scholarly journals Effect of Seedling Size and Transplant Bed Density on Performance of Eastern Hemlock Planting Stock

1985 ◽  
Vol 3 (2) ◽  
pp. 81-84
Author(s):  
L. Eric Hinesley

After grading two-year-old Eastern hemlock (Tsuga canadensis (L.) Carr.) seedlings by height, performance was examined for one year under various transplant bed densities, and for 2 years in the field. In the nursery, average diameter growth and dry matter production were influenced by bed density; height growth was not. A transplant bed density of 65 plants/m2 (6/ft2) resulted in the greatest average diameter and dry weight, but densities up to 151 plants/m2 (14/ft2) yielded more usable transplants per unit of nursery bed. Although there were residual effects of transplant bed density, the major differences in growth after 2 growing seasons in the field were due to initial seedling size. Transplants originating from large seedlings outperformed those from small seedlings. Compared to small seedlings, larger plants require less time in transplant beds, are less troublesome to maintain in the field, and reach marketable size in fewer years, all of which increase their value relative to small seedlings.

1980 ◽  
Vol 60 (4) ◽  
pp. 757-761 ◽  
Author(s):  
C. G. KOWALENKO ◽  
E. F. MAAS ◽  
C. I. VANLAERHOVEN

In a field plot study to examine the residual effects of heavy rates of coarse limestone (0, 11, 22 and 44 t/ha) in combination with P (560 kg/ha), K (1120 kg/ha), Mg (560 kg/ha) and PKMg (560 + 1120 + 560 kg/ha) applied five growing seasons previously, dry matter production of oats (grain and straw) decreased with increasing rate of limestone application. The decrease was attributed to lime-induced Mn and Zn deficiency. Both Mn and Zn uptake decreased significantly with increased limestone applications. Plant Mn and Zn concentrations were below critical levels in the heavily limed treatments. Neutral normal ammonium acetate soil extractable Mn was significantly related to oats Mn uptake and yield. This same extractant for Zn was not related to uptake of Zn or yield of oats. After the fifth season of cropping, residual limestone (Ca), P and K effects were evident as increased plant uptake and soil extractable Ca, P and K. Residual Mg was shown only by soil extractable Mg.


Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 751-757 ◽  
Author(s):  
David T. Patterson ◽  
Maxine T. Highsmith ◽  
Elizabeth P. Flint

Cotton, spurred anoda, and velvetleaf were grown in controlled-environment chambers at day/night temperatures of 32/23 or 26/17 C and CO2concentrations of 350 or 700 ppm. After 5 weeks, CO2enrichment to 700 ppm increased dry matter accumulation by 38, 26, and 29% in cotton, spurred anoda, and velvetleaf, respectively, at 26/17 C and by 61, 41, and 29% at 32/23 C. Increases in leaf weight accounted for over 80% of the increase in total plant weight in cotton and spurred anoda in both temperature regimes. Leaf area was not increased by CO2enrichment. The observed increases in dry matter production with CO2enrichment were caused by increased net assimilation rate. In a second experiment, plants were grown at 350 ppm CO2and 29/23 C day/night for 17 days before exposure to 700 ppm CO2at 26/17 C for 1 week. Short-term exposure to high CO2significantly increased net assimilation rate, dry matter production, total dry weight, leaf dry weight, and specific leaf weight in comparison with plants maintained at 350 ppm CO2at 26/17 C. Increases in leaf weight in response to short-term CO2enrichment accounted for 100, 87, and 68% of the observed increase in total plant dry weight of cotton, spurred anoda, and velvetleaf, respectively. Comparisons among the species showed that CO2enrichment decreased the weed/crop ratio for total dry weight, possibly indicating a potential competitive advantage for cotton under elevated CO2, even at suboptimum temperatures.


2016 ◽  
Vol 51 (9) ◽  
pp. 1633-1642 ◽  
Author(s):  
Claudio Hideo Martins da Costa ◽  
Carlos Alexandre Costa Crusciol ◽  
Jayme Ferrari Neto ◽  
Gustavo Spadotti Amaral Castro

Abstract The objective of this work was to evaluate the long-term effects of the surface application of lime on soil fertility and on the mineral nutrition and grain yield of soybean, and of black oat and sorghum in crop succession. The experiment was carried out on a clayey Oxisol, in a randomized complete block design, with four replicates. Treatments consisted of lime the rates of 0, 1,000, 2,000, and 4,000 kg ha-1, applied in October 2002 and November 2004. Soil samples were collected at five soil layers, down to 0.60-m depth. Surface liming was effective in reducing soil acidity and increasing Ca2+ and Mg2+ contents in the subsurface. Moreover, it increased available phosphorus contents and soil organic matter in the long term (48 to 60 months after the last lime application). Surface liming improved plant nutrition, mainly for N, Ca, and Mg, and increased dry matter production and grain yield of the crops, even in years with regular distribution of rainfall. The greatest productivities of soybean, black oat, and sorghum were obtained with the respective estimated lime doses of 4,000, 2,333, and 3,281 kg ha-1, for shoot dry matter, and of 2,550, 3,555, and over 4,000 kg ha-1, for grain yield.


1969 ◽  
Vol 20 (3) ◽  
pp. 417 ◽  
Author(s):  
JH Silsbury

Lolium rigidum Gaud. and a summer-dormant and a non-dormant form of Lolium perenne L. were grown as seedling plants for 32 days in controlled environment cabinets at constant temperatures of either 10, 20, or 30°C and in all cases with a 16-hr photoperiod at a light intensity of 3600 lm ft-2. Sampling at 4-day intervals permitted the detailed examination of dry matter growth curves. Differences in total dry matter production were related to initial differences in seedling dry weight, and the general responses to temperature were similar for each ryegrass. Total dry matter production was greatest at 20°C and lowest at 10°. A temperature of 30° did not induce dormancy in the summer-dormant ryegrass but did depress growth. Relative growth rate fell with time at each temperature.


1979 ◽  
Vol 6 (2) ◽  
pp. 187 ◽  
Author(s):  
JHM Thornley

A model of the wheat plant is described which consists of two components, the grain and storage material. Photosynthesis supplies further substrate to the store, from which material is used for grain growth at a rate that depends on the substrate level. The model allows predictions of grain dry weight at maturity and its dependence on total post-anthesis dry matter production, and leads to an interpretation of the source-sink interactions in this situation.


1970 ◽  
Vol 34 (1) ◽  
pp. 67-73
Author(s):  
M SH Islam ◽  
MSU Bhuiya ◽  
AR Gomosta ◽  
AR Sarkar ◽  
MM Hussain

Pot experiments were conducted during T. aman 2001 and 2002 (wet season) at Bangladesh Rice Research Institute (BRRI) in net house. Hybrid variety Sonarbangla-1 and inbred modern variety BRRI dhan-31 were used in both the seasons and BRRI hybrid dhan-l was used in 2002. The main objective of the experiments was to compare the growth and yield behaviour of hybrid and inbred rice varieties under controlled condition. In 2001, BRRI dhan-3l had about 10-15% higher plant height, very similar tillers/plant, 15-25% higher leaf area at all days after transplanting (DAT) compared to Sonarbangla-1. Sonarbangla- 1 had about 40% higher dry matter production at 25 DAT but had very similar dry matter production at 50 and 75 DAT, 4-11% higher rooting depth at all DATs, about 22% higher root dry weight at 25 DAT, but 5-10% lower root dry weight at 50 and 75 DAT compared to BRRI dhan-31. The photosynthetic rate was higher (20 μ mol m-2/sec-1) in BRRI dhan-3l at 35 DAT (maximum tillering stage) but at 65 DAT, Sonarbangla-l had higher photosynthetic rate of 19.5 μ mol m-2 sec-1. BRRI dhan-3l had higher panicles/plant than Sonarbangla-1, but Sonarbangla-1 had higher number of grains/panicle, 1000-grain weight and grain yield than BRRI dhan-31. In 2002, BRRI dhan-31 had the highest plant height at 25 DAT, but at 75 DAT, BRRI hybrid dhan-l had the highest plant height. Sonarbangla-1 had the largest leaf area at 25 and 50 DAT followed by BRRI dhan-31, but at 75 DAT, BRRI dhan-31 had the largest leaf area. The highest shoot dry matter was observed in BRRI dhan-31 followed by Sonarbangla-1 at all DATs. Sonarbangla-1 had the highest rooting depth and root dry weight at all DATs. BRRI dhan-31 gave the highest number of panicles/plant followed by Sonarbangla-I, BRRI hybrid dhan-l had the highest grains/panicle followed by BRRI dhan-31 and Sonarbangla-I had the highest 1000-grain weight followed by BRRI dhan-31. The highest amount of grains/plant (34.6 g) was obtained from BRRI dhan-31. Key Words: Shoot dry matter; root dry weight; leaf area; photosynthesis; grain yield. DOI: 10.3329/bjar.v34i1.5755Bangladesh J. Agril. Res. 34(1) : 67-73, March 2009


2019 ◽  
Vol 65 (No. 8) ◽  
pp. 377-386 ◽  
Author(s):  
Bogdan Kulig ◽  
Edward Gacek ◽  
Roman Wojciechowski ◽  
Andrzej Oleksy ◽  
Marek Kołodziejczyk ◽  
...  

The study aimed at comparing the yield of dry biomass and energy efficiency of 22 willow cultivars depending on the harvesting frequency and variable plant density. The field experiment was established in 2010. The willow cultivars were planted in two densities; 13 300 and 32 500 plants per ha. Among the compared cultivars in the second year (2013) of full production, high yield of dry matter was obtained from cvs. Tordis (33.1 t/ha/year), Inger (30.4 t/ha/year) and Klara (29.0 t/ha/year). After six years of cultivation, the highest aboveground dry matter was given by cvs. Tora (27.4 t/ha/year) and Tordis (27.0 t/ha/year). The gross calorific value of willow biomass ranged from 15.2–20.1 GJ/t dry weight. Greater energy efficiency (329.3 GJ/ha/year) occurred in willow cultivars collected in a two-year cycle than in the one-year cycle (286.4 GJ/ha/year). In the two-year cycle collected in the third year after planting, energy efficiency was greater (379.5 GJ/ha/year) than in the two-year cycle harvested in the sixth year after planting (279.15 GJ/ha/year). The initial slower growth of biomass does not determine plant yielding.


1980 ◽  
Vol 10 (3) ◽  
pp. 426-428
Author(s):  
S. Thompson

The components of shoot growth and dry matter production in 1 + 0 lodgepole pine (Pinuscontorta Dougl. ex Loud. spp. contorta) seedlings raised under clear polythene cloches for 12 weeks at five seedbed densities (180–720 plants/m2) were studied. The greater plant height found at the highest seedbed density was the result of increased stem unit length, not increased number of stem units. The increase in plant dry weight as seedbed density decreased was largely due to greater dry weight of roots, branchwood, and branch foliage, and not to increases in stemwood and stem foliage weight. Seedbed densities of less than 460 seedlings/m2 are required to produce yields of suitably sturdy seedlings in excess of 50% of the crop.


1984 ◽  
Vol 20 (3) ◽  
pp. 215-224 ◽  
Author(s):  
S. N. Azam-Ali ◽  
P. J. Gregory ◽  
J. L. Monteith

SUMMARYPearl millet was grown on stored water at Niamey, Niger, using three row spacings. Water extraction based on neutron probe readings was compared with crop transpiration using a porometer and allied measurements. Between 23 and 52 days after sowing, plants at the narrow and medium spacings used about 77 and 100 mm of water, respectively, and those at the wide spacing used between 59 and 75 mm. Estimates of seasonal crop evaporation from leaf resistances and from the green leaf area index (GLAI) of the crops were 103, 130 and 123 mm for the narrow, medium and wide spacings, respectively. The water use per unit of dry weight produced was similar for both narrow and medium spacings but water was used more efficiently in the wide spacing. Dry weight increased in proportion to intercepted radiation with the same efficiency (1·3 g MJ−1) irrespective of spacing.


1969 ◽  
Vol 73 (1) ◽  
pp. 75-86 ◽  
Author(s):  
A. B. Hearn

SUMMARYVariety, water and spacing were treatments in two experiments with cotton in 1963 and 1964 in which fruiting points, flowers and bolls were counted and the dry weights and leaf areas of plants were measured at intervals during the season.Until leaf-area index, L, started to decrease, the equation described how dry weight, W, changed. The equation gave smoothed estimates of crop growth rate, C, which were consistent with estimates of photosynthesis made with de Wit's (1965) model. The relationship between G and L conformed to , derived from Beer's Law, rather than C = aL — bL2 derived from the linear regression of E on L. When L > 3 the crop appeared to use most of the available light, so that C approached a maximum. Treatments initially affected dry-matter production through the numbers and types of branches and nodes, which in turn affected the sinks available and thus the proportion of dry matter reinvested in new leaf. This initial period, when growth was simple to describe in conventional terms, was denned as the vegetative phase of growth.The start of the reproductive phase of growth overlapped the vegetative phase. The change from one to the other was completed when the rate of dry weight increase of the bolls, CB, equalled C. This indicated that the sink formed by the bolls had increased sufficiently in size to use all the assimilates available for growth. Sink size increased as the crop flowered and was estimated from the product of the number of bolls and the growth rate of a single boll.When CB equalled C, bolls were shed which prevented the size of the sink to increase beyond the ability of the plant to supply it with assimilates. This agrees with Mason's nutritional theory of boll shedding. Because of the crop's morphology and because age decreased the photosynthesis of the crop, the size of the sink inevitably increased out of phase with the supply of assimilates. The extent to which this was so determined when CB equalled C. It is postulated that environment, genotype and agronomic practice affect yield according to whether they increase or decrease the extent to which the sink size and the supply of assimilates are out of phase.


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