Morphology of caryopses, seedlings and seedling emergence of the grass Calamovilfa longifolia from various depths in sand

Oecologia ◽  
1981 ◽  
Vol 49 (1) ◽  
pp. 137-142 ◽  
Author(s):  
M. A. Maun ◽  
Susan Riach
Keyword(s):  
Seedling Emergence ◽  
Calamovilfa Longifolia

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

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

Seedling emergence of Lupinus diffusus in response to abrasion in an electric seed scarifier

2019 ◽  
Vol 20 (1) ◽  
pp. 14-24
Author(s):  
Gabriel Campbell-Martínez ◽  
Mack Thetford ◽  
Deborah L Miller ◽  
Héctor E Pérez
Keyword(s):  
Seedling Emergence

Effects of salinity on seedling emergence and early seedling growth of Irvingia gabonensis (Irvingiaceae)

2017 ◽  
Vol 45 (2) ◽  
pp. 282-295
Author(s):  
R. Vihotogbé ◽  
C. Watson ◽  
R. Glèlè Kakaï ◽  
F. Wichern ◽  
B. Sinsin ◽  
...  
Keyword(s):  
Seedling Growth ◽  
Seedling Emergence ◽  
Early Seedling Growth ◽  
Early Seedling ◽  
Irvingia Gabonensis

Drought stress and osmo-priming effects on physiological and biochemical characteristics of Ocimum basilicum

2016 ◽  
Vol 6 (1) ◽  
pp. 905-913
Author(s):  
Bahram Majd Nassiry ◽  
Neda Mohammadi
Keyword(s):  
Drought Stress ◽  
Total Protein ◽  
Catalase Activity ◽  
Seedling Emergence ◽  
Seed Priming ◽  
Ocimum Basilicum ◽  
Field Development ◽  
Physiological And Biochemical Characteristics ◽  
Germination Characteristics ◽  
And Control

    One of the effects of reducing water content on soil is reduction of growth and development of seedlings and variation of field development. Seed priming technique has been known as a challenge to improve germination and seedling emergence under different environmental stresses. The objectives of this research were to evaluate the effects of osmo-priming on germination characteristics and changes of proline, protein and catalase activity of Ocimum basilicum seeds. Results showed that drought stress reduced the germination characteristics and drought stress in -8 bar was the critical stress.  Priming treatments were include KNO3, PEG and NaCl by 0, -4 and -8 bar concentrations. The seeds were primed with those materials for 8 and 16 hours. The highest germination characteristics were obtained from nitrate potassium in -8 bar for 16 hours priming. Therefore the best seed treatment under drought stress during germination was obtained from the osmo-primed with -8 bar nitrate potassium for 16 hours. The drought stress increased proline and catalase activity but reduced total protein. Priming treatment increases proline, total protein and catalase activity under drought and control conditions. It is concluded that priming results in improvement in germination components of Ocimum basilicum in drought stress conditions and increases the resistance to drought stress with improvement of proline, protein and catalase activity in germination phase.

EFFECT OF TEMPORARY COVERING ON EARLY POTATO YIELD IN THE CONDITIONS OF THE MOSCOW REGION

2020 ◽  
pp. 31-38
Author(s):  
MARINA E. DIYKANOVA ◽  
◽  
ALEKSANDR G. LEVSHIN ◽  
IRINA N. GASPARYAN ◽  
NATALIA F. DENISKINA ◽  
...  
Keyword(s):  
Seedling Emergence ◽  
Maximum Yield ◽  
Moscow Region ◽  
Cold Weather ◽  
Test Plot ◽  
Early Potato ◽  
Emergence Period ◽  
Potato Varieties ◽  
Russian State ◽  
Covering Material

In the Moscoww region, frosts are quite probable to return until the fi rst decade of June. To protect potatoes from the returning cold weather, it is possible to use a temporary covering material in the “planting – seedling emergence” period. The authors have studied the use of covering materials on early potato varieties of Udacha, Zhukovsky early, Red Scarlet, Snegir’, and Meteor. Studies have been conducted on the test plot of the Vegetable Growing Department of Russian State Agrarian University – Moscow Timiryazev Agricultural Academy in 2017-2019. Non-woven white and black material of the same density of 17 g/m2 was used for covering. No covering was used in the check variant. The cultivation technology was standard,it included tillage (plowing, spring tillage, and cutting ridges before planting), as well as plant care (inter-row cultivation and hilling-up). Planting was carried out with a single-row potato planter. The earliest emergence of seedlings was observed under white covering material with a diff erence of 5-6 days in relation to the check variant. In the variant with a black covering material, the diff erence averaged 3-4 days. Due to covering, planting was carried out earlier than expected and the crop was formed by July 15. The interphase period between potato planting and seddling emergence decreased, while that from seddling emergence to harvesting increased, consequently, the yield increased by 11.6…14.7%. The maximum yield was obtained with the Red Scarlet variety using the white covering material, the minimum – in the check variant without covering. The same trend is typical for other varieties. It has been established that covering with any material has a positive eff ect on the duration of the potato growing season and the yield by increasing the period of tuberization. Covering allows getting early potato varieties 2 weeks earlier in the Moscow region.

Competitive attributes ofA. sativa, T. aestivum, andH. vulgareare conserved in no-till cropping systems

Weed Science ◽  
1999 ◽  
Vol 47 (6) ◽  
pp. 712-719 ◽  
Author(s):  
Anne Légère ◽  
Yuguang Bai
Keyword(s):  
Hordeum Vulgare ◽  
Avena Sativa ◽  
Growth Parameters ◽  
Cropping Systems ◽  
Seedling Emergence ◽  
Biomass Accumulation ◽  
Tillage Systems ◽  
Area Index ◽  
No Till ◽  
Lower Test

The robustness of competitive attributes of cereals such as rapid and uniform seedling emergence, tillering, early biomass accumulation and canopy closure, and height advantage over weeds have not yet been tested under environmental conditions typical of no-till (NT) cropping systems. Our objective was to evaluate the effects or NT practices on growth and productivity ofAvena sativa, Triticum aestivum, Hordeum vulgare, and associated weeds. The experiment was conducted on a Kamouraska clay at La Pocatière, QC, in 1994, 1995, and 1996.Avena sativa, T. aestivum, andH. vulgarewere grown under tilled and NT practices. Cereal growth parameters were measured six (1994) or seven (1995) times between planting and the 11th week after planting but only once in 1996. Grain yields and yield components were determined at crop maturity.Avena sativaandH. vulgarepopulations were little affected by tillage, whereasT. aestivumpopulations were reduced by 16 to 20% in NT systems. Growth in height in NT systems was either similar or greater than in tilled systems in all three cereals. Cereal leaf area index (LAI) and biomass accumulation was also comparable between tillage systems, except forT. aestivumLAI in 1994, which was greater in tilled plots on two sampling dates. Response of annual dicots to tillage was inconsistent in all crops. Annual monocots dominated in some but not all NT systems. Perennial dicots dominated in NT systems, whereas perennial monocots were more abundant in tilled systems in all three cereals.Avena sativaandT. aestivumyields in NT plots were comparable or greater than in tilled plots, in spite of having either lower test weights (A. sativa) or lower 1,000-grain weights (T. aestivum). NTT. aestivumproductivity was maintained in spite of reduced plant establishment.Hordeum vulgareyields were also similar across tillage systems, except in 1995, when yields in tilled plots were greater than in NT plots. The height advantage observed for NTH. vulgaredid not result in improved yields. All three cereals, and particularlyA. sativa, appeared well suited to NT systems, despite the pressure provided by different weed groups, compared to tilled systems. However, results suggest that NT production of cereals could benefit from improved attention to perennial dicot control and crop seedling establishment, particularly forT. aestivum.

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