Corrigendum - 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):  
Light Interception ◽  
Yield Potential ◽  
Canopy Photosynthesis

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.

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.

Analysis of the regrowth of a tropical grass/legume sward subjected to different frequencies and intensities of defoliation

1980 ◽  
Vol 31 (4) ◽  
pp. 673 ◽  
Author(s):  
MM Ludlow ◽  
DA Charles-Edwards
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Dry Weight ◽  
Light Interception ◽  
Photosynthetic Characteristics ◽  
Dry Matter Production ◽  
Canopy Photosynthesis ◽  
Area Index ◽  
Matter Production ◽  
Cutting Height

Dry weight, leaf area, light interception and canopy photosynthesis were measured during 3- or 5-week regrowth periods of Setaria anceps/Desmodium intortum swards cut to 7.5 or 15 cm. Dry matter production during the experiment and over the growing season increased with cutting height and with interval between defoliations, but the proportion of grass to legume was unaffected. These effects of defoliation on dry matter production were similar to those estimated for integrated canopy photosynthesis from measured light interception and calculated leaf photosynthetic characteristics. Height and frequency of defoliation had no effect on canopy extinction coefficient for light, nor on the leaf photosynthetic characteristics, except for the first 1-2 weeks after defoliation when leaf photosynthetic rates appeared to be depressed. The main effects of height and frequency of defoliation on dry matter production were through their effects on leaf area index and light interception.

scholarly journals Modelling the effects of row configuration on sorghum yield reliability in north-eastern Australia

2005 ◽  
Vol 56 (1) ◽  
pp. 11 ◽  
Author(s):  
Jeremy Whish ◽  
Giles Butler ◽  
Michael Castor ◽  
Shayne Cawthray ◽  
Ian Broad ◽  
...  
Keyword(s):  
Light Interception ◽  
Yield Potential ◽  
Annual Rainfall ◽  
Average Yield ◽  
Crop Failure ◽  
Production Risk ◽  
Eastern Australia ◽  
The Difference ◽  
Sorghum Production

In recent years, many sorghum producers in the more marginal (<600 mm annual rainfall) cropping areas of Queensland and northern New South Wales have used skip row configurations in an attempt to improve yield reliability and reduce sorghum production risk. This paper describes modifications made to the APSIM sorghum module to account for the difference in water usage and light interception between alternative crop planting configurations, and then demonstrates how this new model can be used to quantify the long-term benefits of skip sorghum production. Detailed measurements of light interception and water extraction from sorghum crops grown in solid, single and double skip row configurations were collected from on-farm experiments in southern Qld and northern NSW. These measurements underpinned changes to the APSIM-Sorghum model so that it accounted for the elliptical water uptake pattern below the crop row and the reduced total light interception associated with skip row configurations. Long-term simulation runs using long-term weather files for locations near the experimental sites were used to determine the value of skip row sorghum production as a means of maintaining yield reliability. These simulations showed a trade-off between long-term average production (profitability) and annual yield reliability (risk of failure this year). Over the long term, the production of sorghum in a solid configuration produced a higher average yield compared with sorghum produced in a skip configuration. This difference in average yield is a result of the solid configuration having a higher yield potential compared with the skip configurations. Skip configurations limit the yield potential as a safeguard against crop failure. To achieve the higher average yield in the solid configuration the producer suffers some total failures. Skip configurations reduce the chance of total failure by capping the yield potential, which in turn reduces the long-term average yield. The decision on what row configuration to use should be made tactically and requires consideration of the starting soil water, the soil’s plant-available water capacity (PAWC), and the farm family’s current attitude to risk.

Yield Determinants and Prediction for California’s Almond Orchards Based on Machine Learning Analytics

2020 ◽  
Author(s):  
Yufang Jin ◽  
Bin Chen ◽  
Bruce Lampinen ◽  
Patrick Brown
Keyword(s):  
Machine Learning ◽  
Meteorological Data ◽  
Maximum Yield ◽  
Light Interception ◽  
Tree Age ◽  
Yield Potential ◽  
Maximum Temperature ◽  
Potential Yield ◽  
Yield Variation ◽  
Almond Orchards

&lt;p&gt;Agricultural productivity is subject to various stressors, including abiotic and biotic threats, many of which are exacerbated by a changing climate. The productivity of tree crops, such as almond orchards, is particularly complex. Moreover, the State of California has implemented legislatively mandated nitrogen (N) management strategies of all growers statewide to minimize nitrogen losses to the environment, and almond growers must now apply N in accordance with the estimated yield in early spring. To understand and mitigate these threats requires a collection of multi-layer large data sets, and advanced analytics is also critical to integrate these highly heterogeneous datasets to generate insights about the key constraints on the yields at tree and field scales. Here we used machine learning approaches to predict orchard-level yield and examine the determinants of almond yield variation in California&amp;#8217;s almond orchards, based on a unique 10-year dataset of field measurements of light interception, remote sensing metrics, and almond yield, along with meteorological data. We found that overall the maximum almond yield was highly dependent on light interception, e.g., with each one percent increase in light interception resulting in an increase of 57.9 lbs/acre in the potential yield. Light interception was highest for mature sites with higher long term mean spring incoming solar radiation, and lowest for younger orchards and when March maximum temperature was lower than 19 &lt;sup&gt;o&lt;/sup&gt;C. However, at any given level of light interception, actual yield often falls significantly below full yield potential, driven mostly by tree age, temperature profiles in June and winter, and summer maximum vapor pressure deficit (VPDmax). The full random forest model was found to explain 82% (&amp;#177;1%) of yield variation, with a RMSE of 480&amp;#177;9 lbs/acre. When excluding light interception from the predictors, overall orchard characteristics (such as age, location and tree density) and key meteorological variables could still explain 78% of yield variation. The model analysis also showed that warmer winter conditions often limited mature orchards from reaching maximum yield potential and higher summer VPDmax &amp;#160;significantly limited the yield. Our findings through the machine learning approach improved our understanding of the complex interaction between climate, canopy light interception, and almond nut production. The demonstrated relatively robust predictability of almond yield, driven by &amp;#8220;big data&amp;#8221;, also provides quantitative information and guidance to make informed orchard nutrient management decisions, allocate resources, determine almond price targets, and improve market planning.&lt;/p&gt;

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