The physiology of forage rye (Secale cereale)

1983 ◽  
Vol 101 (1) ◽  
pp. 63-70 ◽  
Author(s):  
R. K. M. Hay ◽  
M. K. Abbas Al-Ani
Keyword(s):  
Leaf Area ◽  
Photosynthetic Apparatus ◽  
Early Spring ◽  
Net Assimilation Rate ◽  
Winter Rye ◽  
Assimilation Rate ◽  
Light Conditions ◽  
Net Assimilation ◽  
Leaf Appearance ◽  
Forage Yields

SUMMARYField and pot investigations of the vegetative and early reproductive growth of a winter wheat and a winter rye cultivar over three seasons (1978–9, 1980–2) have shown that higher and earlier forage yields of rye are due to a combination of factors, notably more rapid rates of germination, crop emergence, leaf appearance and leaf expansion coupled with higher leaf area ratios. There was no evidence, from studies of net assimilation rate, that the photosynthetic apparatus of rye plants is better adapted than wheat to the low temperature and light conditions of winter and early spring. However, the earlier initiation of rye stem extension was associated with significant increases in net assimilation rate, which compensated for reductions in the leaf area ratio. Practical aspects of these results are discussed briefly.

The growth of maize

1978 ◽  
Vol 90 (3) ◽  
pp. 569-577 ◽  
Author(s):  
G. O. Iremiren ◽  
G. M. Milbourn
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Matter Content ◽  
Net Assimilation Rate ◽  
Dry Matter Content ◽  
Dry Matter Yield ◽  
Assimilation Rate ◽  
Maize Silage ◽  
Area Index ◽  
Net Assimilation

SummaryTotal dry-matter yield of maize silage rose asymptotically as density was increased up to 17 plants/m2. Over the range 11–17 plants/m2, which is generally higher than is used in the U.K., the increase in yield was 1–1·6 t dry matter/ha which can justify the higher seed cost and although there was no adverse affect on time of maturity the risk of lodging increased at the highest density. During the harvest period whilst whole crop dry-matter percentage was rising from 23 to 28%, the ear dry-matter content rose steadily from 29 to 35%, whereas the leaf and stem dry-matter content remained essentially constant and only dried out at a later stage after a frost.Caldera 535 had a higher leaf area index and net assimilation rate than the earlier variety Julia which it outyielded by 15%. The additional yield was mainly stem tissue and the greater vegetative production caused an 11-day delay in reaching the silage stage of maturity (25% crop D.M.). NO differences occurred between density treatments and varieties in the forage quality components considered, namely percentage drymatter digestibility, modified acid-detergent fibre, crude protein and ash. Thus in U.K. conditions, total dry-matter yield exerts an overriding influence on the yields per unit area of these quality constituents. This contrasts with reports from the U.S.A. in which a reduced grain/stover ratio adversely influences silage quality.Removal of the whole ear (including husk and rachis) at an early stage in ear development resulted in a 50% reduction in the final dry-matter yield. In the earless plants, leaf area and net assimilation rate was lower, but the dry-matter content of the leaves and stem was considerably higher, and a marked purple coloration developed indicative of excess starch concentration. These results emphasize the need in maize silage not only for an adequate leaf canopy, best obtained early in the growing season by using high planting density and subsequently by using late maturing varieties, but also for sufficient sink capacity in the ear as well as in the stem fraction.

scholarly journals Growth of canola hybrids resistant and sensitive to herbicides

2020 ◽  
Vol 41 (6supl2) ◽  
pp. 2911-2922
Author(s):  
Miria Rosa Durigon ◽  
◽  
Joanei Cechin ◽  
Franciele Mariani ◽  
Gerarda Beatriz da Silva Pinto ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Dry Matter ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Net Assimilation

Plant growth analysis is useful for determining adequate management practices and exploring the maximum yield potential of cultivars or hybrids. Canola hybrids with resistance to herbicides have been studied and registered for Brazilian conditions, as they improve weed management in canola crops. This study evaluated the growth of canola hybrids resistant to triazine or imidazolinone herbicides compared to a sensitive hybrid. The experiment was conducted using a completely randomized design, with four replications, in a bifactorial scheme using three hybrids and six sampling times. The canola hybrids used were Hyola 571CL (resistant to imidazolinones), Hyola 555TT (resistant to triazines), and Hyola 61 (sensitive to both herbicides). Height, leaf area, and dry matter of roots, leaves, stems, and shoots of the plants were evaluated at 14, 28, 42, 56, 70, and 119 days after emergence (DAE). The physiological indices absolute growth rate, leaf area ratio, specific leaf area, and net assimilation rate were calculated, and yield indices evaluated. Compared to Hyola 61, the Hyola 555TT hybrid showed lower values of leaf dry matter at 70 DAE, absolute growth rate up to 56 DAE, and net assimilation rate at 14 and 28 DAE, and a higher leaf area ratio at 56 DAE, whereas the hybrid Hyola 571CL presented lower leaf area and lower leaf dry matter at 70 DAE. At flowering, compared to Hyola 61, the hybrid Hyola 571CL presents lower leaf area, and the hybrids Hyola 555TT and Hyola 571CL have lower leaf dry matter accumulation. Differences in the growth of canola hybrids Hyola 555TT, Hyola 571CL and Hyola 61 do not cause differences in their grain yield.

scholarly journals Crescimento de crambe na presença ou ausência de competição interespecífica

Revista CERES ◽  
2015 ◽  
Vol 62 (5) ◽  
pp. 460-468 ◽  
Author(s):  
Germani Concenço ◽  
Luiz Alberto Staut ◽  
Igor Vinicius Talhari Correia ◽  
Luiz Carlos Yamamoto Vieira ◽  
César José da Silva
Keyword(s):  
Leaf Area ◽  
Growth And Development ◽  
Dry Mass ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Mass Ratio ◽  
Leaf Mass ◽  
Leaf Mass Ratio ◽  
Leaf Area Duration ◽  
Net Assimilation

RESUMOCrambe (Crambe abyssinica) has a cropping cycle of around 90 days, being suitable as an alternative to the second grain crop planted after soybean is harvested in the Center West region of Brazil. It is necessary to understand the growth and development dynamics of crambe plants in order to allow correct management of the production factors. This study aimed to describe the growth and development parameters of crambe plants under presence or absence of interspecific competition. The experiment was installed in the fall-winter 2011 in an Oxisoil, in completely randomized blocks design with three replications. Treatments comprised crambe plants growing either in presence or absence of interspecific simulated competition, throughout the cropping cycle. Plants were collected for the growth analysis every 15 days from harvest until 75 days after emergence. Growth parameters leaf area (AF), dry mass of stems/culms (MSC), leaves (MSF) and total (MST) dry mass, leaf area index (IAF), absolute (TCA) and relative (TCR) growth rates, net assimilation rate (TAL), specific leaf area (AFE), leaf area duration (DAF), leaf area ratio (RAF) and leaf mass ratio (RMF) were determined for the crop plants, subjected or not to competition, as well as for the simulated competitor. Crambe is a low competitive crop, being the competition more severe until 60-70 days after emergence. Besides, crop performance under field conditions was properly described by the net assimilation rate (TAL), which is also affected by the leaf area duration (DAF) and leaf mass ratio (RMF).

scholarly journals Growth of marandu palisadegrass subjected to strategies of intermittent stocking

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 ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Weight Ratio ◽  
Crop Growth ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Relative Growth ◽  
Crop Growth Rate ◽  
Net Assimilation

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.

scholarly journals Leaf area of common bean genotypes during early pod filling as related to plant adaptation to limited phosphorus supply

2010 ◽  
Vol 34 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Roberto Santos Trindade ◽  
Adelson Paulo Araújo ◽  
Marcelo Grandi Teixeira
Keyword(s):  
Common Bean ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Leaf Size ◽  
Net Assimilation Rate ◽  
Leaf Number ◽  
Growth Stages ◽  
Assimilation Rate ◽  
Plant Adaptation ◽  
Net Assimilation

Low phosphorus supply markedly limits leaf growth and genotypes able to maintain adequate leaf area at low P could adapt better to limited-P conditions. This work aimed to investigate the relationship between leaf area production of common bean (Phaseolus vulgaris) genotypes during early pod filling and plant adaptation to limited P supply. Twenty-four genotypes, comprised of the four growth habits in the species and two weedy accessions, were grown at two P level applied to the soil (20 and 80 mg kg-1) in 4 kg pots and harvested at two growth stages (pod setting and early pod filling). High P level markedly increased the leaf number and leaf size (leaf area per leaf), slightly increased specific leaf area but did not affect the net assimilation rate. At low P level most genotypic variation for plant dry mass was associated with leaf size, whereas at high P level this variation was associated primarily with the number of leaves and secondarily with leaf size, specific leaf area playing a minor role at both P level. Determinate bush genotypes presented a smaller leaf area, fewer but larger leaves with higher specific leaf area and lower net assimilation rate. Climbing genotypes showed numerous leaves, smaller and thicker leaves with a higher net assimilation rate. Indeterminate bush and indeterminate prostrate genotypes presented the highest leaf area, achieved through intermediate leaf number, leaf size and specific leaf area. The latter groups were better adapted to limited P. It is concluded that improved growth at low P during early pod filling was associated with common bean genotypes able to maintain leaf expansion through leaves with greater individual leaf area.

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