Is crop N demand more closely related to dry matter accumulation or leaf area expansion during vegetative growth?

2007 ◽  
Vol 100 (1) ◽  
pp. 91-106 ◽  
Author(s):  
Gilles Lemaire ◽  
Erik van Oosterom ◽  
John Sheehy ◽  
Marie Hélène Jeuffroy ◽  
Angelo Massignam ◽  
...  
Keyword(s):  
Leaf Area ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Dry Matter Accumulation ◽  
Leaf Area Expansion ◽  
Area Expansion ◽  
N Demand

EFFECTS OF TEMPERATURE ON PRIMARY GROWTH AND REGROWTHS OF ALFALFA

1972 ◽  
Vol 52 (6) ◽  
pp. 1017-1027 ◽  
Author(s):  
C. J. PEARSON ◽  
L. A. HUNT
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Dry Weight ◽  
Growth Responses ◽  
Primary Growth ◽  
Whole Plant ◽  
Leaf Area Expansion ◽  
Medicago Sativa L ◽  
Effects Of Temperature ◽  
Area Expansion

The cumulative gain and distribution of dry matter are described for both primary growth and three subsequent regrowths of alfalfa (Medicago sativa L.) cults Vernal and Moapa at an irradiance (400–700 nm) of 25 nE cm−2 s−1 and day/night temperatures of 20/15 C and 30/25 C. Whole plant dry weight and leaf areas increased curvilinearly with time in primary growth and linearly in regrowth. Root plus stubble weight after cutting, increased from first to third regrowth. Rates of leaf area expansion increased with time in primary growth but were constant in regrowth; they were higher in regrowth than in primary growth, and higher at 20/15 C than at 30/25 C. Individual leaf area was greater at 20/15 C than at 30/25 C, whereas average specific leaf weight was less at 20/15 C than at 30/25 C. This latter finding probably reflected longer leaf life at 20/15 C. Number of days to 50% flowering was greater at 20/15 C than at 30/25 C. Growth responses to temperature were similar during primary growth and regrowths.

The association between altitude, environmental variables, maize growth and yields in Kenya

1979 ◽  
Vol 93 (3) ◽  
pp. 635-649 ◽  
Author(s):  
P. J. M. Cooper
Keyword(s):  
Leaf Area ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Ground Cover ◽  
Development Stage ◽  
Dry Matter Accumulation ◽  
High Altitudes ◽  
Leaf Emergence ◽  
Thermal Growth ◽  
Rate Of Increase

SUMMARYA Kenya Highland maize was planted at three altitudes, 1268, 1890 and 2250 m. Development rate, dry-matter accumulation and leaf area production were recorded during vegetative growth, together with grain formation and dry-matter accumulation in the primary cob. Rainfall, insolation, soil and air temperatures were continuously recorded at all sites. Maize developed faster at low warm altitudes, the rate being dependent on soil and air temperature. During vegetative growth, this relationship could be satisfactorily explained by an integrated temperature, but during the reproductive phase, some allowance had to be made for over optimal temperatures at low warm altitudes. Altitude had little effect on crop leaf area at any particular development stage, but leaf area production rates were closely related to leaf emergence rates. Before establishment of complete ground cover, large differences in dry-matter accumulation rates were observed which appeared related to rate of leaf area production. Once full ground cover was established, crop growth rates became much more similar. Potential number of grains per embryonic primary cob was greatest at low altitudes, but the final number of grains per cob at harvest was greatest at high altitudes. Rate of increase of grain weight was constant and very similar at all sites until growth stopped abruptly at 69, 83 and 96 days after tasselling at low, medium and high altitudes respectively. Rate of accumulation and partition of total dry matter in the primary cobs was similar at all sites, but owing to greater duration of development at high altitudes, dry matter per cob increased with altitude. Large yield differences were found at harvest, yield decreasing with decreasing altitude. Yield differences were mainly due to variations in number of grains per plant, although grain size also contributed. In this and other trials it was shown that the number of grains per plant at harvest was closely related to the mean thermal growth rate (expressed in units of g/plant/growing degree day) during the grain site initiation period.

Effects of CO2Enrichment on Competition Between a C4Weed and a C3Crop

Weed Science ◽  
1984 ◽  
Vol 32 (1) ◽  
pp. 101-105 ◽  
Author(s):  
David T. Patterson ◽  
Elizabeth P. Flint ◽  
Jan L. Beyers
Keyword(s):  
Leaf Area ◽  
Relative Yield ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Dry Matter Accumulation ◽  
Leaf Area Expansion ◽  
Leaf Area Duration ◽  
Net Assimilation ◽  
Area Expansion

The C4weed johnsongrass [Sorghum halepense(L.) Pers. ♯3SORHA] and the C3crop soybean [Glycine max(L.) Merr. ‘Ransom’] were grown separately and in inter- and intraspecific competition at 350 and 675 ppm CO2in controlled environment chambers with 29/23 C day/night temperatures and 950 μE·m-2· s-1PPFD (photosynthetic photon flux density). In the absence of competition, the higher CO2concentration stimulated dry matter accumulation, leaf area expansion, net assimilation rate, and leaf area duration of soybean more than that of johnsongrass. The plant relative yield (PRY) of soybean in competition with johnsongrass increased, and the PRY of johnsongrass in competition with soybean decreased, as the CO2concentration was increased from 350 to 675 ppm. Thus, the competitiveness of the C3crop with the C4weed increased with increasing CO2concentration. Relative yield totals were not significantly different from 1.0, indicating that the two species were competing for the same resources. With the increases in global atmospheric CO2concentration predicted for the next 50 to 100 yr, the competitiveness of C3crops with C4weeds could be increased.

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.

scholarly journals Responses of Rice Growth to Day and Night Temperature and Relative Air Humidity—Leaf Elongation and Assimilation

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 134
Author(s):  
Sabine Stuerz ◽  
Folkard Asch
Keyword(s):  
Leaf Area ◽  
Leaf Growth ◽  
Crop Growth ◽  
Air Humidity ◽  
Leaf Elongation ◽  
Night Temperature ◽  
Relative Air Humidity ◽  
Leaf Area Expansion ◽  
Plant Level ◽  
Area Expansion

Predictions of future crop growth and yield under a changing climate require a precise knowledge of plant responses to their environment. Since leaf growth increases the photosynthesizing area of the plant, it occupies a central position during the vegetative phase. Rice is cultivated in diverse ecological zones largely differing in temperature and relative air humidity (RH). To investigate the effects of temperature and RH during day and night on leaf growth, one variety (IR64) was grown in a growth chamber using 9 day/night regimes around the same mean temperature and RH, which were combinations of 3 temperature treatments (30/20 °C, 25/25 °C, 20/30 °C day/night temperature) and 3 RH treatments (40/90%, 65/65%, 90/40% day/night RH). Day/night leaf elongation rates (LER) were measured and compared to leaf gas exchange measurements and leaf area expansion on the plant level. While daytime LER was mainly temperature-dependent, nighttime LER was equally affected by temperature and RH and closely correlated with leaf area expansion at the plant level. We hypothesize that the same parameters increasing LER during the night also enhance leaf area expansion via shifts in partitioning to larger and thinner leaves. Further, base temperatures estimated from LERs varied with RH, emphasizing the need to take RH into consideration when modeling crop growth in response to temperature.

The influence of seed size and depth of sowing on pre-emergence and early vegetative growth of subterranean clover (Trifolium subterraneum L.)

1956 ◽  
Vol 7 (2) ◽  
pp. 98 ◽  
Author(s):  
JN Black
Keyword(s):  
Leaf Area ◽  
Seed Size ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Relative Rate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Total Leaf Area ◽  
Pot Culture

Changes in the pre-emergence distribution of dry matter in subterranean clover (Trifolium subterraneum L.) variety Bacchus Marsh were followed at 21°C, using three sizes of seed and three depths of sowing, ½, 1¼, and 2 in. Decreasing seed size and increasing depth of sowing both reduce the weight of the cotyledons a t emergence. Seed of the three sizes were sown a t three depths in pot culture a t staggered intervals so that emergence was simultaneous. Dry weight in the early vegetative stage was proportional to seed size, and total leaf area and leaf numbers showed similar trends. Plants of each seed size grew at the same relative rate. No effect of depth of sowing could be detected, and this was shown to be due to the cotyledon area a t emergence being constant for any given seed size, regardless of varying depth of sowing and hence of cotyledon weight. It was concluded that seed size in a plant having epigeal germination and without endosperm is of importance: firstly, in limiting the maximum hypocotyl elongation and hence depth of sowing, and secondly, in determining cotyledon area. Cotyledon area in turn influences seedling growth, which is not affected by cotyledon weight. Once emergence has taken place, cotyledonary reserves are of no further significance in the growth of the plants.

scholarly journals Acclimation of Photosynthetic Activity of Zantedeschia `Best Gold' in Response to Temperature and Photosynthetic Photon Flux

2002 ◽  
Vol 127 (2) ◽  
pp. 290-296 ◽  
Author(s):  
Keith A. Funnell ◽  
Errol W. Hewett ◽  
Julie A. Plummer ◽  
Ian J. Warrington
Keyword(s):  
Quantum Yield ◽  
Leaf Area ◽  
Photosynthetic Rate ◽  
Photosynthetic Activity ◽  
Natural Habitat ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Leaf Area Expansion ◽  
Response To Temperature ◽  
Area Expansion

Photosynthetic activity of individual leaves of Zantedeschia Spreng. `Best Gold' aff. Z. pentlandii (Wats.) Wittm. [syn. Richardia pentlandii Wats.] (`Best Gold'), were quantified with leaf expansion and diurnally, under a range of temperature and photosynthetic photon flux (PPF) regimes. Predictive models incorporating PPF, day temperature, and percentage leaf area expansion accounted for 78% and 81% of variation in net photosynthetic rate (Pn) before, and postattainment of, 75% maximum leaf area, respectively. Minimal changes in Pn occurred during the photoperiod when environmental conditions were stable. Maximum Pn (10.9μmol·m-2·s-1 or 13.3 μmol·g-1·s-1) occurred for plants grown under high PPF (694 μmol·m-2·s-1) and day temperature (28 °C). Acclimation of Pn was less than complete, with any gain through a greater light-saturated photosynthetic rate (Pmax) at high PPF also resulting in a reduction in quantum yield. Similarly, any gain in acclimation through increased quantum yield under low PPF occurred concurrently with reduced Pmax. It was concluded that Zantedeschia `Best Gold' is a shade tolerant selection, adapted to optimize photosynthetic rate under the climate of its natural habitat, by not having obligate adaptation to sun or shade habitats.

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