International Journal of Agronomy The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Evaluating the Impact of Starter Fertilizer on Winter Canola Grown in Oklahoma Tue, 06 Dec 2016 12:03:05 +0000 Increased canola production costs and acres have driven Oklahoma (OK) farmers to ask more questions about their nutrient management recommendations in their production system. A study was conducted in 2011–2013 at Lahoma and Perkins, OK, to evaluate the effect of applying diammonium phosphate (DAP, 18-20-0:N-P-K) directly with seed on crop stand, grain yield, and grain quality of canola. In addition, the impact of proportion nitrogen (N) applied as a preplant and topdress was also evaluated. Diammonium phosphate was banded with the seed at planting at 0, 17, 34, 51, 67, and 84 kg DAP ha−1. Remaining N was applied as urea (46-0-0) either as split (40% preplant and 60% topdress) application or as topdress only. Stand count reduction of up to 71% was observed with seed-placed DAP. However, loss of stand did not impair grain yield due to canola’s ability to compensate for open areas via branching. Application of DAP of up to 84 kg ha−1 with seed may be possible; however, soil and climatic conditions should be considered when deciding how much DAP will be placed with seed. Moreover, when climatic conditions limit early season growth and favor late spring growth, applying all N at topdress (no preplant) tended to provide greater canola grain yield. M. Joy M. Abit, Katlynn Weathers, and D. Brian Arnall Copyright © 2016 M. Joy M. Abit et al. All rights reserved. Revealing Seed Coat Colour Variation and Their Possible Association with Seed Yield Parameters in Common Vetch (Vicia sativa L.) Wed, 30 Nov 2016 09:21:21 +0000 The seed coat colour variation of 70 common vetch genotypes were determined by using uniform colour scale and their possible correlation with seed yield parameters including the number of pods per plant, the number of seeds per pod, pod dimension, and seed yield (kg/da) was determined. The results revealed presence of highly significant () variations for both the seed yield and the seed coat colour parameters measured. The number of pods per plant, the number of seeds per pod, and seed yield ranged from 5.8 to 16.03, from 5.2 to 7.66, and from 143.37 to 531.1, respectively. The lightness value varied from 19.00 to 40.28 while chromaticity and values ranged from −0.16 to 8.99 and from 0.79 to 22.11, respectively. The highest correlation coefficients were determined between and (), and and (). The seed coat colour traits and seed yield parameters generally showed weak negative correlations. Seed yellowness () and seed yield had correlation coefficient of −0.25, while correlation between and seed yield was determined as −0.23. The results indicated that lightness and yellowness of seed coat may be used as an important parameter to prescreen high yield genotypes of common vetch. Gulgun Yildiz Tiryaki, Abdullah Cil, and Iskender Tiryaki Copyright © 2016 Gulgun Yildiz Tiryaki et al. All rights reserved. Assessing the Economic Impact of Inversion Tillage, Cover Crops, and Herbicide Regimes in Palmer Amaranth (Amaranthus palmeri) Infested Cotton Tue, 29 Nov 2016 09:44:29 +0000 Cotton (Gossypium hirsutum L.) producers in Alabama are faced with a rapidly expanding problem that decreases yields and increases production costs: herbicide-resistant weeds. Producers increasingly rely on integrated weed management strategies that raise production costs. This analysis evaluated how tillage, cover crops, and herbicide regime affected net returns above variable treatment costs (net returns) for cotton production in Alabama from 2009 to 2011 under pressure from Palmer amaranth (Amaranthus palmeri S. Wats.). Annual net returns were compared for two tillage treatments (inversion and noninversion tillage), three cover crops (crimson clover [Trifolium incarnatum L.], cereal rye [Secale cereal L.], and winter fallow), and three herbicide regimes (PRE, POST, and PRE+POST). Results indicate that under heavy Palmer amaranth population densities one year of inversion tillage followed by two years of noninversion tillage, along with a POST or PRE+POST herbicide application had the highest net returns in the first year; however, the economic benefit of inversion tillage, across all herbicide treatments, was nonexistent in 2010 and 2011. Cotton producers with Palmer amaranth infestations would likely benefit from cultural controls, in conjunction with herbicide applications, as part of their weed management system to increase net returns. Leah M. Duzy, Andrew J. Price, Kipling S. Balkcom, and Jatinder S. Aulakh Copyright © 2016 Leah M. Duzy et al. All rights reserved. Factors Affecting the Presence and the Diversity of Bryophytes in the Petrifying Sources Habitat (7220) in Wallonia and the Brussels-Capital Region, Belgium Tue, 15 Nov 2016 12:04:47 +0000 Bryological composition, water chemistry, and environmental factors were characterized on 67 Belgian travertines. We explore the relationship between these environmental factors and the community composition, species richness, or presence of individual species using Redundancy Analysis with Hellinger’s transformation (tb-RDA) or Generalized Linear Models (GLMs). The best variables explaining the community composition are slope, NO3, NH4, and PO4. The species richness is negatively related to canopy cover and PO4. Palustriella commutata tends to be more frequent when the slope is steeper and to a lesser degree when the canopy cover is lower. Eucladium verticillatum tends to be slightly more frequent when canopy cover and NH4 concentrations are lower. Cratoneuron filicinum is more frequent at higher Mg concentrations and Pellia endiviifolia is more frequent at lower PO4 concentrations and higher NO3 concentrations. Brachythecium rivulare showed wide ecological amplitude and almost none of the tested environmental factors seem to be related to its presence. The study identifies eutrophication as the main factor responsible for habitat deterioration. Practical indications on the best ways to maintain or to enhance the quality of these petrifying sources are given. J.-M. Couvreur, G. San Martin, and A. Sotiaux Copyright © 2016 J.-M. Couvreur et al. All rights reserved. Response of Boron and Light on Morph-Physiology and Pod Yield of Two Peanut Varieties Sun, 30 Oct 2016 08:46:29 +0000 Boron is an important micronutrient that enhances vegetative growth and yield of crops, like peanut. Light also plays an important role in pegging of peanut. There has been little information regarding the application of boron and light in peanut in Bangladesh. Therefore, a field experiment was conducted to study the response of boron and light on morph-physiology and pod yield of two peanut varieties. Treatments considered two peanut varieties, namely, Dhaka-1 and BARI Chinabadam-8, three levels of boron (B), namely, 0-kg B ha−1 (B0), 1-kg B ha−1 (B1), and 2-kg B ha−1 (B2), and two levels of light, namely, normal day light (≈12 h light) and normal day light + 6 h extended red light at night (≈18 h light). Result revealed that days to first-last emergence and days to first-50% flowering took shorter times and vegetative growth, pods dry weight plant−1, pod yield, and germination were markedly increased with the application of boron. Vegetative growth and germinations were significantly increased in light, but the lowest leaf area, pods dry weight plant−1, and pod yield were found in light. Without germination, the highest vegetative growth, reproductive unit, and pod yield were observed from BARI Chinabadam-8. Days to first-last emergence, days to first-50% flowering, and number of branches plant−1 were found linearly related to pod yield. Md. Quamruzzaman, Md. Jafar Ullah, Md. Fazlul Karim, Nazrul Islam, Md. Jahedur Rahman, and Md. Dulal Sarkar Copyright © 2016 Md. Quamruzzaman et al. All rights reserved. Commercialization of Sago through Estate Plantation Scheme in Sarawak: The Way Forward Thu, 27 Oct 2016 14:04:49 +0000 Sago has been hailed as a next viable commodity in Sarawak, Malaysia, given its potential as a versatile crop. Realising its potential, Sarawak state government has started initiatives to stimulate sago plantation from subsistence farming to estate plantation. The move of introducing sago estate plantation is a bold one considering that Malaysia is the first country introducing such plantation design. This is a reflection on sago estate plantation in the state of Sarawak. It is observed that, in order to ensure success of the plantation scheme, factors such as rigorous land consolidation programme aiming to maximize sago production; introduction of a modern planting method that integrates well with the traditional planting method; rigorous scientific research in finding the best sago variety that produces high yield; effective communication between related agencies and smallholders; and concentrated involvement of all actors, governmental agencies, mills, and smallholders, have to be addressed accordingly. To conclude, it is hoped that this writing can be utilized as part of a contribution to accelerating commercialization of sago as a next viable commodity crop not only in Sarawak but in Southeast Asia as a whole. Hafizan Mohamad Naim, Ahmad Nizar Yaakub, and Dayang Asmah Awang Hamdan Copyright © 2016 Hafizan Mohamad Naim et al. All rights reserved. Fungicides and Application Timing for Control of Early Leafspot, Southern Blight, and Sclerotinia Blight of Peanut Tue, 18 Oct 2016 14:50:40 +0000 Field studies were conducted in 2013 and 2014 in south Texas near Yoakum and from 2008 to 2011 in central Texas near Stephenville to evaluate various fungicides for foliar and soilborne disease control as well as peanut yield response under irrigation. Control of Sclerotinia blight caused by Sclerotinia minor Jagger with penthiopyrad at 1.78 L/ha was comparable to fluazinam or boscalid; however, the 1.2 L/ha dose of penthiopyrad did not provide consistent control. Peanut yield was reduced with the lower penthiopyrad dose when compared with boscalid, fluazinam, or the high dose of penthiopyrad. Control of early leaf spot, caused by Cercospora arachidicola S. Hori or southern blight, caused by Sclerotium rolfsii Sacc., with penthiopyrad in a systems approach was comparable with propiconazole, prothioconazole, or pyraclostrobin systems and resulted in disease control that was higher than the nontreated control. Peanut yield was also comparable with the penthiopyrad, propiconazole, prothioconazole, or pyraclostrobin systems and reflects the ability of the newer fungicides to control multiple diseases found in Texas peanut production. W. James Grichar and Jason E. Woodward Copyright © 2016 W. James Grichar and Jason E. Woodward. All rights reserved. Effects of Biochar Amendment on Tomato Bacterial Wilt Resistance and Soil Microbial Amount and Activity Tue, 20 Sep 2016 09:50:15 +0000 Bacterial wilt is a serious soilborne disease of Solanaceae crops which is caused by Ralstonia solanacearum. The important role of biochar in enhancing disease resistance in plants has been verified; however, the underlying mechanism remains not fully understood. In this study, two different biochars, made from peanut shell (BC1) and wheat straw (BC2), were added to Ralstonia solanacearum-infected soil to explore the interrelation among biochar, tomato bacterial wilt, and soil microbial properties. The results showed that both BC1 and BC2 treatments significantly reduced the disease index of bacterial wilt by 28.6% and 65.7%, respectively. The populations of R. solanacearum in soil were also significantly decreased by biochar application. Ralstonia solanacearum infection significantly reduced the densities of soil bacteria and actinomycetes and increased the ratio of soil fungi/bacteria in the soil. By contrast, BC1 and BC2 addition to pathogen-infected soil significantly increased the densities of soil bacteria and actinomycetes but decreased the density of fungi and the ratios of soil fungi/bacteria and fungi/actinomycetes. Biochar treatments also increased soil neutral phosphatase and urease activity. Furthermore, higher metabolic capabilities of microorganisms by biochar application were found at 96 and 144 h in Biolog EcoPlates. These results suggest that both peanut and wheat biochar amendments were effective in inhibiting tomato bacterial wilt caused by R. solanacearum. The results suggest a relationship between the disease resistance of the plants and the changes in soil microbial population densities and activity. Yang Lu, Shuang Rao, Fei Huang, Yixia Cai, Guoping Wang, and Kunzheng Cai Copyright © 2016 Yang Lu et al. All rights reserved. Relative Efficacy of Liquid Nitrogen Fertilizers in Dryland Spring Wheat Sun, 18 Sep 2016 08:49:31 +0000 The study was conducted in 2012 and 2013 at three locations in North Central and Western Montana (total of 6 site-years) to evaluate the relative efficacy of three liquid nitrogen (N) fertilizer sources, urea ammonium nitrate (UAN, 32-0-0), liquid urea (LU, 21-0-0), and High NRGN (HNRGN, 27-0-0-1S), in spring wheat (Triticum aestivum L.). In addition to at-seeding urea application at 90 kg N ha−1 to all treatments (except for the unfertilized check plot), the liquid fertilizers were applied utilizing an all-terrain vehicle- (ATV-) mounted stream-bar equipped sprayer at a rate of 45 kg N ha−1 at Feekes 5 growth stage (early tillering). Three dilution ratios of fertilizer to water were accessed: 100/0 (undiluted), 66/33, and 33/66. The effects of N source and the dilution ratio (fertilizer/water) on N uptake (NUp), N use efficiency (NUE), spring wheat grain yield (GY), grain protein (GP) content, and protein yield (PY) were assessed. The dilution ratios had no effect on GY, GP, PY, NUp, and NUE at any of the site-years in this study. Taking into account agronomic and economic factors, LU can be recommended as the most suitable liquid N fertilizer source for spring wheat cropping systems of the Northern Great Plains. Olga S. Walsh and Robin J. Christiaens Copyright © 2016 Olga S. Walsh and Robin J. Christiaens. All rights reserved. Elucidating the Potential of Native Rhizobial Isolates to Improve Biological Nitrogen Fixation and Growth of Common Bean and Soybean in Smallholder Farming Systems of Kenya Sun, 18 Sep 2016 07:35:17 +0000 Identification of effective indigenous rhizobia isolates would lead to development of efficient and affordable rhizobia inoculants. These can promote nitrogen fixation in smallholder farming systems of Kenya. To realize this purpose, two experiments were conducted under greenhouse conditions using two common bean cultivars; Mwezi moja (bush type) and Mwitemania (climbing type) along with soybean cultivar SB 8. In the first experiment, the common bean cultivars were treated with rhizobia inoculants including a consortium of native isolates, commercial isolate (CIAT 899), a mixture of native isolates and CIAT 899, and a control with no inoculation. After 30 days, the crop was assessed for nodulation, shoot and root dry weights, and morphological features. In the second experiment, soybean was inoculated with a consortium of native isolates, commercial inoculant (USDA 110), and a mixture of commercial and native isolates. Remarkably, the native isolates significantly () increased nodulation and shoot dry weight across the two common bean varieties compared to the commercial inoculant, CIAT 899. Mixing of the native rhizobia species and commercial inoculant did not show any further increase in nodulation and shoot performance in both crops. Further field studies will ascertain the effectiveness and efficiency of the tested indigenous isolates. Ernest Wandera Ouma, Anne Mercy Asango, John Maingi, and Ezekiel Mugendi Njeru Copyright © 2016 Ernest Wandera Ouma et al. All rights reserved. Leaf Growth and Canopy Development of Three Sugarcane Genotypes under High Temperature Rainfed Conditions in Northeastern Mexico Tue, 23 Aug 2016 10:54:03 +0000 The aim of this study was to compare sugarcane (Saccharum spp.) canopy developmental components of three commercial varieties (CP 72-2086, Mex 79-431, and Mex 68-P-23) in a subtropical environment under rainfed and high temperature conditions, a poorly described topic in the literature. A field experiment was carried out in southern Tamaulipas, Mexico, throughout November 2011–January 2013 crop cycle, during which 111 of the days had daily maximum temperatures at or above 35°C. Number of leaves, leaf area, leaf appearance rate, and leaf area index (LAI) were determined. Thermal time exposure, °Cd (°C day−1), was determined based on total number of green ligulate leaves using 10°C as the base temperature. At 5000°Cd the number of leaves per plant ranged from 32 to 40 and the dependence of leaf emergence rate as a function of temperature was confirmed. The leaf emergence rate of CP 72-2086 was significantly greater than that of the other two varieties. Cultivars did not differ with respect to leaf length but differed for all other parameters measured. These results show the potential importance of considering sugarcane varietal differences in leaf phenology and canopy development for breeding programs focusing on rainfed and high temperature conditions. Sergio Castro-Nava, Alfredo J. Huerta, José Manuel Plácido-de la Cruz, and Epifanio Mireles-Rodríguez Copyright © 2016 Sergio Castro-Nava et al. All rights reserved. Effects of Short-Day and Gibberellic Acid Treatments on Summer Vegetative Propagation of Napier Grass (Pennisetum purpureum Schumach) Sun, 14 Aug 2016 06:07:54 +0000 The effects of short-day (SD) and gibberellic acid (GA3) treatments on promoting vegetative propagation during the summer were examined in Napier grass (Pennisetum purpureum Schumach). A dwarf variety of late heading type (DL) Napier grass was exposed to three SD treatments (5, 10, and 20 short days plus a spray of 400 ppm GA3 solution following each SD treatment, GASD) or no treatment (control). Additionally, then, a dwarf variety of early heading (DE) and the normal variety of Merkeron (ME) were exposed to 10 days of GA-SD treatment together with nontreated controls. For DL and DE, GA-SD treatments showed the following effects: 10-day GA-SD treatment increased significantly () the length of lateral tiller buds, maintained a high rooting percentage, and increased the diameter of the tiller buds. This resulted in a taller plant, one with enhanced tiller numbers, and thus a greater number of established nursery plants for the two dwarf varieties. In contrast, there was only a limited positive effect of the GA-SD treatments on the normal variety, ME. Thus, 10 days of GA-SD treatment was judged to be the most effective treatment for promoting lateral tiller bud elongation and early maturation in tiller buds for the two dwarf varieties of Napier grass. Yasuyuki Ishii, Asuka Yamano, and Sachiko Idota Copyright © 2016 Yasuyuki Ishii et al. All rights reserved. Evaluation of the Effect of Irrigation and Fertilization by Drip Fertigation on Tomato Yield and Water Use Efficiency in Greenhouse Tue, 26 Jul 2016 07:02:21 +0000 The water shortage in China, particularly in Northwest China, is very serious. There is, therefore, great potential for improving the water use efficiency (WUE) in agriculture, particularly in areas where the need for water is greatest. A two-season (2012 and 2013) study evaluated the effects of irrigation and fertilizer rate on tomato (Lycopersicum esculentum Mill., cv. “Jinpeng 10”) growth, yield, and WUE. The fertilizer treatment significantly influenced plant height and stem diameter at 23 and 20 days after transplanting in 2012 and 2013, respectively. As individual factors, irrigation and fertilizer significantly affected the leaf expansion rate, but irrigation × fertilizer had no statistically significant effect on the leaf growth rate at 23 days after transplanting in 2012. Dry biomass accumulation was significantly influenced by fertilizer in both years, but there was no significant difference in irrigation treatment in 2012. Our study showed that an increased irrigation level increased the fruit yield of tomatoes and decreased the WUE. The fruit yield and WUE increased with the increased fertilizer rate. WUE was more sensitive to irrigation than to fertilization. An irrigation amount of 151 to 208 mm and a fertilizer amount of 454 to 461 kg·ha−1 (nitrogen fertilizer, 213.5–217 kg·ha−1; phosphate fertilizer, 106.7–108 kg·ha−1; and potassium fertilizer, 133.4–135.6 kg·ha−1) were recommended for the drip fertigation of tomatoes in greenhouse. Wang Xiukang and Xing Yingying Copyright © 2016 Wang Xiukang and Xing Yingying. All rights reserved. Effect of Insecticide Seed Treatment on Safening Rice from Reduced Rates of Glyphosate and Imazethapyr Tue, 19 Jul 2016 09:09:27 +0000 Field experiments were conducted in 2013 and 2014 to evaluate the effect of insecticide seed treatments on exposure of young conventional rice to reduced rates of glyphosate and imazethapyr. During the two-year study, “Roy J” rice seed was treated with CruiserMaxx® Rice, thiamethoxam plus fungicide, or a fungicide-only treatment. Subsequently, glyphosate (Roundup PowerMax®) at 39.42, 78.76, or 157.54 g ae/ha or imazethapyr (Newpath®) at 4.39, 8.74, or 17.49 g ai/ha was applied at the 2- to 3-leaf growth stage of rice. Results in 2013 indicated that rice plants from seed treated with CruiserMaxx Rice exhibited significantly less injury 1, 3, and 6 weeks after either imazethapyr or glyphosate was applied in comparison to the plants having fungicide-only treated seed. The addition of an insecticide seed treatment also resulted in higher yields when both herbicides were applied compared to the fungicide-only seed treatment receiving the same herbicide treatments. In 2014, an overall decrease in injury from both herbicides was observed when rice seed was treated with CruiserMaxx Rice compared to receiving a fungicide-only seed treatment. Significant yield loss from low rates of glyphosate or imazethapyr was not observed in 2014, with or without a seed treatment. Based on the positive effects observed from the CruiserMaxx Rice seed treatment in reducing injury and maintaining rice yields, the insecticide seed treatment appears to provide some safening to rice against low rates of glyphosate and imazethapyr. M. R. Miller, R. C. Scott, G. Lorenz, J. Hardke, and J. K. Norsworthy Copyright © 2016 M. R. Miller et al. All rights reserved. Phenotypic Response of Two Garlic Varieties to Different Nitrogen Fertilization Grown under Irrigation in Sudan Savannah Ecological Zone of Nigeria Sun, 17 Jul 2016 09:53:23 +0000 A study was conducted under irrigation during dry season at the Katsina State Irrigation Site, Ajiwa. The aim of the experiment was to enhance the productivity of garlic through the choice of appropriate levels of nitrogenous fertilizer and suitable cultivar which maximizes yield. The experiment consisted of two varieties (ex-kofa and ex-sokoto) and four levels of nitrogen (0, 50, 100, and 150 kgN/ha). They were arranged in a randomized complete block design in three replications. The variety ex-sokoto was found superior to ex-kofa with respect to plant height, number of leaves, leaf area, and days to maturity, number of bulbs, bulb diameter, bulb weight, and number of cloves per bulb, cloves weight per bulb, and fresh and cured bulb yield. Application of 50 kgN/ha significantly increased plant height (cm), number of leaves per plant, leaf area, number of bulbs, and the total yield of the garlic. Significant effects of interaction between variety and nitrogen on leaf area and number of cloves per bulb of the garlic were observed. The combination of ex-sokoto variety and 50 kgN/ha was found to increase garlic yield. Maximum growth and yield could be realized using a combination of ex-sokoto variety and 50 kgN/ha at Ajiwa. Magaji G. Usman, A. S. Fagam, Rilwanu U. Dayi, and Zaharaddeen Isah Copyright © 2016 Magaji G. Usman et al. All rights reserved. Growth, Development, and Water Consumption of Irrigated Bean Crop Related to Growing Degree-Days on Different Soil Tillage Systems in Southeast Brazil Sun, 26 Jun 2016 11:58:57 +0000 Degree-days may be an alternative for predicting the influence of temperature on physiological aspects of plants in a changing climate. The objective of this research was to evaluate the relation between cumulative degree-days index () and the development, growth, and water consumption of irrigated bean under different soil tillage systems (STS). We developed an experiment in Southeast Brazil in plots managed with the following STS: chisel ploughing (CP), disk ploughing (DP), and revolving hoe (RH). The treatments did not influence the crop phenology when correlated to . The parameters of canopy ground cover, leaf area index, total dry matter, and the plant height presented a highly significant relationship with (). We also compared the results of field water balance with a simulation developed between the crop coefficient and and found a strong relationship ( = 0.93∗∗; ∗∗: high statistical significance ()) between these measurements and the model. The total water consumption measured at the irrigated bean crop reached 383 mm, 386 mm, and 375 mm while that simulated from dual crop coefficient approach based on reached 378 mm, 373 mm, and 349 mm to CP, DP, and RH, respectively, representing a mean difference of 4.2%. Gerson Araujo de Medeiros, Luiz Antonio Daniel, and Felipe Hashimoto Fengler Copyright © 2016 Gerson Araujo de Medeiros et al. All rights reserved. Efficiency on the Use of Radiation and Corn Yield under Three Densities of Sowing Thu, 23 Jun 2016 09:11:26 +0000 Aiming to evaluate sowing densities and efficiency of radiation use, six corn genotypes, three from open pollination (“Amarillo Almoloya,” “Cacahuacintle,” and “Jiquipilco”) and three hybrids (“Z-60,” “Condor,” and “H-50”), were sown at densities of 6.9, 7.8, and 8.9 plants m−2, under a split plot design, within a factorial arrangement of treatments during three years (2008, 2009, and 2010). Evaluated variables were yield, harvest index, biomass production, attenuation coefficient, and radiation use efficiency. Results indicate that 2008 was the best year because yield, biomass, and radiation use efficiency were 1132.6, 3505 gm−2, and 0.79 g MJ−1, respectively. “Jiquipilco” was the genotype that exhibited the best adaptability to climatic conditions of the zone; thus, it is recommended to be grown on the studied zone. A. Morales-Ruiz, J. M. Loeza-Corte, E. Díaz-López, E. J. Morales-Rosales, O. Franco-Mora, M. D. Mariezcurrena-Berasaín, and G. Estrada-Campuzano Copyright © 2016 A. Morales-Ruiz et al. All rights reserved. Insight into the Interaction between Plants and Associated Fluorescent Pseudomonas spp. Thu, 09 Jun 2016 06:17:15 +0000 Fluorescent Pseudomonas are known for their plant growth promoting and disease protection abilities. In past years, a number of studies have focused on how these bacteria suppress disease and induce resistance. They are known to produce antibiotics and siderophores, promote growth, and induce systemic resistance in the host plant. This bacterium has come out as a model organism for ecological studies going on in rhizosphere and for studying plant-beneficial microbe interaction. This review focuses on the current state of knowledge on biocontrol potential of fluorescent Pseudomonas strains and the mechanisms adopted by them. Akansha Jain and Sampa Das Copyright © 2016 Akansha Jain and Sampa Das. All rights reserved. Environmentally Smart Nitrogen Performance in Northern Great Plains’ Spring Wheat Production Systems Mon, 06 Jun 2016 05:57:12 +0000 Experiments were conducted in Montana to evaluate Environmentally Smart Nitrogen (ESN) as a nitrogen (N) source in wheat. Plots were arranged in a split-plot design with ESN, urea, and a 50%-50% urea-ESN blend at low, medium, and high at-seeding N rates in the subplot, with four replications. Measurements included grain yield (GY), protein (GP), and N uptake (GNU). A partial budget economic analysis was performed to assess the net benefits of the three sources. Average GY varied from 1816 to 5583 kg ha−1 and grain protein (GP) content ranged from 9.1 to 17.3% among site-years. Urea, ESN, and the blend resulted in higher GYs at 3, 2, and 2 site-years out of 8 evaluated site-years, respectively. Topdressing N improved GY for all sources. No trend in GP associated with N source was observed. With GP-adjusted revenue, farmer would not recover investment costs from ESN or blend compared with urea. With ESN costing consistently more than urea per unit of N, we recommend urea as N source for spring wheat in Northern Great Plains. Olga S. Walsh and Kefyalew Girma Copyright © 2016 Olga S. Walsh and Kefyalew Girma. All rights reserved. Response of Sorghum (Sorghum bicolor L.) to Residual Phosphate in Soybean-Sorghum and Maize-Sorghum Crop Rotation Schemes on Two Contrasting Nigerian Alfisols Thu, 02 Jun 2016 13:13:22 +0000 The effectiveness of finely ground Sokoto Rock Phosphate and Morocco Rock Phosphate to enhance productivity of maize- (Zea mays L.) Sorghum (Sorghum bicolor) and soybean- (Glycine max L.) Sorghum crop rotation schemes was evaluated using Single Super Phosphate as reference fertilizer. The experiments were carried out in the screen house of the Department of Agronomy, University of Ibadan, in February and June 2013. The experiments involved 2 × 2 × 4 × 3 factorial in a Completely Randomized Design. In the first and second croppings, the slightly acidic loamy sand still produced higher biomass than the strongly acidic sandy clay loam. On average, MRP was more efficient than SSP for maize dry biomass but, for soybean dry biomass, MRP was less efficient than SSP in the two soils. Sokoto Rock Phosphate was less efficient in the two location soils compared to SSP for the test crops. There was no difference in performance of P-sources in the second cropping. Soybean-Sorghum crop rotation scheme produced greater Sorghum biomass than maize-Sorghum crop rotation scheme. It is evident that pH and clay contents of soils as well as the rotation crop concerned influence the efficiency of finely ground soluble phosphates in crop rotation schemes. Abdulmajeed Hamza and Ezekiel Akinkunmi Akinrinde Copyright © 2016 Abdulmajeed Hamza and Ezekiel Akinkunmi Akinrinde. All rights reserved. The Role of Rhizobial ACC Deaminase in the Nodulation Process of Leguminous Plants Wed, 18 May 2016 06:51:22 +0000 Symbiotic rhizobia-legumes associations are extremely important in terms of sustainable agricultural practices. This symbiosis involves a complex interaction between both partners, plant and bacterium, for bacterial infection and the formation of symbiotic N-fixing nodules. In this regard, the phytohormone ethylene plays a significant role in nodule formation, acting as an inhibitor of the nodulation process. Ethylene not only regulates nodule development but also regulates many other plant developmental cues, including various stress responses that inhibit overall plant growth. Some rhizobia produce the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, thus, being able to decrease ACC and, consequently, decrease deleterious ethylene levels that affect the nodulation process. This occurs because ACC is the immediate precursor of ethylene in all higher plants. Hence, rhizobia that express this enzyme have an increased symbiotic potential. In addition to the direct role that ACC deaminase plays in the nodulation process per se, in a limited number of instances, ACC deaminase can also modulate nodule persistence. This review focuses on the important role of rhizobial ACC deaminase during the nodulation process, emphasizing its significance to legume growth promotion. Francisco X. Nascimento, Clarisse Brígido, Bernard R. Glick, and Márcio J. Rossi Copyright © 2016 Francisco X. Nascimento et al. All rights reserved. Weed Control in Corn (Zea mays L.) as Influenced by Preemergence Herbicides Tue, 10 May 2016 14:19:13 +0000 Field studies were conducted in central and south-central Texas from 2013 through 2015 to evaluate crop tolerance and efficacy of various preemergence herbicides alone and in combination for weed control in field corn. Acetochlor and pendimethalin alone, S-metolachlor plus mesotrione, and the three-way combination of S-metolachlor plus atrazine plus mesotrione provided the most consistent control of annual grasses including browntop panicum (Panicum fasciculatum L.), Texas millet (Urochloa texana L.), barnyardgrass (Echinochloa crus-galli L.), and sprawling signalgrass (Brachiaria reptans L.). Palmer amaranth [Amaranthus palmeri (S.) Wats.] control was at least 90% with fluthiacet-methyl plus pyroxasulfone, atrazine plus either acetochlor, alachlor, dimethenamid-P, S-metolachlor, or S-metolachlor plus mesotrione, saflufenacil plus dimethenamid-P, and S-metolachlor plus mesotrione. Hophornbeam copperleaf (Acalypha ostryifolia L.) was difficult to control; however, acetochlor, saflufenacil or pyroxasulfone alone, saflufenacil plus dimethenamid-P, and S-metolachlor plus mesotrione provided at least 90% control. Acetochlor or saflufenacil alone, thiencarbazone-methyl plus isoxaflutole, dimethenamid-P plus atrazine, rimsulfuron plus mesotrione, and saflufenacil plus dimethenamid-P controlled common sunflower (Helianthus annuus L.) at least 90%. Corn injury was minimal (≤3%) with all herbicides. In general, corn grain yield was greatest with herbicide treatments containing more than one active ingredient compared with a single active ingredient. Travis W. Janak and W. James Grichar Copyright © 2016 Travis W. Janak and W. James Grichar. All rights reserved. The Effects of Organic Wastes on Soil and Cotton Quality with respect to the Risk of Boron and Heavy Metal Pollution Tue, 10 May 2016 13:41:00 +0000 The effects on soil and cotton quality of organic wastes from medicinal and aromatic plant factories were investigated with regard to the risks of boron and heavy metal pollution. Oily cumin, oregano, oilless oregano wastes, and mineral fertilizers were applied to cotton in two field experiments performed in the years 2003 and 2006. The Pb content of the soil differed significantly in the 2003 experiment and oregano wastes had significantly decreasing effect. Boron of soil to which oily cumin wastes had been applied reached a toxic limit value in 2006. Boron in soil adversely affected long fibres; B in leaves had a positive effect on the fineness of fibres in 2006. Soil Ni adversely affected plant height in 2006 and seed cotton yield in 2003. Leaf Ni had an adverse effect on fibre elasticity in 2006. Soil Co increased ginning out-turn and Cr decreased the fibre fineness of cotton in 2003. Müzeyyen Seçer, Ömer Lütfü Elmaci, and Şafak Ceylan Copyright © 2016 Müzeyyen Seçer et al. All rights reserved. Effect of Two Biological Formulations Based on Bacillus subtilis and Pseudomonas fluorescens on Control of Didymella applanata, the Causal Agent of Red Raspberry Cane Spur Blight Wed, 27 Apr 2016 12:57:04 +0000 In vitro and in vivo studies were conducted to estimate the efficacy of the two microbial formulations based on Bacillus subtilis Cohn. and Pseudomonas fluorescens Mig. on the fungus Didymella applanata (Niessl.) Sacc., the causal agent of red raspberry (Rubus idaeus L.) spur blight. In vitro, both bacteria reduced the growth of D. applanata. In inoculation experiments with raspberry canes in two cultivars with different susceptibility to D. applanata, these antagonistic bacteria suppressed fungal development by reducing the lesions area and the number of D. applanata fruiting bodies. Field trials of two biological formulations under natural conditions showed a significant suppression of the disease. B. subtilis and P. fluorescens included in the formulations revealed antagonistic activity towards D. applanata that depended on the red raspberry cultivar and weather conditions. In all cases, B. subtilis showed better results than P. fluorescens in biocontrol of the raspberry spur blight. This study demonstrated for the first time the ability of the biocontrol agents B. subtilis and P. fluorescens to suppress red raspberry cane spur blight, a serious worldwide disease. Margarita Shternshis, Tatyana Shpatova, and Anatoly Belyaev Copyright © 2016 Margarita Shternshis et al. All rights reserved. Morphological and Physiological Plant Responses to Drought Stress in Thymus citriodorus Mon, 18 Apr 2016 13:43:48 +0000 Water availability is considered as a determinant factor that affects plant growth. The commercial medicinal values of an aromatic plant rely on the presence of secondary metabolites that are affected under water shortage. Two-year-old Thymus citriodorus plants were subjected to different polyethylene glycol (PEG-6000) levels (0, 2%, and 4%) under greenhouse condition. PEG treatment lasted for 15 days. Thyme plant showed a morphological drought avoidance mechanism by maintaining the root system development through shoot fresh weight reduction resulting in promoted root absorption capacity and sustained plant growth. Moreover, stressed plants were able to maintain water use efficiency and root : shoot ratio suggesting a strong relation between root water uptake and water use saving strategies. Furthermore, thyme plants reduced tissue dehydration through stomatal closure and improved root water uptake. Content of volatile oil constituents of geraniol and diisobutyl phthalate increased upon drought stress while pseudophytol was reduced. Unexpectedly, thymol was not reported as a main oil element under either control or mild stress condition, while it was increased upon high drought stress in measure of 4.4%. Finally, carvacrol significantly accumulated under high drought stress (+31.7%) as compared to control plants. Zdzislaw Attila Tátrai, Rabab Sanoubar, Zsuzsanna Pluhár, Silvia Mancarella, Francesco Orsini, and Giorgio Gianquinto Copyright © 2016 Zdzislaw Attila Tátrai et al. All rights reserved. Viability Assessment of Genipa americana L. (Rubiaceae) Embryonic Axes after Cryopreservation Using In Vitro Culture Wed, 06 Apr 2016 07:07:00 +0000 Embryonic axes excised from seeds of Genipa americana L. desiccated to different water contents were successfully cryopreserved by rapidly plunging seed samples directly into liquid nitrogen. Control and cryopreserved embryonic axes were excised and grown in WPM culture medium for viability assessment. All control embryonic axes (−LN2) excised from fully hydrated seeds (43.89% moisture content) germinated after 21 days of culture in vitro. These high germination percentages persisted even after the water content of the seeds was as low as 6.79%. After freezing in liquid nitrogen high germination percentages, 93%, 96%, and 93%, were observed for embryonic axes excised from seeds dehydrated to 13.26%, 9.57%, and 6.79 moisture content, respectively. The cryopreservation technique described here is recommended for long term conservation of G. americana germplasm. Izulmé Rita Imaculada Santos and Antonieta Nassif Salomão Copyright © 2016 Izulmé Rita Imaculada Santos and Antonieta Nassif Salomão. All rights reserved. Efficacy of a Phosphate-Charged Soil Material in Supplying Phosphate for Plant Growth in Soilless Root Media Mon, 04 Apr 2016 09:24:43 +0000 A soil material high in crystalline Fe hydrous oxides and noncrystalline Al hydrous oxides collected from the Bw horizon of a Hemcross soil containing allophane from the state of Oregon was charged with phosphate-P at rates of 0, 2.2, and 6.5 mg·g−1, added to a soilless root medium at 5% and 10% by volume, and evaluated for its potential to supply phosphate at a low, stable concentration during 14 weeks of tomato (Solanum esculentum L.) seedling growth. Incorporation of the soil material improved pH stability, whether it was charged with phosphate or not. Bulk solution phosphate-P concentrations in the range of 0.13 to 0.34 mg·dm−3 were associated with P deficiency. The only treatment that sustained an adequate bulk solution concentration of phosphate-P above 0.34 mg·dm−3 for the 14 weeks of testing contained 10% soil material charged with 6.5 mg·g−1 P, but initial dissolved P concentrations were too high (>5 mg·g−1 phosphate-P) from the standpoint of phosphate leaching. The treatment amended with 10% soil material charged with 2.2 mg·g−1 P maintained phosphate-P within an acceptable range of 0.4 to 2.3 mg·dm−3 for 48 d in a medium receiving no postplant phosphate fertilization. Young-Mi Oh, Paul V. Nelson, Dean L. Hesterberg, and Carl E. Niedziela Jr. Copyright © 2016 Young-Mi Oh et al. All rights reserved. Growth Response of Two Phaseolus mungo L. Cultivars Induced by Arbuscular Mycorrhizal Fungi and Trichoderma viride Tue, 29 Mar 2016 13:30:31 +0000 The present investigation aimed to quantify the difference in response of two Phaseolus mungo L. cultivars (i.e., UH-1 and IPU-94-1) to Glomus mosseae (G), that is, Funneliformis mosseae, Acaulospora laevis (A), and Trichoderma viride (T), in different combinations or alone. All the treatments were inoculated with Bradyrhizobium japonicum to ensure nodulation as soil used in the experiment was sterilized. After 120 days of inoculation, plants were analyzed for chlorophyll content, nodulation, mycorrhization, leaf area, and protein content. Results indicate variation in growth response of two cultivars with different treatments. Triple inoculation of plants with G + A + T proved to be the best treatment for growth followed by G + T in both cultivars. Our work allowed the selection of P. mungo L. cultivar UH-1 as highly mycorrhizal responsive as compared to IPU-94-1 and G. mosseae to be an efficient bioinoculant as compared to A. laevis for growth enhancement of P. mungo. Further characterization of P. mungo genotypes will enhance our knowledge of physiological and genetic mechanism behind increase in plant growth and yield due to AM symbiosis. Navnita Sharma, Kuldeep Yadav, and Ashok Aggarwal Copyright © 2016 Navnita Sharma et al. All rights reserved. Quick Decline Disease Disturbs the Levels of Important Phytochemicals and Minerals in the Stem Bark of Mango (Mangifera indica) Wed, 23 Mar 2016 10:41:51 +0000 Quick decline is one of the deadly diseases of mango (Mangifera indica) which causes a serious damage to the tree and its production. In the current study, we examined the levels of important phytochemicals and minerals in the stem bark of healthy and infected mango tree. Infected stem bark showed 12.5% lower levels of total sugars and 51.1% higher levels of proteins as compared to healthy parts, whereas no variation was observed in reducing sugar, free amino acid, and ascorbic acid. Among micronutrients, the levels of Zn, Na, Cr, and Cl were lowered by 25%, 54.3%, 25%, and 75.4%, respectively, whereas the level of Ni was 62.5% higher in the infected stem bark when compared with the healthy stem bark. However, other micronutrients did not show significant differences between healthy and infected parts. Among macronutrients, the quantity of N, P, and Mg showed an increase of 51.2%, 34.7%, and 27.6%, respectively, whereas the quantity of Ca and K was decreased by 25.2% and 7.66% in the infected stem barks as compared to healthy ones. The results of this study provide some basic but important information that may ultimately be helpful in managing the quick decline disease in the mango trees. Abdul Saeed, Muhammad Aslam Shad, Haq Nawaz, Mustafa Nawaz Shafqat, Zahid Muneer, Aqeela Shaheen, and Syed Tahir Abbas Shah Copyright © 2016 Abdul Saeed et al. All rights reserved. Detection of Bacterial Wilt Pathogen and Isolation of Its Bacteriophage from Banana in Lumajang Area, Indonesia Tue, 22 Mar 2016 14:15:25 +0000 Bacterial wilt disease on banana is an important disease in Lumajang District and causes severe yield loss. Utilizing bacteriophage as natural enemy of pathogenic bacteria has been widely known as one of the control strategies. This research was aimed at determining the causing agent of bacterial wilt on banana isolated from Lumajang area, to obtain wide-host range bacteriophages against bacterial wilt pathogen and to know the basic characteristic of bacteriophages, particularly its nucleic acid type. Causative agent of bacterial wilt was isolated from symptomatic banana trees from seven districts in Lumajang area on determinative CPG plates followed by rapid detection by PCR technique using specific pair-primer. Bacteriophages were also isolated from soil of infected banana crop in Sukodono District. Morphological observation showed that all bacterial isolates have similar characteristic as common bacterial wilt pathogen, Ralstonia solanacearum. In addition, detection of FliC region in all isolates confirmed that all isolates were R. solanacearum according to the presence of 400 bp of FliC DNA fragment. Moreover, two bacteriophages were obtained from this experiment (RSSKD1 and RSSKD2), which were able to infect all nine R. solanacearum isolates. Nucleic acid analysis showed that the nucleic acid of bacteriophages was DNA (deoxyribonucleic acid). Hardian Susilo Addy, Norita Fatatik Azizi, and Paniman Ashna Mihardjo Copyright © 2016 Hardian Susilo Addy et al. All rights reserved.