Physiological and Morphological Traits Associated With Spring Wheat Yield Under Hot, Irrigated Conditions

1994 ◽  
Vol 21 (6) ◽  
pp. 717 ◽  
Author(s):  
MP Reynolds ◽  
M Balota ◽  
MIB Delgado ◽  
I Amani ◽  
RA Fischer

Sixteen spring wheat genotypes were grown under hot, irrigated, low latitude conditions, during the 1990-1991 and 1991-1992 winter cropping cycles in Mexico, Egypt, India and the Sudan, and in the 1990 and 1991 winter cycles in Brazil. The genotypes were chosen to represent a range of genetlc diversity within modem wheat varieties. In addition to grain yield, in Mexico a number of morphological and physiological traits were measured throughout the growing season on two sowing dates (December and February), to evaluate their correlation with yield in the other countries. The morphological traits - above-ground biomass at maturity, grains m-2, days to anthesis and days to maturity - measured on both sowing dates in Mexico showed generally significant correlations with yields measured at the other sites. Moreover, ground-cover estimates early in establishment, and at anthesis, also showed some association with performance at these sites, but only when measured on the hotter, February sowing date in Mexico. Membrane thermostability (MT), measured on field-acclimated flag leaves showed generally significant correlations with performance at all sites, and with MT measurements made on heat- acclimated seedlings of the same genotypes grown in growth chambers. Flag-leaf photosynthesis measured at booting, anthesis and during grain filling on both sowing dates, was generally significantly correlated with grain yield at all sites, as was rate of loss of leaf chlorophyll content during grain filling. Stomatal conductance was also significantly correlated with performance at all three stages. Canopy temperature depression (CTD) measured with an infrared thermometer was significantly positively correlated with performance at the international sites when measured between 1200 and 1600 hours, after full canopy establishment. The correlation of CTD with yield was not affected by the irrigation status of the crop under well-watered conditions. The possible use of these traits in selection for yield under hot conditions is discussed.

2008 ◽  
Vol 110 (3) ◽  
pp. 366-375 ◽  
Author(s):  
Johanna Gelang ◽  
Håkan Pleijel ◽  
Ebe Sild ◽  
Helena Danielsson ◽  
Suhaila Younis ◽  
...  

1981 ◽  
Vol 97 (1) ◽  
pp. 45-53 ◽  
Author(s):  
F. M. Khalifa

SUMMARYAn experiment was carried out over a 3-year period at two locations in the central rainlands of Sudan under rainfed conditions at one site and under supplementary irrigation at the other to study the effects of cultivars and cultural practices on growth and grain yield of sunflower. Four cultivars, namely, Manohurian, Peredovik, Hungarian-A and Hungarian-B and four intra-row spacings of 15, 30, 45 and 60 cm (in rows 60 cm apart) were tested with three sowing dates starting on 15 July and following at 15-day intervals. Manchurian outyielded the other three varieties under supplementary irrigation whereas under rainfed conditions the reverse was true. This was attributed to the relative earliness in flowering of the varieties and their moisture requirements. Manchurian was the tallest with the thickest stem and a larger head at both locations compared with the other three varieties. Under rainfed conditions, the early sowing date of 15 July gave a significantly higher grain yield than the other two sowing dates, with the last sowing date of 15 August giving significantly least. This is attributed to decreasing moisture availability with delayed sowings. But under supplementary irrigation the effect of sowing date was less marked. Contrasting effects of sowing dates on plant height and stem circumference were obtained under the two systems of production. Under rainfed conditions there was a decrease in plant height and stem circumference with delayed sowing, whereas under supplementary irrigation the reverse was true. A contrasting response of plant height to spacing was also obtained; wider intra-row spacing was associated with taller plants under rainfed conditions and shorter plants under supplementary irrigation. Wider spacing was associated with thicker stems and larger heads at both locations. On the evidence obtained, 45 cm intra-row spacing is recommended for rainfed planting and 30 cm intra-row spacing for irrigated production of sunflower.


1995 ◽  
Vol 125 (1) ◽  
pp. 25-37 ◽  
Author(s):  
J. Webb ◽  
R. Sylvester-Bradley ◽  
J. D. Wafford

SUMMARYAt 14 sites in the UK, spring wheat (Triticum aestivum) cv. Tonic, was sown on three or four dates at each site between October and March in the 1988/89, 1989/90 and 1990/91 seasons. Responses to spring-applied fertilizer N over the range 0–320 kg/ha were determined. Earlier sowing did not increase uptake of soil N by the crop. Fertilizer N increased grain N offtake by between 25 and 140 kg/ha and yield by between 0·3 and 5·5 t/ha, although grain yield was less responsive to fertilizer N at later sowing dates. Apparent recovery of fertilizer N (AFR) also decreased as sowing was delayed but there was no effect of delayed sowing on the amount of grain produced from each kg of fertilizer N recovered. Because fertilizer N recovery decreased with later sowing, the amount of fertilizer N needed to produce the optimum economic grain yield was not reduced. Neither AFR nor optimum fertilizer (Nopt) was related to optimum yield. Regression of Nopt on the difference between optimum yield and yield without fertilizer N (△y) explained 77% of the variance in Nopt. There was an inverse relationship between △y and soil mineral N (SMN) in spring; regression of △y, on SMN in spring accounted for 29% of the variance in △y Current advisory systems which adjust economic fertilizer N recommendations according to anticipated yield are not justified by these results. Moreover the adjustments made, based on yield expectation, appear about three times as large as those needed to minimize residues of fertilizer N left unrecovered by the crop and to reduce the risk of nitrate leaching in the following winter.


1990 ◽  
Vol 62 (3) ◽  
pp. 227-236 ◽  
Author(s):  
Jari Peltonen ◽  
Tuomo Karvonen ◽  
Erkki Kivi

Interrelationships between climatic factors and spring wheat yield and quality were examined with 21 years field experiments. The formation of gluten was less at dry conditions (total precipitation under 50 mm) and total precipitation exceeded 130—140 mm. The optimum daily temperature for gluten production was some 15—17°C during grain filling. The gluten content decreased if daily minimum and maximum temperatures exceeded 11—12°C and 21—22°C, respectively. The effect of temperature and rainfall were not, however, significant in early maturing varieties. The climatic factors and grain yield did not correlate. Grain yield and protein yield had strong positive relationship, which was perhaps a consequence of supply and utilization of nitrogen. It is concluded that climatic factors affecting yield to quality ration in wheat may be excessive rains before heading and high temperature during grain filling. Interaction between weather and nitrogen are discussed to optimize correct timing of nitrogen fertilization for amount and quality of economic wheat yield.


1971 ◽  
Vol 19 (4) ◽  
pp. 211-222 ◽  
Author(s):  
J.H.J. Spiertz ◽  
B.A. ten Hag ◽  
L.J.P. Kupers

Spring wheat cv. Opal, Orca and Gaby, sown in 1967-8 on various dates at different seed rates or with different levels of N and chlormequat, were assessed for green area of leaves, internodes and ears. Green-area duration (D) for flag leaf and for peduncle were closely correlated with grain yield, the combined value for the 2 parameters accounting for 81 and 61% of the variance in grain yield in the 2 years, respectively. Including all the values of D in a multiple correlation increased the predictive value to 83 and 74%. D for ears was closely correlated with grain yield in 1968 only. The grain: leaf ratio was higher for Gaby than for the other 2 cv. (Abstract retrieved from CAB Abstracts by CABI’s permission)


2001 ◽  
Vol 137 (2) ◽  
pp. 139-145 ◽  
Author(s):  
O. MERAH

Water status traits have been proposed as criteria for drought tolerance improvement in several species especially in bread wheat, oat and barley. In order to test this possibility in durum wheat, in 1995 and 1997, a collection of 144 genotypes from different geographical origins was cultivated under rainfed Mediterranean conditions in Montpellier (southern France). Relative water content (RWC), osmotic potential (OP), as well as leaf morphological traits, grain yield (GY), total above-ground biomass and harvest index (HI) were measured. Large genotypic variations were observed for all traits. Differences between the 2 years were also noticed for all the traits which could be attributed to differences in water availability between the 2 growing seasons. The correlation analysis has revealed significant positive associations between water status traits and both GY and HI within and across years. These results suggest that genotypes which can maintain higher water status and then higher transpiration rates during grain filling, are more efficient in dry matter partitioning to grain and hence higher yield. Heritabilities of water status characters were higher than those of productivity traits. Our results emphasized the value of RWC and OP as criteria for durum wheat grain yield improvement under rainfed Mediterranean conditions. Relationships between RWC, OP and flag leaf morphological traits are also discussed.


Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 507
Author(s):  
Yuxin Dong ◽  
Bingqi Wei ◽  
Lixue Wang ◽  
Yuhan Zhang ◽  
Huaying Zhang ◽  
...  

Growing spring wheat in Inner Mongolia is challenging because of the short growing period, dry-hot winds, and heat-forced maturity. There are also problems with growing winter wheat varieties, such as frost damage, spring droughts, and “late spring cold”. These factors have restricted efforts to increase yields. In order to address these challenges, this study adopted a “spring wheat winter-sowing” planting model for growing wheat in the Hetao Plain Irrigation District in Inner Mongolia and studied wheat varieties with different vernalization requirements through three consecutive field trials. The effects of different sowing dates were analyzed on seed germination and seedling emergence, growth, material accumulation, and yield formation, and the differences were characterized from traditional spring wheat. The results indicated that delaying the sowing date increased the spring emergence rate of the wheat varieties. The winter-seeded spring wheat germinated and ripened after three and seven days, respectively, earlier than the spring-seeded. The grain yield for the winter-seeded wheat was parallel to the spring-seeded wheat. Compared with the spring-seeded wheat, the winter-seeded wheat displayed less panicles, but greater grains per spike, and a 1000-grain weight. When seeded in winter, Yongliang 4 performed better than Ningdong 11 and Henong 7106 in terms of the emergence rate, material accumulation, and grain yield. The best seeding time for the winter-seeded spring wheat in the Hetao Irrigation District of Inner Mongolia is early November.


1973 ◽  
Vol 21 (4) ◽  
pp. 282-296
Author(s):  
J.H.J. Spiertz

Wheat cv. Juliana (culm length 117 cm), Manella (82 cm), Lely (80 cm), Mex-cross (69 cm) and Gaines (79 cm) were sprayed twice before flowering with 2 kg maneb/ha and twice after flowering with 1 kg benomyl/ha. Combined treatment greatly delayed the spread of Septoria tritici and S. nodorum in the crop, the flag leaf remained green longer, the grain filling period was lengthened, and the growth rate of the grain between the milk stage and the dough stage was increased from 204 to 230 kg/ha day; effects were greater in the susceptible cultivars Lely and Gaines. Increases in grain yield were 14, 23, 32, 16 and 42% for the 5 cultivars, respectively. The green area of the flag leaf accounted for 85% of the variance in grain yield. The degree of disease infection was not significantly correlated with culm length or amount of leaf area. ADDITIONAL ABSTRACT: Spraying with maneb at 2 kg/ha twice before flowering and with benomyl at 1 kg/ha twice after flowering greatly delayed the spread of Septoria tritici and S. [Leptosphaeria] nodorum and increased yields, particularly in the 2 susceptible cvs. (Abstract retrieved from CAB Abstracts by CABI’s permission)


MAUSAM ◽  
2021 ◽  
Vol 67 (3) ◽  
pp. 677-682
Author(s):  
J. L. CHAUDHARY ◽  
S. R. PATEL ◽  
N. MANIKANDAN ◽  
RAJESH KHAVSE ◽  
P. K. VERMA

Field experiment was conducted during Rabi seasons of 2010-11, 2011-12 and 2012-13 at Research and Instructional Farm of Indira Gandhi Krishi Vishwavidyalaya, Raipur to examine and study the phenology, accumulation of growing degree days (GDD), heliothermal units (HTU), photothermal unit (PTU) and performance of wheat (Triticum aestivam L.) of four wheat varieties grown under five different sowing dates in factorial Randomized Block Design. It was observed that GDDs got reduced significantly with subsequent delay in sowing time. For our study purpose and as per package of practices, 25 November D1 can be taken as early sowing and D2 - 5 December as timely sowing conditions.  The wheat varieties Amar and Sujata took highest GDD, HTU and PTU to maturity.  On the mean basis the variety Kanchan produced highest grain yield (3147 kg/ha) followed by GW-273 (2947 kg/ha).  The significant reduction in grain yield was recorded when sowing was delayed beyond D2 - December 05.  Among the wheat varieties Kanchan showed better performance in terms of RUE followed by GW-273 and Sujata. Highest HUE was observed in wheat variety Kanchan followed by Sujata and GW-273. Varieties giving higher yield, RUE and HUE are identified under varying growing environments so as to suggest the appropriate sowing dates of wheat varieties in Chhattisgarh plains. GDD is giving consistent results as its variability is least varying between 3.4-5.3 per cent for different varieties and therefore it is reliable index for studying environmental effects on wheat in this region. Lowest RUE was observed under 5 January sowing (D5) in the all varieties which leads to conclusion that this sowing date must be avoided and wheat crop sowing must be completed latest by 25 December to avoid adverse effects on productivity.       


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