Canopy Development, Light Interception and Seed Production in Sunflower as Influenced by Temperature and Radiation

1984 ◽  
Vol 11 (4) ◽  
pp. 255 ◽  
Author(s):  
HM Rawson ◽  
RL Dunstone ◽  
MJ Long ◽  
JE Begg
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Seed Production ◽  
Harvest Index ◽  
Growth Patterns ◽  
Light Extinction ◽  
Seed Number ◽  
Area Index ◽  
Radiation Interception ◽  
Temperature Regimes

Well watered mini-crops of sunflower were grown either in summer or winter in glasshouses maintained under five temperature regimes and a 16 h photoperiod. A field crop was grown concurrently with the summer glasshouse study. Summer radiation (25.5 MJ day-1) increased the size and/or number of many of the variables measured compared with winter radiation (9.5 MJ day-1). However, there was interaction between light and temperature upon phenological development, plant height, leaf number and harvest index. Seed production declined at temperatures above 18/13°C in summer and above 24/19°C in winter radiation, but fatty acid composition of the seed oil changed progressively with increasing temperature and was unaffected by radiation. Leaf area per plant increased faster under summer than winter radiation and in almost all temperature regimes reached considerably higher final values which resulted in a greater percentage of the incident radiation being intercepted. Temperature, though affecting the growth patterns and final areas of individual leaves in the canopies, did not alter the relationship between leaf area index and radiation interception. The light extinction coefficient changed with leaf area index and differed between summer and winter. Biomass per plant at maturity (B, g) was best related to radiation interception up to anthesis (I, MJ m-2), such that B = -234 + 541ogl, r2 = 0.91, but seed number (S) was correlated similarly with radiation interception and with the number of degree days (D) accumulated between floral initiation and anthesis (S = 1137+ 0.0051-0.762D, R2 = 0.90). Yield (Y, g per plant) was dependent on seed number, mean temperature (T) and radiation intercepted between anthesis and maturity, and the leaf area present at anthesis. However, over 97% of the variation in yield could be accounted for by the temperature and radiation factors in the manner Y = 39.07+0.047I- 1.26T. Harvest index and yield were not correlated for the cultivar examined.

Compost effects on leaf area index and seed production enhancement in an important arid land leguminous tree Acacia tortilis subsp. Raddiana

2016 ◽  
Author(s):  
A. A. Elfeel ◽  
R. A. Abohassan
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Seed Production ◽  
Seed Weight ◽  
Seed Quality ◽  
Organic Fertilizers ◽  
Diameter Growth ◽  
Acacia Tortilis ◽  
Area Index ◽  
Higher Doses

This study aimed to investigate the effects of compost addition on leaf area index (LAI), diameter growth and enhancement of seed production and quality in Acacia tortilis established under supplementary drip irrigation. Three composted fertilizer doses (2.5 kg, 5 kg and 7.5 kg/ tree) were compared to NPK (18-18-5 at a rate of 250 gram per tree) and control unfertilized plots. Effects of compost application on leaf area index (LAI), diameter growth, relative monthly diameter increment (RMDI) were monitored during two consecutive years (2014 and 2015). Then the impacts on pods and seeds production, seed weight, seed number per kg, seed quality (NPK and protein), germination per cent and mean germination time (MGT) were determined. Addition of fertilizers produced high effects on LAI. In 2014 NPK resulted in highest LAI values in most measurements, alternatively the status was changed in 2015 where, higher doses of compost produced higher LAI values. LAI results exhibited temporal variability that was associated with the seasonal variation of the year. The results demonstrate higher RMDI and diameter growth under NPK and compost at rate of 7.5 kg/tree treatments. Pods production was higher in plots treated with higher doses of compost. However, seed/husk ratio was higher in NPK plots. There is observed association between fruit and seed production with LAI. NPK and protein contents in seeds, were also, influenced by the presence of organic fertilizers. Cumulative germination and MGT were correlated with seed weight and were higher in plots treated with compost. The results highlight the importance of organic fertilizers under dry land conditions that produced higher LAI and growth which enhanced seed production and quality.

scholarly journals Switchgrass Leaf Area Index and Light Extinction Coefficients

2011 ◽  
Vol 103 (1) ◽  
pp. 119-122 ◽  
Author(s):  
Jim Kiniry ◽  
Mari-Vaughn Johnson ◽  
Robert Mitchell ◽  
Ken Vogel ◽  
Jerry Kaiser ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Light Extinction ◽  
Area Index ◽  
Extinction Coefficients

Physiological Characteristics for Cassava Selection

1988 ◽  
Vol 24 (4) ◽  
pp. 443-448 ◽  
Author(s):  
James H. Cock ◽  
Mabrouk A. El-Sharkawy
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Harvest Index ◽  
Selection Strategy ◽  
Storage Roots ◽  
Area Index ◽  
Simultaneous Formation ◽  
Breeding Programmes ◽  
Selection For ◽  
Stressful Environments

SummaryBreeding for high and stable yields is a major objective for cassava breeding programmes. Owing to the simultaneous formation of steins and leaves (source) and storage roots (sink), competition for assimilates implies that there is an optimum leaf area index for yield. This has led to the use of the harvest index as a practical criterion for selection. The optimal harvest index and leaf area index are discussed for selection for stressful environments. A successful strategy for developing high yielding varieties for favourable conditions is presented. Recent information has shown that selection for a slightly larger than optimal leaf area index, and hence greater biomass, can lead to stable yield in both favourable and stressful environments. Moreover, yield levels can be increased by selecting for moderate harvest indices (e.g. 0.5-0.65) and increased biomass. Longer leaf life is an integral part of this selection strategy. These concepts are discussed in detail.James H. Cock y Mabrouk A. El-Sharkawy: Caracteristicas fisiológicas para la selección de la mandioca.

Tracking leaf area index and coefficient of light extinction over the harvesting cycle of black wattle

2016 ◽  
Vol 27 (6) ◽  
pp. 1211-1217 ◽  
Author(s):  
Alexandre Behling ◽  
Carlos Roberto Sanquetta ◽  
Ana Paula Dalla Corte ◽  
Sylvio Péllico Netto ◽  
Aurélio Lourenço Rodrigues ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Light Extinction ◽  
Area Index ◽  
Black Wattle

scholarly journals Lodging Resistance and Yield Performance of Two Traditional Rice Varieties Applied with Nitrogen and Paclobutrazol

2016 ◽  
pp. 106-129
Author(s):  
Ariel Mactal ◽  
Justo Canare
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Harvest Index ◽  
Lodging Resistance ◽  
Rice Varieties ◽  
Yield Performance ◽  
Area Index ◽  
Spikelets Per Panicle ◽  
Traditional Rice

Vulnerability of rice growing areas to strong typhoons coupled by the susceptibility of traditional rice varieties to lodging lead to low yield and poor quality of harvested rice. To address these problems, two experiments using factorial in Randomized Complete Block Design were conducted during the wet season to determine the effects of paclobutrazol and nitrogen on the lodging resistance, agro-morphological characteristics and yield performance of two traditional rice varieties Elon-elon and Palawan Red. Application of increasing concentration of paclobutrazol did not significantly affect the percentage filled spikelets per panicle, number of spikelets per panicle, weight of 1000 grains, dry matter yield, harvest index and grain yield. At all concentrations of paclobutrazol, Palawan red had the longest first and fourth internodes, more unfilled spikelets per panicle, heavier 1000 grains weight and higher leaf area index than Elonelon. On the other hand, smaller stem diameter, more productive tillers per hill and longer panicles were obtained from Elon-elon than Palawan red. Elon-elon applied with increasing rates of nitrogen in combination with 500 ppm paclobutrazol had bigger stem diameter, higher productive tillers per hill, higher number of filled spikelets per panicle, higher percentage filled spikelets per panicle, longer panicles, higher harvest index and higher grain yield than Palawan red. Apparently, Palawan red had longer first, second and third internodes, more unfilled spikelets per panicle, heavier 1000 grain weight and higher leaf area index than Elon-elon. Applications of 30 and 60 kg N per ha had significantly higher lodging index than the untreated plants. Harvest index and grain yield were lowest in plants applied with 30 and 60 kg N per ha, attributable to high lodging index. Paclobutrazol is effective in shortening the length of the lower internodes and inhibits stem elongation resulting to shorter plants with increased lodging resistance. This ultimately produced higher yield than those plants that lodged. Culm strength was reduced by high rates of nitrogen causing significant increase in lodging index. The time of lodging is crucial in predicting the yield performance of the plants. Early lodging resulted to huge reduction in yield while it has little or no effect on yield when it occurs at later stages of the rice crop.

scholarly journals Validation of Maize (Zea mays L.) Hybrids for the Study on Variability, Trait Association, and Path Analysis

2021 ◽  
pp. 298-308
Author(s):  
M. Ramesh Kanna ◽  
Hiramani Barman ◽  
Kasireddy Sivasankarreddy ◽  
Dikshita Gogoi ◽  
T. V. Rao ◽  
...  
Keyword(s):  
Grain Yield ◽  
Path Analysis ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Harvest Index ◽  
Area Index ◽  
Ear Height ◽  
Positive Direct ◽  
Pollen Shed

The present investigation was conducted with nine genotypes in randomized block design during Rabi, 2019-20 at the instructional-cum-research farm, Assam Agricultural University, Jorhat. All the characters exhibited significant genotypic mean squares in analysis of variance except anthesis silking interval, kernel rows per ear and 100 kernel weights. High heritability coupled with high genetic advance was observed for the traits plant height, ear height, ears per plant, ear length, kernels per row, chlorophyll content, leaf area index 60 days after sowing (LAI 60 DAS), LAI 90 DAS, harvest index, grain yield per plant and grain yield per hectare. Significant genetic association of grain yield per plant and grain yield per hectare with days to 50% pollen shed, days to 50% silk, days to 100% dry husk, ear height, kernels per row, LAI 60DAS and LAI 90 DAS. Genotypic path analysis revealed that the characters, days to 50% silk, days to 100% dry husk, plant height, ears per plant, ear diameter and harvest index had the highest positive direct effects on grain yield per hectare while days to 50% pollen shed and ear height had the highest negative direct effect on grain yield per hectare. The hybrids namely, PAC 751, CP 333 and PAC 751 ELITE, were found to be the three best hybrids to possess a high estimate of desirable traits such as days to 50% pollen shed, days to 50% silk, days to 100% dry husk, plant height, ear height, ear diameter, leaf area index at 60 days after sowing, lea area index at 90 days after sowing, grain yield per plant and grain yield per hectare.

Effects of shading on the growth and nitrogen content of green panic and Siratro in pure and mixed swards defoliated at two frequencies

1980 ◽  
Vol 31 (2) ◽  
pp. 269 ◽  
Author(s):  
CC Wong ◽  
JR Wilson
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Nitrogen Fertilizer ◽  
Light Extinction ◽  
Panicum Maximum ◽  
Nitrogen Accumulation ◽  
Nitrogen Status ◽  
Area Index ◽  
Full Sunlight ◽  
Nitrogen Yield

A study was made of the effect of illumination at 100, 60 and 40% of sunlight on the growth of Macroptilium atropurpureum cv. Siratro and Panicum maximum var. trichoglume cv. Petrie (green panic) in pure and 50150 mixture swards, dcfoliated every 4 (D4) 01 8 (D8) weeks. The plants were grown without nitrogen fertilizer on a soil of moderate nitrogen status. Shading to 60 and 40% of full sunlight increased the shoot yield of green panic in pure sward by 30 and 27% respectively in the D8, but reduced it in the D4 treatment by 3 and 14%. Shade (40% full sunlight) reduced the shoot yield of Siratro in pure swards by 38 and 33 % in the D4 and D8 treatments. Nitrogen accumulation in green panic was markedly improved by shading: the increase in shoot nitrogen yield in pure sward under 60 and 40% light levels was 29 and 32% for the D4 and 45 and 76 % for the D8 treatment. All plant fractions of green panic increased in percentage nitrogen with increasing shade. The nitrogen yield of Siratro in pure sward declined with shading in proportion to dry weight. Shaded green panic swards had a higher leaf area index, better distribution of leaf area with height, and lower light extinction coefficients. The individual leaves had greater photosynthetic activity than those from the full sunlight swards. Shade-grown Siratro swards had a lower leaf area index and their leaves had a lower photosynthetic potential than in the full sunlight treatment. Nodulation was reduced under shade. Competition between green panic and Siratro was most severe in relation to shoot yield, and was accentuated by shading, frequent defoliation, and time. The proportion of Siratro in the mixture declined from 40 % initially to as low as 4-6 %. The extra competitiveness of the tropical grass, green panic, under shade in this experiment was due to a substantially increased ability to accumulate nitrogen and also to changes in canopy structure. In soils of markedly different nitrogen status or with nitrogen fertilizer the shade response might be modified.

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