Rate Of Grain Yield Research Articles

IMPACT OF SOIL STERILIZATION FROM DIFFERENT LOCATIONS, WHEAT SEEDS CLEANING AND THEIR INTERACTIONS ON WEED CONTROL, AND YIELD AND YIELD COMPONENTS

IMPACT OF SOIL STERILIZATION FROM DIFFERENT LOCATIONS, WHEAT SEEDS CLEANING AND THEIR INTERACTIONS ON WEED CONTROL, AND YIELD AND YIELD COMPONENTS

Effectiveness of the use of biologically active substances (bas) at different levels of mineral nutrition of beans (paseolus vulgaris l.) grown under condition Afghanistan

This experiment was carried out in experimental field of Alberoni University of Kapisa province of Afghanistan, in the summer of 2022 and 2023. The experiment was carried out in the form of randomized complete block design with three replications. The treatment included three different levels nitrogen (N30, N45, N60), phosphorus (P20, P40, P60), potassium (K10, K20, K30), and one level of gibberellic acid GA3 (G1 = 100ppm). This study flowing the weight of 1000-grain, Grain yield, biological yield and straw yield were affected by experimental treatments. In evaluating the effects, the highest rate of studies traits was obtained at yield parameters in bean. Moreover, due to the application of 100ppm gibberellic acid with N60, P60, K30 kg/ha the highest rate was obtained from weight of 1000 grain, Grain yield and biological yield, but in the parameter of straw yield was earned low amount then T4 during 2022 and 2023 year. In addition, investigating the effect of gibberellic acid showed that the highest rate of grain yield was obtained at T7.

Breeding increases grain yield, zinc, and iron, supporting enhanced wheat biofortification

AbstractEstimation of the rate of genetic gain over time allows quantification of breeding progress. Here we report on the rate of grain yield and zinc (Zn) concentration increase over 11 yr of targeted wheat (Triticum aestivum L.) biofortification breeding at the International Maize and Wheat Improvement Center (CIMMYT). Data from yield trials evaluated across multiple locations in South Asia and beyond showed that average annual increases in grain yield potential of ∼1.5% and 0.9% per year gains for grain Zn and Fe concentrations. Across locations in all countries, mean yields of the five highest‐yielding entries showed an annual gain of 109 kg ha−1 yr−1 in yield and 0.3 mg kg−1 for grain Fe and Zn as well as 0.66 g for the yield component thousand‐grain weight. There was a strong positive correlation between Fe and Zn (r = .42) across locations, whereas no genetic correlation was observed between grain yield and Zn (r = .05) across locations. Despite the slight negative relationship between yield and Zn, through targeted crossing and development of large segregating populations we were able to identify transgressive segregants combining increased yield and Zn concentrations. Significant differences between lines for grain micronutrient concentrations were detected, and significant location effects on grain Zn and Fe concentrations were observed. These results demonstrate that continuous and simultaneous genetic gain for grain yield and concentrations of Fe and Zn is possible in elite spring bread wheat lines with potential to deliver global impact through identification of superior parents for use by national breeding programs and the release of biofortified wheat cultivars.

Light absorption and light extinction in barley (Hordeum vulgare L.) as affected by planting dates and plant genotypes

Plant light absorption and extinction may affect plant growth and yield. A split plot experiment (with three replications) was carried out in the Research Field of Agricultural College, Islamic Azad University, Isfahan, Iran, during 2011–2012 in order to determine the influence of light absorption and extinction on barley growth and yield. Planting dates including Oct 10th (P1), 25th (P2), and Nov 10th (P3) and plant genotypes including Nosrat (N), 4Shur (S), and Fajr 30 (F) were used as the main- and sub-plots, respectively. Plant growth and yield as well as crop light absorption and extinction were determined at different growth stages. Using a light meter, the rate of photosynthetically active radiation of canopy in the range of 400–700 nm was determined (41–57%). Light extinction coefficients (0.355–0.485) were also determined according to the Beer-Lambert law. Planting dates and genotypes significantly affected crop growth, yield, and response to light. S resulted in the highest rate of light extinction and absorption at P1 and P3, respectively, and it also resulted in the highest rate of grain yield (4228 kg ha−1) and harvest index (40.9). These results indicated the positive correlation between the growth and yield of barley genotypes with light absorption and extinction. Such findings can be used for a more efficient designing of a barley canopy with higher growth and yield.

Optimum N rate for grain yield coincides with minimum greenhouse gas intensity in flooded rice fields

Excessive application of N fertilizer to rice results in water and atmospheric pollution including greenhouse gas (GHG) emissions. Therefore, N fertilizer management needs to be optimized taking into account grain yield, global warming potential (GWP, Mg CO2 eq. ha−1) and GHG intensity (GHGI, kg CO2 eq. kg−1 grain). However, the tradeoffs between the effects of N rate on rice grain yield, GWP and GHGI have not been adequately evaluated. Therefore, field experiments to determine the effect of N rate (as urea) on yield, GWP and GHGI were conducted in a typical flooded, transplanted rice paddy in a temperate environment. Methane (CH4) and nitrous oxide (N2O) emission rates were determined throughout the entire year (both during growing and fallow seasons) over two years. Rice grain yield showed a quadratic response to N rate, and the maximum yield (6.7–6.8 t ha−1) was achieved at 112–119 kg N ha−1, 50% higher than the yield of the control (0 kg N ha−1). Increasing N rate increased the seasonal N2O flux by 4.56–7.11 g N2O kg−1 N, but N2O flux contributed less than 7% of the total GWP. The GWP was mainly determined by the CH4 flux, which showed a relatively flat quadratic response to N rate, peaking at 124–138 kg N ha−1. Thus, GWP also showed a quadratic response to N rate, peaking at 122–130 kg N ha−1. The GHGI decreased as N rate increased and was the lowest (1.10–1.28 kg CO2-eq. kg−1 grain yield) at 104–112 kg N ha−1, approximately 20% lower than GHGI in the 0 N treatment. In conclusion, the N rate for maximum yield was similar to the N rate for minimum GHGI, mainly because of the small effect of N rate on CH4 emissions and the low magnitude of N2O emissions. Thus, GHGI was largely driven by grain yield, so the N rate for maximum grain yield was similar to the N rate for maximum GHGI. Proper N fertilization is essential in rice farming systems to increase crop productivity and reduce the global warming impact (GWP and GHGI).

Crop systems and topdressing nitrogen on grain yield and technological attributes of common bean under no-tillage

ABSTRACT Common bean has been the main crop in succession to corn and Brachiaria in no-tillage systems, in the Brazilian Savannah. This study aimed to evaluate the influence of crop systems and topdressing nitrogen on grain yield and technological attributes of common bean under no-tillage. A randomized block design, in a split-plot arrangement, with four replications, was used. The plots consisted of three crop systems (corn in sole crop, corn + Urochloa ruziziensis intercropped and U. ruziziensis in sole crop) and the subplots by five nitrogen rates (0 kg ha-1, 40 kg ha-1, 80 kg ha-1, 120 kg ha-1 and 160 kg ha-1). There is interaction between predecessor cropping systems and N rates for grain yield, milling efficiency specifically on sieve 13, as well as for the grain hydration ratio. Increasing topdressing N rates applied on common bean in succession to corn in sole crop promote increases in grain yield, resulting in a milling efficiency in the oblong-hole sieve 14 higher than in the other crop systems evaluated. The increase of the topdressing N rates applied on common bean in succession to corn and U. ruziziensis in sole crops or intercropped does not influence the time for maximum hydration of the grains, but reduces their cooking time, mainly in succession to U. ruziziensis and corn in sole crops.

Photosynthetic Characteristics and Chloroplast Ultrastructure of Summer Maize Response to Different Nitrogen Supplies.

Maize (Zea mays L.) is the important crop over the world. Nitrogen (N) as necessary element affects photosynthetic characteristics and grain yield of summer maize. In this study, N0 (0 kg N ha-1), N1 (129 kg N ha-1), N2 (185 kg N ha-1), and N3 (300 kg N ha-1) was conducted using hybrid ‘ZhengDan958’ at Dawenkou research field (36°11′N, 117°06′E, 178 m altitude) in the North China Plain to explore the effects of N rate on photosynthetic characteristics and chloroplast ultrastructure. Gas exchange parameters, chlorophyll fluorescence parameters, leaf area index (LAI), chlorophyll SPAD value, chloroplast ultrastructure, dry matter weight and grain yield were measured. At physiological maturity stage, dry matter weight and grain yield of N2 increased by 33–52% (P ≤ 0.05) and 6–32% (P ≤ 0.05), respectively, compared with other treatments. During the growing from silking (R1) to milk (R3) stage, LAI of N0 and N1 were 35–38% (P ≤ 0.05) and 9–23% (P ≤ 0.05) less than that of N2, respectively. Chlorophyll SPAD value of N0 and N1 were 13–22% (P ≤ 0.05) and 5–11% (P ≤ 0.05) lower than that of N2. There was no significant difference in LAI and chlorophyll SPAD value between N2 and N3 during the period from R1 to R3 (P > 0.05). The net photosynthetic rate (Pn), maximal quantum efficiency of PSII (Fv/Fm) and quantum efficiency of PSII (ΦPSII) were higher with the increase of N rate up to N2 (P ≤ 0.05), and those of N3 were significantly less than N2 (P ≤ 0.05). In compared with N2, the chloroplast configuration of N0 and N1 became elliptical, almost circular or irregular. The membrane of chloroplast and thylakoid resolved with growing stage, and the number of chloroplast per cell and lamellae per grana decreased under N0 and N1 treatment (P ≤ 0.05). Under N0 and N1 treatments, summer maize had more negative photosynthetic characteristics. The more number of osmium granule and vesicle and the larger gap between lamellae were shown in N3. Therefore, N2 treatment, 185 kg N ha-1, is the appropriate application rate for grain yield, photosynthesis and chloroplast ultrastructure.

Effect of phosphorus applied as monoammonium phosphate-coated polymers in corn culture under no-tillage system

The use of phosphate fertilizers as coated polymers reduces phosphorus losses that occur by adsorption of P to soil particles, thereby providing this essential nutrient for a longer period. The objective of this study was to evaluate the effect of phosphorus doses applied as conventional monoammonium phosphate or as coated polymers on corn grown in a clayey Oxisol, in the Cerrado region. The experiment was conducted in Selvíria - MS, located at 22°22? S and 51°22? W. The experiment was laid out in a randomized block design arranged as a 4 × 2 factorial, with four doses of P2O5 (0, 50, 100, and 150 kg ha-1) and two sources of phosphorus (monoammonium phosphate (MAP) and monoammonium phosphate coated polymers). The experiment was conducted under no-tillage system during the cropping seasons in 2008/09 and 2009/10. The MAP and MAP-coated sources did not differ in most of the yield components in either of the two seasons. We found a quadratic function adjustment for P doses up to 117 and 98 kg ha-1 of P2O5 for P concentration in leaf tissue and grain yield in the 2008/2009 crop, respectively. We also obtained a quadratic function adjustment for P rates for grain yield and number of plants, up to 118 and 113 kg ha-1 of P2O5, respectively, in the 2009/2010 harvest.

Light response of sunflower and canola as affected by plant density, plant genotype and N fertilization

Crop response to light is an important parameter determining crop growth. Three field (split plots) experiments were conducted to investigate the effects of plant density, plant genotype and N fertilization on the light absorption and light extinction of sunflower (Helianthus annuus L.) and canola (Brassica napus L.). A detailed set of plant growth, light absorption and crop yield and oil related parameters were determined. Light was measured at noon during the sunny days with clear sky. In experiment I, although the plant density (PD) of 14 resulted in the highest rate of sunflower light absorption (31.37%) and light extinction (0.756), the highest rate of grain yield and grain oil yield was resulted at PD12 at 3639 and 1457.9kg/ha, respectively; as well as by genotype SUP.A. In experiment II (canola), PD80 resulted in the highest rate of light absorption (13.13%), light extinction (0.63), grain yield (2189.4kg/ha) and grain oil yield (556.54kg/ha). This was also the case for Genotype H. In experiment III (canola), although N150 resulted in the highest rate of light absorption (10.74%) and light extinction (0.48), the highest rate of grain yield (3413.6kg/ha) and grain oil yield (891.86kg/ha) was resulted at N100 as well as by Genotype H401. Results indicate how light properties, crop growth and yield of sunflower and canola can be affected by plant and environmental parameters, which are also of practical use by farmers.

Morphological and physiological responses of different wheat genotypes to chilling stress: a cue to explain yield loss.

The eco-physiological mechanism of wheat yield loss resulting from chilling stress is a fundamental scientific issue. However, previous studies have focused on hexaploid wheats, and few studies on the morphological and physiological plasticity of wheat plants. Six different wheat genotypes were tested under chilling stress to investigate the physio-morphological parameters as well as the loss of grain yield in growth chambers. Chilling stress resulted in significant loss in grain yield in all genotypes. Under chilling stress, diploid wheats generated zero harvest, and tetraploid genotypes also suffered from a pronounced loss in grain yield, compared with the control group. In contrast, hexaploid genotypes acquired relatively high maintenance rate of grain yield among three species. Diploid and tetraploid wheat genotypes maintained relatively large leaf area and high photosynthetic rates, but they were subjected to significant declines in vascular bundle number and productive tillers as a consequence of the inhibition by sink growth under chilling stress. The hexaploid wheats were found to have relatively low leaf area and photosynthetic rates. These genotypes also stored more soluble carbohydrates and exhibited stronger sink enhancement, ensuring the translocation and redistribution of assimilates. Our findings provided a new theoretical understanding of yield stabilization in the domestication process of wheat genotypes under chilling stress. © 2017 Her Majesty the Queen in Right of Canada. Journal of The Science of Food and Agriculture © 2017 Society of Chemical Industry.

Soil Enzymes and Microbial Activity as Influenced by Tillage and Fertilization in Wheat Production

to investigate the influence of five fertilization treatments and three tillage systems on wheat productivity, soil microbial biomass and some enzymes activity. Fertilization treatments were control (without treatment) (F1), Farmyard manure (F2), Compost (F3), Mineral fertilizers (F4) and a mixture of farmyard manure + compost + chemical fertilizers (F5). Tillage systems were no-tillage (NT), minimum tillage (MT) and conventional tillage (CT). Experiments were designed in a split plot based on randomized complete block design (RCBD) with three replications in 2010-11 and 2011-12 growing seasons. Main plots were the tillage systems while the fertilization treatments were arranged in sub plots. The highest rate of grain yield was produced in MT system under F5 treatment. CT system showed the average reduction in grain yield of about 17% than MT; while CT showed average increasing of about 4% than NT in wheat grain yield. MT and NT systems increased soil microbial biomass compared to CT. Farm yard manure or compost applications increased soil microbial biomass significantly compared with mineral fertilizer. The urease, dehydrogenase and phosphatase activities in the F4 treatment were significantly lower than in the other fertilizer treatments F2, F3, and F5. The highest value of urease activity was under NT + F2 treatment in the two years of this study.

China’s Food Security Evaluation Based on Factor Analysis

China’s food security has been a hot issue of social concern. Based on existing studies, this paper chose 12 factors to establish comprehensive evaluation system of good security, including the arable land area per capital, the fluctuation rate of grain yield, the grain price rising rate, the degree of agricultural mechanization, etc. Comprehensive evaluation of China’s food security over the years by factor analysis shows that China’s food security is in a tense balance state, the sources of which are the supportability factor slowdown and the score of stability factor decrease. Base on the analysis, we proposed to strengthen financial support to agriculture, improve the land protection mechanism, and improve the utilization rate of grain and other countermeasures to ensure China’s food security in the future.

The interactive effect of different levels of nitrogen and drought stress on yield and yield components of the mung bean

In order to investigate the interactive effect of different levels of nitrogen and drought stress on yield and yield components of the Mung Bean, field experiment was carried out in the city of Ahwaz field healthy martyr in a split plot randomized complete block design with four replications in crop year of 2011-2012. In this experiment three levels of drought stress (50, 75, 100 mm evaporation from class A evaporation pan) as the main factor and three levels of nitrogen (50, 100, 150 kg/ha) as the sub factor were examined. The results of the research showed that the effect of different levels of drought stress on the grain yield, number of grains per pod, 100-grain weight, and number of pods per plant was significant, so that the highest rate of grain yield, number of grains per pod, 100-grain weight, and number of pods per plant belonged to the treatment with 50 mm evaporation. Furthermore, the results showed that the effect of different level of nitrogen on abovementioned traits was significant except the number of pods per plant and 100-grain weight. The results also showed that drought stress had a negative effect on most agronomic and physiological traits associated with the yield, but nitrogen fertilizer had a positive effect on them.

The effect of plants density and population on yield and yield components and forage in dual purpose cultivation of barley cultivars (Hordeum vulgare L.)

In order to study the effect of plant population and Density on the yield components and forage in dual cultivation of barley cultivars, a split plot experiment in the form of randomized complete block design with for replications was carried out in Khuzestan agricultural and natural resources research farm in 2011-2012. The main factor consisted of two barley cultivars (midday, 10th global) and the sub factor consisted of four levels of planting density (250, 350, 450, 550 seed per square meter). The results of the experiment showed that the effect of cultivar and planting density on grain yield was significant at 1% level. The interactive effect of cultivar and density on 1000-grain weight, biomass yield of final harvest time, forage, and harvest index was not significant. However, the difference between various cultivars in terms of total biomass yield was significant at 5% level. The highest rate of grain yield, biological yield, number of grains per area unit, and 1000-grain weight belonged to 10th global cultivar with density of 550 seeds per square meter. The interactive effect of cultivar and planting density on the yield of forage was not significant while the effect of planting density on forage was significant at 1% level. The highest forage yield belonged to 10th global cultivar with density of 550 seeds per square meter and the lowest yield belonged to midday cultivar with density of 250 seeds per square meter. The results of the experiment indicated that 10th global cultivar with high yield potential produced more vegetative organs and its early season vegetative growth was more than midday cultivar and consequently it had higher yield of forage, and also had produced more fertile tillers and foliages than the midday cultivar; moreover, it had higher forage and grain production potential than the midday cultivar while the midday cultivar had the lowest vegetative growth and its grain and forage production potential was less than 10th global cultivar. * Corresponding Author: Roya Dashti Nejad  dashti1287@.yahoo.com

Effects of Shading on Grain-Filling Properties and Yield of Maize at Different Growth Stages

The objective of this study was to explore the effect of shading at different growth stages on grain filling properties and yield of maize(Zea mays L.). The Field experiments were carried out using maize cultivars(Jingke 968, Zhengdan 958) with shading of 50% at the 13 th leaf fully expanded(T1), the silking(T2) and the15 th day after silking(T3) for seven days in 2012–2013. The natural light condition without shading was used as the control. The Logistic equation was used to analyze the grain filling process. The results showed that grains per ear, 1000-kernel weight and yield were all decreased to a different degree under shading conditions at different growth stages, and the decrease rate of grain yield was increased with lasting shading duration. The yield was significantly different under different shading treatments. The duration of the maximum grain filling and active grain-filling period(P) were shortened, the maximum and mean grain-filling rate(Gmax) decreased and the final grain weight(A) reduced under shading conditions. The relation among grain weight, grain number per ear and grain yield was determined by characteristics of maize cultivar. The grain weight of the same cultivar was significantly positively correlated with grain weight with the maximum grain-filling rate(Wmax), and the grain weight of different maize cultivars was determined by active grain-filling period(P). The grain number per ear of the same maize cultivar was significantly positively correlated with Gmax, and the grain number per ear of different maize cultivars was determined by Wmax. It is an important way to keep a high or stable yield by selecting the suitable cultivar, improving Wmax and Gmax and prolonging active grain-filling period(P) under weak light stress.

Tillage effects on soil properties and wheat cultivars traits

Information regarding the evaluation of tillage effects on soil properties and rainfed wheat (Triticum aestivum L.) cultivars of Iranian fields is not available. Therefore, this research was conducted in Sanandaj (west of Iran) using a randomized complete block design in a split-plot arrangement. Three types of tillage including conventional tillage (moldboard plow to soil depth of 30 cm plus disk harrow twice), minimum tillage (chisel plow to soil depth of 15 cm plus disk harrow once) and no-tillage are assigned to the main plots. Wheat cultivars (Sardari and Azar2) were randomly distributed within the subplots in each tillage system. Results showed that the greatest bulk density and cone index were found in the minimum tillage and no tillage systems. The highest rate of grain yield was obtained in the minimum tillage system. The grain yield of Sardari cultivar (1624.1 kg ha−1) was significantly greater than that of Azar2 (1572 kg ha−1). Minimum tillage improved soil physical properties and wheat growth compared with the other tillage systems. No tillage increased microbial biomass carbon and bacteria number in soil compared with the other tillage systems. We conclude that using minimum tillage for Sardari cultivar will be more effective compared with other treatments.

Drought stress mitigation using supplemental irrigation in rainfed chickpea ( Cicer arietinum L.) varieties in Kermanshah, Iran

An experiment was carried out in 2007 to investigate the effects of different irrigation regimes, and chickpea cultivars on chickpea production in the Agricultural Research Station, College of Agriculture, Islamic Azad University, Kermanshah Branch, Iran. The experimental design was split-plot with three replications. Supplemental irrigation at three levels, that is, control treatment (without irrigation) (I0), one time irrigation at 50% flowering stage (I1) and one time irrigation at pod-filling stage(I2), was allocated to main plots and the varieties ILC-482 (V1), Hashem (V2) and Arman (V3) were allotted to sub plots. A significant difference was observed between irrigation treatments in terms of grain yield, plant height, number of axillary branches, distance to the first pod from soil surface, number of grain per plant, number of pod per plant, biological yield, harvest index and 100-grain weight. Such differences were also observed between testing varieties in terms of all traits rather than 100-grain weight. Grain yield was significantly higher for Arman than that of Hashem which was significantly higher than that of ILC-482. Of course, there was no significant difference between Hashem and ILC-482 in terms of grain yield. Arman had the highest values of the number of grain per plant and the highest pod per plant pertained to Arman and Hashem, respectively. High rate of grain yield in irrigation treatment at podfilling stage was associated with yield components, especially with the number of pod per plant and 100-grain weight. Grain yield was positively correlated with number of pod per plant (r = 0.654**), number of grain per plant (r = 0.902**) and 100-grain weight (r = 0.707**). This research showed that podfilling is the most sensitive stage to drought stress, and under water limitation conditions, we can considerably increase grain yield at this stage by one time irrigation, especially for Arman cultivar.

Yield Increase Has Been More Rapid for Maize than for Grain Sorghum

In the United States, much grain sorghum [Sorghum bicolor (L.) Moench] production area has shifted to maize (Zea mays L.) during the last 25 yr, which has been partially due to grain yield differences between these crops. The objective of this study was to document the rate of grain yield increases for maize and sorghum hybrids from 1950 to 1999 in rainfed and irrigated environments in eastern Nebraska. Across all production environments and years, maize produced 1.7 to 4.3 Mg ha−1 greater yield than sorghum. The rate of yield increase was approximately three times faster for maize than sorghum but varied with production environments. The highest rate of yield increase (0.050 Mg ha−1 yr−1) was found for rainfed, high water‐holding capacity soil conditions; the second highest rate of increase was for irrigated maize (0.028 Mg ha−1 yr−1). The rate of sorghum yield increase under all environments and maize under rainfed, low water‐holding capacity soil conditions was low at 0.010 to 0.015 Mg ha−1 yr−1 Pearson correlations indicated that the number of ears (panicles) per square meter had the highest association with yield (r = 0.68 for maize and r = 0.59 for sorghum) while both the number of kernels per ear (per panicle) and kernel weight were significantly correlated to yield for both crops. Yield component analysis for maize shows that yield increases with introduction year resulted from increased number of ears per square meter and kernel weight, while sorghum saw no significant correlation between yield and yield components.

Optimum Stand Density of Spring Triticale for Grain Yield and Alfalfa Establishment

Triticale (×Triticosecale Wittmack) has potential as a feed crop in the north central United States and could also function as a companion crop for alfalfa (Medicago sativa L.) establishment. The objectives of this research were to assess the suitability of a short‐statured spring triticale as a companion crop and determine optimum triticale seeding rates for grain yield and alfalfa establishment. Spring triticale ‘Trimark 37812’ and alfalfa were grown in companion at Ames and Sioux Center, IA during 2004 and 2005. Triticale was seeded at 198, 297, 396, 495, and 594 pure live seeds (PLS) m−2 and alfalfa was seeded at 600 PLS m−2. The grain yield response to changes in stand density was quadratic with maximum yield occurring at 516 plants m−2. A plant density of 325 plants m−2 and a seeding rate of 374 seeds m−2 resulted in maximum profit. The grain yield at the stand density for maximum profit was 4.4 Mg ha−1. Increasing the triticale seeding rate had no effect on alfalfa stand density or dry matter yield. Alfalfa stand densities exceeded the 130 plants m−2 threshold required for maximum long‐term productivity suggesting the short‐statured spring triticale cultivar used in this study was well suited for companion cropping with alfalfa.

The cooperative relation between non‐hydraulic root signals and osmotic adjustment under water stress improves grain formation for spring wheat varieties

Non-hydraulic root signals (nHRS) and osmotic adjustment (OA) are two important adaptive responses of plants to water stress. There is little understanding of their relationships during water stress. The threshold range of soil water potential to occurrence of nHRS, the capacity for OA, grain yield and water use efficiency (WUE) were examined in three spring wheat (Triticum aestivum L.) varieties (two bred after 1975 and one bred before 1900) under water stress conditions. The threshold range of nHRS was significantly correlated with the maintenance rate of grain yield (MRGY) (r = 0.99, P < 0.05) under moderate drought (-0.49 to -0.55 MPa) but not under severe drought (-0.70 to -0.76 MPa). There were similar correlations between OA and the MRGY. However, regulation of nHRS precedes OA during gradual water stress. The threshold range of nHRS and OA was positively correlated (r = 0.93, P < 0.05), suggesting a mechanism for adapting to drought. WUE was higher for modern than for old varieties and was correlated with the root efficiency (full biomass weight including root per root weight, r = 0.78, P < 0.05) and the root water uptake efficiency (water consumption per root weight, r = 0.72, P < 0.05). However, there was a significant negative correlation between WUE and root weight (r = -0.84, P < 0.01). The cooperative relationship between the threshold range of nHRS and OA under water stress was beneficial for improving grain formation for spring wheat varieties.