproductive biomasses were not significantly different between row spacings or defoliation conditions. Vegetative biomass, seed yield, pod dehiscence, and shattered seed varied between seeding dates in different years, and within the same year between seeding seasons. Harvest seed yield was greater for autumn 2007 than for spring 2008 and autumn 2008 seeding (181.67 ± 9.76, 71.41 ± 4.16, and 41.73 ± 3.39 g/m2, respectively). Lost seed (shattered seed) was greater for spring 2008 than for autumn 2008 and autumn 2007 (76.04 ± 5.29, 71.43 ± 3.31, and 16.11 ± 2.61 g/m2, respectively). Under defoliation conditions, harvest seed yield and lost seed were 92.59 ± 3.07 and 2.07 ± 0.63 g/m2, respectively. Potential seed yield was highly correlated with avoveground vegetative biomass (R2 = 0.758; P < 0.0001), no. of umbels with pods/m2 (R2 = 0.859; P < 0.0001), and pod biomass/m2 (R2 = 0.949; P < 0.0001). Thousand-seed weight was not significantly different between row spacings, but was greater with spring seeding and lower if the crop was defoliated. Air temperature and relative humidity during reproduction affected seed shattering and, consequently, seed yield. The results are discussed in relation to the management of L. tenuis seed crops and the importance of row spacing, seeding date, and plant defoliation for seed production.

Sign in / Sign up

Export Citation Format

Share Document