Response of Cassava Leaf Area Expansion to Water Deficit: Cell Proliferation, Cell Expansion and Delayed Development

Alves, Alfredo Augusto Cunha; Setter, Tim L.

doi:10.1093/aob/mch179

Cited by 145 publications

(92 citation statements)

References 30 publications

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“…This time lag was possibly caused by the dryness of the upper layer of soil in which the cassava cuttings were developing roots, which later went down to much moister layers (Alves & Setter, 2004). On the other hand, the real-time response of the percentage of leaf-likely pixels to mean cassava leaf fresh weight ( Figure 5) again indicates the leaf-likeliness of the black pixels in the binarized target areas (Figure 1).…”

Section: Discussionmentioning

confidence: 99%

“…The digital images were pasted into a single digital image, and the best R/G value for discriminating between the leaves and other objects was statistically determined. The discriminatory power was evaluated by determining the fitness of the increase in leaf-likely pixels to a sigmoidal curve as the typical pattern of increase in cassava leaf biomass (Alves & Setter, 2004). Also, the authors examined greenness per luminosity when luminosity was given as a measure of brightness.…”

Section: Introductionmentioning

confidence: 99%

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Detection of Cassava Leaves in Multi-Temporally Acquired Digital Images of a Cassava Field Under Different Brightness Levels by Simultaneous Binarization of the Images Based on Indices of Redness/Greenness

Srisutham¹,

Doi²,

Polthanee³

et al. 2014

MAS

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Plant leaf area reveals various types of abnormalities which can enable appropriate plant/crop management actions. The quantification of plant leaf area is now feasible using commonly available digital photographing tools. Changes in brightness, however, make it difficult to compare leaf areas in digital photographs acquired at multiple time points. This difficulty could be overcome by employing an index of redness/greenness (R/G), which was suggested to be one of the best indices to discriminate between plant leaves and other objects such as soils. R/G and other indices were examined when discriminating cassava leaves from other objects in a field. A surveillance camera captured digital photographs on a daily basis. Of these, 183 photographs were stored. They were pasted into a single image file and simultaneously analyzed. The International Commission on Illumination color model's a* was the best index in the discrimination, with a distinctiveness score of 1.36. R/G was the second best, with a distinctiveness score of 0.70. The percentage of leaf-likely pixels followed sigmoidal patterns with time, resulting in great coefficients of determination of 0.981 (a*) and 0.965 (R/G). The percentage of leaf-likely pixels and cassava leaf weight had a real-time response relationship. The range of the 95% confidence limit was narrowed from -16 to +14% of a predicted value of 98% leaf-likely pixels for R/G to ±12% for a*. Thus, the simultaneous binarization and the detection of leaf-likely pixels in the photographs acquired under different brightness levels was enabled with improved discrimination accuracy by employing a*.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Detection of Cassava Leaves in Multi-Temporally Acquired Digital Images of a Cassava Field Under Different Brightness Levels by Simultaneous Binarization of the Images Based on Indices of Redness/Greenness

Srisutham¹,

Doi²,

Polthanee³

et al. 2014

MAS

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“…However, water use efficiency was highest when less irrigation was applied. Poor performance of these growth parameters in elevated temperature may be due to enhanced leaf senescence and growth retardation (Rehman et al, 2009) during growth phase, while it was recorded that as water plays its substantial role in cell division and elongation, ultimately in growth so restricted cell division and expansion (Alves and Setter, 2004) and more rate of leaf senescence (Hafsi et al, 2000) was reported due to water stress ( Table 2). The significantly different periodic trend regarding LAI, LAD and CGR under temperature regimes and irrigation levels is also elaborated in pictorial representation (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Detrimental effects of water stress on crops depend on the developmental stage, its duration as well as on crop genotype (Beltrano and Marta, 2008). Wheat is sensitive to water stress, which results in low photosynthesis because of less intercepted area due to restricted cell division and expansion (Alves and Setter, 2004), more leaf senescence, smaller grain size and reduction in grain growth duration (Hafsi et al, 2000). The productivity of wheat relays on yield related attributes and these parameters show positive response to irrigation (Jahfari, 2004).…”

Section: Introductionmentioning

confidence: 99%

Impact of Various Irrigation Levels on Growth, Yield and Water Use Efficiency of Wheat at Variable Temperatures

Asad¹,

Ahmad²,

Khaliq³

et al. 2014

JGIASS

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to check the influence of various irrigation regimes on growth, yield and water use efficiency of wheat at variable temperatures. The treatments were comprised of three irrigation levels: I 1 = (irrigation at tillering, stem elongation, booting and grain development), I 2 = (irrigation at tillering, stem elongation and grain development) and I 3 = (irrigation at tillering and grain development) and two temperature levels viz. existing field temperature and an elevated temperature of 4°C above the existing temperature in controlled conditions. The experiment was laid out in Randomized Complete Block Design (RCBD) in split plot arrangement with four replications with a net plot size of 1.32 m × 5 m. The results showed that the growth, yield and water use efficiency was significantly affected by various irrigation regimes and temperature variables. Growth and yield related traits were significantly higher when irrigation was applied at tillering, stem elongation, booting and grain development followed by I 2 (Irrigation at tillering, stem elongation and grain development). Similarly, growth, yield and water use efficiency was highest under normal existing field conditions. Among irrigation levels, water use efficiency and NAR was highest when only two irrigations at tillering and grain development were applied. In conclusion, at the face of declining water availability and in water deficient areas, water application may be done at tillering and grain development stage for achieving better Water Use Efficiency (WUE). However in water sufficient areas, water application at tillering, stem elongation, booting and grain development is recommended to achieve higher yields. Similarly, current climate change scenario resulting in temperature elevation will severely affects wheat yields.

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“…Em condições de deficit de água no solo ou de alta demanda evaporativa da atmosfera, as plantas de mandioca apresentam controle estomático bastante eficiente (El-Sharkawy et al, 1989;Alves & Setter, 2000, 2004El-Sharkawy, 2007). Contudo, a redução da abertura estomática pode limitar a taxa de difusão de CO 2 para o interior da folha, com efeitos diretos sobre a fotossíntese e o crescimento (Alves, 2002;El-Sharkawy, 2007).…”

Section: Introductionunclassified

Transpiração e crescimento foliar de plantas de mandioca em resposta ao deficit hídrico no solo

Lago

Streck

Bisognin

et al. 2011

Pesq. agropec. bras.

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Resumo -O objetivo deste trabalho foi determinar a transpiração e o crescimento foliar de duas cultivares de mandioca, em resposta ao conteúdo de água disponível no solo representado pela fração de água transpirável no solo (FATS). Foram realizados dois experimentos, em vasos de 8 L, com as cultivares Fécula Branca e Fepagro RS 13. O plantio foi feito em 11/9/2009 e 8/9/2010, em delineamento experimental inteiramente casualizado. A água disponível, a transpiração e o crescimento foliar foram medidos diariamente, em cada experimento, durante o período de imposição da deficiência hídrica. A FATS crítica, em que a transpiração começa a ser reduzida, foi de 0,45 para 'Fécula Branca' e 0,50 para 'Fepagro RS 13'. A redução do crescimento foliar começou quando a FATS atingiu 0,51 para 'Fécula Branca' e 0,49 para 'Fepagro RS 13'. A FATS crítica para transpiração e crescimento foliar difere em condições de atmosfera com baixa e com alta demanda evaporativa do ar, conforme a cultivar de mandioca utilizada.Termos para indexação: Manihot esculenta, deficit hídrico, fechamento estomático, fração de água transpirável, umidade crítica no solo. Transpiration and leaf growth of cassava plants as a response to soil water deficitAbstract -The objective of this work was to determine the transpiration and leaf growth of two cassava cultivars, as a response to the available soil water content represented by the fraction of transpirable soil water (FTSW). Two experiments were carried out in 8-L pots with the cassava cultivars Fécula Branca and Fepagro RS 13. Planting was done on 9/11/2009 and on 9/8/2010, in a completely randomized design. The available soil water, the transpiration and the leaf growth were measured on a daily basis, in each experiment, during the period of soil drying. The threshold FTSW, at which the transpiration begins to reduce, was 0.45 for 'Fécula Branca' and 0.50 for 'Fepagro RS 13'. Reduction of leaf growth started at 0.51 FTSW for 'Fécula Branca' and at 0.49 for 'Fepagro RS 13'. Threshold FTSW for transpiration and for leaf growth differs in atmosphere conditions with high and low atmospheric demand, depending on the utilized cassava cultivar.

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Response of Cassava Leaf Area Expansion to Water Deficit: Cell Proliferation, Cell Expansion and Delayed Development

Abstract: Although cell growth processes were sensitive to mild water deficit, they recovered to a large extent, and much of the reduction in leaf area was caused by developmental delay and a reduction in cell division in the youngest, meristematic leaves.

Cited by 145 publications

References 30 publications

Detection of Cassava Leaves in Multi-Temporally Acquired Digital Images of a Cassava Field Under Different Brightness Levels by Simultaneous Binarization of the Images Based on Indices of Redness/Greenness

Detection of Cassava Leaves in Multi-Temporally Acquired Digital Images of a Cassava Field Under Different Brightness Levels by Simultaneous Binarization of the Images Based on Indices of Redness/Greenness

Impact of Various Irrigation Levels on Growth, Yield and Water Use Efficiency of Wheat at Variable Temperatures

Transpiração e crescimento foliar de plantas de mandioca em resposta ao deficit hídrico no solo

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