The effect of photoperiod and temperature on the first crop and ratoon growth of Pennisetum purpureum Schum

1978 ◽  
Vol 29 (5) ◽  
pp. 941 ◽  
Author(s):  
R Ferraris

Elephant grass (Pennisetum purpureum Schum.) was grown in phytotron cabinets for 60 days at 30/25° or 21/16°C (daylnight) in either 8 or 16 hr photoperiods. During the juvenile phase the higher temperature increased the leaf appearance rate, tillering rate and main stem elongation rate. Once plants in the 8 hr photoperiod became reproductive, the stem elongation, tillering rate and leaf appearance rate increased. The higher temperature continued to stimulate development. At harvest at 60 days plants grown at 30/25° had higher leaf, stem and total dry matter yields, a greater leaf area but lower carbohydrate content in the stubble. The 16 hr photoperiod produced higher dry matter yields at harvest than the 8 hr photoperiod. A comparison pot experiment grown in short day and long day photoperiods under field conditions in north Queensland produced similar findings to the phytotron experiment. After harvest, stubbles were ratooned into either short day (8 hr) or long day (16 hr) photoperiods, the temperature difference being maintained. Leaf number per main stem and main stem elongation were similar to those of the first crop, but more tillers and higher yields were produced in the ratoon crop. Temperature and photoperiod effects were similar in both crops. It was concluded that low temperatures rather than reduced photoperiod would be the greatest limitation to the adaptation of the species as an industrial or forage crop where yearround production is required.

2009 ◽  
Vol 66 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Omar Scheneiter ◽  
Beatriz Rosso ◽  
Mauro Corletto

When breeding temperate forage species is investigated, some attributes such as herbage accumulation and seasonal growth patterns have to be considered. To modify some of these traits, knowledge of the detailed process might be useful. In order to evaluate seasonal growth of contrasting white clover populations an experiment was carried out. Treatments were five cultivars and three local populations collected in Argentina. Weekly measures were taken during each season to calculate leaf appearance and flower appearance rates, stolon growing rate and dry matter (DM) net accumulation. Different germplasm of this species have different mechanisms for DM accumulation. Leaf size, more than leaf appearance rate, was the variable with most differences among germplasm and mostly related to dry matter accumulation. During spring and summer, inflorescences production had important effects on growing stolon rate, and differences among germplasm were evident. Some local populations showed favourable attributes that could be useful for breeding.


2016 ◽  
Vol 37 (4) ◽  
pp. 2099
Author(s):  
Priscila Beligoli Fernandes ◽  
Carlos Augusto Brandão de Carvalho ◽  
Domingos Sávio Campos Paciullo ◽  
Carlos Augusto De Miranda Gomide ◽  
Mirton José Frota Morenz ◽  
...  

This work was carried out to evaluate the morphogenetic and structural characteristics of basal and aerial tillers of two dwarf elephant grass clones (BRS Kurumi and CNPGL 00-1-3) managed under intermittent stocking in six grazing cycles. A completely randomized experimental design with three replications (paddocks) in split-split-plot arrangements was used. The clones were allocated to the plots, tiller classes were assigned to the subplots and grazing cycles to sub subplots. Higher values for basal tillers than aerial tillers were seen for the following characteristics: leaf elongation rate (12.8 and 5.1 cm/tiller/day), leaf appearance rate (0.26 and 0.19 leaves/tiller/day), stem elongation rate (0.38 and 0.16 cm/tiller/day), senescence rate (0.98 and 0.47 cm/tiller/day), total number of leaves (9.3 and 7.1 leaves/ tiller), number of live leaves (7.7 and 5.8 leaves/tiller) and final length of leaf blades (33.5 and 20.0 cm). Phyllochron was lower for basal (4.0 days/leaf) than aerial tillers (5.5 days/leaf). The leaf life span increased with the advance of the grazing cycles, averaging 31.2 days. The tiller density increased with the advance of the grazing cycles showing an average increase of 167% of aerial tillers and 62% of basal tillers for both clones. The morphogenetic and structural characteristics of dwarf clones were influenced jointly by the clones and the availability of the environmental factors of growth during the spring and summer. The high leaf elongation rates, associated with high leaf appearance rate, reveal the potential of high production dry matter of leaves and restoration of leaf area after grazing.


2020 ◽  
Vol 43 ◽  
pp. e50984
Author(s):  
Ana Beatriz Graciano da Costa ◽  
Gelson dos Santos Difante ◽  
Antonio Leandro Chaves Gurgel ◽  
Emmanuel Lievio de Lima Veras ◽  
Jéssica Gomes Rodrigues ◽  
...  

This study aimed to evaluate the morphogenic and structural characteristics of six Panicum maximum cultivars during the establishment period. A completely randomized block design with four replicates and six treatments (Tamani, Mombaça, Massai, Tanzania, Aruana and Zuri cultivars) was used. Morphogenic (leaf appearance rate, leaf elongation rate e stem elongation rate), structural (final leaf length, tiller population density e number of leaves per tiller) and productive (forage mass, leaf blade mass, stem mass, senescent material mass and leaf:stem ratio) characteristics were evaluated. There was no difference (p > 0.05) between the cultivars in terms of the number of live leaves per tiller (2.95 leaves/tiller). Mombaça cultivar had (p < 0.05) higher canopy height (50.64 cm) compared with other cultivars. The highest (p < 0.05) tiller population density was observed in Tamani (235.90 tillers m-2) and Massai (201.60 tillers m-2) cultivars. Leaf lifespan (54.18 days), phyllochron (17.40 days/leaf) and leaf senescence rate (0.87 cm tiller day-1) were not different (p > 0.05) between cultivars. However, leaf appearance rate was higher (p < 0.05) in Tanzania (0.07 leaves tiller day-1) than in Aruana cultivar (0.05 leaves tiller day-1). Leaf blade mass was higher (p < 0.05) in Mombaça cultivar (1518.31 kg DM ha-1), whereas Massai showed higher (p < 0.05) leaf:stem ratio (9.25). Panicum cultivars Tamani, Tanzania and Massai establishment after 75 days, while the other cultivars establish at 105 days of sowing in the Brazilian Northeast.


2021 ◽  
Vol 73 (6) ◽  
pp. 1413-1421
Author(s):  
M.E.R. Santos ◽  
I.C. Ferreira ◽  
B.H.R. Carvalho ◽  
G.O. Rocha ◽  
G.S. Borges ◽  
...  

ABSTRACT The objective this study was to identify differences in the morphogenic patterns of four Urochloa brizantha cultivars (marandu, piatã, xaraés and paiaguás grasses) during the stockpiling period. A completely randomized design was used, with three replications, in experimental plots of 9m². The evaluations took place over 2 years. The grasses were stockpiled for 92 (Year 1) and 95 (Year 2) days. The leaf appearance rate of paiaguás grass was higher, compared to other grasses. In Year 1, the stem elongation rate of xaraés grass was higher than other grasses. At the end of stockpiling period of Year 1, the tiller population density (TPD) was higher in the paiaguás grass, intermediate in the xaraés and marandu grasses and lower in the piatã grass. At the end of the stockpiling period in Year 2, TPD was higher in the paiaguás grass canopy, intermediate in the marandu and piatã grasses canopies, and lower in the xaraés grass canopy. Paiaguás grass has greater leaf growth during the stockpiling period and is therefore suitable for use under stockpiled grazing. Xaraés grass has high stem elongation during the stockpiling period, which is why its use under stockpiled grazing must be accompanied by adjustments in pasture management.


Author(s):  
Ezio Riggi ◽  
Danilo Scordia ◽  
Concetta Foti Cuzzola ◽  
Giorgio Testa ◽  
Salvatore L. Cosentino

In the present study, a two-year field trial was carried out with the aim to evaluate daylength and air temperature effects on leaf appearance and related rates in two durum wheat (Triticum durum Desf.), two bread wheat (Triticum aestivum L.) and two barley (Hordeum vulgare L.) cultivars, using six different sowing dates (SD). Significant effects of SD on final main stem leaf number (FLN), thermal leaf appearance rate (TLAR), daily leaf appearance rate (DLAR) and phyllochron (PhL) were found. Cultivars resulted inversely correlated to mean air temperature in the interval emergence - fifth leaf full expansion (E-V). Linear response of leaf number over days after sowing was shown for all SD and cultivars, with R2 higher than 0.95. FLN linearly decreased from the first to the last SD for durum wheat, while more variable behaviour was observed in bread wheat. TLAR and DLAR showed a linear increment of the rate from the first to the last SD in durum wheat, while did not for bread wheat and barley. PhL in durum wheat decreased from the first to the last SD. Barley and bread wheat showed the highest values on those SDs which did not reach flowering. The increase of TLAR was affected by photoperiod and photothermal units in durum wheat, while by temperatures only in barley and bread wheat. Present results might find practical application in the improvement of phenology simulation models for durum wheat, bread wheat and barley grown in Mediterranean area in absence of water and nutrient stress.


Weed Science ◽  
2008 ◽  
Vol 56 (5) ◽  
pp. 729-734 ◽  
Author(s):  
Prashant Jha ◽  
Jason K. Norsworthy ◽  
Melissa B. Riley ◽  
Douglas G. Bielenberg ◽  
William Bridges

Experiments were conducted to investigate the acclimation of Palmer amaranth to shading. Plants were grown in the field beneath black shade cloths providing 47 and 87% shade and in full sunlight (no shading). All photosynthetic measurements were taken 4 wk after initiating the shade treatments. Photosynthetic rates of Palmer amaranth grown under 47% shade increased with increasing photosynthetic active radiation (PAR) similar to 0% shade-grown plants. Light-saturated photosynthetic rates were predicted beyond the highest measured PAR of 1,200 µmol m−2s−1for plants grown under 0 and 47% shade. Plants acclimated to increased shading by decreasing light-saturated photosynthetic rates from 60.5 µmol m−2s−1under full sun conditions to 26.4 µmol m−2s−1under 87% shade. Plants grown under 87% shade lowered their light compensation point. Rate of increase in plant height was similar among shade treatments. Plants responded to increased shading by a 13 to 44% reduction in leaf appearance rate (leaf number growing degree days [GDD]−1) and a 22 to 63% reduction in main-stem branch appearance rate (main-stem branch number GDD−1) compared with full sunlight. Palmer amaranth specific leaf area increased from 68 to 97 cm2g−1as shading increased to 87%. Plants acclimated to 47% shade by increasing total leaf chlorophyll from 22.8 µg cm−2in full sunlight to 31.7 µg cm−2when shaded; however, the increase was not significant at 87% shading. Thus, it is concluded that Palmer amaranth shows photosynthetic and morphological acclimation to 87% or less shading.


2016 ◽  
Vol 54 (2) ◽  
pp. 243-256 ◽  
Author(s):  
ANDERSON DE MOURA ZANINE ◽  
DOMICIO NASCIMENTO ◽  
WILTON LADEIRA DA SILVA ◽  
BRAULIO MAIA DE LANA SOUSA ◽  
DANIELE DE JESUS FERREIRA ◽  
...  

SUMMARYThe objective of this study was to evaluate morphogenetic and structural characteristics of Guinea grass pastures subjected to two grazing frequencies (90 and 95% light interception) and two post-grazing heights (30 and 50 cm), during the rainy season and dry year. The leaf appearance rate varied only in the summer, the grazing pastures managed at 90/50 (light interception/post-grazing height) presented higher values in the leaf appearance rate (0.440 leaf/tiller.day), compared with those managed at 90/30 (0.275 leaf/tiller.day) and 95/50 (0.228 leaf/tiller.day), respectively. In the winter/beginning of the spring, pastures managed at 90/30 (0.03 cm/tiller.day) presented lower stem elongation rate in comparison with those managed at 90/50 (0.19 cm/tiller.day) and 95/30 (0.16 cm/tiller.day). Management strategies do not compromise the tissue flow in tillers and, consequently, can be utilized for the management of Guinea grass.


2011 ◽  
Vol 40 (2) ◽  
pp. 270-276 ◽  
Author(s):  
Domingos Sávio Campos Paciullo ◽  
Priscila Beligoli Fernandes ◽  
Carlos Augusto de Miranda Gomide ◽  
Carlos Renato Tavares de Castro ◽  
Fausto de Souza Sobrinho ◽  
...  

It was studied the effects of shading (0, 36 and 54%) and of four nitrogen doses (0, 50, 100 and 150 mg N/dm³ of soil) on the morphogenetic traits and on the tillering of grasses of Brachiaria genus (B. decumbens, B. ruziziensis and B. brizantha cv. Marandu and cv. Xaraes), cultivated in pots with 5 kg substrate. It was used a complete random design, in a 3 × 4 × 4 factorial scheme with three replications. Nitrogen promoted increase in leaf appearance rate and in average leaf blade length, whereas shading increased stem elongation rate. Leaf elongation rate and tillering varied with the interaction among shading percentages and nitrogen doses. Shading increased response efficiency of leaf elongation rate to nitrogen doses, but reduced for tillering, evidencing priority existing tillering growth in detriment to appearance of new tillers when there is light restriction for the plants. Phenotypic adjustments, in response to light reduction, indicate that the studied grasses present tolerance to moderate shading.


2021 ◽  
Vol 9 (3) ◽  
pp. 256-267
Author(s):  
Nauara Moura Lage Filho ◽  
Aline Da Rosa Lopes ◽  
Aníbal Coutinho Do Rêgo ◽  
Felipe Nogueira Domingues ◽  
Cristian Faturi ◽  
...  

The objective of this study was to evaluate regrowth period (RP), morphogenetic, structural and productive characteristics of the guinea grass cultivar Tanzania [Megathyrsus maximus (syn. Panicum maximum)] under different stubble heights (SH) during dry (DS) and rainy (RS) seasons in the eastern Amazon region. The treatments were: 5, 15, 25, 35, 45 and 55 cm SH, distributed in a randomized complete block design with 6 replicates. In the 2 seasons, RP decreased linearly with increase in SH, and was considerably shorter in the RS (47 d). Leaf appearance rate decreased linearly from 0.071 to 0.051 leaves/tiller/d with increasing SH, and it was higher during the RS. Increase in SH increased leaf elongation rate, stem elongation rate and leaf area index. In the RS, climatic conditions favored the morphogenesis, resulting in higher herbage accumulation (8,693 kg DM/ha) than in the DS (2,597 kg DM/ha). In associating seasons with SH, we recommend that Tanzania grass be managed at SH between 35 and 45 cm in the DS, resulting in RP from 61 to 64 days, and at SH of 35 cm in the RS, resulting in RP of 41 days. Studies to test this management strategy seem warranted.


1979 ◽  
Vol 59 (1) ◽  
pp. 7-13 ◽  
Author(s):  
T. LAWRENCE

Progenies from a six-genotype diallel cross in Altai wild ryegrass (Elymus angustus Trin.) were studied to assess the pattern of genetic control for F1 seed weight and a number of seedling and adult plant characters. Variation in F1 seed weight was largely determined by the maternal parent, but some control by the pollen parent was apparent. Gene action was additive, but some nonadditive genetic effects were also present. All of the seedling characters, days to emerge, rate of leaf appearance, rate of tiller appearance and seedling dry matter yield showed additive control which is amenable to direct selection. Diallel analyses indicated that the adult plant characters, days to inflorescence appearance, digestible organic matter, total dry matter yield and total seed yield were controlled by strong additive control which is amenable to direct selection. The seedling characters, rate of leaf appearance, rate of tiller appearance and seedling dry matter yield were interrelated but only rate of tiller appearance was associated with adult plant yield.


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