Possibility of Increasing Yield Potential of Rice by Reducing Panicle Height in the Canopy. II. Canopy Photosynthesis and Yield of Isogenic Lines

1996 ◽  
Vol 23 (2) ◽  
pp. 161 ◽  
Author(s):  
TL Setter ◽  
EA Conocono ◽  
JA Egdane
Keyword(s):  
Field Experiments ◽  
Grain Filling ◽  
Canopy Height ◽  
Yield Potential ◽  
Isogenic Line ◽  
Canopy Photosynthesis ◽  
Area Index ◽  
Beneficial Effects ◽  
Isogenic Lines ◽  
Single Leaf

Reduced panicle height in a rice crop canopy may have beneficial effects of increasing yield potential through reduced shading of leaves leading to greater canopy photosynthesis. Effects of different panicle height in the canopy were evaluated in glasshouse and field experiments using isogenic lines with elongated upper internodes (EUI lines) from two cultivars. Isogenic lines of IR36 and IR50 with elongated upper internodes (IR36EUI and IR50EUI) had panicle heights at the top of the canopy of 96-100% of canopy height, while lines with low panicle heights had panicles which were 74 and 82% of canopy height respectively. Lines with low panicle height had about 10% more of the total leaf area index (LAI) above panicles and this resulted in up to 35% greater light interception by leaves above panicles relative to high panicle height plants. At 5 days before flowering IR36 and IR36EUI had equal canopy photosynthesis, while at flowering, lines had equal shoot nitrogen percentage and LAI. At maturity spikelets per mainstem were not significantly different. At 0, 7, 14 and 21 days after flowering (DAF), IR36, with low panicle height, had 10-30% greater canopy photosynthesis than IR36EUI; greater canopy photosynthesis was observed for IR50 relative to IR50EUI. These beneficial effects of low panicle height on canopy photosynthesis occurred even though the maximum single leaf photosynthesis and respiration rates were similar in both isogenic lines during grain filling. In the field and in a glasshouse experiment where plants were arranged into canopies, IR36, with low panicle heights had 15-40% greater yields than the isogenic line IR36EUI with high panicle heights; greater yields also occurred for IR50 than IR50EUI.

Possibility of Increasing Yield Potential of Rice by Reducing Panicle Height in the Canopy. I. Effects of Panicles on Light Interception and Canopy Photosynthesis.

1995 ◽  
Vol 22 (3) ◽  
pp. 441 ◽  
Author(s):  
TL Setter ◽  
EA Conocono ◽  
JA Egdane ◽  
MJ Kropff
Keyword(s):  
Oryza Sativa L ◽  
Dark Respiration ◽  
Grain Filling ◽  
Light Interception ◽  
Yield Potential ◽  
High Yield ◽  
Canopy Photosynthesis ◽  
Plant Type ◽  
Light Competition ◽  
Area Index

A new rice (Oryza sativa L.) plant type is proposed which is aimed at greater light interception by the leaves during grain filling and reduced susceptibility to lodging. This plant type is based on lowering panicle height in the canopy so that leaves are able to intercept more radiation. Panicle height of four cultivars with high yield potential ranged from 80 to 95% of canopy height at 14 days after flowering (DAF). Harvested panicle area index of two of these which were two tropical cultivars amounted to 0.45-0.57 m2 m-2, while the leaves above the panicles intercepted only 4-12% incident radiation at midday in these cultivars at 14 DAF. The potential impact of lowering panicle height in the canopy on canopy photosynthesis was evaluated by panicle removal. When panicles were removed, the irradiance at the bottom of the panicle layer of the canopy increased from 52 to 80%. At 11 DAF, net canopy photosynthesis of two cultivars similarly increased by 42-52% following removal of panicles. Increases in canopy photosynthesis were mainly due to increased light interception by leaves within the canopy since there were little or no changes in canopy dark respiration or in net leaf photosynthesis rates at the same irradiance following panicle removal. Optimum panicle height in the canopy and the effect of different panicle area index is further examined using a physiological model for light competition, INTERCOM. Reduced panicle height in the canopy is discussed in terms of considerations for and impacts of lowering panicle height in the canopy on canopy photosynthesis and yield of rice.

Modelling Canopy Production. II. From Single-Leaf Photosynthesis Parameters to Daily Canopy Photosynthesis

1995 ◽  
Vol 22 (4) ◽  
pp. 603 ◽  
Author(s):  
PJ Sands
Keyword(s):  
Simple Algorithm ◽  
Light Response ◽  
Daily Maximum ◽  
Canopy Photosynthesis ◽  
Leaf Photosynthesis ◽  
Daily Production ◽  
Area Index ◽  
Single Leaf ◽  
Diurnal Temperature Variation ◽  
Analytical Expressions

This paper presents a simple algorithm for calculating daily canopy photosynthesis given parameters of the single-leaf light response, the canopy extinction coefficient, canopy leaf area index, daylength, daily solar irradiance and daily maximum and minimum temperatures. Analytical expressions are derived for total daily production by a canopy of leaves whose light response is either a rectangular hyperbola or a Blackman response. An expression which gives an excellent approximation to canopy photosynthesis for an arbitrary hyperbolic light response is then derived. These expressions assume photosynthetically active radiation (PAR) within the canopy follows Beer's law, light-saturated photosynthetic rate at any point in the canopy is proportional to the ratio of local PAR to full-sun PAR, diurnal variation of PAR is sinusoidal, and parameters of the single-leaf photosynthetic light response do not vary diurnally. It is shown how these expressions can be used to accommodate diurnal temperature variation of photosynthesis in a simple manner. The accuracy of the approximation to the basic integral of leaf photosynthesis over the canopy and over time is illustrated by applying the algorithm to compute the seasonal variation of daily canopy photosynthesis and comparing these data with corresponding values obtained by numerical integration.

scholarly journals Spatial arrangement of plants on leaf growth and development and the yield potential of soybean

2020 ◽  
pp. 913-922
Author(s):  
José Eduardo Minussi Winck ◽  
Thomas Newton Martin ◽  
Marlo Adriano Bison Pinto ◽  
Lucas Allan Bruning ◽  
Guilherme de Almeida Arismendi
Keyword(s):  
Growth And Development ◽  
Field Experiments ◽  
Leaf Growth ◽  
Block Design ◽  
Grain Filling ◽  
Spatial Arrangement ◽  
The Other ◽  
Plant Distribution ◽  
Yield Potential ◽  
Randomized Block Design

This study aimed at determining the effect of a variety of plants arrangements on foliar growth and development as well as the productive potential in soybean. The field experiments were performed over two agricultural years (2015/16 and 2016/17) on Argisoil in subtropical environment. The two selected cultivars, viz., BMX Tornado RR and FPS Urano RR were sown in four spatial distribution of the plants such as conventional spacing (0.45 m spacing between rows), reduced spacing (0.225 m spacing between rows), paired spacing (two rows with 0.225 m and 0.45 m spacing from the other rows) and crossed spacing (0.45 m spacing between the rows with crosses of two rows, at a 90° angle). The randomized block design was adopted for the experiments with the treatments in a 2x4 factorial distribution and four replications. The first factor was the cultivar and the second types of plant distribution. The results showed that plant arrangement affected the plant profile regarding the behavior of the ecophysiological variables like plastochron, leaf lifetime and yield distribution. Leaf life in each stratum was caused by the foliar senescence rhythm, explained by a 4th degree polynomial model, revealing two peaks in the senescence rate, one during pre-flowering stage and the other when the grain filling stage was completed. According to the results, we do not recommend changes in conventional spacing.

scholarly journals Comparative Performance of Hybrid and Elite Inbred Rice Varieties with respect to Their Source-Sink Relationship

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Md Moinul Haque ◽  
Habibur Rahman Pramanik ◽  
Jiban Krishna Biswas ◽  
K. M. Iftekharuddaula ◽  
Mirza Hasanuzzaman
Keyword(s):  
Field Experiments ◽  
Hybrid Rice ◽  
Flag Leaf ◽  
Yield Potential ◽  
Rice Varieties ◽  
Comparative Performance ◽  
Area Index ◽  
Crop Growth Rate ◽  
Late Planting ◽  
Source Sink

Hybrid rice varieties have higher yield potential over inbred varieties. This improvement is not always translated to the grain yield and its physiological causes are still unclear. In order to clarify it, two field experiments were conducted including two popular indica hybrids (BRRI hybrid dhan2 and Heera2) and one elite inbred (BRRI dhan45) rice varieties. Leaf area index, chlorophyll status, and photosynthetic rate of flag leaf, postheading crop growth rate, shoot reserve translocation, source-sink relation and yield, and its attributes of each variety were comprehensively analyzed. Both hybrid varieties outyielded the inbred. However, the hybrids and inbred varieties exhibited statistically identical yield in late planting. Both hybrids accumulated higher amount of biomass before heading and exhibited greater remobilization of assimilates to the grain in early plantings compared to the inbred variety. Filled grain (%) declined significantly at delayed planting in the hybrids compared to elite inbred due to increased temperature impaired-inefficient transport of assimilates. Flag leaf photosynthesis parameters were higher in the hybrid varieties than those of the inbred variety. Results suggest that greater remobilization of shoot reserves to the grain rendered higher yield of hybrid rice varieties.

Modelling Canopy Production. I. Optimal Distribution of Photosynthetic Resources

1995 ◽  
Vol 22 (4) ◽  
pp. 593 ◽  
Author(s):  
PJ Sands
Keyword(s):  
Photosynthetic Rate ◽  
Homogeneous Function ◽  
Nitrogen Concentration ◽  
Light Response ◽  
Leaf Nitrogen ◽  
Optimal Distribution ◽  
Canopy Photosynthesis ◽  
Area Index ◽  
Single Leaf ◽  
Canopy Nitrogen

On the basis of detailed numerical simulations, Field (1983. Oecologia 56, 341-347) stated that total canopy photosynthesis will be a maximum for a fixed total canopy leaf nitrogen provided the derivative δA/δN, where A is photosynthetic rate and N is leaf nitrogen concentration, has the same value throughout the canopy. This paper uses the calculus of variations to formally prove Field's assertion. It shows that if the single-leaf light response is a first-degree homogeneous function of both light-saturated photosynthetic rate Amax and intensity I of photosynthetically active radiation and if Amax is linearly related to N, then the optimal distribution of leaf nitrogen is linearly related to the decline in I with canopy depth, and Amax is proportional to this decline. The nature of photosynthetic gains due to optimisation of canopy nitrogen distribution is illustrated numerically for a simple model canopy. It is found that, for canopies with fixed mean leaf nitrogen, canopy photosynthesis is approximately proportional to canopy leaf area index (LAI), and the gain due to canopy optimisation compared with a uniform canopy is small for shallow canopies but pronounced for deep canopies. It is also found that, for canopies with fixed total leaf nitrogen, there is a canopy LAI which maximises canopy photosynthesis, and that this LAI and the corresponding canopy photosynthesis are approximately proportional to total canopy nitrogen.

scholarly journals Relationship of Photosynthesis and Harvest Index to Sweet Potato Yield

1990 ◽  
Vol 115 (2) ◽  
pp. 288-293 ◽  
Author(s):  
Ajmer S. Bhagsari ◽  
Doyle A. Ashley
Keyword(s):  
Sweet Potato ◽  
Harvest Index ◽  
Ipomoea Batatas ◽  
Field Experiments ◽  
Storage Root ◽  
Canopy Photosynthesis ◽  
Storage Roots ◽  
Physiological Basis ◽  
Area Index ◽  
Stage Of Development

Field experiments with 15 sweet potato [Ipomoea batatas L. (Lam.)] genotypes were conducted to study the physiological basis of yield in 1981 and 1982. The leaf area index differed significantly among the sweet potato genotypes during early and late phases of growth, hut showed an inconsistent relationship with yield. Single leaf net photosynthesis ranged from 0.74 to 1.12 mg CO2/m' per sec. Canopy photosynthesis for sweet potato genotypes differed significantly in 1981, but not in 1982. It ranged from 0.81 to 1.16 mg CO2/m2 per sec in Aug. 1981. and from 0.63 to 0.88 mg CO2/m2 per sec in 1982. Four hours after “C-labeling, 14C-assimilate translocation from the treated leaf ranged from 21% to 46%, but did not differ significantly among the genotypes. At final harvest, harvest index [HI, defined as (storage root yield/total biological yield) × 100] of the genotypes varied from 43% to 77% and 31% to 75% for 1981 and 1982, respectively. Canopy photosynthesis during September was significantly correlated with storage root dry matter yield (r = 0.54*) in 1981 and with phytomass (above-ground biomass plus storage roots) (r = 0.60*) in 1982. Both phytomass and HI were significantly correlated with storage root matter yield. Canopy photosynthetic evaluation of sweet potato germplasm may be-more relevant when the storage root sinks are at an advanced stage of development. Our study suggests that yield is poorly predicted by Pn, particularly when the genotypes have different leaf sizes.

Triticale and barley for grain and for dual-purpose (forage+grain) in a Mediterranean-type environment. I. Growth analyses

1997 ◽  
Vol 48 (4) ◽  
pp. 411 ◽  
Author(s):  
C. Royo ◽  
F. Tribó
Keyword(s):  
Dry Matter ◽  
Field Experiments ◽  
Grain Filling ◽  
Barley Grain ◽  
Forage Yield ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Winter Triticale ◽  
Growing Seasons ◽  
Spring Triticale

Field experiments were conducted for 2 growing seasons (1992 and 1993) at 2 sites in north-eastern Spain under irrigated conditions and high soil fertility. Two 6-rowed barley varieties, 3 spring triticales, and 2 winter triticales were evaluated for grain yield and for forage and grain production in the same cropping season. Forage was cut when the first node was detectable, and grain was harvested at ripening in both cut and uncut plots. Barley, spring triticale, and winter triticale did not differ in biomass at cutting. The number of tillers per plant at the beginning of jointing was about 3·2 in both barley and winter triticale, and 0·7 in spring triticale. Almost all of the biomass components at cutting were positively and significantly correlated with forage yield. Changes in dry matter accumulation and leaf area index and its components in the uncut treatment fitted accurately to the same logistic curve. The maximum number of living leaves per plant was reached between the beginning of jointing and booting in barley and spring triticale, and around jointing in winter triticale. The number of living tillers per plant at anthesis was significantly higher in barley than in triticale. The number of spikes per plant at anthesis was significantly lower in spring triticale than in barley and winter triticale. The efficiency of the plant to accumulate dry matter was greater in triticale than in barley. In barley, grain filling in both cut and uncut harvesting treatments was mainly dependent on current photosynthesis after anthesis. In triticale, which was more affected by terminal abiotic stresses, both photosynthesis and translocation of assimilates contributed to grain filling, independent of the harvesting treatment.

scholarly journals Aerobic Rice with or without Strategic Irrigation in the Subtropics

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1831
Author(s):  
Sachesh Silwal ◽  
Surya P. Bhattarai ◽  
David J. Midmore
Keyword(s):  
Low Temperature ◽  
Field Experiments ◽  
Yield Potential ◽  
Wet Season ◽  
Rice Varieties ◽  
Area Index ◽  
Late Season ◽  
Tropical Conditions ◽  
Rainfed Conditions ◽  
Semi Arid

Modern rice varieties adapted to aerobic (dryland) conditions have expanded to new rice growing systems thanks to their plasticity in adapting to rainfed and irrigated conditions. This is important because, as water becomes scarce in paddy rice regions (as it is already in Australia), there will be a move towards tropical to subtropical dryland rainfed rice with attendant problems of drought and low temperature. To assess rice adaptability in the wet season of the semi-arid subtropical conditions of coastal central Queensland, field experiments were established for a late season (in January) planting in 2014 and early season planting in November 2015 with 13 varieties developed by Australian Agriculture Technologies (AAT) Ltd were seeded in a vertisol soil. This was to assess their adaptation to rainfed conditions and their response to strategic irrigation. Water scarcity and low temperature prior to and at flowering were important factors constraining yield. Early flowering varieties in the late season planting escaped the otherwise cold and drought stress during the reproductive stage and had higher yields. In the second year, earlier planting made possible with strategic irrigation avoided the low temperature constraint on yield, but without follow-up strategic irrigation, yields were still low. The average yield of varieties increased from 1.5 times (AAT 4) to 16.3 times (AAT 15) with strategic irrigation compared with rainfed yields averaged across years. The increase in yield with strategic irrigation was associated with a greater leaf area index, spikelet fertility, and instantaneous water use efficiency during flowering. Strategic irrigation concentrated roots in the top 15 cm, but differences in yield between varieties under rainfed conditions were not related to root properties. It is important to consider variations in flowering time, yield potential, and drought patterns when developing rice varieties for rainfed semi-arid tropical conditions, as well as when quantifying the benefits of strategic irrigation.

scholarly journals Evaluation of soybean (Glycine max L.) adaptation to northern European regions under different agro-climatic scenarios

2021 ◽  
Author(s):  
Guénolé Boulch ◽  
Chloé Elmerich ◽  
Amina Djemel ◽  
Bastien Lange
Keyword(s):  
Negative Impact ◽  
Precipitation Amount ◽  
Genetic Material ◽  
Grain Filling ◽  
Limiting Factors ◽  
Yield Potential ◽  
Limiting Factor ◽  
European Regions ◽  
Area Index ◽  
Northern European

Abstract Soybean is a candidate crop to increase the independency of Europe in leguminous protein crops. However, its adaptation to northern European regions is not yet well defined due to lack of long-term references. Herein, we simulated soybean yield potential in northern France and identified the main yield limiting factors under rainfed vs irrigated conditions. Two cultivars representing maturity groups 000 and 00 were planted within three different trials. Leaf area index, shoot and pod biomass, main phenological stages and yield were recorded to evaluate CROPGRO-soybean model predictability. Adjustment of genetic coefficients was performed prior to simulate yield on 21-years weather database (1999-2018) at Beauvais (France, N 49.46°, E 2.07°) and Estrées-Mons (France, N 49.88°, E 3.01°) under different water regimes and planting dates. Predictions showed that adding irrigation at grain filling period would increase yield potential to the level of non-water limited scenarios. Although simulated yield variability is reduced with irrigation, the remaining variability suggests that water is not the only yield-limiting factor. A tentative explanation is proposed by deriving environmental covariates from the model. The analysis confirmed the importance of precipitation amount (optimum around 200 mm) and duration (optimum around 60 days) of the flowering to physiological maturity period under rainfed conditions. Under irrigated conditions, increasing evapotranspiration and average minimum temperature affected simulated yield positively while increasing the number of days below 10°C had a negative impact. These results give insights for soybean crop management and bring indications to breeders for adapting the existing genetic material to northern Europe.

scholarly journals Canopy assimilation surface and yield of winter wheat varieties under atypical weather conditions

2020 ◽  
Vol 27 ◽  
pp. 259-264
Author(s):  
V. V. Morgun ◽  
G. O. Pryadkina ◽  
O. O. Stasik ◽  
O. V. Zborivska
Keyword(s):  
Winter Wheat ◽  
Field Experiments ◽  
Weather Conditions ◽  
Grain Filling ◽  
Total Biomass ◽  
Wheat Varieties ◽  
Fresh Matter ◽  
Area Index ◽  
Grain Productivity ◽  
Winter Wheat Varieties

Aim. Comparative analysis of the traits of the assimilation surface of winter wheat varieties under unfavorable environmental conditions to evaluate its adaptive capacity. Methods. Morphometric, spectrophotometric, statistical. Results. In the field experiments under natural conditions (close to optimal in spring, arid - during the grain filling period and prolonged rainfall during a harvest), the variability of leaves chlorophyll content, the green leaves fresh matter per 1 m2 of ground and chlorophyll index in 10 modern middle-early varieties at anthesis and milky-wax ripeness were studied. Under such conditions, the difference in grain productivity between the highest and the lowest yielding varieties was about 1.6 t/ha. Positive correlation of grain productivity of winter wheat varieties with chlorophyll area index of leaves at milky-wax ripeness (r = 0.61) was established. Conclusions. It was found that the varieties with better adaptation to drought conditions during the period of grain filling had a higher area of assimilation surface at anthesis and milky-wax ripeness. Therefore, their higher yield was related to the higher photosynthetic capacity and the ability to storage and remobilization of carbohydrates deposited in the stem as well as to the efficiency of converting total biomass into grain yield (HI). Keywords: Triticum aestivum L., grain productivity, chlorophyll area index of leaves.

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