R. Figueroa-Brito, P. Villa-Ayala, J.F. López-Olguín, A. Huerta-de la Peña, J.R. Pacheco- Aguilar, and M.A. Ramos-López. 2013. Nitrogenfertilization sources and insecticidal activity of aqueous seeds extract of Carica papaya against Spodoptera frugiperda in maize. Cien. Inv. Agr. 40(3): 567-577. The damage caused by the fall armyworm Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) to vegetative-stage maize cultivated with chemical nitrogen fertilizers, vermicompost, and Carica papaya L. (Caricaceae) seed extract was estimated. Each shoot was infested with one first instar larva of S. frugiperda. The variables measured included the percentage of germination, length of the second and fifth leaves, stem diameter and plant height, and the estimation of damage caused by S. frugiperda larvae on maize. The results indicated that vermicompost helped seed germination on a relation 3:1 from black soil and vermicompost, the emergence was 100%, while the emergence with black soil was 80%. The ammonium sulfate increased the length of the second and fifth leaves 89.6% and 160.4% respectively, augmented the stem diameter and the plant height 290.2% and 13.3% respectively, respect to water treatment. The exogenous nitrogen sources stimulate S. frugiperda to cause more damage to the plant, the treatment urea showed 70% of damage, with phosphonitrate 62.3% and with ammonium sulfate 51.8%, when were evaluated without aqueous seed extract of C. papaya. Ammonium sulfate + aqueous extract of C. papaya seeds showed the lowest insect damage to maize with 29.6%.
The objective of this work was to evaluate the influence of nitrogenfertilization on the expression of yield and grain protein content in wheat in different environments of the semiarid Pampa region. The field experiments were carried out in Embajador Martini, Macachín and Anguil. The treatments were: control (0N), fertilization at seeding with 40 kg N.ha 1 (40+0) and 80 kg N.ha 1 (80+0), delayed fertilization with 40 kg N.ha 1 (between Z3.9 and Z5.0) (0+40) and divided fertilization (40+40). The treatments were arranged in a completely randomized block design with four replicates. Five filed experiments were carried out in each site and yield, grain protein content, water use efficiency and nitrogen use efficiency were determined. The sites with IMO> 4,5% had more response to yields in comparation with control, than the sites with IMO>4,5%. The soils with >50% A+L had grater soil potential fertility, and there were significant differences between the control and 80 kg.ha 1 at seeding o divided fertilization. Instead, the soils with <50% A+L did not show significant differences in the yields between treatments. The lowest yields in these soils were translated in higher protein grain content, reaching 11%. More soil nitrogen content increases the grain nitrogen content but decreases nutrient use efficiency. Although, rainfalls are the main restriction of this region, with a good water availability, the wheat productivity is limited by low nitrogen content.
and seven plants per experimental parcel. The experiment lasted for a period of 270 days. The diameter of stem (mm) and the height of the plant (cm) were evaluated every 30 days and the number of branches and total length of branches (cm) were evaluated every 90 days. At the end of the experiment, chlorophyll a index, dry mass of the leaves (g), dry mass of the branches (g), dry mass of the roots (g), total dry mass (g), and the Dickson Quality Index (DQI) were evaluated. According to the results, camu-camu plants that did not receive nitrogenfertilization had a lower initial growth and the doses of N significantly influenced all parameters evaluated in the camu-camu plants, including parameters from a linear and a quadratic model. The dose of 123 kg ha -1 of N, applied via fertirrigation, produced better quality camu-camu plants. Furthermore, greater doses
(12.3, 15.5, 20.0, 23.3, 26.5 months). The sugarcane cultivar H32-8560 (cane plant) was developed. In each harvest, an analysis of the quality of the cane was carried out: sucrose, brix, purity, reducing sugars, fiber and humidity. An Analysis of Variance was carried out to study the effect of N doses and cane age on quality. The quality results were related (via regression analysis) with the average salinity of the first 60 cm of the soil, of each plot, to the plantation, with the doses of N, and with the age of the cane. It was found that the applications of N did not affect the quality of the cane. The moderate salinity of the soil before planting was not related to any quality characteristic of the cane. The quality was not affected, either by the doses of nitrogen or by the salinity of the soil. The quality of the cane varied with the age of the plantation at the time of harvest, presenting a behavior similar to that in non-saline soils. The lack of water did not affect the ripening of the cane.
Lignocellulosic crops have been developed as an alternative in the energy matrix. Three species of interest in Uruguay are Arundo donax, Pennisetum purpureum and Panicum virgatum. In these crops nitrogenfertilization is the largest energy input. The objective was to compare the production of these three species, quantify the response to the addition of nitrogen and phosphorus and compare the final carbon content in the soil. The cultures were installed in 2007 and were evaluated from September 2011 to August 2013. The fertilization treatments after cutting were: witness without fertilization; 100 kg ha -1 N; 100 kg ha -1 of P
These results are not consistent with other stud- ies, in which there were no significant differences in the kinetics of development observed during the first rounds of cleavage (Paffoni et al., 2008; Miyauchi, 2012). However, it has been suggested that the first divisions after activation of the oocyte depend specifically on the content inher- ited by the oocyte, with little participation from the spermatozoon. In another study, Gomez et al. (2009) contrary to what was reported here, a sig- nificant difference was found in the rate of initial development in embryos produced using IVF, suggesting that many biological aspects of par- thenogenetic embryos are still unknown, consti- tuting a potential subject for future research. One of the more interesting results of the present study was the observed percentage of bovine clone embryo production, as a higher percentage of blastocytes was obtained compared with other studies (29% vs. 19%) (Forell, 2008). This percent- age was not statistically significantly different from that in the group of embryos generated through in vitro fertilization, which was between 30 and 35%, typical of commercial levels (Barreto de Almeida, 2008). This comparison represents an important finding, as there are few studies that have compared cloning techniques with IVF, which has been used successfully at the commer- cial level for many years.
The results obtained showed that VCT, prepared from the VC (made with horse and goat manure with alfalfa straw, mixed in a 1:1 ratio by volume), caused positive effects on development indicators of jalapeñ o pepper. During this study, the organic production of jalapeñ o pepper under protected conditions and using organic fertilizers resulted in a high yield. The use of VCT, C and VC can be considered as an alternative fertilization method for organic production in greenhouses, since they contain soluble nutrients that can satisfy the nutrient demand of this plant.
alkalinity, salinity, nutrient deficiency and toxicity stresses are potentially harmful to plants. The role of nitrogen as an essential nutrient and structural component of amino acids, proteins, nucleic acids and other essential components for the development has been widely documented in several species because of the importance in the processes of growth and agricultural production. However, at present, there is little literature the effect of nitrogen deficiency and toxicity on osmoregulators compounds as indicators of stress in plants. So the aim of this work was to study nitrogen compounds indicators of stress (proline, glycine betaine and choline) in response to toxic doses of N and deficient in green beans developed in a culture chamber under controlled conditions.
Earthworms play an important role in the maintenance of soil ecosystem services. Their presence and activity are influenced by agricultural practices as fertilization. The objective of this research was to identify earthworm species and to quantify their abundance and biomass in a field experiment where different fertilization strategies were applied for a period of 12 years. The experiment was carried out under a semiarid Mediterranean climate, in a fallow year of a rainfed cereal system. Fertilization strategies were based on pig slurries from fattening pigs (PE) and from sows (PM) at different fresh doses distributed in six treatments: three treatments only included PE (one rate was 30 t ha −1 yr −1 applied at pre-sowing, and the other two treatments received 40 and 60 t ha −1 yr −1 applied at cereal tillering), two treatments only included PM (60 and 90 t ha −1 yr −1 applied at cereal tillering) and the last, it combined PE and PM (30 t ha −1 yr −1 of PE at pre-sowing plus 90 t ha −1 yr −1 of PM at cereal tillering). Fertilization included a mineral fertilization treatment (0−FM) acting as a control. There were no variations in the abundance and biomass of earthworms registered according to the type of fertilization. Two earthworm species were identified. The endogeic species Koinodrilus roseus was the most abundant (80%−100%). The anecic species Nicodrilus trapezoides was not detected in plots receiving the two highest doses of PE at cereal tillering. The absence of
Fertilizing agricultural soils is one of the most expensive agricultural practices, although its economic return is usually high due to its effects on productivity, product uniformity and qual- ity (Ricci et al., 1995). In horticulture, because fertilization has a high economic return, farmers usually do not economize when applying fertil- izers to the plants.
Production of bovine embryos of known sex combined with cryopreservation and successful outcome following ET will become commercially applicable. The use of sexed sperm cells for IVF promises an attractive alternative to currently employed sexing requiring removal of embryonic cells by biopsy. Recent improvements in sperm cell sorting (16) make it possible to sort around 10 x 10 6 sexed sperm/h. Cran et al. (17) produced blastocysts from 17% of oocytes inseminated with sexed sperm and 106 twin transfers resulted in birth of 37 males and 4 females (90% efficiency in production of the desired sex). More recently, Hamano et al. (18) reported the birth of 10 calves from sorted, injected sperm with 80% efficiency in producing the desired sex. Sorted sperm provide cleavage rates comparable to unsorted sperm but blastocyst development is impaired (19, 20). Lu et al. (20) reported similar blastocyst development (around 70% of the rate with non-sorted sperm) with sorted fresh, and sorted, then frozen sperm. In this work fertilization and culture were in semi- defined conditions and use of sorted or non-sorted sperm for insemination in drops or in straws yielded 16 to 21% blastocyst development from oocytes (20). Lu and Seidel (21) reported in vitro maturation (IVM) in M199 + 10% estrous cow serum + 2 million granulosa cells/ml, sexed sperm insemination in citrate and EDTA-containing defined medium and IVC after the first 48h in the same medium with essential amino acids, no EDTA, but supplemented with 0.12 iu/ml insulin to improve results. Cleavage of 74%, and blastocyst development of 21.8% of oocytes resulted, and 62.4% of the day 7 blastocysts were grade 1 to 2.
The NFC content registered on this experimental study with organic fertili- zation was 32.5% lower than the value obtained with inorganic fertilization. Similarly, it resulted 35% lower than the mean values for NFC reported by Reta- Sánchez et al. (2010) for developed maize on the spring and summer cycles on the Comarca Lagunera region and those reported by Corral-Luna et al. (2013) for five maize hybrids developed on the central region of the Chihuahua state in Mexico, it was also slightly inferior to the 21.7 and 23.8% NFD values reported by Reta-Sánchez et al. (2013) for four leguminous species also from the Comarca Lagunera, during the 2005 and 2006 productive cycles, respectively.
(Ho et al., 2009), and NLP7 (Castaings et al., 2011; Marchive et al., 2013), SPL9 (Krouk et al., 2010b), LBD37/38/39 (Rubin et al., 2009), and TGA1/TGA4 (Alvarez et al., 2014) as transcription factors regulating nitrate-dependent gene expression. However, most of the work identifying these fac- tors has centred on root responses of young seedlings and N-dependent root phenotypes, and little is known of the role of these signalling molecules on developmental phase transi- tions. As summarized in this review, N availability impacts on the timing of developmental events during the entire life cycle of Arabidopsis, probably by regulating the expression level of genes that are key regulators of phase changes. Although some shared molecular components could participate in con- trolling these developmental check points, different devel- opmental stages and plant tissues express different sets of transcripts (Schmid et al., 2005), and therefore it is expected that tissue- and cell-developmental-stage-specific signalling pathways play a role in transducing the nitrate signal into plant developmental programmes. Although progress made in understanding N control of developmental phase transi- tions has come from the use of molecular genetic techniques on the model species Arabidopsis thaliana, this knowledge could be used to investigate the effect of N in transition phase changes in other plant species. For example, it has been described that miRNAs involved in the control of the floral transition stage are conserved throughout the plant king- dom (Chen et al., 2013; Luo et al., 2013). Designing strate- gies to control the timing of developmental phase transitions is of pivotal importance for fruit and crop production and also for biotechnological purposes. For example, overexpres- sion of maize miR156 (CORNGRASS1) in switchgrass has been shown to prevent flowering, improve digestibility, and increase starch content (Chuck et al., 2011). Thus, modify- ing N fertilization of crops can directly impact on shoot bio- mass content in crops utilized for biofuel production. Specific analysis of the N response of plants during development of different organs and cell types might shed light into N-gene regulatory networks coordinating plant growth and develop- ment to N availability.
Nitrogen-vacancy centers in diamond are promising candidates for a wide range of applica- tions due to their quantum sensing capabilities at room temperature and easy optical readout and manipulation by means of confocal microscopy and the application of microwave radiation. Applying microwave radiation is not a trivial task depending on the application. If a single NV center is addressed, then a thin (20 —m diameter) copper wire is sufficient if the NV is within 50 —m from the wire. However in a large area with a lot of NV centers that must be addressed simultaneously with a homogeneous microwave intensity, then a more specialized microwave an- tenna is required.
Minimum and no‐tillage systems are characterized by a crop residue mulch protecting the soil surface. Crop residue and straw mulch can be easily implemented by local farmers as materials are easily accessible, low cost and contribute to soil quality (Mupangwa, 2015). Originally developed for soil and water conservation, the crop residue mulch reduces evaporation losses increasing WUE (Unger, 1978). The effect on NUE is not so clear as several processes in the soil N cycle are affected. Crop residues retain water and reduce soil temperature (Quemada and Cabrera, 2002). Decomposition rates of crop residues covering the soil are lower than incorporated residues, the risk of ammonia volatilization increases when stubble and fertilizers remain on the soil surface, and larger N immobilization is expected in conservation tillage (Quemada et al., 1997). Because of these factors, optimum fertilization is even more important with conservation than with conventional tillage (Wang et al., 2011). As a whole, conservation tillage increases crop N uptake in semi‐arid areas mainly because of the higher soil water content, and this synergetic effect on NUE and WUE is particularly significant in dry years (Morell et al., 2011; Wang et al., 2011).