Maize Evapotranspiration, Yield Production Functions, Biomass, Grain Yield, Harvest Index, and Yield Response Factors under Full and Limited Irrigation

2013 ◽  
Vol 56 (2) ◽  
pp. 373-393 ◽  
Author(s):  
Koffi Djaman ◽  
Suat Irmak ◽  
William R. Rathje ◽  
Derrel L. Martin ◽  
Dean E. Eisenhauer
Keyword(s):  
Grain Yield ◽  
Harvest Index ◽  
Production Functions ◽  
Yield Response ◽  
Response Factors ◽  
Yield Production

Grain Yield, Crop and Basal Evapotranspiration, Production Functions and Water Productivity Response of Drought-tolerant and Non-drought-tolerant Maize Hybrids under Different Irrigation Levels and Population Densities: Part I. In Western Nebraska’s Semi-

2019 ◽  
Vol 35 (1) ◽  
pp. 61-81 ◽  
Author(s):  
Ali T. Mohammed ◽  
Suat Irmak ◽  
William L. Kranz ◽  
Simon van Donk ◽  
C. Dean Yonts
Keyword(s):  
Grain Yield ◽  
Annual Variation ◽  
Production Functions ◽  
Yield Response ◽  
Substantial Variation ◽  
Population Densities ◽  
Drought Tolerant ◽  
Yield Production ◽  
Irrigation Levels ◽  
Semi Arid

Abstract.Grain yield, crop evapotranspiration (ETc), basal evapotranspiration (ETb), ETc-yield production functions (ETYPF), and crop water use efficiency (CWUE) response of three drought-tolerant (DT) and one non-drought-tolerant (NDT) maize ( L.) hybrids to two plant population densities (PPDs) [84,000 plants ha-1 (high PPD) and 59,300 plants ha-1 (low PPD)] and three irrigation levels were researched at two semi-arid locations: North Platte (WCREC) and Scottsbluff (MAL), Nebraska, in 2010, 2011, and 2012. The irrigation levels were fully irrigated (FIT), early cutoff (ECOT), and rainfed (RFT). Precipitation in 2010 was above average, 2011 was a normal year, and 2012 was one of the driest and hottest years in Nebraska’s recorded history. Generally, DT hybrids performed better than the NDT hybrid. The performances of the DT hybrids were stronger in the driest year and driest location (MAL), especially with low PPD. ETc exhibited inter-annual variation for the same hybrid in the same location and between the two locations and also with the PPD and irrigation treatments. There were significant differences (P<0.05) between the ETc values for the same hybrids across three irrigation treatments. The grain yield response to hybrids and treatments also exhibited substantial variation for the same hybrid between the PPDs and had inter-annual variation between the years and locations. The greatest grain yields of 14.6 and 18.0 Mg ha-1 were observed with 548 and 837 mm of ETc, which were recorded for the DT hybrid H3 (high PPD) at WCREC and MAL, respectively. There were significant differences (P<0.05) in performance among the DT hybrids in performance variables (ETc, ETb, ETYPF, CWUE). In most cases, the DT hybrids produced greater grain yield than the NDT hybrid with lower ETc. In terms of ETYPF response for individual hybrids, the slope of the production functions exhibited an inter-annual variation between the hybrids and for the same hybrids between the years and location for both high and low PPDs. All hybrids exhibited a linear yield response to increasing ETc in all years at both locations with positive slopes in all cases with DT hybrids having the greatest slopes. The ETb values also exhibited a substantial variation between the hybrids, years, locations, and PPDs. Generally, DT hybrids had sizably lower ETb values than the NDT hybrid in both PPD levels. It was concluded that DT hybrids increase the grain yield production per unit of ETc in semi-arid regions not only during very dry and hot year, but also during the growing season with favorable rainfall and climate conditions. Keywords: Basal evapotranspiration, Drought-tolerance, Maize, Yield production functions.

scholarly journals Irrigation-Yield Production Functions and Irrigation Water Use Efficiency Response of Drought-Tolerant and Non-Drought-Tolerant Maize Hybrids under Different Irrigation Levels, Population Densities, and Environments

2020 ◽  
Vol 12 (1) ◽  
pp. 358
Author(s):  
Suat Irmak ◽  
Ali T. Mohammed ◽  
William Kranz ◽  
C.D. Yonts ◽  
Simon van Donk
Keyword(s):  
Production Functions ◽  
Yield Response ◽  
Population Densities ◽  
Irrigation Water Use Efficiency ◽  
Drought Tolerant ◽  
Yield Production ◽  
Irrigation Water Use ◽  
Use Efficiency ◽  
Irrigation Levels ◽  
Semi Arid

Irrigation-yield production functions (IYPFs), irrigation water use efficiency (IWUE), and grain production per unit of applied irrigation of non-drought-tolerant (NDT) and drought-tolerant (DT) maize (Zea mays L.) hybrids were quantified in four locations with different climates in Nebraska [Concord (sub-humid), Clay Center (transition zone between sub-humid and semi-arid); North Platte (semi-arid); and, Scottsbluff (semi-arid)] during three growing seasons (2010, 2011, and 2012) at three irrigation levels (fully-irrigated treatment (FIT), early cut-off (ECOT), and rainfed (RFT)) under two plant population densities (PPDs) (low-PPD; 59,300 plants ha−1; and, high-PPD, 84,000 plants ha−1). Overall, DT hybrids’ performance was superior to NDT hybrid at RFT, ECT, and FIT conditions, as confirmed by the yield response, IYPF and IWUE when all locations, years, and PPDs were averaged. The yield response to water was greater with the high-PPD than the low-PPD in most cases. The magnitude of the highest yields for DT hybrids ranged from 7.3 (low-PPD) to 8.5% (high-PPD) under RFT, 3.7 (low-PPD) to 9.6% (high-PPD) under ECOT, and 3.9% (high-PPD) under FIT higher than NDT hybrid. Relatively, DT hybrids can resist drought-stress conditions longer than NDT hybrid with fewer penalties in yield reduction and maintain comparable or even higher yield production at non-stress-water conditions.

Grain Yield, Crop and Basal Evapotranspiration, Production Functions, and Water Productivity Response of Drought-tolerant and Non-drought-tolerant Maize Hybrids under Different Irrigation Levels, Population Densities, and Environments: Part II. In South-c

2019 ◽  
Vol 35 (1) ◽  
pp. 83-102 ◽  
Author(s):  
Suat Irmak ◽  
Ali T. Mohammed ◽  
William L. Kranz
Keyword(s):  
Grain Yield ◽  
Annual Variation ◽  
Water Productivity ◽  
Production Functions ◽  
Yield Response ◽  
Crop Evapotranspiration ◽  
Crop Water ◽  
Population Densities ◽  
Drought Tolerant ◽  
Irrigation Levels

Abstract. Information and data on newer drought-tolerant maize hybrid response to water in different climates are extremely scarce. This research quantified the performance of non-drought-tolerant (NDT) (H1) and drought-tolerant (DT) (H2, H3, and H4) maize ( L.) hybrids response to grain yield, crop evapotranspiration (ETc), basal evapotranspiration (ETb), ETc-yield production functions (ETYPF), and crop water use efficiency (CWUE) at three irrigation levels and two plant population densities (PPDs) at two locations (transition zone between sub-humid and semi-arid climates at Clay Center (SCAL), Nebraska, in 2010 and 2012; and in a sub-humid climate at Concord (HAL), Nebraska, in 2010, 2011, and 2012). Irrigation treatments were: fully irrigated (FIT), early cutoff (ECOT) (i.e., no irrigation after blister stage), and rainfed (RFT) under two PPDs of 59,300 plants ha-1 (low PPD), and 84,000 plants ha-1 (high PPD). Generally, DT hybrids performed superior to NDT hybrid consistently at both locations, treatments, and years. DT H3 and DT H4 had highest grain yield consistently at SCAL and HAL, respectively. DT H3 and H4 hybrids’ productivity was not only superior in the RFT, but also in FIT. The highest yield of 16.3, and 15.3 Mg ha-1 were achieved by DT H3 (high PPD) and DT H2 (high PPD), respectively, associated with 471 and 590 mm of ETc in the FIT in 2012 at SCAL, and HAL, respectively. In most cases, all hybrids had highest grain yield under low PPD than high PPD at the RFT. All hybrids exhibited a linear yield response to increasing ETc in all years at both locations with positive slopes in all cases. The individual ETYPF response for individual hybrids had inter-annual variation in slopes between the hybrids and for the same hybrids between the years and location for both low and high PPDs. The ETYPF slopes ranged from 0.004 to 0.102 Mg ha-1 mm-,1 including all treatments (i.e., irrigation and PPDs) at SCAL for 2010 and 2012; and they ranged from 0.008 to 0.057 Mg ha-1 mm-1 including all treatments at HAL for 2010, 2011, and 2012. The ETb values exhibited inter-annual variation for the same hybrid between the irrigation levels, PPDs, and locations and they also exhibited an inner-annual variation between the hybrids and treatments in a given year with DT hybrids having consistently lower ETb values than the NDT hybrid. The greatest CWUE values were found in DT hybrids consistently at both locations. The DT hybrids can significantly increase yield productivity as well as crop water productivity per unit of ETc with respect to conventional hybrids not only in dry conditions, but also in average or above average years in terms of precipitation. Keywords: Basal evapotranspiration, Crop evapotranspiration, Drought-tolerance, Efficiency, Maize, Production functions.

Intraspecific competition in oat varieties selected for grain yield and milling

2018 ◽  
Vol 69 (7) ◽  
pp. 673 ◽  
Author(s):  
Victor O. Sadras ◽  
M. Mahadevan ◽  
Pamela K. Zwer
Keyword(s):  
Grain Yield ◽  
Intraspecific Competition ◽  
Harvest Index ◽  
Competitive Ability ◽  
High Yield ◽  
Yield Response ◽  
Index Number ◽  
Environment Interaction ◽  
Grain Number ◽  
Panicle Number

Oats likely emerged as part of the weedy grass assemblage in early wheat and barley crops. Some Avena species, such as A. fatua and A. sterilis, evolved into aggressive weeds, and the high interspecific competitive ability of cultivated oats (A. sativa) is valued agronomically to facilitate weed control in rotations. We tested the hypothesis, verified in many crops, that high yield of oats is related to low intraspecific competitive ability. Ten contemporary oat varieties, selected for grain yield and milling attributes, where grown in three environments. Response to competition was calculated as 100 × (Yb – Yc)/Yc, where Y is yield measured in border (b) and centre (c) rows. The same definition was used to calculate response to competition of yield components (biomass, harvest index, grain number, grain weight) and the components of grain number (panicle number and grains per panicle). Yield response to competition was affected by all three sources of variation, i.e. environment, variety and variety × environment interaction. The interaction demonstrates the plasticity of yield response to intraspecific competition; for example, the response to competition of variety Mortlock varied from 9% to 71% among environments. This plasticity in yield response to competition was partially related to variety-dependent responses to competition for biomass and harvest index, number of panicles and number of grains per panicle. We did not find the expected negative association between yield and variety-dependent response to competition. We discuss how this lack of correlation could relate to sampling issues, i.e. a limitation in the range of environments and varieties explored in this study, or reflect a legitimate feature of oat crops arising from early and contemporary selective pressures.

IMPROVEMENT OF SPRING DURUM WHEAT SELECTION METHODOLOGIES UNDER CLIMATE CHANGE CONDITIONS

1970 ◽  
pp. 33-36
Author(s):  
А. I. Grabovets ◽  
V. P. Kadushkina ◽  
S. А. Kovalenko
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Correlation Coefficient ◽  
Harvest Index ◽  
Unit Area ◽  
Correlation Coefficients ◽  
Chemical Mutagenesis ◽  
Main Method ◽  
The Relationship ◽  
Selection Of

With the growing aridity of the climate on the Don, it became necessary to improve the methodology for conducting the  breeding of spring durum wheat. The main method of obtaining the source material remains intraspecific step hybridization. Crossings were performed between genetically distant forms, differing in origin and required traits and properties. The use of chemical mutagenesis was a productive way to change the heredity of genotypes in terms of drought tolerance. When breeding for productivity, both in dry years of research and in favorable years, the most objective markers were identified — the size of the aerial mass, the mass of grain per plant, spike, and harvest index. The magnitude of the correlation coefficients between the yield per unit area and the elements of its structure is established. It was most closely associated with them in dry years, while in wet years it decreased. Power the correlation of the characteristics of the pair - the grain yield per square meter - the aboveground biomass averaged r = 0.73, and in dry years it was higher (0.91) than in favorable ones (0.61 - 0.70) , between the harvest and the harvest index - r = 0.81 (on average). In dry years, the correlation coefficient increased to 0.92. Research data confirms the greatest importance of the mass of grain from one ear and the plant in the formation of grain yield per unit area in both dry and wet years. In dry years, the correlation coefficient between yield and grain mass per plant was on average r = 0.80; in favorable years, r = 0.69. The relationship between yield and grain mass from the ear was greater — r = 0.84 and r = 0.82, respectively. Consequently, the breeding significance of the aboveground mass and the productivity of the ear, as a criterion for the selection of the crop, especially increases in the dry years. They were basic in the selection.

Sign in / Sign up

Export Citation Format

Share Document