International Journal of Agronomy The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Growth Performance and Nutrient Uptake of Oil Palm Seedling in Prenursery Stage as Influenced by Oil Palm Waste Compost in Growing Media Mon, 08 Feb 2016 07:10:31 +0000 The use of composted oil palm wastes in the oil palm nursery as an organic component of growing medium for oil palm seedlings seems promising in sustainable oil palm seedling production. This study was conducted to investigate the effects of six oil palm waste compost rates (0, 20, 40, 60, 80, and 100%) on the growth performance of oil palm seedling and nutrient uptake in the prenursery stage (0–3 months). The addition of oil palm compost reduced the soil bulk density (1.32 to 0.53 g cm−3) and increased soil pH (4.7 to 5.1) of growth media. Oil palm waste compost treatment produced positive growth performance up to 70%. A regression analysis indicated in 72% of compost and topsoil mixture as a polybag growth medium was optimum in producing best growth performance of oil palm seedling in the prenursery stage. Foliar analysis implied highest nutrients uptake (N, P, K, Mg, Ca, Fe, Zn, and Cu) for seedlings grown in 60 to 100% compost media. A. B. Rosenani, R. Rovica, P. M. Cheah, and C. T. Lim Copyright © 2016 A. B. Rosenani et al. All rights reserved. Variation of Wheat Cultivars in Their Response to Elevated Temperature on Starch and Dry Matter Accumulation in Grain Wed, 03 Feb 2016 11:28:54 +0000 Three wheat cultivars, namely, BARI Gom 25, BARI Gom 26, and Pavon 76, were sown in experimental field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, in Bangladesh, on 18 November, 2013. Two temperature regimes, namely, normal (23°C in open field) and elevated (6 ± 1°C higher compared to open field mean air temperature in polythene chamber) temperature, were created immediately after anthesis to investigate the response of wheat cultivars to heat stress. Elevated temperature cuts back the duration of grain filling by 5 days in BARI Gom 25 and BARI Gom 26 and 10 days in Pavon 76. Starch synthesis was also cut back by the same duration in respective cultivars under elevated temperature condition. Results indicate that failure of conversion of sugar to starch rather than limited supply of sugar under high temperature condition was responsible for shortening of grain filling duration in all wheat cultivars. However, the response of elevated temperature on grain starch and main stem grain dry matter was less profound in BARI Gom 25 and BARI Gom 26 compared to Pavon 76 indicating their better tolerance to elevated temperature. Soyema Khatun, Jalal Uddin Ahmed, Tofazzal Hossain, M. Rafiqul Islam, and Mohammed Mohi-Ud-Din Copyright © 2016 Soyema Khatun et al. All rights reserved. Effects of Curing Period of Livestock Droppings on the Growth and Yield of Okra (Abelmoschus esculentus L.) Varieties Sun, 24 Jan 2016 06:21:14 +0000 A field study was carried out across two cropping seasons (2010 and 2011) to explore the effects of curing periods of cow dung and poultry droppings used in soil amendment on the performance of two okra (Abelmoschus esculentus L.) varieties: NHAe 47-3 and LD 88-1. The effects of cow dung and poultry droppings cured for 3, 6, and 9 weeks were compared to that of NPK fertilizer (100 kg N ha−1 and 60 kg ha−1 each of P2O5 and K2O) and a control (no amendment). The application of organic amendment cured for 3 to 6 weeks enhanced the growth and yield of okra when compared with inorganic fertilizer or the unamended soil across the two cropping seasons. Based on this outcome, the use of adequate quantity of livestock droppings cured for 3–6 weeks, in case of poultry dropping, and for 6 weeks, in case of cow dung, is recommended as an alternative to inorganic fertilizer. The variety NHAe 47-4 was also demonstrated to give better yield (1.73 and 2.18 t ha−1) than LD 88-1 (1.63 and 1.80 t ha−1) in the years 2010 and 2011, respectively. S. Y. Abdulmaliq, Y. A. Abayomi, M. O. Aduloju, and O. Olugbemi Copyright © 2016 S. Y. Abdulmaliq et al. All rights reserved. Apple Cultivation and Breeding in Afghanistan: S-RNase Genotypes and Search System for Suitable Cultivar Combination Wed, 20 Jan 2016 16:10:16 +0000 We investigated S-RNase genotypes of nine useful Afghan apple cultivars including six original cultivars and one rootstock. We also determined S-RNase genotypes of 11 apple cultivars and lineages and seven rootstocks in Japan. We speculated regarding the unidentified parents of cultivars and lineages from the S-RNase genotypes and their fruit and branch characteristics and also identified mistaken parents. We compiled a database of the apple S-RNase genotypes of 622 apple cultivars investigated, which included a survey system of cultivar combinations showing those that were fully incompatible, semicompatible, and fully compatible, written in the Pashto language. Matiullah Akbari, Mao Yamaguchi, Tsutomu Maejima, Shungo Otagaki, Katsuhiro Shiratake, and Shogo Matsumoto Copyright © 2016 Matiullah Akbari et al. All rights reserved. Phytotoxicity and Benzoxazinone Concentration in Field Grown Cereal Rye (Secale cereale L.) Wed, 06 Jan 2016 06:28:30 +0000 Winter rye (Secale cereale L.) is used as a cover crop because of the weed suppression potential of its mulch. To gain insight into the more effective use of rye as a cover crop we assessed changes in benzoxazinone (BX) levels in rye shoot tissue over the growing season. Four rye varieties were planted in the fall and samples harvested at intervals the following spring. Two different measures of phytotoxic compound content were taken. Seed germination bioassays were used as an estimate of total phytotoxic potential. Dilutions of shoot extracts were tested using two indicator species to compare the relative toxicity of tissue. In addition, BX (DIBOA, DIBOA-glycoside, and BOA) levels were directly determined using gas chromatography. Results showed that rye tissue harvested in March was the most toxic to indicator species, with toxicity decreasing thereafter. Likewise the BX concentration in rye shoot tissue increased early in the season and then decreased over time. Thus, phytotoxicity measured by bioassay and BX levels measured by GC have a similar but not identical temporal profile. The observed decrease in phytotoxic potential and plant BX levels in rye later in the season appears to correlate with the transition from vegetative to reproductive growth. C. La Hovary, D. A. Danehower, G. Ma, C. Reberg-Horton, J. D. Williamson, S. R. Baerson, and J. D. Burton Copyright © 2016 C. La Hovary et al. All rights reserved. High-Throughput Screening of Sensory and Nutritional Characteristics for Cultivar Selection in Commercial Hydroponic Greenhouse Crop Production Sun, 27 Dec 2015 10:12:04 +0000 Hydroponic greenhouse-grown and store-bought cultivars of tomato (cherry and beefsteak), cucumbers, bibb lettuce, and arugula were investigated to see if they could be distinguished based on sensory qualities and phytonutrient composition. Only the more dominant sensory criteria were sufficiently robust to distinguish between cultivars and could form the core of a consolidated number of criteria in a more discriminating sensory evaluation test. Strong determinants for cultivar selection within each crop included the following: mineral analysis (particularly Cu, Fe, K, Mg, and P); total carotenoids (particularly β-carotene, lycopene, and lutein); total carbohydrate (except in arugula); organic acids; total phenolics and total anthocyanins (except in cucumber). Hydroponically grown and store-bought produce were of similar quality although individual cultivars varied in quality. Storage at 4°C for up to 6 days did not affect phytonutrient status. From this, we conclude that “freshness,” while important, has a longer duration than the 6 days used in our study. Overall, the effect of cultivar was more important than the effect of growing method or short-term storage at 4°C under ideal storage conditions. Atef M. K. Nassar, Stan Kubow, and Danielle J. Donnelly Copyright © 2015 Atef M. K. Nassar et al. All rights reserved. Efficient Rooting System for Apple “M.9” Rootstock Using Rice Seed Coat and Smocked Rice Seed Coat Sun, 27 Dec 2015 06:08:43 +0000 “M.9” rootstock is considered as one of the most useful apple (Malus x domestica Borkh.) rootstocks; it produces dwarfing trees efficiently. As “M.9” rootstock shows a poor, brittle, and shallow roots system, we grafted “M.9” rootstocks onto “Marubakaidou” (M. prunifolia Borkh. var. ringo Asami Mo 84-A). We then propagated them by mound layering to establish a high-density root system. It was found that covering the roots with rice seed coat (RSC), RSC + smoked rice seed coat (SRSC), and vermiculite during mound layering was effective for the initiation of rooting. Utilizing RSC and SRSC seemed especially effective for producing “M.9” roots efficiently. Matiullah Akbari, Tsutomu Maejima, Shungo Otagaki, Katsuhiro Shiratake, and Shogo Matsumoto Copyright © 2015 Matiullah Akbari et al. All rights reserved. Evaluation of Animal Dungs and Organomineral Fertilizer for the Control of Meloidogyne incognita on Sweet Potato Thu, 24 Dec 2015 08:36:58 +0000 Root-knot nematode, Meloidogyne incognita, is an important animate pathogen causing major damage and severe reductions in the growth, yield, and quality of sweet potato. Nematicides are expensive and their application also causes environmental pollution. A field experiment was therefore conducted to evaluate the effectiveness of poultry dung (10 or 20 t/ha), cow dung (10 or 20 t/ha), horse dung (10 or 20 t/ha), goat dung (10 or 20 t/ha), organomineral fertilizer (2 or 4 t/ha), and carbofuran (3 kg a.i/ha) in the management of M. incognita on sweet potato using a randomized complete block design. The unamended plots served as control. Data were analysed using ANOVA (). All organic materials and carbofuran significantly () reduced nematode reproduction and root damage compared with control. Poultry dung (10 and 20 t/ha) and carbofuran were, however, more efficient in nematode control than other organic materials. Sweet potato plants that were grown on soil treated with organomineral fertilizer had the highest mean number of vines and fresh shoot weight, while poultry dung improved sweet potato quality and yield. It is therefore recommended that the use of poultry dung be employed in combination with other nematode control strategies to achieve sustainable, economic, and environment-friendly nematode management. Oluremi Solomon Osunlola and Bamidele Fawole Copyright © 2015 Oluremi Solomon Osunlola and Bamidele Fawole. All rights reserved. Preharvest and Postharvest Factors Affecting the Quality and Shelf Life of Harvested Tomatoes: A Mini Review Tue, 15 Dec 2015 09:46:53 +0000 Tomato production can serve as a source of income for most rural and periurban producers in most developing countries of the world. However, postharvest losses make its production unprofitable in these parts of the world. Postharvest losses in tomatoes can be as high as 42% globally. Postharvest losses in tomatoes can be either quantitative or qualitative. Even though emphasis in crop research nowadays is increasing shifting from quantity to quality of produce, there is still little improvement in the quality of commercially produced tomato varieties, hence resulting in high quality losses. From the study it was discovered that the postharvest quality status of tomatoes partly depended on some preharvest practices carried out during production. Some of these factors are fertiliser application, pruning, maturity stage, cultivar selection, and irrigation. Using best postharvest handling practices or factors such as temperature, relative humidity, gases in storage, postharvest calcium chloride application, and physical handling procedures to maintain the quality after harvest was also critical. It was concluded by this study that understanding and managing both preharvest and postharvest factors properly will reduce the postharvest quality losses in tomatoes. Isaac Kojo Arah, Harrison Amaglo, Ernest Kodzo Kumah, and Hayford Ofori Copyright © 2015 Isaac Kojo Arah et al. All rights reserved. Effect of Priming and Seed Size on Germination and Emergence of Six Food-Type Soybean Varieties Thu, 10 Dec 2015 12:44:10 +0000 Soybean (Glycine max (L.) Merr.), a good source of protein and oil, is used to produce nutritious isoflavone-rich soybean-based foods. The objectives of this study were (i) to determine the germination difference among soybean seeds in various seed sizes and (ii) to evaluate effects of seed pretreatment on germination and seedling emergence. Six varieties of different seed size class were used: (i) small size (MFS-561 and V08-4773), (ii) medium size (Glen and V03-47050), and (iii) large size (MFL-159 and V07-1897). Pregermination treatments include 0, 5, or 10 hours soaking and germinating/planting with or without nitrogen fertilizer. Large seed size varieties showed low germination rate and N addition caused the least reduction in germination in these seeds during the first 24 hours. While N had no effect on seed germination after 72 hours, growth in N treated seed was low. Seedling emergence was comparable across varieties in 2013 and water priming and N application had no effect. However, while varieties did not differ in final emergence for nonprimed seeds in 2014, water priming led to a high reduction in seedling emergence of large seed varieties in this study. Application of N fertilizer had no effect on seedling emergence in field experiments. Maru K. Kering and Bo Zhang Copyright © 2015 Maru K. Kering and Bo Zhang. All rights reserved. Short-Term Changes in Fertility Attributes and Soil Organic Matter Caused by the Addition of EM Bokashis in Two Tropical Soils Wed, 09 Dec 2015 11:47:24 +0000 The present work aimed to evaluate the behavior of ten fertility attributes of soil organic matter physical fractions and total organic carbon upon addition of three EM Bokashis to a Rhodic Ferralsol (FRr) and a Dystric Cambisol (CMd). An experiment was carried out in greenhouse in which the soils were placed into plastic trays and cultivated with tomato. A completely randomized design was used with four repetitions and factorial scheme of 2 × 3 + 2, consisting of two soils (FRr and CMd), three EM Bokashis (Poultry Manure Bokashi (BPM); CNPH Bokashi (BC); and Cattle Manure Bokashi (BCM)), and two controls (both soils without addition of Bokashi). The following fertility attributes were evaluated: pH, Ca2+, Mg2+, K+, Na+, P, SB, H + Al, CEC, and . Particulate organic carbon (POC) and mineral-associated organic carbon (MOC) and total organic carbon (TOC) were also investigated. Finally, the Principal Component Analysis was conducted in order to identify possible patterns related to soils when fertilized with EM Bokashi. The addition of EM Bokashi increased the soil fertility and contents of POC. Different EM Bokashi presents distinguished effects on each soil. The PCA suggests that BPM presents higher capacity to modify the analyzed chemical attributes. Carlos Eduardo Pacheco Lima, Mariana Rodrigues Fontenelle, Luciana Rodrigues Borba Silva, Daiane Costa Soares, Antônio Williams Moita, Daniel Basílio Zandonadi, Ronessa Bartolomeu Souza, and Carlos Alberto Lopes Copyright © 2015 Carlos Eduardo Pacheco Lima et al. All rights reserved. Winter Annual Weed Response to Nitrogen Sources and Application Timings prior to a Burndown Corn Herbicide Wed, 02 Dec 2015 09:55:16 +0000 Autumn and early preplant N applications, sources, and placement may affect winter annual weed growth. Field research evaluated (1) the effect of different nitrogen sources in autumn and early preplant on total winter annual weed growth (2006–2010), and (2) strip-till and broadcast no-till N applied in autumn and early preplant on henbit (Lamium amplexicaule L.) growth (2008–2010) prior to a burndown herbicide application. Total winter annual weed biomass was greater than the nontreated control when applying certain N sources in autumn or early preplant for no-till corn. Anhydrous ammonia had the lowest average weed density (95 weeds m−2), though results were inconsistent over the years. Winter annual weed biomass was lowest (43 g m−2) when applying 32% urea ammonium nitrate in autumn and was similar to applying anhydrous ammonia in autumn or early preplant and the nontreated control. Henbit biomass was 28% greater when applying N in the autumn compared to an early preplant application timing. Nitrogen placement along with associated tillage with strip-till placement was important in reducing henbit biomass. Nitrogen source selection, application timing, and placement affected the impact of N on winter annual weed growth and should be considered when recommending a burndown herbicide application timing. Kelly A. Nelson Copyright © 2015 Kelly A. Nelson. All rights reserved. Climate Change and Sugarcane Production: Potential Impact and Mitigation Strategies Thu, 22 Oct 2015 08:19:29 +0000 Sugarcane (Saccharum officinarum L.) is an important crop for sugar and bioenergy worldwide. The increasing greenhouse gas emission and global warming during climate change result in the increased frequency and intensity of extreme weather events. Climate change is expected to have important consequences for sugarcane production in the world, especially in the developing countries because of relatively low adaptive capacity, high vulnerability to natural hazards, and poor forecasting systems and mitigating strategies. Sugarcane production may have been negatively affected and will continue to be considerably affected by increases in the frequency and intensity of extreme environmental conditions due to climate change. The degree of climate change impact on sugarcane is associated with geographic location and adaptive capacity. In this paper, we briefly reviewed sugarcane response to climate change events, sugarcane production in several different countries, and challenges for sugarcane production in climate change in order for us to better understand effects of climate change on sugarcane production and to propose strategies for mitigating the negative impacts of climate change and improving sugarcane production sustainability and profitability. Duli Zhao and Yang-Rui Li Copyright © 2015 Duli Zhao and Yang-Rui Li. All rights reserved. Effects of Fungicides, Time of Application, and Application Method on Control of Sclerotinia Blight in Peanut Wed, 07 Oct 2015 08:50:17 +0000 Field studies were conducted from 2007 to 2010 to evaluate the response of peanut cultivars to different fungicides, application timings, and methods. Overall, fungicides reduced Sclerotinia blight incidence and increased pod yields when applied to susceptible and partially resistant cultivars. Disease suppression was greater when full fungicide rates were applied preventatively; however, yields between fungicide treated plots were similar. Lower levels of disease and higher yields were achieved with the partially resistant cultivar Tamrun OL07 compared to the susceptible cultivars Flavor Runner 458 and Tamrun OL 02. Despite possessing improved resistance Tamrun OL07 responded to all fungicide applications. While similar levels of disease control were achieved with broadcast or banded applications made during the day or at night, the yield response for the different application methods was inconsistent among years. A negative relationship (slope = −73.8; ; ) was observed between final disease incidence ratings and yield data from studies where a fungicide response was observed. These studies suggest that both boscalid and fluazinam are effective at controlling Sclerotinia blight in peanuts. Alternative management strategies such as nighttime and banded applications could allow for lower fungicide rates to be used; however, additional studies are warranted. Jason E. Woodward, Scott A. Russell, Michael R. Baring, John M. Cason, and Todd A. Baughman Copyright © 2015 Jason E. Woodward et al. All rights reserved. Growth, Development, and Mineral Nutrient Accumulation and Distribution in Tulip from Planting through Postanthesis Shoot Senescence Mon, 03 Aug 2015 06:09:24 +0000 Tulips were grown under field conditions from mid-November through early-June. Plants were harvested and dissected into eight organs on twenty-one dates. These parts were dried, weighed, and analyzed for N, P, K, Ca, and Mg. A transition (as determined by curve join points) from a linear to a steep negative cubic response occurred prior to shoot emergence for N (82 days after planting (DAP)), at shoot emergence for K (93 DAP) and Ca (94 DAP), and after shoot emergence for Mg (102 DAP) and dry matter (118 DAP). A transition from a linear to a steeper linear response occurred at shoot emergence for P (93 DAP). Growth, organ development, and nutrient accumulation occurred continuously from planting to maturity (188 DAP), except for K which did not accumulate during the initial linear phase. Since the increase in accumulation of all five nutrients preceded the dry matter accumulation, these nutrients could be used as predictors in growth models. Practical implications from this study include the importance of maintaining soil Ca levels through liming and applying the N, P, and Mg as split applications with smaller rates at planting and larger rates at emergence. The entire K application may be applied at emergence. Carl E. Niedziela Jr., Paul V. Nelson, and David A. Dickey Copyright © 2015 Carl E. Niedziela Jr. et al. All rights reserved. Seedling Performance Associated with Live or Herbicide Treated Tall Fescue Thu, 19 Feb 2015 17:30:04 +0000 Tall fescue is an important forage grass which can host systemic fungal endophytes. The association of host grass and endophyte is known to influence herbivore behavior and host plant competition for resources. Establishing legumes into existing tall fescue sods is a desirable means to acquire nitrogen and enhance the nutritive value of forage for livestock production. Competition from existing tall fescue typically must be controlled to ensure interseeding success. We used a soil-on-agar method to determine if soil from intact, living (L), or an herbicide killed (K) tall fescue sward influenced germination and seedling growth of three cultivars of tall fescue (E+, MaxQ, and E−) or legumes (alfalfa, red clover, and white clover). After 30 days, seedlings were larger and present in greater numbers when grown in L soil rather than K soil. Root growth of legumes (especially white clover) and tall fescue (especially MaxQ) were not as vigorous in K soil as L soil. While shoot biomass was similar for all cultivars of tall fescue in L soil, MaxQ produced less herbage when grown in K soil. Our data suggest establishing legumes or fescue cultivars may not be improved by first killing the existing fescue sod and seedling performance can exhibit significant interseasonal variation, related only to soil conditions. Jonathan J. Halvorson, David P. Belesky, and Harry W. Godwin Copyright © 2015 Jonathan J. Halvorson et al. All rights reserved. Productivity of Onions Using Subsurface Drip Irrigation versus Furrow Irrigation Systems with an Internet Based Irrigation Scheduling Program Sun, 08 Feb 2015 10:33:20 +0000 Selection of the proper irrigation method will be advantageous to manage limited water supplies and increase crop profitability. The overall objective of this study was to evaluate the effect of subsurface drip irrigation (SDI) and furrow irrigation on onion yield and irrigation use efficiency. This study was conducted in two locations, a commercial field and a field located at the Texas A&M AgriLife Research Center in Weslaco, TX. This study was conducted as a split-plot design for both sites with two treatments (SDI and furrow irrigation) and three replications per treatment. The total onion yield obtained with the SDI systems was more than 93% higher than the yield obtained with furrow irrigation systems. The large onion size was 181% higher for the SDI system than the furrow system in both sites. The colossal size yield was also higher. At one site colossal yield was 206% higher than furrow, while at another site furrow yielded no colossal onions and SDI had some production. It was concluded that drip irrigation systems more than double yields and increased onion size while using almost half of the water. This was due to SDI allowing for more frequent and smaller irrigation depths with higher irrigation efficiency than furrow irrigation systems. Juan Enciso, John Jifon, Juan Anciso, and Luis Ribera Copyright © 2015 Juan Enciso et al. All rights reserved. Sugarcane Yield Response to Furrow-Applied Organic Amendments on Sand Soils Mon, 02 Feb 2015 14:26:14 +0000 Organic amendments have been shown to increase sugarcane yield on sand soils in Florida. These soils have very low water and nutrient-holding capacities because of the low content of organic matter, silt, and clay. Because of high costs associated with broadcast application, this field study was conducted to determine sugarcane yield response to furrow application of two organic amendments on sand soils. One experiment compared broadcast application (226 m3 ha−1) of mill mud and yard waste compost, furrow application (14, 28, and 56 m3 ha−1) of these materials, and no amendment. Another experiment compared furrow applications (28 and 56 m3 ha−1) of mill mud and yard waste compost with no amendment. There were significant yield (t sucrose ha−1) responses to broadcast and furrow-applied mill mud but responses to furrow applications were not consistent across sites. There were no significant yield responses to yard waste compost suggesting that higher rates or repeated applications of this amendment will be required to achieve results comparable to mill mud. Results also suggest that enhancing water and nutrient availability in the entire volume of the root zone with broadcast incorporation of organic amendments is the more effective approach for low organic matter sands. J. Mabry McCray, Shangning Ji, and Leslie E. Baucum Copyright © 2015 J. Mabry McCray et al. All rights reserved. Winter Wheat Row Spacing and Alternative Crop Effects on Relay-Intercrop, Double-Crop, and Wheat Yields Mon, 19 Jan 2015 12:43:38 +0000 In Missouri as well as much of the Midwest, the most popular double-cropping system was winter wheat (Triticum aestivum L.) followed by soybean (Glycine max (L.) Merr). These two crops can also be used in an intercrop system, but optimal row spacing was important to increase crop productivity. Research was conducted to evaluate (1) winter wheat inter- and double-crop production systems, using a variety of alternative crops, and (2) the impact of different wheat row spacings on intercrop establishment and yields within the various cropping systems. Field research was conducted during droughts in 2012 and 2013. Spacing of wheat rows impacted wheat yields by 150 kg ha−1, as well as yields of the alternative crops. Narrower row spacings (150 kg ha−1) and the double-crop system (575 kg ha−1) increased yield due to the lack of interference for resources with wheat in 2013. Land equivalent ratio (LER) values determining productivity of intercrop systems of 19 and 38 cm row showed an advantage for alternative crops in 2013, but not 2012. This signified that farmers in Northeast Missouri could potentially boost yield potential for a given field and produce additional forage or green manure yields in a year with less severe drought. Leah Sandler, Kelly A. Nelson, and Christopher Dudenhoeffer Copyright © 2015 Leah Sandler et al. All rights reserved. Indirect Estimations of Lentil Leaf and Plant N by SPAD Chlorophyll Meter Mon, 12 Jan 2015 06:09:29 +0000 A Soil Plant Analysis Development (SPAD) chlorophyll meter can be used to screen for leaf nitrogen (N) concentration in breeding programs. Lentil (Lens culinaris L.) cultivars were grown under varied N regimes, SPAD chlorophyll meter readings (SCMR) were recorded from the cultivars leaves, and leaf N concentration was measured by combustion. Linear regression and the nonlinear Radial Basis Functions (RBF) neural networks models were employed to estimate leaf N concentration (LNC) based on the SCMR values. The closest estimates of LNC were obtained from the multivariate models in which the combination of plant age, leaf thickness, and SCMR was employed as the independent variable. In comparison, SCMR as the single independent variable in both models estimated less than 50% of LNC variations. The results showed significant effects of soil moisture and plant age on the association of LNC –SCMR as well as the relationship of LNC with plant N, grain yield, and days to maturity. However, the effect of cultivar on the measured variables was negligible. Although lentil N can be diagnosed by comparing SCMR values of the crop with those from a well-fertilized (N fixing) plot, the results did not support using SPAD chlorophyll meter for screening lentil LNC. Hossein Zakeri, Jeff Schoenau, Albert Vandenberg, Mohammadreza Tayfeh Aligodarz, and Rosalind A. Bueckert Copyright © 2015 Hossein Zakeri et al. All rights reserved. Ear Leaf Photosynthesis and Related Parameters of Transgenic and Non-GMO Maize Hybrids Thu, 08 Jan 2015 08:46:54 +0000 Hybrid maize (Zea mays L.) through transgenics now includes δ-endotoxins for insect control and tolerance to the herbicides glyphosate and glufosinate. Some hybrids have multiple transgenic traits as part of their genotype (stacked gene). Limited information is available on how these traits alone affect (net assimilation rate; µmol CO2 m−2 s−1) and related physiological parameters. A two-year, two-location, irrigated experiment comparing four stacked gene, four glyphosate tolerant, and two non-GMO hybrids for ear leaf , (stomatal conductance; mol H2O m−2 s−1), Em (transpiration; mol H2O m−2 s−1), IWUE (intrinsic water use efficiency; ), and Ci (intercellular [CO2] µmol CO2 mol air−1) was completed at Stoneville, MS, in 2012. Data were collected at growth stages R1 (anthesis) and R2 (early kernel filling) using a Li-Cor LI-6400XT set at 355 μmol mol−1 CO2 with a flow rate of 500 μmol s−1 and a 6400-02 light source set at 87.5% full sunlight. Measurements were made between 08:30 h and 11:30 h CST, within 48 h of 25 ha mm irrigation and ≥33.0% cloud cover. Transgenic traits did not influence the physiological parameters of , , Em, IWUE, or Ci during the critical growth stages of R1 or R2. H. Arnold Bruns Copyright © 2015 H. Arnold Bruns. All rights reserved. Effect of Irrigation and Preplant Nitrogen Fertilizer Source on Maize in the Southern Great Plains Wed, 17 Dec 2014 00:10:21 +0000 With the demand for maize increasing, production has spread into more water limited, semiarid regions. Couple this with the increasing nitrogen (N) fertilizer costs and environmental concerns and the need for proper management practices has increased. A trial was established to evaluate the effects of different preplant N fertilizer sources on maize cultivated under deficit irrigation or rain-fed conditions on grain yield, N use efficiency (NUE), and water use efficiency (WUE). Two fertilizer sources, ammonium sulfate (AS) and urea ammonium nitrate (UAN), applied at two rates, 90 and 180 kg N ha−1, were evaluated across four site-years. Deficit irrigation improved grain yield, WUE, and NUE compared to rain-fed conditions. The preplant application of a pure ammoniacal source of N fertilizer, such as AS, had a tendency to increase grain yields and NUE for rain-fed treatments. Under irrigated conditions, the use of UAN as a preplant N fertilizer source performed just as well or better at improving grain yield compared to AS, as long as the potential N loss mechanisms were minimized. Producers applying N preplant as a single application should adjust rates based on a reasonable yield goal and production practice. Jacob T. Bushong, Eric C. Miller, Jeremiah L. Mullock, D. Brian Arnall, and William R. Raun Copyright © 2014 Jacob T. Bushong et al. All rights reserved. Effect of Seed Distribution and Population on Maize (Zea mays L.) Grain Yield Tue, 09 Dec 2014 06:31:22 +0000 Maize planting is normally accomplished by hand in the developing world where two or more seeds are placed per hill with a heterogeneous plant spacing and density. To understand the interaction between seed distribution and distance between hills, experiments were established in 2012 and 2013 at Lake Carl Blackwell (LCB) and Efaw Agronomy Research Stations, near Stillwater, OK. A randomized complete block design was used with three replications and 9 treatments and a factorial treatment structure of 1, 2, and 3 seeds per hill using interrow spacing of 0.16, 0.32, and 0.48 m. Data for normalized difference vegetation index (NDVI), intercepted photosynthetically active radiation (IPAR), grain yield, and grain N uptake were collected. Results showed that, on average, NDVI and IPAR increased with number of seeds per hill and decreased with increasing plant spacing. In three of four site-years, planting 1 or 2 seeds per hill, 0.16 m apart, increased grain yield and N uptake. Over sites, planting 1 seed, every 0.16 m, increased yields by an average of 1.15 Mg ha−1 (range: 0.33 to 2.46 Mg ha−1) when compared to the farmer practice of placing 2 to 3 seeds per hill, every 0.48 m. Bee Khim Chim, Peter Omara, Natasha Macnack, Jeremiah Mullock, Sulochana Dhital, and William Raun Copyright © 2014 Bee Khim Chim et al. All rights reserved. Erratum to “Apple Pollination Biology for Stable and Novel Fruit Production: Search System for Apple Cultivar Combination Showing Incompatibility, Semicompatibility, and Full-Compatibility Based on the S-RNase Allele Database” Thu, 06 Nov 2014 07:10:51 +0000 Shogo Matsumoto Copyright © 2014 Shogo Matsumoto. All rights reserved. Modelling the Effects of Soil Conditions on Olive Productivity in Mediterranean Hilly Areas Sun, 19 Oct 2014 07:51:29 +0000 The majority of olive (Olea europaea L.) production in Mediterranean environments is characterized by low external inputs and is practiced in hilly areas with shallow soils. This study aimed to study the yield and nutritional status for olive (cv. “Zeiti”) trees in northwestern Syria and establish correlations between yield, on the one hand, and soil/land factors and tree nutrition, on the other hand, to determine the most yield-affecting factors. Land and soil fertility parameters (field slope, soil depth, and soil nutrients) and concentrations of leaf minerals were determined. As olive roots can go deep in the soil profile to extract nutrients, the total available nutrients per tree (over the whole profile) were estimated. Multiple regression analyses were performed to determine the model that best accounts for yield variability. Total available soil potassium amount (), soil total N amount (), and soil depth () had the highest correlations with olive fruit yields. Available soil potassium amount and soil depth explained together 77% of the yield variability observed. In addition to these two factors, adding leaf B and Fe concentrations to the model increased the variability explained to 83%. Ashraf Tubeileh, Francis Turkelboom, Anwar Al-Ibrahem, Richard Thomas, and Kholoud Sultan-Tubeileh Copyright © 2014 Ashraf Tubeileh et al. All rights reserved. Physical and Aerodynamic Properties of Lavender in relation to Harvest Mechanisation Tue, 07 Oct 2014 10:06:01 +0000 A laboratory study evaluated the physical and aerodynamic properties of lavender cultivars in relation to the design of an improved lavender harvester that allows removal of flowers from the stem using the stripping method. The identification of the flower head adhesion, stem breakage, and aerodynamic drag forces were conducted using an Instron 1122 instrument. Measurements on five lavender cultivars at harvest moisture content showed that the overall mean flower detachment force from the stem was 11.2 N, the mean stem tensile strength was 36.7 N, and the calculated mean ultimate tensile stress of the stem was 17.3 MPa. The aerodynamic measurements showed that the drag force is related with the flower surface area. Increasing the surface area of the flower head by 93% of the “Hidcote” cultivar produced an increase in drag force of between 24.8% and 50.6% for airflow rates of 24 and 65 m s−1, respectively. The terminal velocities of the flower heads of the cultivar ranged between 4.5 and 5.9 m s−1, which results in a mean drag coefficient of 0.44. The values of drag coefficients were compatible with well-established values for the appropriate Reynolds numbers. Christos I. Dimitriadis, James L. Brighton, Mike J. O’Dogherty, Maria I. Kokkora, and Anastasios I. Darras Copyright © 2014 Christos I. Dimitriadis et al. All rights reserved. Phosphorus Placement Effects on Phosphorous Recovery Efficiency and Grain Yield of Wheat under No-Tillage in the Humid Pampas of Argentina Tue, 23 Sep 2014 12:57:35 +0000 No-till (NT) affects dynamics of phosphorus (P) applied. Wheat response to P fertilization can be affected by available soil P, grain yield, placement, rate, and timing of fertilization. Furthermore, mycorrhizal associations could contribute to improving plant P uptake. Three experiments were used to evaluate P rate (0, 25, and 50 kg P ha−1) and fertilizer placement (broadcasted or deep-banded) effects in NT wheat on P recovery efficiency (PRE) yield and arbuscular mycorrhizal colonization (AMC) which was assessed in one experiment. Fertilization increased dry matter (DM) and accumulated P. Broadcasted P produced lower P accumulation than deep-banded P only at tillering. Phosphorus rate decreased PRE, and placement method did not affect it. Grain yield response was increased by P rate (857 and 1805 kg ha−1 for 25 and 50 kg P ha−1, resp.) and was not affected by placement method (4774 and 5333 kg ha−1 for broadcasted and deep-banded, resp.). Deep-banded P depressed root AMC compared with broadcast applications. Highest AMC in P broadcasted treatments could help to explain the lack of differences between placement methods. These results indicate that Mollisol have low P retention capacity. Therefore, broadcasted P could be used as an alternative of fertilizer management for NT wheat. Pablo Andrés Barbieri, Hernán René Sainz Rozas, Fernanda Covacevich, and Hernán Eduardo Echeverría Copyright © 2014 Pablo Andrés Barbieri et al. All rights reserved. Effect of Cultivars and Planting Date on Yield, Oil Content, and Fatty Acid Profile of Flax Varieties (Linum usitatissimum L.) Mon, 15 Sep 2014 00:00:00 +0000 In order to determine the effect of cultivars and planting date on flax fatty acid profile, seed yield, and oil content, an assay with seven cultivars (Baikal, Prointa Lucero, Prointa Ceibal, Panambí INTA, Curundú INTA, Carapé INTA, and Tape INTA) was carried out at Parana Agricultural Experimental Station, Argentina. Significant differences among cultivars were found for content of palmitic (5–7 g/100 g), stearic (5–8 g/100 g), linoleic (13–19 g/100 g), saturated (11–15 g/100 g), and unsaturated acids (92–96 g/100 g) within the seven cultivars. The best seed yields were observed in Prointa Lucero and Carapé INTA varieties (2091.50 kg·ha−1 and 2183.34 kg·ha−1, respectively) in the first planting date and in Carapé INTA and Prointa Lucero (1667 kg·ha−1 and 1886 kg·ha−1, respectively) in the second planting date. A delayed planting date had a negative effect on seed yield (1950 kg·ha−1 and 1516 kg·ha−1) and oil content (845 kg·ha−1 and 644 kg·ha−1) but did not affect oil composition. Maricel Andrea Gallardo, Héctor José Milisich, Silvina Rosa Drago, and Rolando José González Copyright © 2014 Maricel Andrea Gallardo et al. All rights reserved. Root Distribution and Nitrogen Fixation Activity of Tropical Forage Legume American Jointvetch (Aeschynomene americana L.) cv. Glenn under Waterlogging Conditions Mon, 08 Sep 2014 08:33:16 +0000 We investigated the root distribution and nitrogen fixation activity of American jointvetch (Aeschynomene americana L.) cv. Glenn, under waterlogging treatment. The plants were grown in pots under three different treatments: no waterlogging (control), 30 days of waterlogging (experiment 1), and 40 days of waterlogging (experiment 2). The plants were subjected to the treatments on day 14 after germination. Root dry matter (DM) weight distribution of waterlogged plants was shallower than controls after day 20 of waterlogging. Throughout the study period, the total root DM weight in waterlogged plants was similar to that in the controls. Enhanced rooting (adventitious roots) and nodule formation at the stem base were observed in waterlogged plants after day 20 of waterlogging. The average DM weight of individual nodules on the region of the stem between the soil surface and water surface of waterlogged plants was similar to that of individual taproot nodules in the controls. Waterlogged plants had slightly greater plant DM weight than the controls after 40 days of treatment. The total nitrogenase activity (TNA) of nodules and nodule DM weight were higher in waterlogged plants than in the controls. Waterlogged American jointvetch had roots with nodules both around the soil surface and in the area between the soil surface and water surface after 20 days of waterlogging, and they maintained high nitrogenase activity and net assimilation rate that resulted in an increased growth rate. Manabu Tobisa, Masataka Shimojo, and Yasuhisa Masuda Copyright © 2014 Manabu Tobisa et al. All rights reserved. Management of Vegetation by Alternative Practices in Fields and Roadsides Sun, 24 Aug 2014 07:25:11 +0000 In attempts to reduce the amounts of conventional herbicides used, alternative practices are sought in the management of roadside vegetation. In this investigation, alternative herbicides (citric-acetic acids, clove oil, corn gluten meal, limonene, and pelargonic acid), flaming, and mulching were assessed in management of annual and perennial, herbaceous vegetation in field and roadside plots. Several formulations of alternative herbicides applied singly or repeatedly during the growing season were evaluated and compared with conventional herbicides (glyphosate and glufosinate ammonium) or with flaming or mulching. Citric-acetic acid formulations, clove oil, limonene, or pelargonic acid applied as foliar sprays immediately desiccated foliage, but the efficacy lasted for no longer than five weeks. Repeated applications were better than single applications of these herbicides in suppressing plant vegetative growth. Corn gluten meal imparted little or no early control and stimulated late-season growth of vegetation. A single flaming of vegetation gave no better control than the alternative herbicides, but repeated flaming strongly restricted growth. Mulching with wood chips or bark gave season-long suppression of vegetation. Glyphosate gave season-long inhibition of vegetation, but the efficacy of glufosinate ammonium waned as the growing season progressed. For season-long suppression of vegetation with alternative herbicides or flaming repeated applications will be required. Allen V. Barker and Randall G. Prostak Copyright © 2014 Allen V. Barker and Randall G. Prostak. All rights reserved.