scholarly journals Analysis of leaf wetting effects on gas exchanges of corn using a whole-plant chamber system

2018 ◽  
Vol 64 (No. 5) ◽  
pp. 233-239 ◽  
Author(s):  
Yasutake Daisuke ◽  
Yokoyama Gaku ◽  
Maruo Kyosuke ◽  
Wu Yueru ◽  
Wang Weizhen ◽  
...  

A whole-plant chamber system equipped with a transpiration sap flow meter was developed for measuring the transpiration rate even if leaves are wetted. A preliminary experiment in which dynamics of transpiration rate and/or evaporation rate of wetted and non-wetted plants were measured and compared with each other demonstrated the validity of the measurement system. The system was then used to analyse leaf wetting effects on gas exchange of corn under slight water stress conditions of soil (a volumetric soil water content of 9.7%). Leaf wetting decreased vapour pressure in leaves by decreasing leaf temperature but it increased vapour pressure in the air; therefore, vapour pressure difference between leaves and air, as a driving force of transpiration, was significantly lower in wetted plant. As a result, transpiration rate decreased by 44% and leaf conductance as an index of stomatal aperture was increased by leaf wetting. Such increasing leaf conductance due to leaf wetting increased the photosynthetic rate by 30% and therefore it improved water use efficiency (2.4 times). These results suggest that morning leaf wetting due to night time dew formation may have an advantage in crop production in semi-arid regions.

2013 ◽  
Vol 93 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Alison E. Walden-Coleman ◽  
Istvan Rajcan ◽  
Hugh J. Earl

Walden-Coleman, A. E., Rajcan, I. and Earl, H. J. 2013. Dark-adapted leaf conductance, but not minimum leaf conductance, predicts water use efficiency of soybean (Glycine max L. Merr.). Can. J. Plant Sci. 93: 13–22. The conductance to water vapor of dark-adapted leaves (gdark) has been shown to be negatively correlated with whole-plant water use efficiency (WUE) in soybean, but the physiological basis of this relationship is unknown. It is also not clear how gdark compares with the minimum leaf conductance of wilted leaves (gmin), a trait that has been studied extensively across a broad range of species. We compared gdark to gmin of soybean leaves and found that gdark values were consistently much higher than gmin values measured on the same leaves. Also, across seven soybean varieties known to differ for WUE, gdark but not gmin was correlated with WUE. Thus, gdark and gmin should be considered distinct traits. We measured gdark at two different leaf positions, and found that gdark measured at the lower leaf position (two main stem nodes below the youngest fully expanded leaf) was best correlated with WUE. We then used this method to screen a selection of current commercial soybean varieties adapted to Ontario, Canada, for variation in gdark. The range in gdark among the commercial varieties was as broad as that measured previously among more diverse genotypes, suggesting that Ontario soybean varieties might also vary widely for WUE.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aung Zaw Oo ◽  
Yasuhiro Tsujimoto ◽  
Mana Mukai ◽  
Tomohiro Nishigaki ◽  
Toshiyuki Takai ◽  
...  

AbstractImproved phosphorus (P) use efficiency for crop production is needed, given the depletion of phosphorus ore deposits, and increasing ecological concerns about its excessive use. Root system architecture (RSA) is important in efficiently capturing immobile P in soils, while agronomically, localized P application near the roots is a potential approach to address this issue. However, the interaction between genetic traits of RSA and localized P application has been little understood. Near-isogenic lines (NILs) and their parent of rice (qsor1-NIL, Dro1-NIL, and IR64, with shallow, deep, and intermediate root growth angles (RGA), respectively) were grown in flooded pots after placing P near the roots at transplanting (P-dipping). The experiment identified that the P-dipping created an available P hotspot at the plant base of the soil surface layer where the qsor1-NIL had the greatest root biomass and root surface area despite no genotyipic differences in total values, whereby the qsor1-NIL had significantly greater biomass and P uptake than the other genotypes in the P-dipping. The superior surface root development of qsor1-NIL could have facilitated P uptakes from the P hotspot, implying that P-use efficiency in crop production can be further increased by combining genetic traits of RSA and localized P application.


2021 ◽  
Vol 13 (12) ◽  
pp. 2349
Author(s):  
Jingchun Ji ◽  
Jianli Liu ◽  
Jingjing Chen ◽  
Yujie Niu ◽  
Kefan Xuan ◽  
...  

Topdressing accounts for approximately 40% of the total nitrogen (N) application of winter wheat on the Huang-Huai-Hai Plain in China. However, N use efficiency of topdressing is low due to the inadaptable topdressing method used by local farmers. To improve the N use efficiency of winter wheat, an optimization method for topdressing (THP) is proposed that uses unmanned aerial vehicle (UAV)-based remote sensing to accurately acquire the growth status and an improved model for growth potential estimation and optimization of N fertilizer amount for topdressing (NFT). The method was validated and compared with three other methods by a field experiment: the conventional local farmer’s method (TLF), a nitrogen fertilization optimization algorithm (NFOA) proposed by Raun and Lukina (TRL) and a simplification introduced by Li and Zhang (TLZ). It shows that when insufficient basal fertilizer was provided, the proposed method provided as much NFT as the TLF method, i.e., 25.05% or 11.88% more than the TRL and TLZ methods and increased the yields by 4.62% or 2.27%, respectively; and when sufficient basal fertilizer was provided, the THP method followed the TRL and TLZ methods to reduce NFT but maintained as much yield as the TLF method with a decrease of NFT by 4.20%. The results prove that THP could enhance crop production under insufficient N preceding conditions by prescribing more fertilizer and increase nitrogen use efficiency (NUE) by lowering the fertilizer amount when enough basal fertilizer is provided.


1985 ◽  
Vol 105 (1) ◽  
pp. 1-7 ◽  
Author(s):  
R. De ◽  
M. A. Salim Khan ◽  
M. S. Katti ◽  
V. Raja

SUMMARYExperiments made with winter fodder crops, lucerne (Medicago sativa), berseem (Trifolium alexandrinum) and oats (Avena sativa) and summer fodder crops, cow pea (Vigna unguiculata), guar (Cyamopsis tetragonoloba), sunhemp (Crotolaria juncea) and pearl millet (Pennisetum americanum) showed that a sequential crop of Sudan grass yielded more after the legumes than after the cereal fodders, oats or pearl millet. The legume advantage was noted in the crop not given fertilizers but also when Sudan grass was given N fertilizer. The yield increase in Sudan grass grown after legumes was equivalent to 32–60 kg fertilizer N/ha applied to Sudan grass following pearl millet.After harvesting the legumes more available N and NO3-N was present in the soil and the apparent recovery of fertilizer N by a subsequent crop was increased by the legume.


2005 ◽  
Vol 32 (10) ◽  
pp. 945 ◽  
Author(s):  
Thomas R. Sinclair ◽  
Graeme L. Hammer ◽  
Erik J. van Oosterom

Limitations on maximum transpiration rates, which are commonly observed as midday stomatal closure, have been observed even under well-watered conditions. Such limitations may be caused by restricted hydraulic conductance in the plant or by limited supply of water to the plant from uptake by the roots. This behaviour would have the consequences of limiting photosynthetic rate, increasing transpiration efficiency, and conserving soil water. A key question is whether the conservation of water will be rewarded by sustained growth during seed fill and increased grain yield. This simulation analysis was undertaken to examine consequences on sorghum yield over several years when maximum transpiration rate was imposed in a model. Yields were simulated at four locations in the sorghum-growing area of Australia for 115 seasons at each location. Mean yield was increased slightly (5–7%) by setting maximum transpiration rate at 0.4 mm h–1. However, the yield increase was mainly in the dry, low-yielding years in which growers may be more economically vulnerable. In years with yield less than ∼450 g m–2, the maximum transpiration rate trait resulted in yield increases of 9–13%. At higher yield levels, decreased yields were simulated. The yield responses to restricted maximum transpiration rate were associated with an increase in efficiency of water use. This arose because transpiration was reduced at times of the day when atmospheric demand was greatest. Depending on the risk attitude of growers, incorporation of a maximum transpiration rate trait in sorghum cultivars could be desirable to increase yields in dry years and improve water use efficiency and crop yield stability.


2021 ◽  
Author(s):  
Aung Zaw Oo ◽  
YASUHIRO TSUJIMOTO ◽  
Mana Mukai ◽  
Tomohiro Nishigaki ◽  
Toshiyuki Takai ◽  
...  

Abstract Improved phosphorus (P) use efficiency for crop production is needed given the depleting phosphorus ore deposits and increasing ecological concerns about its excessive use. Root system architecture (RSA) is important in efficiently capturing immobile P in soils, while agronomically, localized P application near the roots is a potential approach to address this issue. However, the interaction between genetic traits of RSA and localized P application has been little understood. Near-isogenic lines (NILs) and their parent of rice (qsor1-NIL, Dro1-NIL, and IR64, with shallow, deep, and intermediate root growth angles (RGA), respectively) were grown in flooded pots after placing P near the roots at transplanting (P-dipping). The experiment identified that the P-dipping created an available P hotspot at the soil surface; the qsor1-NIL had the greatest root biomass and root surface area in the 0–3 cm soil layer despite no genotype differences in total values; the qsor1-NIL had significantly greater biomass and P uptake than the other genotypes in the P-dipping. The superior surface root development of qsor1-NIL could have facilitated P uptakes from the P hotspot, implying that P-use efficiency in crop production can be further increased by combining genetic traits of RSA and localized P application.


Sign in / Sign up

Export Citation Format

Share Document