The canopy structure of tall and short sorghum

1970 ◽  
Vol 75 (1) ◽  
pp. 123-131 ◽  
Author(s):  
P. R. Goldsworthy

SUMMARYChanges in the leaf area and light profiles of a tall and a short sorghum are described and the development of leaf area in these and in two other sorghums of intermediate height is examined in relation to the rate of appearance, the size and the length of life of the leaves. The extent to which these changes are related to the seasonal fluctuations in crop growth rate is discussed.

2017 ◽  
Vol 14 (2) ◽  
pp. 147-154 ◽  
Author(s):  
MM Kamrozzaman ◽  
MAH Khan ◽  
S Ahmed ◽  
N Sultana

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


1962 ◽  
Vol 13 (4) ◽  
pp. 615 ◽  
Author(s):  
WR Stern ◽  
CM Donald

A study was made of the light regime and the growth of clover: (a) in mixed swards with varying proportions of grass; (b) in specially designed cultures in which grass and clover competed for light alone. The growth of the clover showed direct dependence on the level of radiation at the surface of the clover leaf canopy; it was positive when radiation values were above about 60–80 cal/cm²/day but fell to zero or negative rates at lower radiation levels. A relationship is presented between the level of radiation, the leaf area index, and the crop growth rate. It is shown that the optimum leaf area index increases with increasing levels of radiation; and further that as the leaf area index increases, the level of radiation required for maximum growth rate also rises. The implications in agricultural practice are discussed briefly.


2009 ◽  
Vol 66 (6) ◽  
pp. 733-741 ◽  
Author(s):  
Alessandra Aparecida Giacomini ◽  
Sila Carneiro da Silva ◽  
Daniel Oliveira de Lucena Sarmento ◽  
Cauê Varesqui Zeferino ◽  
Salim Jacaúna Souza Júnior ◽  
...  

Grazing strategies alter sward leaf area patterns of growth, affecting herbage accumulation and utilisation. The objective of this experiment was to evaluate the growth of marandu palisadegrass (Brachiaria brizantha cv. Marandu) swards subjected to strategies of intermittent stocking. The experiment was carried out in Piracicaba, São Paulo, Brazil, from October/2004 to September/2005. Swards were grazed at 95 and 100% canopy light interception (LI) to post-grazing heights of 10 and 15 cm, following a 2 × 2 factorial arrangement with four replications in a randomised complete block design. The response variables evaluated were: crop growth rate, relative growth rate, net assimilation rate, leaf area ratio and leaf weight ratio. In early and late spring, the highest crop growth rate was recorded for treatment 95/15 (11.2 and 10.1 g m-2 day-1, respectively), along with high values of net assimilation rate (4.4 and 6.9 g m-2 day-1, respectively), leaf area ratio (0.0095 and 0.0103 m-2 g-1, respectively) and leaf weight ratio (0.56 and 0.56 g g-1, respectively). To compensate reductions in net assimilation rate plants made some morphological and physiological adjustments increasing leaf area and leaf weight ratio. Relative growth rate and net assimilation rate were 26 and 50% higher, respectively, on swards grazed at 95% than at 100% LI. In early spring treatments 100/10 and 95/15 resulted in the highest relative growth rate (0.086 and 0.059 g m-2 day-1, respectively). Treatment 95/15 resulted in the most favourable pattern of growth (crop growth rate, relative growth rate, net assimilation rate), particularly during the transition period between winter and spring.


1975 ◽  
Vol 26 (1) ◽  
pp. 31 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson

Growth analysis was applied to grain sorghum (cv. RS610) grown at low, medium and high population densities, i.e. 14,352, 143,520 and 645,836 plants ha-1 respectively. The medium densities had two arrangements of plants, square (S) and rectangular (R). Crop growth rates, inflorescence growth rates, leaf area indices, net assimilation rates and leaf growth rates were calculated from growth functions of plant dry matter and leaf area over time. Differences in crop growth rate between populations in the early stages were attributed to leaf area development—specifically to the initial leaf area (dependent on seedling number) and not to differences in leaf growth rates. Peak crop growth rates were 15.0, 27.5, 26.0 and 45.8 g m-2 day-1 for the low, medium (S), medium (R) and high populations respectively.The large difference between the growth rates of the medium (S) and the high populations was not explained by differences in the amount of radiation intercepted. Although leaf area indices were 4.6 and 10.2 respectively for the two populations, both canopies intercepted almost all of the noon radiation. Light extinction coefficients were 0.45 and 0.29 respectively. The relationship between net assimilation rate and leaf area index was such that for comparable leaf area indices above 2, plants at higher densities showed greater improvement in yield per unit increment in leaf area index. A maximum grain yield of 14,250 kg ha-1 was obtained at the high population density as a result of higher dry matter production, but a similar harvest index to that of the crops grown at the other densities. Inflorescence growth rate (g m-2 day-l) slightly exceeded crop growth rate in the latter part of grain filling, which indicated that there was some retranslocation to the grain of previously assimilated material. The maximum grain yield represents an efficiency of utilization of short-wave solar radiation during crop life of 2.5 x 10-6g cal-1. *Part IV, Aust. J. Agric. Res., 26: 25 (1975).


1982 ◽  
Vol 33 (2) ◽  
pp. 233 ◽  
Author(s):  
B Chung

A growth analysis study of the effects of two contrasting environments on the yield of field grown poppies (Papaver somnifevum L.) was undertaken using regression techniques. The change in total plant yield during the 1977-78 season was found to be adequately fitted by a cubic polynomial equation. In contrast, the change in total plant yield during the 1976-77 season and the development of leaf area index in both seasons were found to be adequately fitted by quartic polynomial equations. The total plant yield in the 1977-78 season was considerably higher than that in the 1976-77 season from the beginning of December to dry maturity with a maximum difference of 2 200 kg/ha on 15 January. This yield difference can be attributed to the higher crop growth rate in the 1977-78 season from 30 November to 18 January with a maximum difference of 12 g/m2/day on 30 December. Leaf area index was considered to be more important than net assimilation rate in influencing the crop growth rate up to 20 December. The differences in leaf area between the two seasons could be attributed to the climatic conditions. Under Tasmanian conditions, poppy yields could be expected to be reasonably stable from year to year, provided that the crop is encouraged to grow at its optimum during the whole season.


1971 ◽  
Vol 7 (2) ◽  
pp. 129-136 ◽  
Author(s):  
R. H. V. Corley ◽  
B. S. Gray ◽  
Ng Siew Kee

SUMMARYCrop Growth Rate, Leaf Area Index, Net Assimilation Rate and Harvest Index were estimated for oil palms in nine age groups growing on coastal alluvial soils in Malaysia. The mean Crop Growth Rate of mature palms was 29·83 t./ha./yr, with a Leaf Area Index of 3·61, and Net Assimilation Rate was 0·16 gm./dm.2/wk. Photosynthetic efficiency was about 2·2 per cent. Oil constituted about 17 per cent of total dry matter production. Possibilities for improving the yield of oil are briefly discussed.


Author(s):  
Iskandar Lubis ◽  
Heni Purnamawati ◽  
Roedhy Poerwanto ◽  
, Yudiwanti ◽  
Ahmad Ghozi Mansyuri ◽  
...  

This research was conducted to determine peanut cultivar differences in sink and source sizes as represented by vegetative growth and yields. Two sets of experiments were conducted at Bogor Agricultural University farms, Sawah Baru and Cikarawang (06o33’, S, 106o45’E, 250 m altitude). Planting was conducted on June 12 and June 20, 2007 using 20 local and national cultivars in each location. Both experiments used randomized complete block design with three replications. Data were analyzed using correlation and regression analysis. Size of experimental unit was 1.6 m x 4.0 m, with planting density 125,000 plants ha-1. Urea, SP36 and KCl were applied at planting date in the rate of (kg ha-1) 45 N, 100 P2O5 and 50 K2O. Four stages of plant growth were studied: 25 days after planting (DAP); 6 weeks after planting (WAP); 10 WAP (pod filling) and 14 WAP (harvest). Five plants were sampled at 25 DAP, two plants at 6 WAP, 10 WAP and 14 WAP, and separated into leaves, stems, roots and pods. The average yield of two experimental stations showed that Biawak cultivar had the highest yield due to relatively higher aboveground dry weight (source), pod filling percentage and maximum number of gynophor+pods (potential sink). Jepara cultivar had the lowest yield due to low pod filling percentage and potential sink, although its source was considered to be in the medium category. Above ground dry weight at 6 and 10 WAP had close relation with Crop Growth Rate (CGR) during 25 DAP-6 WAP and 6-10 WAP, and the higher CGR during those periods were more related to leaf area index than to single leaf photosynthetic capacity. Keywords: crop growth rate, pod filling percentage, leaf area index, single leaf photosynthetic capacity


1977 ◽  
Vol 13 (1) ◽  
pp. 101-110 ◽  
Author(s):  
B. A. C. Enyi

SUMMARYDodoma Edible outyielded Natal Common groundnut, due to varietal effects associated with differences in pod number, leaf area duration, crop growth rate, number of grains/pod and m2, and weight of individual grain. Increase in plant density led to an increase in grain yield. There was a close and positive relation between stem and pod dry weight; grain yield and leaf area duration; and crop growth rate, grain yield and grain number/m2 of land surface. A greater proportion of total dry matter was diverted into the stems of Dodoma Edible than Natal Common.


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