Yield Performance Of Wheat Research Articles

Charcoal and compost application induced changes in growth and yield of Wheat (Triticum aestivum L.)

The utilization of organic fertilizers in farmlands to enhance crop productivity and soil health is increasing globally. Compost and charcoal obtained from the decomposition and slow pyrolysis (respectively) of plants and animals wastes. Here we evaluated the effect of charcoal and compost on the growth and yield of wheat (Triticum aestivum L.) at Agriculture Research Farm Peshawar, Pakistan during 2014-2015. Results showed that the application of compost and charcoal as sole or in combination significantly affected the yield and yield attributes of wheat. Data divulged that the maximum numbers of plant tillers (337 m-2), number of productive tillers per plant (313 m-2), number of grains per spike (56 spike-1) and 1000 seeds weight (50.2 g) were produced by the combined application of compost and charcoal at 5+5 Mg ha-1 while plant height (95.3 cm) was enhanced with the application of charcoal at 10 Mg ha-1. The gain (4106.7 kg ha-1) and biological yield (8473.3 kg ha-1) was significantly increased with the compost application at the rate of 10 Mg ha-1. These results proved that charcoal and compost can be used as organic fertilizers for boosting growth and yield performance of wheat under the agro-climatic conditions of Peshawar, Pakistan.

Quantifying Genotype × Environment Effects in Long‐Term Common Wheat Yield Trials from an Agroecologically Diverse Production Region

Multienvironment trials (METs) are used to investigate the performance of crop genotypes. To efficiently generate reliable performance estimates, the magnitude and patterns of genotype × environment interaction (G×E) in MET data must be known. We quantified G×E in fall‐planted common wheat (Triticum aestivum L.) in California, with the goal of increasing the reliability and efficiency of statewide variety testing activities. Linear mixed models and the genotype main effects plus G×E interaction effects (GGE) biplot method were used to analyze MET data for 211 common wheat genotypes, the MET consisted of 9 locations and 14 seasons. The representativeness and discriminating power of the MET locations were tested, and estimates of the optimum number of test locations were made. The analyses did not find evidence for significant, repeatable, crossover G×E. The genotype and G×E effects were of a similar magnitude, and the G×E effects were relatively strong compared with other sources of variance but were dominated by seasonal effects, with potentially repeatable genotype‐by‐location (G×L) effects being relatively weak. The GGE analyses did not detect repeatable G×L patterns across seasons. As a result, we conclude that the cereal production regions of California consist of a single, but unstable, mega‐environment for common wheat grain yield. The test location evaluation found few significant differences between test locations in terms of how well they represent the target production environment. We estimate that the number of test locations could be reduced while maintaining trial accuracy, which would improve the resource use efficiency of statewide trial activities without sacrificing information about variety‐specific common wheat yield performance.

Yield performance based selection of superior mutant lines from mutant wheat genotypes

Wheat is the most widely grown cereal crop in the world. However, yield performance of wheat in Bangladesh is very low and the amount of cultivating land is decreasing drastically. Wheat cultivation in coastal saline regions can be a new dimension to increase the wheat production. Therefore, the first step of our research project was conducted out to evaluate the genotypic variability among the salt tolerant mutant lines of wheat genotypes to select superior lines based on yield performance on non-saline soil to bring them in the next step of screening process in salt affected areas. The performance of yield and yield contributing characters of 154 wheat genotypes were evaluated through Francis and Kannenberg’s method of selection. To evaluate the yield performance of mutant wheat lines, ‘Prodip’, a high yielding variety, developed by Bangladesh Agriculture Research Institute (BARI), was used as check variety. Thirty-seven wheat mutant lines, which perform better than ‘Prodip’ were selected based on yield contributing characters i.e. plant height, flag leaf duration, spike length, spikelet per spike, number of tillers, 100-grain weight and yield per plant. During selection of mutant lines, more emphasize given on the character 100-grain weight and yield per plant. The result of this study can be used for further evaluation of selected genotypes on saline soil before going to farmer level evaluation.
 Progressive Agriculture 30 (1): 10-19, 2019

Modulation of photosynthate supply by CO2 elevation affects the post‐head‐emergence frost‐induced grain yield loss in wheat

AbstractPost‐head‐emergence frost (PHEF) has a detrimental impact on grain yield of wheat, and an enhanced photosynthate supply could alleviate the negative impact. However, modulation of photosynthate availability at different growth stages may exert different effects on the plant physiology and grain yield. The objective of this study was to investigate the roles of the enhanced photosynthate supply by growing the plants at elevated [CO2] (800 ppm) during different growth stages on yield performance of wheat exposed to PHEF. The results showed that the PHEF caused a high grain yield loss in wheat, and an increase in photosynthate supply during the reproductive growth stage mitigated the negative impact, whereas that at vegetative growth stage exacerbated the negative impact of PHEF. The opposite effects exerted by the enhanced photosynthate supply at vegetative stage versus at reproductive stage on yield performance could be associated with its distinguished roles in influencing plant physiology at the two growth stages. The positive effect of the increased photosynthate supply at reproductive stage was due to an improved grain filling and regeneration of effective tillers upon recovery from frost, whereas the negative effects of the enhanced photosynthate supply at vegetative growth stage were primarily due to an accelerated early vegetative growth that increased the sensibility of the plants to PHEF.

Effect of predicted climate change on growth and yield performance of wheat under varied nitrogen and zinc supply

Sustainable crop production is crucial to address global food security and requires a solid input of chemical fertilizers containing macro (e.g. nitrogen: N) and micro (e.g. zinc: Zn) nutrients. However, climatic factors beyond farmers’ management capabilities determine the final crop yields, and world’s climate has been changing more rapidly than ever due to human activities such as industrialization and deforestation. This study evaluates the interactive effects of predicted climate change and N and Zn supply on performance of bread wheat as a model staple food crop. Bread wheat (T. aestivum cv. Ceyhan-99) was cultivated in soil fertilized with adequate or low N and Zn in pots under ambient climate (ambient CO2 and temperature) or predicted climate (700 μmol mol−1 CO2 and 3 °C temperature rise) conditions in dedicated plant growth chambers. Plants were harvested at full maturity and grain yield, and yield attributes along with Zn and N status of grains were determined. Predicted climate (PC) treatment significantly accelerated plant growth rate resulting in early onset of successive growth stages and maturity. In both PC and ambient climate (AC) conditions, adequate supply of N and Zn significantly increased straw and grain yield by increasing number of spikes per plant and number of grains per spike, whereas PC significantly reduced straw and grain yield through reducing number of spikes per plant, particularly in plants supplied with adequate N. Effect of adequate Zn or PC treatments were significant only under adequate N supply. Adequate N not only increased grain protein concentration but also grain Zn, particularly under adequate Zn application. In general, PC tended to increase grain Zn concentration, but the effect was non-significant. PC had no effect on grain protein concentration, whereas it significantly reduced grain protein yield (i.e. total mass of protein in whole grains of a single plant). The future climate with elevated CO2 and raised temperature can dramatically reduce duration of time to complete successive growth stages in wheat. Plants cultured under PC conditions had significantly lower straw and grain yield, although supplied with ample fertilization. Whereas the PC and adequate Zn treatments enhanced main spike gain yield and number of grains per spike, PC declined overall grain yield, particularly due to severe reduction in number of spikes per plant. We conclude that sustaining a higher number of spikes per plant along with adequate nutrition with N and Zn are key factors to benefit from an elevated CO2 atmosphere and to minimize adverse effects of rising temperatures on wheat yield and quality.

English

Soil fertility decline is one of the prime factors contributing to low productivity of crops and food insecurity in Ethiopia. To alleviate this problem and achieve maximum yield, identifying suitable agronomic inputs such as N and P types in wheat production systems is very important. The aim of this study was therefore, to estimate the effects of different N and P fertilizer types and rates on growth, yield and yield components of wheat at Hawassa, southern Ethiopia. For this purpose a treatments consisting of seven N and P sources (F1=Control, F2=Local recommended Urea 100 kg ha-1 and DAP 100 kg ha-1, F3=Urea 100 kg ha-1 and Enhanced DAP 100 kg ha-1, F4=Black Urea 103.3 kg ha-1and Enhanced DAP 100 kg ha-1, F5=100 kg ha-1 Enhanced Urea-1 and Enhanced DAP 100 kg ha-1, F6=Enhanced Urea-2 100 kg ha-1and Enhanced DAP 100 kg ha-1 and F7=Compound fertilizer 256.25 kg ha-1) were studied using a randomized complete block design with three replications. Analysis of the data recorded from the combined application of different N and P treatments revealed that maximum grain yield (3.67 t.ha-1) was obtained from the plots which were supplied with Enhanced Urea-2 and Enhanced DAP at the rate of 100-100 kg ha-1. It can be concluded from the result that wheat crop performed better when fertilized with this treatment. Therefore, the application of enhanced DAP 100 kg ha-1 with Enhanced Urea-2 100 kg ha-1 is recommended to optimize the growth and yield performance of wheat. Key words: Enhanced DAP (diammonium phosphate), enhanced urea, growth, yield components, wheat. &nbsp

Influence of Sowing Date on the Growth and Yield Performance of Wheat (Triticum Aestivum L.) Varieties

A field study was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to investigate the effect of sowing date on the performance of wheat varieties. The experiment, laid out in RCBD with three replications, comprised four sowing dates viz.,15 November, 30 November, 15 December and 30 December, and four varieties of wheat viz. BARI Gom 25, BARI Gom 26, BARI Gom 27 and Shatabdi. The results suggested that the highest plant population m-2 (58.17) and the highest plant height (89.59 cm) were obtained in 15 November sowing. BARI Gom 25 produced the highest plant population m-2 (50.33) and the highest plant height (86.32) while the same trend was observed in the interaction of BARI Gom 25×15 November sowing. The lowest performance of these two parameters was observed in the interaction of Shatabdi × 30 December sowing. The highest grain yield (2.18 ha-1) was found in the interaction of BARI Gom 25 × 15 November sowing as contributed by its highest number of effective tillers hill-1 (4.73), the highest number of spikelets spike-1 (17.77), the highest number of grains spike-1(37.89) and the highest 1000-grain weight (29.99g). The individual effect of the BARI Gom 25 and 15 November sowing on those parameters was also observed as the highest. The lowest grain yield (1.5 t ha-1) was found in the interaction of Shatabdi × 30 December sowing because of the poor performance of the yield components of this treatment combination. The variety BARI Gom 25 and BARI Gom 26 both gave better yield when sown on 15 November. Therefore, BARI Gom 25 and BARI Gom 26 should be sown on 15 November rather than late sowing to obtain better performance and grain yield of wheat.

Effects of Mulching on Growth and Yield Components of Selected Varieties of Wheat (Triticum Aestivum L.) under Field Condition

Wheat is facing increased high temperature during its grain filling period in Bangladesh which reduces yield drastically. Mulching may help to mitigate this problem. Therefore, a field experiment was carried out at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during the period from November 2015 to March 2016 to find out growth and yield performance of wheat as influenced by mulching. The experiment comprised of two factors viz., variety and mulching. The variety comprised of BARI Gom-26, BARI Gom-27 and BARI Gom-28. Mulching comprised of four different levels of treatments viz.no mulch + no irrigation (control), water hyacinth mulch + no irrigation, rice straw mulch + no irrigation and two irrigations at CRI and flowering stage. The experiment was laid out in a randomized complete block design with three replications. BARI Gom-28 showed the highest values in growth parameters (plant height, number of total tillers hill-1, LAI, chlorophyll content and total dry matter) at 30, 45 and 60 DAS. On the other hand, when mulching was compared, rice straw mulch gave higher yield compared to other treatments at 30, 45 and 60 DAS. The interaction effect of variety and mulching showed significant in relation to yield and yield components except plant height, spike length, 1000- grain weight and harvest index (%). The tallest plant (93.20 cm) was obtained from the interaction of BARI Gom-28 and rice straw mulch. The highest number of total tillers hill-1 (4.80), number of effective tillers hill-1 (4.57), spike length (10.23), number of spikelets spike-1 (21.15), 1000-grain weight (48.54 g), grain yield (5.20 t ha-1), straw yield (7.27 t ha-1), and harvest index (41.71%) were obtained from the interaction of BARI Gom-28 and rice straw mulch. The lowest grain yield was obtained from BARI Gom-26 and control (no mulch + no irrigation). It may be concluded from the results of the study that, BARI Gom-28 with rice straw mulching treatment can be used for successful cultivation of wheat.

Yield Performance of Wheat under Split N Application Rates and Timing

Yield Performance of Wheat under Split N Application Rates and Timing

Response of Wheat Plants to Seed Pre-Soaking in Hydrogen Peroxide Solution under Salt Stress Conditions

Under arid and semi-arid condition of limited water resources, salinity is an important environmental constraint, affecting many crop productivity. The objective of this study is being suggested to examine the contribution of H2O2-presoaked seeds and salinity levels of irrigation water on growth and yield performance of wheat grown in different textured soils. To meet these objectives, the 3-way factorial experiment, comprising of 3 pre-soaking intervals (0, 24 and 36h), 3 different levels of saline irrigation water (500, 5000 and 8500 mg NaCl/L) was carried out in two different textured soils (sandy and clay soils), whereas wheat seeds were planted in cemented-bituminized plots (0.75 X 1.5 m) until the maturity stage. At tillering, random leaf samples were removed and analyzed for Na and K contents. At the harvest time, plant growth indices, including height and number of spikes/plot and yield components (straw and grain yields) were recorded. The results have shown that plant growth characteristics and yield potentials were significantly suppressed with increasing the salinity stress of irrigation water, but the rate of decline varied considerably among all trails. The more depressive effects of the salinity exposure were clearly manifested on straw yield, being 74.6 and 85.6% at 5000 and 8500 mg NaCl/L, respectively. The pretreatment of seeds with H2O2 induced acclimation on the plants to salinity. It lessened the deleterious effect of salt stress on the growth of wheat especially when seeds were soaked in H2O2 for 36 h. This treatment caused relative increases in number of spikes /plot, grain yield, straw yield, defined by 44.5, 43.7, and 72.6%, respectively. Progressive results were achieved on all the studied plant criteria, giving better performance of the sand textured soil than the clay type. Superior wheat growth, maximum yield and highest K content were realized on wheat cultivated in sandy soil irrigated with saline water. Pretreatment of seeds with H2O2 for 24h induced acclimation of the plants to salinity. Moreover, seed priming with H2O2 for 36 h improved grain yield potentials and leaf K content in plants grown in sandy soil.

Performance of Wheat as Affected by Different Irrigation Levels and Sowing Dates

The experiment was conducted to determine the effect of irrigations and sowing dates on growth and yield performance of wheat in the experimental field of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period of November 18, 2012 to March 30, 2013. The experiment was comprised of two factors, viz. factor A: two irrigations namely irrigation (I) and no irrigation i.e. control (I0), and factor B: three sowing dates such as S1: 1st sowing on 18 November, S2: 2nd sowing on 03 December and S3: 3rd sowing on 18 December. The experiment was laid out in a split plot design with three replications. Irrigation was assigned in the main plot, while sowing time was in the sub-plots. Data on grain yield and different yield contributing characters were taken after harvest. Results indicated that the highest grain yield was obtained with I (2.915 t ha-1) and S1 (2.983 t ha-1). The interaction of irrigation (I) and sowing on 18 November (S1) showed the maximum yield (3.387t ha-1), spike length (17.08 cm), 1000 grain weight (43.4 g), spikelets spike-1 (20.03) and grain spike-1 (65.58) of wheat.The Agriculturists 2016; 14(2) 77-85

Evaluation of Selected Herbicides on Weed Control Efficiency and Yield of Wheat

Background: Weed control is an important issue for the proper growth of wheat. Objective: The purpose of the present study was to see the effect of selected herbicides on weed infestation behavior in wheat field; to determine the effect of herbicides on growth and development of wheat plants, and to evaluate the effect of herbicides on yield performance of wheat. Methodology: A field experiment was conducted at the Experimental Farm of the Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur, Bangladesh during November to May 2011 -2012. Four herbicides were tested at recommended dose alone and also coupled with supplemental hand weeding in wheat crop. In addition, a weedy check (control) was also imposed for treatment comparison. The herbicides were Pendimethalin, Carfentrazone-ethyl + Isoproturon, Carfentrazone-ethyl and 2,4-D. In this way, nine treatment combinations were arranged in the RCBD experiment with three replications. Result: Carfentrazone-ethyl performed the best in terms of weed control efficiency (79.68%), while Pendimethalin performed the worst (52.74%). Carfentrazone-ethyl + Isoproteuron contributed to the highest tillers per unit area (226.3 m-2) and the highest total dry matter (1342 g m-2). Finally, Carfentrazone-ethyl + Isoproteuron also contributed to the highest grain yield of 3.56 t ha-1 with the highest harvest index of 0.42. Carfentrazone-ethyl + Isoproteuron accompanied by one hand weeding also contributed to statistically identical grain yield of 3.33 t ha-1. Single ingredient Carfentrazone-ethyl alone and when accompanied with one hand weeding also contributed to statistically identical grain yields of 3.26 t ha-1 and 3.46 t ha-1, respectively. Conclusion: The study revealed that, combined ingredient herbicide Carfentrazone-ethyl + Isoproteuron as well as Carfentrazone-ethyl alone might used at field level due to their better weed control efficiency, favourable effect on crop growth and development and higher grain yield.Journal of Science Foundation 2014;12(2):27-33DOI: http://dx.doi.org/10.3329/jsf.v12i2.27734

Effect of tillage method and weeding regime on soil weed seed bank status and yield performance of wheat

An experiment was conducted at the Agronomy Field Laboratory and net house of the Department of Agronomy, Bangladesh Agricultural University, Mymensingh from November 2012 to March 2014. Wheat (cv. BARI Gom-26) was sown with two tillage methods viz., (i) conventional tillage and (ii) stale seedbed technique and nine weeding regimes viz., (i) Unweeded (Control), (ii) Weed free, (iii) Hand weeding (HW) at 15 Days after sowing (DAS), (iv) HW at 15 and 45 DAS, (v) HW at 25 and 45 DAS (vi) HW at 25 DAS (vii) HW at 25 and 60 DAS (viii) 2,4-D amine at 15 DAS and (ix) 2,4-D amine at 15 DAS + HW at 60 DAS. The design was split-plot with three replications where tillage method was assigned to the main plots and weeding regime to the sub plots. Conventionally tilled plots were infested with 12 weed species of which the five most dominant weed species in descent order were Polygonum coccineum L, Chenopodium album L, Cynodon dactylon L., Sonchus arvensis L. and Cyperus rotundus L. In stale seedbed out of 15 weed species Digitaria sanguinalis L. and Hedyotis corymbosa (L.) Lamk. was dominant instead of Chenopodium album L. and Sonchus arvensis L. identified in conventional tillage. In soil weed seed bank study, 28 species were identified in conventional tillage and 30 in stale seedbed. Among them annuals were dominant over perennials and broadleaves over grasses and sedges. In conventional tillage, the five most dominant weed species in descent order were Chenopodium album L., Hedyotis corymbosa L., Sonchus arvensis L., Polygonum coccineum L. and Rotala ramosior L. while in stale seedbed, five dominant weeds were Polygonum coccineum L., Chenopodium album L., Cynodon dactylon L., Lindernia procumbens Krock. and L. hyssopifolia L. Except the number of spikelets spike-1, rest of all other yield attributes and yield of wheat were affected significantly by the tillage methods. Stale seedbed technique yielded the higher grain (3.54 t ha-1) and the conventional tillage yielded the lower (3.13 t ha-1). The effect of weeding regime was significant on wheat except plant height and 1000-grain weight. The highest grain yield (3.85 t ha-1) was recorded from weed free treatment followed by 2,4-D amine at 15 DAS and lowest (3.22 t ha-1) from control. Interaction between the treatments was also. The highest grain yield (4.09 t ha-1) was recorded from the stale seedbed technique kept weed free followed by 2,4-D amine at 15 DAS and lowest grain yield (3.04 t ha-1) recorded from the conventional tillage retained unweeded.Progressive Agriculture 27 (1): 9-19, 2016

PERTUMBUHAN DAN HASIL TANAMAN GANDUM (Triticum aestivum L.) VARIETAS DEWATA DALAM POLYBAG PADA BERBAGAI POPULASI DAN KOMPOSISI MEDIA TANAM

<p>Studies on the growth and yield performance of wheat (Triticum aestivum L. variety of Dewata) planted in polybag with various populations and media compositions, had been conducted in Faculty of Agriculture Satya Wacana Christian University field research, located at Salaran – Kopeng village, Semarang district, from April 2012 to August 2012. Location of the study lies at an altitude of 900 meters above the sea level. Purpose of this study were to determine the appearance of both the growth and yield of wheat grown in polybag with a various population densities and media composition, as well as to determine the combination of treatments that producing the highest yield of wheat. Factorial design used that was consisted of two factors, i.e: (1) growing gedia composition with four different volume ratio of sand, soil and manure (1:1:1), (1:1:0), (1:0:1) and (0:1:1), and (2) population densities consisted of four: 1 seeds per polybag; 2 seeds per polybag; 3 seeds per polybag and 4 seeds per polybag, so that there were 16 combinations of treatments. Each combination was repeated three times. Basic design of the experiments used Randomized Block Design. Experimental data were analyzed by using analysis of variance (ANOVA) and high significant difference (HSD) test at 95% level of confidence. The conclusion of this study were: (1) Combination of treatment of population densities and composition of growing media influence on plant height, number of plants per cluster, panicle length, seed weight per panicle, seed weight per cluster and seed weight per polybag and (2) the highest seed weight per polybag was resulted in the density of population of 4 seeds per polybag and planting on mixed media of sand, soil and manure in the volume ratio of 1:1:1.</p>

Effect of weeding regime on weed vegetation and yield performance of wheat in two locations of Mymensingh district

On-farm two experiments were carried out at the Fulbaria upazila under Mymensingh district and Agronomy Field Laboratory, Department of Agronomy, Bangladesh Agricultural University (BAU), Mymensingh during the period from November 2011 to March 2012. The experiment comprised ten fields for each of the locations which composed of three weeding regime treatments, namely, unweeded, farmers’ weeded and weed free. The design was randomized complete block with ten replications. Data on weed density, yield contributing characters and yield of wheat were recorded. Except straw yield in Fulbaria all others yield contributing characters were affected significantly due to weeding regime treatment. The highest grain yield was recorded in weed-free treatment compared to farmers weeded and unweeded treatment in Fulbaria. Whereas, in Agronomy Field Laboratory at BAU, the highest grain yield was observed in weed-free treatment which was statistically identical to farmers’ weeded treatment. Five dominant weed species were identified in Fulbaria naimly Cynodon dactylon L., Cyperus rotundus L., Alternanthera sessilis L., Polygonum orientale L. and Chenopodium album L. and in Agronomy Field Laboratory at BAU namely Gnaphalium affine L., Cyperus rotundus L., Digitaria sanguinalis L., Cynodon dactylon L. and Panicum repens L. Infestation of Cynodon dactylon L. was more in Fulbaria due to control difficulties and Gnaphalium affine L. was more in BAU due to weed seed bank year after year and poor cultural management. So there is scope to increase yield potential of wheat by improving existing weed control practices.Progress. Agric. 2014. 25: 23-30

Rates of urea with or without urease inhibitor for topdressing wheat

The urease inhibitor NBPT(N-(n-butyl) thiophosphoric triamide) is a management alternative to increase urea efficiency in topdressing because it reduces NH3 volatilization. The objective of this study was to evaluate N recovery and yield performance of wheat ( Triticum aestivum L.) ‘BRS 254’ fertilized with different urea or urea + NBPT rates in topdressing. The experiment was conducted from May to September 2007 in Vicosa, Minas Gerais, Brazil. Treatments followed a 5 × 2 + 1 factorial design consisting of five N fertilizer rates (30, 60, 90, 120, and 150 kg ha-1) as urea or urea + NBPT (Agrotain® ) applied as topdressing and a control without N. The experiment was a randomized complete block design with four replicates. Adding NBPT to urea resulted in better N utilization by wheat plants. The 100 kg N ha-1 topdressing rate provided the best apparent N recovery by wheat plants, whereas 90 kg ha-1 provided the best N use efficiency.

Effectiveness of the GAEC cross-compliance standard management of stubble and crop residues in the maintenance of adequate contents of soil organic carbon

Several studies carried out on the effects of stubble and crop residue incorporation have shown positive effects on chemical-physical soil characteristics. However, not all studies agree on the extent of soil organic matter increase which derives from this process, as this effect is strongly affected by other factors: the pedo-climatic features of the area in which the study is carried out, the type of crop residue incorporation and the agronomical management adopted to improve the decomposition of the incorporated fresh organic material. The burning of stubble and straw is common in the areas where cereals are traditionally grown. The adoption of this method is based on different technical and work-related factors, which become less important when taking into account the impact on the local environment and soil. A research is currently carried out at the CRA-SCA experimental farm in Foggia (Southern Italy) on the effects of either residues incorporation or burning on the chemical-physical characteristics of the soil and on the wheat yield performance since 1977. This experiment allows for a comparison among the effects of burning, the simple incorporation of stubble and crop residues and incorporation carried out with some agronomical techniques (such as the distribution of increasing amounts of nitrogen on crop residue before incorporation) and the simulation of rain (50 mm) on the decomposition of organic material. The objective of the study was to understand the effect of the different residues management practices on soil chemical properties after 32 years of experimentation). The simple incorporation of straw and stubble showed a slight increase in organic soil matter of 0.7% with respect to burning. The best results for soil organic carbon and soil quality were obtained when residual incorporation included a treatment with additional mineral nitrogen.

Grain growth rate and grain yield in relation to ADP-glucose pyrophosphorylase activity in wheat (Triticum aestivumL. em. Thell) under normal and late sown conditions

The impact of high temperature stress, normally encountered during grain development phases in wheat under late sown conditions, was studied by measuring grain growth rate (mg day−1 grain−1), grain yield (g plant−1) in relation to ADP glucose pyrophosphorylase (AGPase) activity (nmol mg−1 min−1), a key regulatory enzyme in starch biosynthesis. The experimental material comprised nine genetically diverse homozygous genotypes of spring wheat and their six F1s. These were grown in randomised block design with three replications at CCS Haryana Agricultural University, Hisar, India on two dates of sowing 26th November, 2007 (timely, E1) and 24th December, 2007 (late, E2). The rate of grain growth was greatly reduced as temperature increased in late sown environment. Grain growth rate among the parental genotypes was highest in UP 2425 and cross PBW 343 × PBW 435 in both the environments. Mean ADP glucose pyrophosphorylase (AGPase) activity was maximum at 14 days after anthesis in timely sown while in late sown the activity was maximum at 21 days after anthesis in PBW 435, EIGN 1 and EIGN 8 and crosses EIGN 8 × UP 2425, EIGN 1 × Raj 3765 and PBW 343 × PBW 435. A significant positive association in both timely and late sown environments was evident between grain yield and grain growth rate, while in late sown environment, strong positive and significant correlation was observed between grain yield and grain growth rate and also between grain growth rate and AGPase activity in crosses PBW 343 ×WH 283, PBW 343 × WH 542 and PBW 343 × PBW 435. This suggested that increase in grain growth rate and AGPase activities resulted in increase in grain yield and have considerable impact on the yield performance of wheat.

Influence of Sulfur Fertility on Wheat Yield Performance on Alluvial and Upland Soils

: In recent years, sulfur (S) deficiencies in winter wheat (Triticum aestivum L.) have become more common, particularly on coarse‐textured soils. In Study I, field experiments were conducted in 2001/2002 through 2003/2004 on Mississippi River alluvial soils (Experiment I) and an upland, loessial silt loam (Experiment II) to evaluate the influence of spring S rates of 0, 5.6, 11.2, and 22.4 kg ha−1 and a fall rate of 22.4 kg sulfate (SO4)‐S ha−1 on grain yield of three varieties. In Study II, field experiments were conducted in 2001/2002 and 2004/2005 on alluvial soils to evaluate the influence of spring S rates of 0, 5.6, 11.2, and 22.4 kg SO4‐S ha−1 in fields where S‐deficiency symptoms were present. Grain yield response to applied S occurred only on alluvial, coarse‐textured, very fine sandy loam soils (Study II) that had soil SO4‐S levels less than the critical level of 8 mg kg−1 and organic‐matter contents less than 1 g kg−1 in the 0‐ to 15‐, 15‐ to 30‐, and 30‐ to 45‐cm depths. Soil pH increased with soil depth. Optimum S rate was 11.2 kg SO4‐S ha−1 in 2001/2002 and 5.6 kg SO4‐S ha−1 in 2004/2005. On the upland, loessial silt loam soil, soil SO4‐S levels accumulated with depth, whereas organic‐matter content and pH decreased. In the loessial soils, average soil SO4‐S levels in the 15‐ to 30‐ and 30‐ to 45‐cm soil depths were 370% greater than SO4‐S in the surface horizon (0 to 15 cm).

Enhanced salt tolerance of transgenic wheat ( Tritivum aestivum L.) expressing a vacuolar Na +/H + antiporter gene with improved grain yields in saline soils in the field and a reduced level of leaf Na +

Wheat productivity is severely affected by soil salinity mainly due to Na + toxicity to plant cells. To improve the yield performance of wheat in saline soils, we have generated transgenic wheat expressing a vacuolar Na +/H + antiporter gene AtNHX1 from Arabidopsis thaliana, to enhance the plant capacity of reducing cytosolic Na + by sequestering Na + in the vacuole. The AtNHX1 transgenic wheat lines exhibited improved biomass production at the vegetative growth stage and germination rates in severe saline conditions. A field trial revealed that the transgenic wheat lines produced higher grain yields and heavier and larger grains in the field of saline soils with the electrical conductivity values of soil saturation extracts (EC e) of 10.6 and 13.7 dS m −1. The transgenic lines accumulated a lower level of Na + and a higher level of K + in the leaves than non-transgenic plants under saline conditions (100 and 150 mM NaCl). These results indicate that the salt tolerance of wheat and grain yield in saline soils can be improved by enhancing the level of the vacuolar Na +/H + antiporter.