Wheat spike temperatures in relation to varying environmental conditions

1999 ◽  
Vol 50 (6) ◽  
pp. 997 ◽  
Author(s):  
J. F. Panozzo ◽  
H. A. Eagles ◽  
R. J. Cawood ◽  
M. Wootton
Keyword(s):  
Soil Moisture ◽  
Grain Filling ◽  
Ambient Air ◽  
Moisture Stress ◽  
Effect Of Temperature ◽  
Crop Canopy ◽  
Ambient Temperatures ◽  
Hot Days ◽  
Stevenson Screen ◽  
Wheat Spike

Most field studies investigating the effect of temperature on growth processes use temperatures recorded within a Stevenson screen. These are likely to deviate from temperatures within the plant. This investigation reports a comparative study of methodologies and applications for measuring temperatures in the field during grain development by comparing Stevenson screen, ambient (air temperatures within the crop canopy), and wheat spike temperatures. Miniature sensors were inserted into wheat spikelets located midway on the spike of a primary tiller at anthesis. Located also within the crop canopy, and at the same height as the spike sensors, were sensors to measure ambient temperatures. Stevenson screen temperatures were also recorded at the site. Temperatures were recorded automatically every 12 min during grain filling from anthesis to maturity. Plants were grown in dryland and irrigated conditions within the same location, with the aim of determining differences in plant temperatures between stressed and non-stressed plants. Stevenson screen temperatures did not relate closely to ambient or spike temperatures. Plants growing in adequate soil moisture conditions had spike temperatures lower than ambient temperatures, but in some dryland trials, where soil moisture was limiting, spike temperatures equalled ambient temperatures, indicating that the plants were under moisture stress. Temperature differences of up to 5˚C were observed between the spikes of irrigated and non-irrigated crops on a hot day. Neither ambient nor screen temperatures gave an accurate measurement of spike temperature on hot days. Spike temperature differences between 2 cultivars, awned and awnless, were investigated. Trends were not consistent over both years; however, in 3 of the 4 environments, the maximum spike temperatures were higher for the awned cultivar (Hartog) than the awnless cultivar (Halberd). On very hot days, when ambient temperatures exceeded 40˚C, spikes of Hartog were cooler than those of Halberd.

The response of rate and duration of grain filling to long-term selection for yield in Italian durum wheats

2010 ◽  
Vol 61 (2) ◽  
pp. 162 ◽  
Author(s):  
Rosella Motzo ◽  
Francesco Giunta ◽  
Giovanni Pruneddu
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Triticum Turgidum ◽  
Unit Area ◽  
Grain Filling ◽  
Moisture Stress ◽  
Significant Negative Correlation ◽  
Grain Number ◽  
Ambient Temperatures ◽  
Selection For

Genetic advance in durum wheat (Triticum turgidum subsp. durum) grain yield in Italy has been achieved by bringing forward flowering time, achieving a larger number of grains per unit area, and altering the pattern of senescence. The performance, in the absence of any moisture stress, of a set of 6 Italian durum wheat cultivars released over the past 100 years was compared under 4 environments and 2 nitrogen rates, to ascertain whether the changes brought about by selection for yield have also indirectly affected the rate and duration of grain filling. Grain filling lasted 35–36 days in all cultivars except ‘Ichnusa’ (39 days), although modern cultivars flowered earlier than older ones. The lack of any breeding effect on grain-filling duration also meant that the later old cultivars were not negatively affected by the higher ambient temperatures during their grain filling. The maximum rate of grain filling ranged from 2.4 to 3.3 mg/day and showed a highly significant negative correlation with the year of cultivar release (r = –0.91*). The variation in grain weight, significant but not correlated with the year of release, was associated with the rate of grain filling, which was in turn related to the grain number per unit area. A compensating variability still exists among modern Italian cultivars in both grain number and grain-filling rate, which demonstrates that durum wheat grain yield can be increased while also preserving high grain weights.

scholarly journals PHYSIOLOGICAL AND YIELD RESPONSE OF SOME UPLAND RICE VARIETIES TO RE-WATERING AFTER IMPOSED SOIL MOISTURE STRESS

2016 ◽  
Vol 15 (1) ◽  
pp. 93-111
Author(s):  
O. S. SAKARIYAWO ◽  
S. O. OLAGUNJU ◽  
M. O. ATAYESE ◽  
K. A. OKELEYE ◽  
P. A.S., SOREMI ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Upland Rice ◽  
Grain Filling ◽  
Moisture Stress ◽  
Yield Response ◽  
Growth Stages ◽  
Soil Moisture Stress ◽  
Rice Varieties ◽  
Filling Stage ◽  
Grain Filling Stage

A pot experiment was conducted in the Screen house of Federal University of Agriculture, Abeokuta, October, 2011 (late dry season) to study drought recovery ability of 13 upland rice varieties exposed to soil moisture stress (20 days) at three growth stages (vegetative, reproductive and grain filling stage). The experiment was in completely randomized design, with three replicates. Under moisture stress significantly higher growth recovery, more erect canopy and flatter leaf surface were obtained in all the rice varieties at vegetative growth stage than other growth stages with increasing duration of re-watering. Under stress condition NERICA 4 maintained a significantly higher leaf area (27.50 cm2 and 40.18 cm2), plant height (53.45 cm and 67.62 cm) and number of tillers (1.67 and 1.67), but with a depressed number of leaf, slanted leaf posture and curved leaf especially during the later stage of its growth (Reproductive and grain filling stage respectively). It could be concluded that NERICA 4 had higher recovery ability than other rice varieties in drought prone upland ecology.

Variation between and within species of rapeseed (Brassica campestris and B. napus) in response to drought stress. II.* Growth and development under natural drought stresses

1978 ◽  
Vol 29 (3) ◽  
pp. 479 ◽  
Author(s):  
RA Richards ◽  
N Thurling
Keyword(s):  
Soil Moisture ◽  
Grain Yield ◽  
Genotypic Variation ◽  
Dry Weight ◽  
Grain Filling ◽  
Moisture Stress ◽  
Sowing Date ◽  
Soil Types ◽  
Dry Matter Accumulation ◽  
Plant Weight

Two rapeseed species and cultivars within each of these species differed significantly with respect to the influence of variation in sowing date on growth, development and yield on two different soil types. Soil moisture stress, particularly after anthesis, was the major environmental factor affecting these processes. Grain yield declined markedly with later sowings in both species, and B. napus, despite its later maturity, was more tolerant of severe soil moisture deficits since its grain yield was consistently higher than B. campestris in the more stressed environments. The major distinguishing feature between species contributing most to this difference in yield was the pattern of dry matter accumulation. In B. campestris most of the dry weight of the plant was accumulated after anthesis when drought was most severe, whereas in B. napus dry weight accumulation occurred before anthesis. This resulted in a greater contribution of reserves accumulated by anthesis to grain-filling in B. napus. Most of the variation in seed yield resulted from differences in sowing dates and soil types. When these environmental effects were excluded, the main determinants of genotypic variation in yield were the numbers of pods and branches and harvest index in both species, growth rate in the post-anthesis phase in B. campestris, and plant weight and root/shoot ratio at anthesis in B. napus. Selection strategies for yield improvement in rapeseed growing in drought-stressed environments are discussed. _____________________ *Part I, Aust. J. Agric. Res., 29: 469 (1978).

scholarly journals Influence of Protective Sprinkler Irrigation on Yield and Water Productivity of Kharif Grown Rain Fed Crops

2021 ◽  
Author(s):  
V. Ramulu ◽  
M. Devender Reddy
Keyword(s):  
Soil Moisture ◽  
Sandy Loam ◽  
Irrigation System ◽  
Water Productivity ◽  
Sprinkler Irrigation ◽  
Grain Filling ◽  
Moisture Stress ◽  
Growth Stages ◽  
Loam Soil ◽  
Food Grain

Background: The food grain and non-food grain crops occupy 48 and 68% area respectively under rain fed condition. Due to uneven rainfall, the rainfed crop suffers for want of adequate soil moisture at critical growth stages. Under such situation, protective irrigation ensures adequate soil moisture which results higher production. Crops like tomato, maize, groundnut and red gram are predominantly grown during kharif as rain fed crops. Relieving the soil moisture stress during the critical crop growth stages with more efficient irrigation system assumes importance in rain fed farming. Methods: An experiment was conducted for three years during kharif 2008, 2009 and 2010 at the College Farm, Prof. Jayashankar Telangana State Agril. University, Rajendranagar, Hyderabad on a sandy loam soil to study the yield advantage of protective sprinkler irrigation to kharif grown rain fed tomato, maize, groundnut and red gram crops. The trial was conducted in strip plot design with protective sprinkler irrigations as main plots and rainfed kharif crops as sub-plots and replicated thrice. The three main treatments comprised of - one protective sprinkler irrigation at flower/peg/tassel initiation, two protective sprinkler irrigations at flower and fruiting, tassel and grain filling, peg formation and pod filling and flowering and pod filling stages and rain fed (control). The sub treatments consisted of four crops- tomato, maize, groundnut and red gram. Result: There was an increase in yield with one and two protective sprinkler irrigations by 16.7 and 27.9; 17.7 and 44 5; 26.4 and 34.5 and 21.1 and 28.9% over their corresponding rain fed crops of tomato, groundnut, maize and red gram, respectively. There was an increase of 20.4 and 31.6% in Maize Equivalent Yield (MEY) with one and two protective irrigations as compared to rain fed crop. The water productivity was lower in all the crops grown under rain fed conditions (0.77 kg MEY m-3) as compared to that of one and two protective irrigations.

Effect of Temperature during Grain Filling Stage on Endosperm Structure and Apperance Quality of Aromatic Rice

2012 ◽  
Vol 460 ◽  
pp. 286-289 ◽  
Author(s):  
Zhen Jiang Xu ◽  
Li Zhong Xiao ◽  
Hong Liu ◽  
Yong Hao Ren ◽  
Zhi Lin Li
Keyword(s):  
Grain Filling ◽  
Effect Of Temperature ◽  
Rice Grain ◽  
Aromatic Rice ◽  
Starch Granules ◽  
Filling Stage ◽  
Appearance Quality ◽  
Endosperm Structure ◽  
Grain Filling Stage

Based on the experiment of two inbred aromatic rice varieties and one hybrid aromatic rice line treated under four different temperatures( daymean temperature 21°C, 23°C, 26°C and 30°C respectively) during grain filling stage in phytotrons, the shape and arrangement of endosperm starch granules in rice grain transection were observed by scanning electron microscope and the related characteristics of rice grain qualities of chalky percent and chalkiness were analyzed at the same time. The results showed that under the lower temperature( daymean temperature21°C and 23°C), many large compound starch granules with clear angulars packed together regularly without significant natural gaps bewteen starch granules in the tansectional endosperm. However, with the increase of temperature, starch granules in the transectional endosperm were changed from regularly shaped and closely and orderly arranged to various shaped and chaoticly arranged with obvious natural gaps between starch granules, which was closely consistent with the poorer appearance quality under the higher temperature, which indicated that the endosperm structure is closely related with appearance quality of aromatic rice.

A MOISTURE STRESS INDEX FOR WHEAT BY MEANS OF A MODULATED SOIL MOISTURE BUDGET

1968 ◽  
Vol 48 (5) ◽  
pp. 535-544 ◽  
Author(s):  
A. R. Mack ◽  
W. S. Ferguson
Keyword(s):  
Soil Moisture ◽  
Stress Function ◽  
Potential Evapotranspiration ◽  
Moisture Stress ◽  
Moisture Distribution ◽  
Stress Index ◽  
Wheat Crop ◽  
Moisture Budget ◽  
Dough Stage ◽  
Soil Moisture Budget

Actual evapotranspiration (AE), soil moisture distribution, and moisture stress for a wheat crop (PE-AE) were estimated by the modulated soil moisture budget of Holmes and Robertson. The estimated soil moisture was reasonably well correlated with soil moisture measured weekly by means of gypsum blocks. Wheat yields from experimental plots in the corresponding area were related more closely to the moisture stress function (PE-AE: r = − 0.83), than to the seasonal precipitation (r = 0.62), the potential evapotranspiration (PE) or the evapotranspiration ratio (AE/PE). Regression analyses showed that the grain yields were reduced by an average of 156 (±sb = 40) kg/ha per cm of moisture stress from emergence to harvest, or by 311 and 69 kg/ha per cm of stress, from the fifth-leaf to the soft-dough stage and from the soft-dough stage to maturity, respectively. The moisture stress function may be used to characterize the soil–plant–atmosphere environment for the growing season of a crop. Precipitation and evapotranspiration data are presented annually for three standardized growing periods at Brandon from 1921 to 1963.

Developmental and physiological traits associated with high yield and stay-green phenotype in wheat

2008 ◽  
Vol 59 (4) ◽  
pp. 354 ◽  
Author(s):  
J. T. Christopher ◽  
A. M. Manschadi ◽  
G. L. Hammer ◽  
A. K. Borrell
Keyword(s):  
Soil Moisture ◽  
Grain Filling ◽  
High Yield ◽  
Limiting Factor ◽  
Deep Soil ◽  
Stay Green ◽  
Physiological Basis ◽  
Winter Crops ◽  
Significant Yield ◽  
Grain Filling Period

Water availability is a key limiting factor in wheat production in the northern grain belt of Australia. Varieties with improved adaptation to such conditions are actively sought. The CIMMYT wheat line SeriM82 has shown a significant yield advantage in multi-environment screening trials in this region. The objective of this study was to identify the physiological basis of the adaptive traits underpinning this advantage. Six detailed experiments were conducted to compare the growth, development, and yield of SeriM82 with that of the adapted cultivar, Hartog. The experiments were undertaken in field environments that represented the range of moisture availability conditions commonly encountered by winter crops grown on the deep Vertosol soils of this region. The yield of SeriM82 was 6–28% greater than that of Hartog, and SeriM82 exhibited a stay-green phenotype by maintaining green leaf area longer during the grain-filling period in all environments where yield was significantly greater than Hartog. However, where the availability of deep soil moisture was limited, SeriM82 failed to exhibit significantly greater yield or to express the stay-green phenotype. Thus, the stay-green phenotype was closely associated with the yield advantage of SeriM82. SeriM82 also exhibited higher mean grain mass than Hartog in all environments. It is suggested that small differences in water use before anthesis, or greater water extraction from depth after anthesis, could underlie the stay-green phenotype. The inability of SeriM82 to exhibit stay-green and higher yield where deep soil moisture was depleted indicates that extraction of deep soil moisture is important.

scholarly journals Correlations of Vegetative and Reproductive Characters with Root Traits of Upland Rice under Imposed Soil Moisture Stress

2017 ◽  
Vol 32 (1) ◽  
pp. 61
Author(s):  
A.L Nassir ◽  
K.M. Adewusi ◽  
S.O. Olagunju
Keyword(s):  
Soil Moisture ◽  
Upland Rice ◽  
Root Traits ◽  
Moisture Stress ◽  
Soil Moisture Stress ◽  
Reproductive Characters

scholarly journals Improved understanding of drought controls on seasonal variation in Mediterranean forest canopy CO<sub>2</sub> and water fluxes through combined in situ measurements and ecosystem modelling

2009 ◽  
Vol 6 (8) ◽  
pp. 1423-1444 ◽  
Author(s):  
T. Keenan ◽  
R. García ◽  
A. D. Friend ◽  
S. Zaehle ◽  
C. Gracia ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Forest Canopy ◽  
Moisture Stress ◽  
Mediterranean Ecosystems ◽  
Forest Growth ◽  
Water Fluxes ◽  
Soil Moisture Stress ◽  
Dynamic Global Vegetation Model ◽  
Forest Growth Model

Abstract. Water stress is a defining characteristic of Mediterranean ecosystems, and is likely to become more severe in the coming decades. Simulation models are key tools for making predictions, but our current understanding of how soil moisture controls ecosystem functioning is not sufficient to adequately constrain parameterisations. Canopy-scale flux data from four forest ecosystems with Mediterranean-type climates were used in order to analyse the physiological controls on carbon and water flues through the year. Significant non-stomatal limitations on photosynthesis were detected, along with lesser changes in the conductance-assimilation relationship. New model parameterisations were derived and implemented in two contrasting modelling approaches. The effectiveness of two models, one a dynamic global vegetation model ("ORCHIDEE"), and the other a forest growth model particularly developed for Mediterranean simulations ("GOTILWA+"), was assessed and modelled canopy responses to seasonal changes in soil moisture were analysed in comparison with in situ flux measurements. In contrast to commonly held assumptions, we find that changing the ratio of conductance to assimilation under natural, seasonally-developing, soil moisture stress is not sufficient to reproduce forest canopy CO2 and water fluxes. However, accurate predictions of both CO2 and water fluxes under all soil moisture levels encountered in the field are obtained if photosynthetic capacity is assumed to vary with soil moisture. This new parameterisation has important consequences for simulated responses of carbon and water fluxes to seasonal soil moisture stress, and should greatly improve our ability to anticipate future impacts of climate changes on the functioning of ecosystems in Mediterranean-type climates.

Sign in / Sign up

Export Citation Format

Share Document