Study of the pest community of velvetleaf (Abutilon theophrasti Medic.)

Velvetleaf (Abutilon theophrasti Medicus 1787) is one of the most economically threatening weed plant in Hungary. Researching biological control against it, and identifying a possible and effective biocontrol agent is an important challenge, as chemical control is difficult and expensive, and there is an increasing claim to practice slight plant protection. Entomological studies were made in several parts of the world, for evaluating the species, occuring in velvetleaf, but none of these kind of experiments were assessed in Hungary. Our observations were made in field and plastic boxes, both under open field circumstances in 2008 and 2009 by visually assessing pests, netting and damage based identifying. Meanwhile 8 pest species were identified, including (Helix pomatia Linnaeus 1758--roman snale; Trialeurodes vaporariorum (Westwood 1856)--greenhouse whitefly; Oxycarenus lavaterae (Fabricius 1787)-- lime seed bug; Pyrrhocoris apterus (Linnaeus 1758)--fire bug; Rhopalus parumpunctatus Schilling 1829--common hyaline bug; Liorhyssus hyalinus--hyaline grass bug (Fabricius 1794); Mamestra brassicae (Linnaeus 1758)--cabbage moth; Helicoverpa armigera (Hübner 1808)--corn earworm). On the whole the literature datas were enlarged with four new velvetleaf pests (roman scale, lime seed bug, common hyaline bug, cabbage moth). Considering the earlier literature and our results, Liorhyssus hyalinus may play an important role on biological management of velvetleaf. However this pest considered as polyphagous, but discovered to occur in great numbers on velvetleaf, this points to the fact that can be its main host plant and by sucking on the plant, can cause decreased germination rate. We suggest the "hyaline velvetleaf bug" name istead of "hyaline grass bug". Of course, additional experiments are needed on this pest to may use safety and effectively in the future.     

Effect of seed depth on germination and growth of velvetleaf (Abutilon theophrasti Medic.)

Importance of several weed species has been considerably increased during the last few decades in Hungary. Velvetleaf (Abutilon theophrasti Medic.) belongs to this spreading weed group as well. This weed species was in the 27th position in the course of the fourth Hungarian weed survey, but at the time of the fifth weed survey in 2007-2008 it stepped forward to the 10th position in the cornfields of Zala County. Requiring a warm climate, global climate warming plays a significant role in its rapid spread. Moreover, its effective reproduction strategy supports its occurrence and continuous spread in almost all field crops. Protection against velvetleaf can only be successful, if we know its biological and ecological characteristics. Comprehensive knowledge of the plant and selection of a proper application of weed control methods together can result velvetleaf free crop fields. The experiment was set up on the 29th of April 2009 at Keszthely where fifty seeds were sown into 50 litres volume plastic pots, in four replications with fifty pieces of seed per each plot. Germination percent of velvetleaf seeds and several growth indexes of seedlings (stem- and root length, leaf area, number of leaves, stem- and root fresh and dry weight) were measured on three different sampling dates.     

The accumulation of five fluorescent compounds in the cotton leaf induced by cell-free extracts of Aspergillus flavus

(?)-Cryptocaryalactone (6-[2-acetoxy-4-phenyl-3-butenyl]-5,6-dihydro-2-pyranone) and (?)-deacetylcryptocaryalactone (6-[2-hydroxy-4-phenyl-3-butenyl]-5,6-dihydro-2-pyranone) isolated from Cryptocarya moschata seeds are natural germination inhibitors. Applied at 0.004 M, the second compound completely arrested germination of velvetleaf (Abutilon theophrasti) and decreased the germination rate of soybeans, but did not appear to affect corn. The first compound was not as effective; 0.004 M reduced velvetleaf germination 50%.     

(−)-Cryptocaryalactone and (−)-deacetylcryptocaryalactone-germination inhibitors from Cryptocarya moschata seeds

(?)-Cryptocaryalactone (6-[2-acetoxy-4-phenyl-3-butenyl]-5,6-dihydro-2-pyranone) and (?)-deacetylcryptocaryalactone (6-[2-hydroxy-4-phenyl-3-butenyl]-5,6-dihydro-2-pyranone) isolated from Cryptocarya moschata seeds are natural germination inhibitors. Applied at 0.004 M, the second compound completely arrested germination of velvetleaf (Abutilon theophrasti) and decreased the germination rate of soybeans, but did not appear to affect corn. The first compound was not as effective; 0.004 M reduced velvetleaf germination 50%.     

Agronomic use of biotechnologically processed grape wastes

Grape waste was composted by biodegradation and subsequently used as an organic fertilizer for 20 day-corn. Combinations of recently compressed grape waste and hen droppings (10% w/w) were prepared to study the activating effect of hen droppings and the effect of aeration on the composting process. The final hydrogen potential (pH), %C, %N and C/N ratio, indicated an adequate development of the bioprocess. Satisfactory results were observed when the products were applied at several doses (1,000-4,000 kg/ ha) as a soil conditioner for corn seed germination in greenhouses. Only the addition of hen droppings had a significant effect (P < 0.05) on corn dry matter (14% increase). A dose of 3000 kg/ha was considered as optimal and was used supplemented with triple superphosphate (TSP) in agronomic trials. All the treatments produced greater corn dry matter (P < 0.05) than the chemical industrial fertilizer used as a control (0.52-0.71 g/pot for the organic fertilizers vs 0.45 g/pot for the control). Anaerobic conditions and hen droppings addition significantly produced (P < 0.05) higher corn dry matter.     

Content of a storage jar from the Late Neolithic site of Hódmez?vásárhely-Gorzsa, south Hungary: a thousand carbonized seeds of Abutilon theophrasti Medic.

The lucky find of 934 carbonized seeds of Abutilon theophrasti Medic. in a storage jar at the Late Neolithic site of Hódmezővásárhely-Gorzsa, south Hungary, suggests that the seeds of velvetleaf were intentionally gathered, processed and stored by the inhabitants of this Tisza culture tell-site. Today this ancient fibre and oil plant, the seeds of which can be used for food and medicine, has become a pestilential weed worldwide. Until now, there has been no archaeobotanical record of velvetleaf. Conflicting reports as to the native origin of velvetleaf exist, including India, China and even the Mediterranean area. Since the progenitors of velvetleaf have not yet been found the centre of origin of the species is still unidentified. The huge floodplain swamps and flood-free loess-silt areas in the heart of the Pannonian plain provide this temperate species with suitable growing conditions.     

石灰和硼砂对果梅生长结果影响初报

针对永泰园艺场果梅立地条件及生长状况,以惯用施肥量(N:P₂O₅:K₂O=1:1.9:1.7,氮磷钾施用量1.83 Kg/年/株)为对照,在N、P₂O₅、K₂O比例均为1:0.4:0.6的基础上施用不同肥料组合,研究其对果梅生长、结果的影响。试验初步表明,在N、P₂O₅、K₂O比例为1:0.4:0.6、氮磷钾施用量1.38kg/年/株的基础上添加石灰和硼砂,与对照相比,硬核期后的坐果率提高9.9%,产量增加14.2%,明显促进新梢生长。有机肥的配施到第二年才产生肥效。     

The response ofPinus caribaea mor. var. Hondurensis seedlings to nitrogen,phosphorous and potassium fertilizers

Summary A soil pot culture experiment was conducted to study the response ofPinus caribaea var. hondurensis seedlings to the N, P, K fertilizers in a 3³ factorial combination of nutrients in four replicates. For this purpose, seedlings were grown in plastic pots in soils collected from Bahau pine experimental area. These soils belong to Durian series and are generally poor in nutrients.The seedlings were supplied with 112 kg/ha, 336 kg/ha and 560 kg/ha (100 lb/ac, 300 lb/ac and 500 lb/ac) of N, P, K in solution form in all possible combinations. Periodic growth measurements were taken and dry matter production was estimated at the conclusion of the experiment.The results indicate that phosphorous is the most important nutrient for the height growth of seedlings. The absolute height increment under the best treatment combination (N₁P₃K₁) was about threefolds (25.7cm) compared to 8.8 cm in the control. It was also found that higher levels of N and K, though not beneficial to height growth, resulted in better radial growth and more dry matter production compared to control plants. However, highest levels of N and K in the present experiment produced inhibitory influence as regards height growth even in the presence of low level of phosphorous.The study indicates that application of phosphorous at least at the rate of 560 kg/ha per plant is necessary on this type of soil to boost the initial height growth ofPinus caribaea var. hondurensis. Nitrogen at the rate of 336 kg/ha and potassium at the rate of 112 kg/ha will induce better radial growth.     

Comparative effect of potassium chloride and potassium sulfate on the yield and protein content of wheat in three different rotations

Comparative effects of potassium chloride and potassium sulfate at various levels of potassium on the performance of ARZ variety of wheat were studied at Agriculture Research Station Dera Ismail Khan, N.W.F.P., Pakistan. The experiment was laid out in three different rotationsviz, rice-wheat, maize-wheat and fallow-wheat. Potassic fertilizers were applied at the rate of 0, 37, 74, 111 and 148 kg k/ha alongwith the basal dose of 135 kgN plus 44 kg P/ha. Wheat yield data showed that the application of 37 kg K/ha of potassium chloride was found better in case of rice-wheat and fallow-wheat rotation and 37 kg K/ha of potassium sulfate for maize-wheat rotation. On the average of the three rotations, potassium sulfate at the rate of 74 kg K/ha (90 kg K₂O/ha) was found better and economical. Both the sources were almost equally effective but potassium sulfate out-yielded potassium chloride. Protein content of grains was significantly increased due to K application irrespective of the source and potassium sulfate was found with significantly higher protein content than potassium chloride.     

Response of Douglas fir seedlings to phosphorus fertilization and influence of temperature on this response

Summary Effects of P fertilizers on growth of Douglas fir (Pseudotsuga menziesii var.menziesii (Mirb.) Franco.) seedlings were examined in pots and nursery beds. In pot experiments levels of P equivalent to 300 kg/ha were adequate for maximum growth over 14–18 weeks and resulted in available soil P levels of 80 ppm after 15 weeks' growth. Maximum growth in pots was obtained with shoot P concentrations of 0.18%–0.20%, with higher values at lower temperatures, but the optimum concentration for one-year old (1-0) nursery seedlings was 0.16% P. Growth of seedlings was greatly restricted at a soil temperature of 5°C and an air temperature of 12°C. At a soil temperature of 10°C and an air temperature of 14°C seedling P requirement was greater than at soil and air temperatures of 20°C.Comparison showed that monammonium phosphate was more effective than calcium superphosphate in stimulating growth in pots and nursery. Triple superphosphate was also effective in the nursery. Diammonium phosphate, potassium dihydrogen phosphate and phosphoric acid had no advantages as P sources in the nursery. Available P levels of 100–130 ppm, in the loamy sand and sandy loam nurseries studied, and needle P concentrations of 0.18%, when sampled in October, were associated with maximum growth of two-year old (2-0) seedlings.P fertilization decreased root/shoot ratio, but did not alter the allometric relationship of shoot to root. Improving P status from a low level increased root growth capacity in 2-0 seedlings and P fertilization of potted seedlings increased dry weight/height ratio. Uptakes per seed bed ha of 236 kg N, 31 kg P, 81 kg K and 73 kg Ca by 2-0 seedlings were comparable with, or greater than, uptake rates of agricultural crops. Recoveries of 6–11% of P from fertilizer were recorded in the nursery.     

Establishment of phosphate-solubilizing strains of Azotobacter chroococcum in the rhizosphere and their effect on wheat cultivars under green house conditions

A pot experiment was conducted in the green house to investigate the establishment of phosphate solubilizing strains of Azotobacter chroococcum, including soil isolates and their mutants, in the rhizosphere and their effect on growth parameters and root biomass of three genetically divergent wheat cultivars (Triticum aestivum L.). Five fertilizer treatments were performed: Control, 90 kg N ha(-1), 90 kg N + 60 kg P2O5 ha(-1), 120 kg N ha(-1) and 120 kg N + 60 kg P2O5 ha(-1). Phosphate solubilizing and phytohormone producing parent soil isolates and mutant strains of A. chroococcum were isolated and selected by an enrichment method. In vitro phosphate solubilization and growth hormone production by mutant strains was increased compared with soil isolates. Seed inoculation of wheat varieties with P solubilizing and phytohormone producing A. chroococcum showed better response compared with controls. Mutant strains of A. chroococcum showed higher increase in grain (12.6%) and straw (11.4%) yield over control and their survival (12-14%) in the rhizosphere as compared to their parent soil isolate (P4). Mutant strain M37 performed better in all three varieties in terms of increase in grain yield (14.0%) and root biomass (11.4%) over control.     

Germination inhibition by 5,7-dihydroxychromone,a flavanoid decomposition product

5,7-Dihydroxychromone1 isolated from seeds ofPolygonum lapathifolium L. inhibits the germination of velvetleaf (Abutilon theophrasti Medic) seeds. Effective molar concentrations ranged from 1 mM to 6 mM. Flavanoids reported or suspected to cause inhibition were not active at concentrations above 10 mM. Compound1 is a flavanoid moiety and can be formed during catabolic degradation, but its role in the allelopathic activity attributed to flavanoids remains to be determined.     

The dynamics of nitrous oxide emission from the use of mineral fertilizers in Russia

The intensity of nitrous oxide (N2O) emission was considered based on literature data on the single input of mineral N (nitrogen) fertilizers into different agricultural soil types in Russia. Ambient environmental factors exert a combined effect on the process of gaseous nitrogen formation from fertilizers applied. To reduce the uncertainty of estimates as much as possible, only experimental results obtained under conditions similar to natural were selected for the assessments. Mineral nitric fertilizers were applied to soil at a rate of 40 to 75 kg/ha and the N2O emissions were measured for approximately 140 days. Daily average emission values varied from 0.08 to 0.45% of fertilizer nitrogen. Correspondingly, 1.26 and 2.38% of fertilizer nitrogen were emitted as N2O from chernozems and soddy podzols. In 1990, the use of fertilizers in Russian agricultural practices for 53 Gg N2O-N, which equates to approximately 6.1% of global nitrous oxide emissions from nitric fertilizers. Later, the emission dropped because of a decrease in the input of nitric fertilizers to agricultural crops, and in 1998, it constituted just 20.5% of the 1990 level. In the period from 2008 to 2012, the nitrous oxide emission is expected to vary from 0.5 to 65.0 Gg N2O-N due to possible changes in national agricultural development. In the most likely scenario, the use of mineral fertilizers in Russia will account for approximately 34 to 40 Gg N2O-N emissions annually from 2008-2012.     

Efficiency of algalization of rice in the Nile Delta with different amounts of nitrogen and potassium fertilization

Indica rice var. IR 28 was inoculated with cyanobacteria (blue-green algae) together with elther 0,72 and 144 kg N/ha or 0,60 and 120 kg K₂O/ha. Plant performance, yield, nitrogen contents and chemical fertilizer-N-use efficiency positively responded to inoculation with the cyanobacteria and increased further with increasing amounts of both N and K. Effects arising from the cyanobacteria, N or K differed under the other two factors.     

Effects of 60-year N,P, K and Ca fertilization on EUF-nutrient fractions in the soil and on yields of rye and potato crops

Summary In field experiments carried out uninterruptedly since 1923 on a sandy, grey-brown luvisol (8% clay) the EUF-nutrient fractions were determined after potato and rye crops in 1982 had been harvested.Annual applications of N fertilizer (90 kg N/ha) over a 60-year period raised both the organic and inorganic EUF-N fractions (Table 1). EUF-N_org values increased depending on crop rotation from 1.1–1.9 to 2.4–3.6 mg/100 g. This increase in EUF-N amounts was higher under rye monoculture than under potato monoculture. N leaching was more intensive under potato monoculture than under rye monoculture.Application of P, K and Ca fertilizers raised the EUF-P, EUF-K and EUF-Ca values at 20°C as well as at 80°C (Figs. 1, 2, 3). Analyses of soil samples from the 25–75 cm layer showed that the contents of EUF-Ca and EUF-K in this layer are as high as in the topsoil or even higher (Table 3).High yields of rye (>4 t/ha) and of potatoes (>30 t/ha) were obtained when in samples taken after harvest EUF-amounts of 3.5 mg N, 2 mg P, 3 mg K (in both topsoil and subsoil), 1.7 mg Mg and 20 mg Ca/100 g were released within 35 min. These levels were obtained with annual fertilizer application rates of 90 kg N, 60 kg P₂O₅ and 110 kg K₂O/ha.Applications of 1.6 t CaO/ha every 4 years were sufficient to maintain the soil pH at 6.0–6.5. Calculated on the basis of EUF-Ca contents, with the amounts of K-selective minerals being taken into account, this rate of liming corresponds with the needs of acid sandy soils.     

Fertilization of poplar clones in the nursery

Summary Results of experiments with four poplar clones and various chemical fertilizers in a nursery in southern Greece are presented. At the end of the first growth period the heights of the four clones, without fertilizers, decreased in the order of I-214>I-262>cv. campeator > black poplar 1/64 with significant differences only between black poplar 1/64 and the rest of the clones.Of the fertilizer nutrients N, P, K and Mg only N improved heights of all clones significantly and especially of the clone I-214. One hundred and 200 kg of P fertilizer per ha had minimal or negative effect on height increase of all clones.Ammonium sulfate, ammonium nitrate and potassium nitrate all at 400 kg N per ha were found equally effective in improving height growth of the clone I-214 but ammonium nitrate is the N fertilizer of choice by its higher N content and relatively lower price.Ammonium nitrate at 200 kg N per ha, in two or three equal dosages, during the first growth period, June–July, gave the maximum height increase for two consecutive years of the clone I-214. Six hundred kgs, of N per ha reduced height increase of the same clone and increased losses of N, as NO₃ ^–, in drainage water.     

Germination inhibition by 5,7-dihydroxychromone, a flavanoid decomposition product

5,7-Dihydroxychromone1 isolated from seeds ofPolygonum lapathifolium L. inhibits the germination of velvetleaf (Abutilon theophrasti Medic) seeds. Effective molar concentrations ranged from 1 mM to 6 mM. Flavanoids reported or suspected to cause inhibition were not active at concentrations above 10 mM. Compound1 is a flavanoid moiety and can be formed during catabolic degradation, but its role in the allelopathic activity attributed to flavanoids remains to be determined.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

The kinetics of amiben absorption and metabolism as related to species sensitivity

The rates of absorption and metabolism of 3-amino-2,5-dichlorobenzoic acid (amiben) were investigated in 3-day-old roots of amiben-sensitive velvetleaf (Abutilon theophrasti Medic.) and amiben-tolerant morningglory [Ipomoea hederacea (L.) Jacq.].     

氮、磷、钾配施对黄花菜产量及2种蒽醌类活性成分含量的影响

为探究黄花菜栽培种植时氮(N)、磷(P)、钾(K)肥的最佳施肥量,给黄花菜科学合理施肥提供依据。本试验以海螺沟本地黄花菜品种为研究对象,运用"3414"肥效试验方案,分别以N13.5kg/667m^2,P2O540kg/667m^2,K2O15kg/667m2为常规施肥水平,通过大田试验,研究氮磷钾配施对黄花菜主要农艺性状、产量和2种蒽醌类活性成分含量的影响。结果表明,合理的氮磷钾配施不仅能促进单株黄花菜生长发育的协调,而且能够显著提高其鲜花中的大黄酸和大黄酚含量;施用氮磷钾肥对黄花菜产量的增产效果明显,处理6(N2P2K2)的产量最高,为1727.73kg/667m^2,比不施肥处理增产457.90kg/667m^2,增产率达36.06%;施用氮、磷、钾肥对黄花菜产量影响的大小顺序为氮>磷>钾,氮肥增产效果最显著,磷肥次之,钾肥最差。一元二次肥效方程推荐的氮、磷、钾施肥量与本实验设计的最适施肥量相似,可以用于黄花菜实际生产施肥指导。综合考虑,在海螺沟地区推荐的氮、磷、钾肥最佳施用量分别为13.69kg/667m^2、31.53kg/667m^2和26.40kg/667m^2,获得的产量为1678.98~1763.31kg/667m^2。     

Loss of Nitrogen,Phosphorus, and Potassium Through Crop Harvests in Agroecosystems of Qianjiang,Hubei Province,PR China

The level of chemical fertilization in China is considerably higher than that normally applied in Western countries. For example, in the last decade the use of N-P-K chemical fertilizers increased, within the province of our study, from about 300 kg/ha in 1980 to about 850 kg/ha in 1990. Data on total amounts on nitrogen, phosphorus, and potassium that are removed with the harvest are necessary in determining and optimizing the amount of chemical fertilizers to be applied to different crops and in different cropping patterns. In this article we report the results of analyses of N, P, and K content of soils and different parts of different plants (soybean, cotton, rice, peanut, radish, Chinese cabbage, sesame, pepper, eggplant, and ambary) typically grown in rural areas of Southern China and provide an estimate of the balance of these nutrients under the five cropping systems that are dominant in the studied area.