INFLUENCE OF ROW SPACING ON YIELD AND CREEPING ROOT DEVELOPMENT OF RAMBLER ALFALFA IN A SEMIARID REGION

1969 ◽  
Vol 49 (3) ◽  
pp. 307-311 ◽  
Author(s):  
M. R. Kilcher ◽  
D. H. Heinrichs

The creeping-rooted alfalfa (Medicago media Pers.) cultivar Rambler was grown in stands for 5–6 years and in rows varying from 30 to 120 cm apart on loam soil at Swift Current, Saskatchewan. This is a semiarid location in the Canadian prairie region.On the average, highest yields were obtained from stands of alfalfa growing in rows spaced 45 to 60 cm apart. Lowest yields were those from alfalfa growing in rows spaced 30 cm apart.New plants originating from creeping roots did not appear between the seeded rows until the third growing year. The number of creeping plants varied between row spacings, increasing numbers occurring with increasing row spacings. After six years, creeping plants made up only 2 to 3% of total stand in the 30-cm spaced rows, but constituted about 20% of stand where row spacings were 90 cm or greater.The significance of row spacings, origin of new plants, and the longevity and productivity of the stands are discussed.

2005 ◽  
Vol 128 (2) ◽  
pp. 192-197 ◽  
Author(s):  
Yuzhen Lin ◽  
Bo Song ◽  
Bin Li ◽  
Gaoen Liu

As an advanced cooling scheme to meet increasingly stringent combustor cooling requirements, multihole film cooling has received considerable attention. Experimental data of this cooling scheme are limited in the open literature in terms of different hole patterns and blowing ratios. The heat-mass transfer analogy method was employed to measure adiabatic film cooling effectiveness of three multihole patterns. Three hole patterns differed in streamwise row spacing (S), spanwise hole pitch (P), and hole inclination angle (α), with the first pattern S∕P=2 and α=30°, the second S∕P=1 and α=30°, and the third S∕P=2 and α=150°. Measurements were performed at different blow ratios (M=1-4). Streamwise coolant injection offers high cooling protection for downstream rows. Reverse coolant injection provides superior cooling protection for initial rows. The effect of blowing ratio on cooling effectiveness is small for streamwise injection but significant for reversion injection.


2019 ◽  
pp. 183-194
Author(s):  
Serhii Vdovenko

In order to study the effect of the time of sowing seeds on the passage of morphogenesis and productivity of rapeseed, the scheme included experiments where the seeds were sown in I, II, III in April, I and II in May. The experiment used varieties of Golden Ball, Purpurleopop, Purpurov and Geisha, and control was the variant in which the seeds of the Golden Ball varieties were sown in the second decade of April with a row spacing of 45 cm. laboratory - to determine the total yield; statistical - to establish the reliability of the investigated factors. Seed germination analysis used in the experiment ranged from 78.9% to 81.1% on average. The highest indicator of seed germination was characterized by the Purpulepop variety, where the studied value was 83.2%, which was dominated by the seed germination of the control variant by 2.1%. In the early stages of sowing seeds, the period of seedling formation was shorter. Seeding of seeds in the first two decades of April on the surface of the soil was observed for 8 days. The short sprouting period was characterized by all varieties of turnips. As a result of sowing turnip seeds at a later date, namely in the third decade of April - the first and second decade of May and the setting of a higher soil temperature, the period of germination was extended and ranged from 8 to 10 days. By using the term of sowing seeds I-II decade of April, the short interphase period was characterized by Purpleupop and Purpurova varieties, where the specified period was only 22 days. The sowing of turnip seeds at a later date ensured the formation of an interphase period of "seedlings - leaf rosette" in 23-25 days except Purpulopop variety. The interphase period "leaf rosette - the beginning of rooting" and "the beginning of rooting - technical maturity" determined the benefits of early seeding, namely in the first decade of April on varieties Purpulopop and Purpurov.The short vegetation period was characterized by the Golden Ball plants for sowing seeds in the first and third decades of April and the first of May. During the specified seeding period the duration of the growing season was only 40 days. A longer vegetation period was characterized by plants of the Geisha variety for sowing seeds in the first two decades of April. As a result of the use of the researched elements of technology to grow turnips in open soil, the total yield varied from 11.0 t / ha to 24.0 t / ha. The most productive is the first sowing of rapeseed, where its value ranged from 20.6 t / ha to 22.7 t / ha. At the same time, when sowing seeds in the first decade of April, the yield of turnip varieties Purpulepop was the highest and was 22.7 t / ha, or the increase was 2.4 t / ha.


Weed Science ◽  
1989 ◽  
Vol 37 (6) ◽  
pp. 748-752 ◽  
Author(s):  
David R. Shaw ◽  
Clyde A. Smith ◽  
Charles E. Snipes

Various 3-yr rotation sequences of 97- and 18-cm row spacings, with appropriate sicklepod control treatments within each row spacing, were implemented to evaluate sicklepod population and soybean yield at two locations. Alachlor plus metribuzin applied preemergence followed by either a postemergence-directed spray of metribuzin plus 2,4-DB or hand hoeing in 97-cm rows consistently reduced sicklepod populations. Reductions with 97-cm rows and preemergence-applied herbicides coupled with cultivation were not as great. At one location, using a split application of metribuzin preplant incorporated followed by preemergence with 18-cm rows reduced sicklepod populations if effective control measures had been used in wide rows the previous year, but the narrow-row treatments did not reduce sicklepod numbers if 18-cm rows had been used previously. Soil-applied metribuzin was more effective under high soil pH conditions, and sicklepod populations were reduced substantially whether the previous row spacing was 18 or 97 cm. After the third year, all plots were planted in 97-cm rows with no herbicides. No differences were found among sicklepod populations with any previous row spacing or sicklepod control program, indicating that, even with 3 yr of effective control, subsequent sicklepod populations were not affected.


1990 ◽  
Vol 70 (2) ◽  
pp. 555-558 ◽  
Author(s):  
A.J. LEYSHON ◽  
H. CUTFORTH ◽  
J. WADOINGTON ◽  
P. C. RYMES

Russian wildrye (Psathyrostachys juncea [Fischer] Nevski) was grown in 15- and 60-cm row spacings at Swift Current, Saskatchewan. Beginning in the third year after establishment and continuing for 4 yr, dry matter yields taken by machine were compared to yields taken by hand in a two-cut system. The machine harvested 54% of the available dry matter in the 60-cm rows but only 27% in the 15-cm rows. Apart from one cut in 1 yr, there were no significant yield differences due to row spacing when the forage was harvested by hand. The results indicate the need for more research on the effects of row spacing, especially with regard to the grazing animal.Key words: Psathyrostachys juncea (Fischer) Nevski in Komarov, hand sampling, machine harvesting, plant morphology, forage yield


1987 ◽  
Vol 5 (2) ◽  
pp. 41-45
Author(s):  
T.H. Whitlow ◽  
L.Y. Mudrak

Small pots containing a loam soil were monitored in a growth chamber and wind tunnel to determine the effect of 13 different lip shapes on evaporation from the soil surface. In the growth chamber, pots with modified lips showed evaporative losses ranging from 52-95% of the unmodified control during the first 24 hrs following watering. The same trend was observed during the second 24 hrs following watering but not during the third 24 hr period. In the wind tunnel, nine treatments showed significant reductions in evaporation in comparison to the control 24 hrs after watering; no differences were observed after three days of drying.


2008 ◽  
Vol 23 (2) ◽  
pp. 107-114
Author(s):  
Milena Simic ◽  
Nebojsa Momirovic ◽  
Zeljko Dolijanovic ◽  
Zeljko Radosevic

The effects of different herbicide combinations: control (1), alachlor+linuron (2), and alachlor+linuron+imazethapyr (3) were investigated in double-cropped soybean grown in two row spacing variants, 38 cm and 76 cm, under conventional tillage (CT) or no-tillage (NT). In trials conducted on a sandy loam soil at Zemun Polje, high weediness had a negative effect of on the yield of double-cropped soybean, especially at the higher row spacing tested and with no-tillage. Regression and correlation data revealed a dependence of weediness in double-cropped soybean on tillage system and herbicide combination, and dependence of soybean yield on tillage system.


2011 ◽  
Vol 27 (4) ◽  
pp. 1523-1530
Author(s):  
S. Petrovic ◽  
S. Vuckovic ◽  
A. Simic

Birdsfoot trefoil grown for seed (cv. Bokor) was examined in agroecological conditions of Western Serbia during period 2007-2009. The goal was to determine herbage yield which could be achieved growing seed crop, using different interrow spacing (12.5, 25 and 50 cm) and various seeding rates (2, 4 and 8 kg ha-1). The highest hay yield was obtained in the third production year at the narrowest spacing and using the highest seeding rate (5.26 t ha-1). Total hay production during 3 years using birdsfoot trefoil seed crop for herbage yield ranged from 9.11 to 14.83 t ha-1 depending on row spacing and from 10.74 to 13.2 t ha-1 depending on seeding rate. The highest stand density (8 kg ha-1 seeding rate and 12.5 cm interrow spacing) produced the highest herbage yield of birdsfoot trefoil in the combined usage (for forage and seed production).


2021 ◽  
Vol 50 ◽  
Author(s):  
Fausto Expedito de Queiroz ◽  
Vicente Ribeiro Rocha ◽  
Flávio Pinto Monção ◽  
João Paulo Sampaio Rigueira ◽  
Rafael Augusto da Costa Parrella ◽  
...  

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