Light Interception, Photosynthetic Activity, and Crop Growth Rate in Canopies of Six Temperate Forage Grasses

1973 ◽  
Vol 10 (1) ◽  
pp. 239 ◽  
Author(s):  
J. E. Sheehy ◽  
J. P. Cooper
Keyword(s):  
Growth Rate ◽  
Photosynthetic Activity ◽  
Crop Growth ◽  
Light Interception ◽  
Forage Grasses ◽  
Crop Growth Rate

scholarly journals Growth and yield of wheat at different dates of sowing under chrland ecosystem of Bangladesh

2017 ◽  
Vol 14 (2) ◽  
pp. 147-154 ◽  
Author(s):  
MM Kamrozzaman ◽  
MAH Khan ◽  
S Ahmed ◽  
N Sultana
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Block Design ◽  
Grain Filling ◽  
Crop Growth ◽  
Growth And Yield ◽  
Area Index ◽  
Crop Growth Rate

An experiment was conducted at Sadipur charland under Farming System Research and Development Site, Hatgobindapur, Faridpur, during rabi season of 2012-13 and 2013-14 to study the growth and yield performance of cv. BARI Gom-24 as affected by different dates of sowing under Agro-ecological Zone-12 (AEZ-12) of Bangladesh. The experiment was laid out in randomized complete block design with six replications, comprising five different dates of sowing viz. November 5, November 15, November 25, December 5 and December 15. Results reveal that the tallest plant, leaf area index, total dry matter, and crop growth rate were observed in November 25 sown crop and leaf area index, total dry matter and crop growth rate were higher at booting, grain filling, and tillering stages of the crop. Maximum effective tillers hill-1 (3.49), spikes m-2, (311), number of grains spike-1 (42.20) and 1000-grain weight (52.10 g) were produced by November 25 sown crop exhibited the highest grain (4.30 t ha-1) and straw yield (4.94 t ha-1) as well as harvest index (46.88%) of the crop. Lowest performance was observed both in early (November 5) and late sown crop (December 15). The overall results indicated that November 25 sown crop showed better performance in respect of growth and yield of wheat under charland ecosystem of Bangladesh.J. Bangladesh Agril. Univ. 14(2): 147-154, December 2016

scholarly journals Formowanie powierzchni asymilacyjnej i biomasy przez rośliny buraków cukrowych [Formation of the assimilation area and biomass by sugar beet plants]

2015 ◽  
Vol 31 (1–2) ◽  
pp. 21-32
Author(s):  
K. Olech ◽  
Z. K. Blamowski
Keyword(s):  
Growth Rate ◽  
Sugar Beet ◽  
Crop Growth ◽  
Crop Growth Rate ◽  
Fast Growing ◽  
Final Yield ◽  
Whole Plants

Measurements were carried out of the assimilation area, NAR value, the crop growth rate (C) and of the yield of roots and leaves of sugar beet plants in a production field during two successive vegetation years. An interdependence was found between the formation of the assimilation area in the canopy and the final yield of biomass. The assimilation area depended mainly on the date of sowing. In 1975, the sowing was earlier by 15 days, amid this resulted in a much more favourable LAI and in a higher yield of biomass. During both vegetation years, a violent decrease of the crop growth rate was observed at the end of August and at the beginning of September. This may be due to an unfavourable change in the ratio of the area of younger, photosynthetically active leaves to older, less active leaves and also to the increased participation of the loss of the assimilates resulting from stronger respiration of the fast growing roots while the photosynthesis of the whole plants decreases.

POTENTIAL VEGETATIVE PRODUCTIVITY IN CANADA

1983 ◽  
Vol 63 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. TOLLENAAR
Keyword(s):  
Photosynthetic Efficiency ◽  
Theoretical Estimate ◽  
Growing Season ◽  
Crop Growth ◽  
Light Interception ◽  
Crop Species ◽  
Potential Productivity ◽  
Crop Growth Rate ◽  
Water Nutrients ◽  
Productivity Estimate

Duration of the growing season appears to be the single most important factor limiting vegetative productivity in Canada. A theoretical estimate of annual vegetative productivity in the absence of limitations due to water, nutrients or soil structure, shows that potential productivity in the 5-mo growing season of Southern Canada is in the range of 25–55 tonne/ha. Maximum productivity, however, lies considerably below the potential productivity estimate due to lower-than-expected photosynthetic efficiency during periods of high solar irradiance. Crop growth rates appear to be rather independent of variation in radiant flux density during the growing season. Consequently, a realistic estimate of maximum vegetative productivity can be obtained by multiplying number of days of full light interception by a crop canopy, by a crop growth rate of 230 kg∙h−1∙day−1 and adding the weight of the crop at the onset of full light interception by the canopy. Maximum vegetative productivity could likely be improved by extending the period of full light interception by crop canopies through the cultivation of perennial species or double-crop sequences. Alternatively, vegetative productivity could likely be improved through increased photosynthetic efficiency. Very high photosynthetic efficiencies of crops grown under field conditions have been reported occasionally in the literature, but factors underlying this high photosynthetic efficiency have not yet been identified.Key words: Vegetative production, photosynthetic efficiency, potential productivity, duration of growing season, crop species

A quantitative examination of the growth of swards of Medicago truncatula cv. Jemalong

1979 ◽  
Vol 30 (1) ◽  
pp. 53 ◽  
Author(s):  
JH Silsbury ◽  
L Adem ◽  
P Baghurst ◽  
ED Carter
Keyword(s):  
Growth Rate ◽  
Medicago Truncatula ◽  
Dry Matter ◽  
Growth Stage ◽  
Crop Growth ◽  
Stage Ii ◽  
Yield Data ◽  
Constant Growth Rate ◽  
Sowing Time ◽  
Crop Growth Rate

Shoot dry matter yield data for swards of Medicago truncatula cv. Jemalong established on two occasions at Adelaide in 1975 have been used to examine the influence of sowing rate on the seasonal growth pattern of this species. The patterns of dry matter growth are assessed: (i) by the use of a logistic function; (ii) by a growth stage approach involving an initial phase of approximately exponential growth (stage I) followed by a phase of almost constant growth rate (stage II). Two methods are given for determining the duration of these stages. It was found that stage I1 began at a shoot dry weight of about 300 g m-2, irrespective of sowing rate. End-of-season yield at about 10 t ha-1 was largely independent of sowing time and of sowing density. A maximum crop growth rate of 14.9 g m-2 d-1 was recorded for low density and late sowing. Sowing density had a marked effect on the shape of the growth curves; both the maximum crop growth rate and the average crop growth rate in stage II decreased with increase in sowing rate for each time of sowing.

Effects of Irradiance and Solar Radiation on Dry Matter Growth and Net CO2 Exchange of Trifolium subterraneum L. Swards at a Constant Temperature

1977 ◽  
Vol 4 (4) ◽  
pp. 485 ◽  
Author(s):  
S Fukai ◽  
JH Silsbury
Keyword(s):  
Growth Rate ◽  
Solar Radiation ◽  
Exchange Rates ◽  
Dry Matter ◽  
Light Transmission ◽  
Dry Weight ◽  
Co2 Exchange ◽  
Crop Growth ◽  
Co2 Efflux ◽  
Crop Growth Rate

Small swards of subterranean clover were grown at 20°C at different times of the year and at the same time under shades of different light transmission. Dry matter production and net CO2 exchange rates at different levels of irradiance were measured during growth. Crop growth rates and net CO2 exchange rates are examined in relation to plant attributes and to the daily solar radiation. Dry matter growth curves varied according to the daily solar radiation. Increase in crop growth rate with increase in daily solar radiation was taken to be linear for swards with similar dry weight and was more rapid for closed canopies than for those not showing full light interception. Once a closed canopy was attained, further increase in total dry matter resulted in decreased crop growth rate due, apparently, to increased loss of dry weight through increased respiration rate. The shape of the CO2 exchange/irradiance curve was linear up to 100 W m-2 (PAR) and curvilinear above that value. The rate of net CO2 exchange at 50 W m-2 (PAR) decreased with increase in shoot dry matter above 100 g m-2 due, apparently, to an increased rate of dark CO2 efflux: the rate was not affected by daily solar radiation during growth. The net CO2 exchange rate at 250 W m-2 (PAR) increased with increase in LAI up to 3 after which it became almost constant, varying only with the variation in daily solar radiation during growth. The rate of dark CO2 efflux was strongly affected by the amount of dry matter present and to a smaller extent by the crop growth rate or the daily solar radiation.

Late Planting Effects on Early Versus Late Pearl Millet Genotypes in Niger

1993 ◽  
Vol 29 (1) ◽  
pp. 121-129 ◽  
Author(s):  
K. C. Reddy ◽  
P. L. Visser
Keyword(s):  
Growth Rate ◽  
Pearl Millet ◽  
Harvest Index ◽  
Plant Density ◽  
Pennisetum Glaucum ◽  
Growth Period ◽  
Fertilizer Application ◽  
Crop Growth ◽  
Planting Dates ◽  
Crop Growth Rate

SummaryThe performance of two contrasting pearl millet (Pennisetum glaucum) genotypes was compared following five planting dates under rainfed conditions in deep sandy soils at Bengou, Niger in 1986 and 1987. The early and partially photo-sensitive cultivar HKB yielded more grain than the late and photo-sensitive cultivar Somno when planted with the first two seasonal rains. But after delayed planting, the crop growth rate and harvest index of cultivar HKB were reduced, leading to smaller grain yields even though the growth period, rainfall, radiation and temperature were similar at all the planting dates. In contrast, cultivar Somno maintained a small but stable harvest index over various planting dates, so that although its growth period and crop growth rate were reduced by delayed planting, the reduction in grain yield was less. Since agronomic manipulation, such as increased plant density and fertilizer application, can be used to increase crop growth rate, photo-sensitive millet genotypes such as cultivar Somno could be used for late July plantings in the Sudano-Sahelian zone.

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