OPTIMIZING NITROGEN MANAGEMENT IN WINTER WHEAT PRODUCTION SYSTEMS FOR IMPROVED BREAD BAKING QUALITY

In Kentucky, there is growing interest among farmers to produce high protein and strong gluten wheat that is suitable for bread baking to meet the demand of local artisanal bakers. Soft red winter wheat (SRW) is the most commonly wheat grown in the state and throughout the Southeastern US. Flours produced from SRW are relatively low in grain nitrogen (N) due to the region’s moderate winters and warm humid conditions during grain filling. As such, SRW is used in baking products where lower protein flours are preferred, such as cookies, cakes, pastries and crackers. Unlike SRW, hard red winter wheat (HRW) is known for high protein content and primarily used in bread baking. The objective of this dissertation was to evaluate the effect of N management on bread baking quality and agronomic traits in winter wheat cultivars grown in conventional and organic farming systems. This work was conducted through three field experiments. The first experiment focused on the variable effects of N fertilizer level on various SRW cultivars. Five SRW cultivars were grown using two levels of N input (high and low) in both conventional and organic systems over two years. The second experiment evaluated the effect of split N application on cultivars selected for their agronomic or bread baking quality potential. In this experiment, two cultivars of SRW were grown under three split N application treatments in both organic and conventional systems for two years. The final study evaluated the effect of combined N fertilizer and biofertilizer N on HRW bred for the southeastern US. One HRW cultivar was grown with three levels of fertilizer N input and two biofertilizer application regimes in both conventional and organic systems over two years. In general, the first experiment showed that yields and protein content were greater in wheat grown in the conventional system at the low N rate compared to wheat grown at the high N rate in the same system. Similarly, in the second experiment, yields and protein content were consistently greater than in the organic system. In the third experiment, results were inconsistent between years. Yields were greater in the organic system in the second year, while the protein content was greater in the conventional system in the first year. Biofertilizer application had a negative or neutral effect on grain yield. Future research to improve understanding of N dynamics in organic farming systems, specifically the interaction between soil N levels and plant uptake, is needed to improve bread baking quality in organic systems

Evaluating Split Timing Fertilizer Applications for Improving Bread Baking Quality of Soft Red Winter Wheat in Kentucky

There is growing interest among farmers to locally produce high protein and strong gluten wheat that is suitable for bread making and meet the demand of local artisanal bakers in Kentucky. The warm and humid weather in southeast region is ideal for soft red winter wheat (SRW) production which characterized by low protein content. The technique of splitting nitrogen (N) fertilization according to the growth stages has been suggested to improve protein content and its composition. This study evaluated the effect of split N application on yield and baking quality traits of two SRW wheat cultivars grown in the eastern U.S. region in conventional and organic cropping systems. One landrace (Purple Straw) and one modern cultivar (Pembroke 2014 ) were grown under three split N application treatments (ST1, ST2 and ST3). Late N applications (ST3) significantly increased protein content for both years by 5.45% and 6.11% respectively compared to a single application; however, this treatment decreased yield. The cropping system had consistent effects in that the conventional system exceeded organic system except for thousand kernel weight. Conventional system had greater yield by 16.11% and 20.17% respectively for both years than organic system. Similarly, sedimentation value (a baking quality trait) was greater by 14.27% and 11.12% respectively in conventional than organic system. This study has generally found improvement in protein content by N application on soft red winter wheat. In addition, more studies should be done on the organic systems to examine other baking quality traits

Biofertilizer (EM-1) effect on growth and yield of three bread wheat cultivars

Farmers keep trying to avoid using chemical fertilizer without losing high yield. A field experiment was conducted in the fields of Agriculture College, University of Baghdad during winter seasons of 2015 and 2016 to investigate the response of three bread wheat cultivars (Ibaa99, Abu-Ghraib3 and Buhooth22) to the frequency of spraying with biofertilizer (EM-1) (one time at tillering stage, twice at tillering and stem elongation stages and three times at tillering, stem elongation and booting stages) in addition to the control (without spraying), to the increase of grain yield. Randomized complete block design (RCBD), in split plots arrangement and four replications, was used. Spraying treatments were placed as main plots and cultivars as subplots. The results showed that the Ibaa99 cultivar, three times of EM-1 spraying and their interaction gave the highest averages of grain yield (3.89 and 4.31), (3.85 and 4.36) and (4.11 and 4.58 ton*ha-1), respectively, for both seasons. It can be concluded that yield responded significantly to the frequency of EM-1 spraying during vegetative stages

Impact of Nitrogen Rate in Conventional and Organic Production Systems on Yield and Bread Baking Quality of Soft Red Winter Wheat

Soft red winter wheat (SRW) is characterized by high yield and relatively low protein content. In Kentucky, there is growing demand from local artisan bread bakers for regionally produced flour, requiring production of grain with increased protein content and/or strength. The objective of this two-year field experiment was to evaluate the effect of nitrogen (N) management on five cultivars of winter wheat on yield and bread baking quality traits of modern and landrace SRW cultivars (Triticum aestivum L.). All five cultivars were evaluated using two N application rates in conventional and organic production systems. All traits measured were significantly affected by the agricultural production system and N rate, although plant height and other quality traits varied by study year. Significantly higher yields were achieved in the conventional system at a relatively low N rate (67.2 kg ha−1) in both study years (2017–2019) (p \u3c 0.01). Results were variable by cultivar and a locally bred, high-yielding cultivar (Pembroke 2014) had the highest lactic acid solvent retention capacity score and thousand kernel weight of the cultivars evaluated. In addition, a landrace cultivar (Purple Straw) had the highest grain N and plant height. A French soft wheat, Soissons, had the highest sedimentation value and Pembroke 2016 achieved the highest yield. The findings from this study suggest the possibility of attaining a desirable grain with quality traits of SRW wheat that meets the needs of local bread wheat production in Kentucky through improving the optimization of cultivar selection, N management and specific considerations for conventional and organic systems

Effect of Biofertilizer in Organic and Conventional Systems on Growth, Yield and Baking Quality of Hard Red Winter Wheat

A two-year study (harvest years 2019 and 2020) was conducted to investigate the effect of a commercially available biofertilizer, in combination with variable nitrogen (N) rate, on bread baking quality and agronomic traits in hard winter wheat grown in conventional (CONV) and organic (ORG) farming systems in Kentucky, USA. The hard red winter wheat cultivar ‘Vision 45’ was used with three N rates (44, 89.6 and 134.5 kg/ha as Low, Med and High, respectively) and three biofertilizer spray regimes (no spray, one spray and two sprays). All traits measured were significantly affected by the agricultural production system (CONV or ORG) and N rate, although trends in their interactions were inconsistent between years. In Y2, yield was greatest in treatments with high N rates and in the ORG system. Biofertilizer treatments had a negative to neutral effect on grain yield. Baking quality traits such as protein content, lactic acid solvent retention capacity and sedimentation value (SV) were consistently greater in the CONV system and increased with the higher N application rates. Similarly, biofertilizer application had no effect on predictive baking quality traits, except for SV in year 1 of the study, where it increased with two sprays. Loaf volume was consistently greater from wheat grown in CONV treatments. From these results, we conclude that further research is warranted to evaluate the potential for biofertilizers to enhance N uptake and affect bread baking quality or other end-use traits. Additional research may be especially useful in organic production systems where biologically based N fertilizers are utilized, and treatments were not negatively affected by biofertilizer applications. Such strategies may be needed to increase protein quantity and gluten quality to optimize winter wheat production for bread baking qualities in the southeastern USA

Biofertilizer (EM-1) effect on growth and yield of three bread wheat cultivars

Farmers keep trying to avoid using chemical fertilizer without losing high yield. A field experiment was conducted in the fields of Agriculture College, University of Baghdad during winter seasons of 2015 and 2016 to investigate the response of three bread wheat (Triticumaestivum L.) cultivars (Ibaa99, Abu-Ghraib3 and Buhooth22) to the frequency of spraying with biofertilizer (EM-1) (one time at tillering stage, twice at tillering and stem elongation stages and three times at tillering, stem elongation and booting stages) in addition to the control (without spraying), to the increase of grain yield. Randomized complete block design (RCBD), in split plots arrangement and four replications, was used. Spraying treatments were placed as main plots and cultivars as subplots. The results showed that Ibaa99 cultivar, three times of EM-1 spraying and their interaction gave the highest averages of grain yield (3.89 and 4.31), (3.85 and 4.36) and (4.11 and 4.58 ton*ha-1), respectively, for both seasons. It can be concluded that yield responded significantly to the frequency of EM-1 spraying during vegetative stages

Impact of Nitrogen Rate in Conventional and Organic Production Systems on Yield and Bread Baking Quality of Soft Red Winter Wheat

Soft red winter wheat (SRW) is characterized by high yield and relatively low protein content. In Kentucky, there is growing demand from local artisan bread bakers for regionally produced flour, requiring production of grain with increased protein content and/or strength. The objective of this two-year field experiment was to evaluate the effect of nitrogen (N) management on five cultivars of winter wheat on yield and bread baking quality traits of modern and landrace SRW cultivars (Triticum aestivum L.). All five cultivars were evaluated using two N application rates in conventional and organic production systems. All traits measured were significantly affected by the agricultural production system and N rate, although plant height and other quality traits varied by study year. Significantly higher yields were achieved in the conventional system at a relatively low N rate (67.2 kg ha−1) in both study years (2017–2019) (p < 0.01). Results were variable by cultivar and a locally bred, high-yielding cultivar (Pembroke 2014) had the highest lactic acid solvent retention capacity score and thousand kernel weight of the cultivars evaluated. In addition, a landrace cultivar (Purple Straw) had the highest grain N and plant height. A French soft wheat, Soissons, had the highest sedimentation value and Pembroke 2016 achieved the highest yield. The findings from this study suggest the possibility of attaining a desirable grain with quality traits of SRW wheat that meets the needs of local bread wheat production in Kentucky through improving the optimization of cultivar selection, N management and specific considerations for conventional and organic systems