Posts Tagged ‘Field Crops Research’

Durum wheat (Triticum durum L.) quality and yield as affected by tillage-straw management and nitrogen fertilization practice under furrow-irrigated conditions

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research 164 : 166-177, 2014

Grahmann, K.Verhulst, N.Peña-Bautista, R.J.Buerkert, A.;Vargas-Rojas, L.Govaerts, B.

Little is documented about the effect of different tillage and residue management practices on durum wheat (Triticum durum L.) quality. This study aims at examining the effect of tillage–residue management systems on wheat yield and quality in two cropping cycles, 19 years after establishment of tillage–residue management systems in 1992. Wheat grain samples were collected in an experiment with a durum wheat-maize (Zea mays L.) rotation and furrow-irrigation, conducted in the arid Yaqui Valley of north-western Mexico. Main plots had five tillage–crop residue management treatments: conventionally tilled raised beds (CTB) with straw incorporated and permanent raised beds (PB) with straw burned, removed, partly retained or fully retained. Split plots had seven nitrogen (N) fertilizer treatments with different rate (0, 150 or 300 kg N ha−1) and timing of application (basal, 1st node and split between both). Highest yields were obtained with PB-straw partly retained and 300 kg N ha−1 split application in 2010/11 (7.48 t ha−1) and with PB-straw removed and 300 kg N ha−1 applied at 1st node in 2011/12 (8.26 t ha−1). Permanent beds with full residue retention had high yellow berry (YB, opaque and starchy endosperm) incidence, even with 300 kg N ha−1; 19.5% in 2010/11 and 9.4% in 2011/12 of the grain kernels were affected by YB. Four groups of tillage–straw systems with different characteristics in relation to the durum wheat quality and yield were distinguished with a principal component analysis: PB-partly retained with high yields and acceptable quality, PB-straw retained with low quality and acceptable yields, CTB with intermediate quality results and lower yields and PB-straw burned with high quality and low yields. Results indicate a significant effect of timing of N application on durum wheat grain quality in PB. For both cycles and both N rates, the application of mineral N resulted in higher grain quality when all N was applied near 1st node. Grain quality was highest in PB-straw burned, but this practice had the lowest yields. For PB-straw fully retained, 1st node application of N fertilizer is recommended to minimize N immobilization. To obtain stable yields and desirable quality, alternative tillage practices such as PB with full or partial residue retention require adjusted, site-specific N management. Further research is required to identify fertilization strategies in tillage systems with full or partial residue retention that include fertilizer applications after first node to improve grain quality.

Seven years of conservation agriculture in a rice-wheat rotation of Eastern Gangetic Plains of South Asia: yield trends, economic profitability and carbon use efficiency

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research, 2014

Jat, R. K.Sapkota, T.B.Singh, R.G.Jat, M.L.Kumar, M.;Gupta, R.K. 

Water, energy and labour scarcity, increasing cost of production, diminishing farm profits and uncertain weather events are major challenges faced by the farmers under intensive tillage based conventional rice–wheat (RW) production system of Indo-Gangetic Plains (IGP) in South Asia. To address these challenges, conservation agriculture (CA) based crop management practices are being developed, adapted and promoted in the region. We evaluated agronomical productivity and economical profitability of various combinations of tillage, crop establishment and residue management practices in rice–wheat rotation of Eastern IGP of India: a smallholder, poorly resourced and most vulnerable regions for the climatic variability. The long-term trial was initiated in 2006 having 7 combinations of tillage, crop establishment and residue management in rice–wheat rotation. These consisted of conventional till puddled transplanted rice followed by conventional tilled wheat (CTR–CTW); CTR followed by zero tilled wheat (CTR–ZTW); direct seeded rice followed by wheat both on permanent raised beds (PBDSR–PBW); zero-till direct seeded rice followed by CTW (ZTDSR–CTW); ZTDSR followed by ZTW without residues (ZTDSR–ZTW); ZTDSR followed by ZTW with residues (ZTDSR–ZTW + R) and unpuddled transplanted rice followed by ZTW (UpTPR–ZTW). All these treatments were completely randomized and replicated thrice within a block.

During the initial three years of experimentation, we recorded higher rice grain yield in conventional tillage based rice systems (i.e. CTR–CTW and CTR–ZTW) than in CA based systems (i.e. ZTDSR–ZTW, UpTPR–ZTW). During the fourth and fifth years, the rice yields under CT and CA were comparable whereas sixth year onwards, higher yields were recorded under CA based system than in CT based systems. However, the wheat yield was higher in CA based system right from second year onwards. We observed the lowest wheat yield in the system where preceding rice crop was grown with intensive tillage operations (CTR). RW system productivity was higher in almost all the CA based systems than in the CT based and mixture of CT and CA based systems from the second year onwards. The net returns were always higher in CA based systems than in CT based system although the significant differences were obvious only from fourth year onwards in rice and second year onwards in wheat as well as at the system level. The higher grain yields and economical advantage of CA was realized after 2–3 years as the adaptation of CA based component technologies evolved over the time. In medium term, we found CA based systems to be agronomically and economically superior to CT based systems for rice–wheat rotation in a smallholder production system of Eastern IGP of South Asia. Hence, CA based RW production system is one of the pathways for improving productivity, income and food security while sustaining the natural resources in smallholder production systems of Eastern IGP.

Relationships between physiological traits, grain number and yield potential in a wheat DH population of large spike phenotype

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research, 2014

 Gaju, O.Reynolds, M.P.Sparkes,D.L.Mayes, S.Ribas-Vargas, G.Crossa, J.Foulkes, M.J. 

Our objective was to investigate the relationships between spike traits, grain number and yield potential and their physiological basis in a doubled-haploid (DH) population derived from a cross between a CIMMYT spring wheat (Triticum aestivum L.) advanced line of large-spike phenotype (LSP2; +Tintiller inhibition gene) and the UK winter wheat cultivar Rialto (R; −Tin1) of conventional spike phenotype. Field experiments were carried out in high radiation, irrigated conditions in NW Mexico in two seasons. Comparing the two groups of +Tin1 and −Tin1 DH lines, results showed the presence of the +Tin1 gene for tiller inhibition increased spike partitioning index (spike DM/above-ground DM at GS61 + 5 d; SPI) from 0.32 to 0.34 (+6.3%) (P < 0.01) and grains spike−1 by 5.1 (+13.9%) (P < 0.001), but reduced spikes m−2 by 20.7 (−5.7%) (P < 0.01). Overall a significant increase in grains m−2 of 865 (+6.6%) was observed in +Tin1 DH lines compared to −Tin1 DH lines (P < 0.05), but the effect on grain yield was not statistically significant. Above-grouund biomass at anthesis was not significantly affected by the presence/absence of the Tin1 gene; although results indicated the presence of the Tin1 gene increased photosynthetically active radiation interception from onset of stem elongation to anthesis, but decreased radiation-use efficiency during this phase. Our results indicated that introgressing the +Tin1 gene into modern wheat germplasm may offer scope to increase grains spike−1 and grains m−2 in irrigated, high radiation environments.

Improved wheat performance with seed treatments under dry sowing on permanent raised beds

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research, 2014

Mulvaney, M.J.Verhulst, N.Herrera, J.M.Mezzalama, M.Govaerts, B. 

Two strategies for seeding irrigation are used for irrigated wheat. Wet sowing utilizes pre-sowing irrigation to germinate weed seeds and thus control weeds, followed by sowing. Dry sowing plants into dry soil that is irrigated soon afterward, resulting in higher soil moisture during germination and emergence than wet sowing. Field observations have indicated reduced emergence, plant stands and yield in dry compared to wet sowing on a Vertisol in northwestern Mexico. This disadvantage is more acute when dry sowing is conducted in permanent beds with residue retention (conservation agriculture) compared to the conventional system involving tillage with residue incorporation. To identify the causes of reduced plant stand and yield and examine control options, chemical seed treatment effects on durum wheat (Triticum durum Desf.) and bread wheat (Triticum aestivum L.) performance under wet and dry sowing were investigated over three seasons in a permanent bed system. Four seed treatments were applied: Control (no seed treatment); Carboxin + thiram + chlorothalonil (Vit-Dac; fungicides); Difenoconazole + mefenoxam (Dif-Mef; fungicides); and Thiamethoxam + difenoconazole + mefenoxam (TMX-Dif-Mef; insecticide and fungicides). Plant stands, root rot scores, normalized difference vegetative index (NDVI), and grain yield were determined. Under dry sowing, Dif-Mef and TMX-Dif-Mef increased plant stands by 87% and 104%, respectively, compared to Vit-Dac, and by 152% and 172%, respectively, compared to the control. Under dry sowing, TMX-Dif-Mef increased yield by 9.76% and 17.7% compared to Vit-Dac and the control, respectively. Bread and durum wheat were significantly different for both emergence and yield every growing season. Seed treatments effects were not significant under wet sowing. Treatment differences were not linked with root rot incidence later in the season. Several mechanistic hypotheses to explain the results were explored. TMX has been reported to alter genetic expression to enhance response to early season abiotic stresses, but this has not been reported for Dif-Mef. The different physical conditions during stand establishment, i.e. increased moisture and reduced temperature, under dry sowing compared to wet sowing, could have affected microbial populations which induced biological suppression of germination and/or emergence. Although more research is required to explain the underlying mechanism, wheat producers transitioning to a dry sowing system under conservation agriculture with permanent raised beds may avoid yield loss by utilization of a Dif-Mef or TMX-Dif-Mef seed treatment.

Regulatory reform of seed systems: Benefits and impacts from a mungbean case study in Nepal

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research 158 : 15-23, 2014

Joshi, K.D.;Khanal, N.P.; Harris, D.; Khanal, N.N.; Sapkota, A.; Khadka, K.; Darai, R.; Neupane, R.K.; Joshi, M.; Witcombe, J.R.

Mungbean (Vigna radiata (L). Wilczek) is becoming an important grain legume in Nepal. It can be grown as an additional crop after harvesting winter crops such as winter wheat, winter legumes and oilseeds and before planting main season rice from the low-altitude Terai through to the middle hills of Nepal. Replacing short fallows in the spring, it provides additional high quality food, enhances soil fertility and increases the yield of the following crop. In spite of continued varietal research by the National Grain Legume Research Programme, no mungbean varieties were released from 1975 to 2006. The old variety, Pusa Baishakhi, was released in 1975, but became susceptible to Mungbean Yellow Mosaic Virus (MYMV) and several other diseases so mungbean became limited to a rarely grown, green manure crop. In 2003, we introduced four mungbean varieties resistant to MYMV from the Asian Vegetable Research and Development Centre. These were evaluated in participatory varietal selection (PVS) mother and baby trials in low fertility and droughted conditions using farmers’ levels of inputs and management. Variety spread was promoted by distributing free small seed samples in a process known as Informal Research and Development (IRD); and community-based seed production and marketing. Of the four varieties, NM94 and VC6372 consistently produced higher grain yields than the local check varieties, were resistant to MYMV and hence were preferred by farmers. The Ministry of Agriculture and Cooperatives endorsed a new variety release procedure in 2005 that permitted the use of data from PVS trials to support the release or registration of new crop varieties. In 2006, on the basis of data generated from PVS trials alone, the National Seed Board released NM94 as ‘Kalyan’ while, on the basis of combined data from the PVS trials and from on-station trials, VC6372 (45-8-1) was released as ‘Prateeksha’. The use of PVS contributed greatly to fast-tracking the release process and this resulted in farmers getting new MYMV-resistant mungbean varieties more quickly. Varieties spread rapidly through IRD and farmer-to-farmer seed networks and provided benefits to farming households. Regulatory reforms to speed up and simplify the process of varietal release are discussed.

Conservation agriculture in an irrigated cotton-wheat system of the western Indo-Gangetic Plains: Crop and water productivity and economic profitability

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research 158 : 24-33, 2014

Das, T.K.; Bhattacharyya, R.; Sudhishri, S.; Sharma, A.R.; Saharawat, Y.S.;Bandyopadhyay, K.K.; Sepat, S.; Bana, R.S.; Aggarwal, P.; Sharma, R.K.; Bhatia, A.; Singh, G.; Datta, S.P.; Kar, A.; Singh, B.; Singh, P.; Pathak, H.; Vyas, A.K.; Jat, M.L.

Cotton–wheat cropping system is the second most important wheat based system in the South Asia (4.5 M ha) and India (2.6 M ha) and contributes significantly to the food security in the region. However, with the conventional method of crop establishment and crop management, the productivity and profitability of the cotton–wheat system is low. Hence, despite non-suitability of growing situations, farmers are inclined towards cultivating the conventionally tilled rice–wheat rotation which has got severe consequences on the natural resources as well as the future food security. Therefore, an attempt was made to develop and evaluate the performances (in terms of system productivity, water productivity and profitability) of conservation agricultural technologies (like permanent narrow and broad-bed planting and residue management under zero tillage) under an irrigated cotton–wheat system in the region. Treatments included farmers’ practice (conventional tillage and flat-bed sowing without residue recycling; CT), and four combinations of raised-bed planting and residue management under zero tillage (viz., narrow-bed and broad-bed sowing with and without crop residue retention) in the first year. During the second year onwards two additional treatments were included: flat-bed sowing under zero tillage with and without residue retention. Results indicate that mean (of last two years) seed cotton yield in the plots under zero tilled permanent broad-bed sowing with residue retention (PBB + R) was about 24 and 51% higher compared with zero tilled narrow-bed sowing without residue retention (PNB; 2.91 Mg ha−1) and CT plots (2.59 Mg ha−1), respectively. Similarly, plots under PBB + R had significantly higher mean (of last two years) wheat grain yield than flat-bed zero tilled (ZT) and CT plots. Unlike seed cotton yield, wheat grain yield was not affected by the treatments in the first year. In the second year, plots under PBB + R had about 9 and 11% higher wheat grain yield than PNB (4.37 Mg ha−1) and CT (4.29 Mg ha−1) plots, respectively. Although the system productivity in terms of wheat equivalent yield (WEY) was similar in the plots under PBB + R and zero tilled-broad permanent bed sowing without residue retention (PBB) and zero tilled narrow-bed sowing with residue retention (PNB + R) in the first year, plots under PBB + R had about 15 and 13% higher WEY than PBB and PNB + R plots. Similarly, mean (of the last two years) water productivity of the system in the PBB + R treated plots (12.58 kg wheat grain ha−1 mm−1) was 48, 22, 12, 15, 13, 24% higher compared with CT, PNB, PNB + R, PBB, ZT + R and ZT plots, respectively. The above-said PBB + R plots also had the highest net returns (based on mean values of last two years) that was 36 and 13% higher compared with CT and PNB plots, but was similar to other treatments. Therefore, growing cotton–wheat system under permanent beds with residue retention is recommended under irrigated conditions in this region due to its potential of increased productivity, profitability and resource conservation.

The use of unbalanced historical data for genomic selection in an international wheat breeding program

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research 154  : 12-22, 2013

Dawson, J.C.; Endelman, J.B.; Heslot, N.; Crossa, J.; Poland, J.; Dreisigacker, S.; Manes, Y.; Sorrells, M.E.; Jean-Luc Jannink

Genomic selection (GS) offers breeders the possibility of using historic data and unbalanced breeding trials to form training populations for predicting the performance of new lines. However, when using datasets that are unbalanced over time and space, there is increasing exposure to different genotype – environment combinations and interactions that may make predictions less accurate. Global cross-validated genomic prediction accuracies may be high when using large historic datasets but accuracies for individual years using a forward-prediction approach, or accuracies for individual locations, are often much lower. The objective of this study was to evaluate the overall accuracy of genomic predictions for untested genotypes using an unbalanced dataset to train a genomic selection model, and to explore ways of combining genomic selection and genotype-by-environment (G×E) interaction models to better target untested lines to different locations. Using the International Center for Maize and Wheat Improvement’s (CIMMYT) Semi-Arid Wheat Yield Trials (SAWYT) we assessed the accuracy of genomic predictions and the potential to subset these nurseries using the concept of mega-environments (ME) adapted to a genomic selection context. We found that there was no difference in accuracy between models accounting for G×E interactions and global models. Data-driven methods of clustering locations based on similarities in genomic predictions also failed to improve accuracies within clusters. Using a simulation based on the empirical SAWYT data, we found that if there were different true genotypic values between clusters, there was an advantage to modeling G×E in prediction models. In the SAWYT dataset it appears that there is not a consistent pattern of genotype-by-environment interaction among the ME, and this dataset is not balanced enough to partition into new clusters that have predictive power.

Genetic variability of maize stover quality and the potential for genetic improvement of fodder value

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research 153 : 79-85, 2013

Berhanu Tadesse Ertiro; Twumasi-Afriyie,S.; Blummel, M.; Friesen, D.; Demewoz Negera; Worku, M.; Demissew Abakemal; Kitenge, K.

Maize stover left after grain harvest constitutes an important source for livestock feed in most parts of East Africa, particularly during the dry season. In spite of its wide use and greater importance, breeding programs have given little attention to the improvement of stover quality and quantity. The objectives of this study were to assess the genetic variability of experimental and released (checks) maize varieties for stover feed quantity and quality, and their relationship with grain yield. Results from different trials conducted across locations using randomized complete block design (RCBD) in different sites in Ethiopia and Tanzania from 2004 to 2006 showed higher genotypic variation for grain and stover yields and stover feed quality traits. This confirmed the existence of exploitable genetic variation not only for grain yield but also for stover fodder quality and quantity. Positive relationship was also observed between grain and stover yields but the relation between stover fodder quality traits and grain yield, in most cases, was weak. Generally, the study pinpointed the possibility for simultaneous improvement of grain yield and stover traits to address the high demand existing for dual purpose food-feed type of maize genotypes in maize-livestock mixed farming system of East Africa.

A note on the correlations between maize grain and maize stover quantitative and qualitative traits and the implications for whole maize plant optimization

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research 153 : 63-69, 2013

Y. Ramana Reddy; D. Ravi; Ch. Ramakrishna Reddy; K.V.S.V. Prasad;P.H. Zaidi; M.T. Vinayan; M. Blümmel

The paper explores opportunities and limitations for concomitant improvement of maize grain quantity and quality traits and maize stover quantity and quality traits in 60 parental lines, 30 crosses/local checks and 12 released hybrids. Investigated grain quality traits were protein (CP), fat, metabolizable energy (ME), lysine and tryptophan. Stovers were investigated for nitrogen (N), neutral (NDF) and acid detergent fiber (ADF), acid detergent lignin (ADL), in vitro organic matter digestibility (IVOMD) and ME. Quality traits were investigated using near infrared spectroscopy (NIRS) applied to whole and ground maize grain and to ground stover. Application of NIRS to whole maize grain was unsuccessful but CP, fat and ME contents in ground maize grain were well predicted with R2 = 0.81, 0.83 and 0.94, respectively, and predictions of lysine and tryptophan were acceptable (R2 = 0.70). Maize stover quality traits were generally well predicted by NIRS (R2 = 0.81–0.96). Genotype and environment effect was significant on the quality traits of grain, whereas G × E effect was not significant. Trade-offs between grain and stover quality traits were generally absent or weak and inconsistent but several grain quality traits were incompatible. Thus grain CP was negatively correlated with grain yield. Lysine and tryptophan were consistently significantly negatively correlated with CP. Line and cultivars-dependent variation in grain and stover quality traits were high enough to be of nutritional significance to monogastrics and ruminants.

Potential for dual-purpose maize varieties to meet changing maize demands: Synthesis

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research 153 : 107-112, 2013

Blummel, M.; Grings, E.;Erenstein, O.

Maize—or corn (Zea mays L.)—now is the most important global cereal in terms of production reflecting its versatility in use, including human food, animal feed and fodder, industrial products and biofuel. Most uses revolve around maize grain as the primary product, although whole plant utilization for silage is also common in industrialized agriculture (e.g. Klopfenstein et al., 2013). Despite being a versatile crop, maize production and maize breeding efforts over time have typically had a single-purpose orientation. For instance, maize breeding has focused on overcoming biotic and abiotic stresses so as to generate high yielding, stress-tolerant and widely-adapted maize varieties through judicious combination of conventional and molecular breeding approaches ( Muttoni et al., 2013 and Shiferaw et al., 2011). Even smallholders within mixed maize–livestock systems typically focus on maize grain yield (De Groote et al., 2013), with maize stover as additional byproduct and benefit. Although farmers may still try to increase fodder off-take, they still try to minimize maize grain yield loss ( Byerlee et al., 1989 and Lukuyu et al., 2013).