Genotypic variations in zinc accumulation and bioaccessibility among wheat (Triticum aestivum L.) genotypes under two different field conditions

Zinc (Zn) is an essential micronutrient for human health. Breeding zinc-rich crop genotypes is considered as potential solution to Zn deficiency. In this study, variation of Zn uptake, accumulation, distribution and the estimated bioaccessibility among 30 wheat genotypes across two locations were investigated with field experiments. A significant difference in grain Zn concentrations occurred across the two locations, with the corresponding values of 55.24 and 57.14 mg kg⁻¹. Grain Zn concentration was significantly and positively correlated with grain Mn concentration (0.698**, 0.617** for two locations). The estimated grain Zn bioaccessibility also showed a significant difference, a trend similar to grain Zn concentrations but with lower values (13.87 and 13.49 mg Zn d⁻¹ for two locations). These results indicate that the interaction of locations * genotypes may play an important role in grain Zn concentrations and Zn bioaccessibility.     

Macro‐ and micromineral content of wrapped forages for horses

A study of macro‐ and micromineral contents in wrapped forages from farms in Sweden and Norway was conducted. Haylage samples were collected from 124 farms and analysed for contents of Ca, P, Mg, K, Na, Co, Cu, I, Fe, Mn, Se and Zn. Information on forage production was collected from each farm. Mean concentrations (standard deviations) of the samples were as follows: Ca, 5·3 (3·41); P, 2·7 (0·80); Mg, 1·8 (0·76); K, 21·8 (7·44); Na, 0·3 (0·61) g kg^?1 dry matter (DM); and Co, 0·09 (0·150); Cu, 4·9 (1·61); I, 0·25 (0·461); Fe, 194 (288·9); Mn, 85 (49·3); Se, 0·03 (0·054); and Zn, 23 (9·5) mg kg^?1 DM. Comparisons with mineral requirements of horses indicated that for Ca, Mg, K, Fe and Mn, the mean values were sufficient for maintenance requirements, but for P, Na, Co, Cu, Zn, I and Se, mean values were insufficient. For horses with requirements higher than maintenance, average contents of all minerals except Fe and Mn were insufficient. There were moderate to weak negative correlation coefficients between contents of neutral detergent fibre and Ca, P, Mg, Cu and Se. Forage harvested at late plant maturity may contain lower concentrations of these minerals.     

Grain concentrations of protein and mineral nutrients in a large collection of spelt wheat grown under different environments

A large number of spelt wheat genotypes (ranging from 373 to 772) were evaluated for grain concentrations of protein and mineral nutrients under 6 different environments. There was a substantial genotypic variation for the concentration of mineral nutrients in grain and also for the total amount of nutrients per grain (e.g., content). Zinc (Zn) showed the largest genotypic variation both in concentration (ranging from 19 to 145 mg kg⁻¹) and content (ranging from 0.4 to 4.1 μg per grain). The environment effect was the most important source of variation for grain protein concentration (GPC) and for many mineral nutrients, explaining between 37 and 69% of the total sums of squares. Genotype by environment (G × E) interaction accounted for between 17 and 58% of the total variation across the minerals. GPC and sulfur correlated very significantly with iron (Fe) and Zn. Various spelt genotypes have been identified containing very high grain concentrations of Zn (up to 70 mg kg⁻¹), Fe (up to 60 mg kg⁻¹) and protein (up to 30%) and showing high stability across various environments. The results indicated that spelt is a highly promising source of genetic diversity for grain protein and mineral nutrients, particularly for Zn and Fe.     

An investigation on minerals,arabinoxylans and other fibres of biofortified hull-less barley fractions obtained by two milling systems

The aims of the present study were to compare arabinoxylan, glucomannan, arabinogalactan, dietary fibre and mineral contents of fibre rich and enriched-fibre rich fractions (FRF, E-FRF) obtained by two milling systems from biofortified (+) and non-biofortified (−) hull-less barley cultivar, Yalin and determine impact of biofortification (Zn, I, Se).Arabinoxylan contents and recoveries of FRF obtained by roller mill (FRF_R) were 6.52% and 6.70%; 82.6% and 83.3% while those of FRF obtained by hammer mill (FRF_H) were 7.36% and 7.24%; 73.9% and 73.5% for Yalin (−) and Yalin (+), respectively. Likewise, arabinoxylan contents and recoveries of E-FRF_R were 11.91, 11.66%; 70.8% and 67.2% while those of E-FRF_H were 11.70%, 12.13%; 61.3% and 64.9% for Yalin (−) and Yalin (+), respectively.Arabinogalactan contents of E-FRF_R and E-FRF_H were comparable (1.32–1.45%) for both Yalin samples. Their glucomannan contents were higher than arabinogalactan contents (1.79–1.90%). Furthermore, total dietary fibre contents of E-FRF_R and E-FRF_H were determined as 2.4–2.7 fold higher than their whole grain Yalin samples. Zinc, iodine, selenium contents (22 mg kg⁻¹, 16 μg kg⁻¹, 122 μg kg⁻¹) of the whole grain of Yalin (−) increased through biofortification and milling and reached to 59 mg kg⁻¹, 383 μg kg⁻¹, 345 μg kg⁻¹ in E-FRF_R of Yalin (+), respectively.     

粳稻“龙锦1号/香软米1578” F3家系群糙米矿质元素含量变异及相关性分析

 利用粳稻品种间杂交组合“龙锦1号/香软米1578”的196份F3家系,对糙米中Fe、Se、Zn、Cu、Mn、Ca、Mg、K、Na和P等10种矿质元素含量的变异及其相关性进行了分析。 10种矿质元素在F3家系间均有较大的变异,其中Na含量变异最大,Zn含量变异最小,变异系数分别为77.69％和12.04％。各矿质元素含量的变异系数大小顺序为Na>Se>Cu>Fe>Mg>Mn>Ca>P>K>Zn。不同矿质元素含量也有较大的差异,F3家系群各矿质元素含量平均值高低排序为P>K>Mg>Ca>Fe>Mn>Zn>Na>Cu>Se。糙米中10种矿质元素含量在F3家系群中均表现为正态分布,为由多基因控制的数量性状。Zn与Fe、Cu,Mn与Mg、Ca、K、P,Ca与Mg、K、Na、P,Mg与K、P,P与K、Na含量呈显著或极显著正相关,而Fe与Se、Mn与Na、Mg与Na含量呈显著或极显著负相关。Mn、Ca、Mg、K、P含量与其他矿质元素含量间的相关关系较Fe、Se、Cu、Zn含量与其他矿质元素含量间的相关关系更为密切。     

Grain concentrations of protein and mineral nutrients in a large collection of spelt wheat grown under different environments

A large number of spelt wheat genotypes (ranging from 373 to 772) were evaluated for grain concentrations of protein and mineral nutrients under 6 different environments. There was a substantial genotypic variation for the concentration of mineral nutrients in grain and also for the total amount of nutrients per grain (e.g., content). Zinc (Zn) showed the largest genotypic variation both in concentration (ranging from 19 to 145 mg kg⁻¹) and content (ranging from 0.4 to 4.1 μg per grain). The environment effect was the most important source of variation for grain protein concentration (GPC) and for many mineral nutrients, explaining between 37 and 69% of the total sums of squares. Genotype by environment (G × E) interaction accounted for between 17 and 58% of the total variation across the minerals. GPC and sulfur correlated very significantly with iron (Fe) and Zn. Various spelt genotypes have been identified containing very high grain concentrations of Zn (up to 70 mg kg⁻¹), Fe (up to 60 mg kg⁻¹) and protein (up to 30%) and showing high stability across various environments. The results indicated that spelt is a highly promising source of genetic diversity for grain protein and mineral nutrients, particularly for Zn and Fe.     

不同木薯种质资源主要矿物质元素差异性分析

为了解不同木薯种质资源矿物质元素含量,优选含量丰富的品种,为木薯的综合利用提供数据支撑,本文采用马弗炉法、原子吸收和原子荧光法分别对113份木薯种质资源灰分与矿物质元素含量进行测定,结果表明：矿物质元素Cr、Cu、Se含量均低于1 mg/kg（干重）,Ca、Fe、K、Mg、Mn、Na、Zn含量分别为66.39~1609.81 mg/kg、4.35~ 38.93 mg/kg、1954.56~8762.78 mg/kg、149.04~1143.73 mg/kg、4.48~37.40 mg/kg、36.80~530.40 mg/kg、6.35~24.83 mg/kg。利用概率分级法将113份木薯种质资源灰分及矿物质元素含量分为5级,即极高、高、中、低和极低,并推荐极高品系作为基础亲本材料。在相关性分析中,灰分与Fe、Mg、Na、Zn含量具有较为显著的相关性,Ca含量与K、Mn含量呈极显著正相关,Ca含量与Mg、Na含量呈极显著负相关,Fe含量与Mg、Na、Zn含量成极显著正相关,K含量与Mn含量呈极显著正相关,与Na含量呈极显著负相关,Mg含量与Na、Zn含量呈极显著正相关,Zn含量与Mn、Na含量呈极显著正相关。Zn与各矿物质元素的吸收有较强的相互促进作用,Fe含量与Mg、Na含量有较强的相互促进作用,Ca含量与K、Mn的吸收有较强的促进作用,而Ca、K、Mn与Fe、Mg、Na的吸收可能存在一定的拮抗作用。结合主成分分析、聚类分析对不同木薯种质资源矿物质元素含量进行综合评价,得到特征值大于1的主成分2个,累计方差贡献率达61.707%。聚类分析可将113个木薯种质资源分为3类,根据矿物质元素含量差异可将不同木薯品种分为Na、Mg、Zn、Fe含量较高和Mn、Ca、K、Zn含量较高两大类,主成分综合评价中‘274'‘50'‘571'‘521'‘417'等木薯种质资源得分较高。     

黄木炎品种茶树不同器官中矿质元素的分布

对１９种矿质元素在黄茶树各器官中的分布情况进行了研究。结果表明,多数元素在茶树体内的分布具有相似的特点,即均以花蕾、叶和细根的含量较高;性质相近的元素,在分布上具有极显著的相关性（Ｐ＜０．０１）;不同器官灰分间各元素的总含量相近;每种无素在器官中的含量表现出一种数量级的顺序;茶树对土壤中的大量元素Ｃａ、Ｋ、Ｎａ、Ｐ、Ｍｇ表现为强至极强积累,对微量元素（除对Ｍｎ、Ｓｒ、Ｂａ为强积累外）为中等至弱积累,对大量元素Ａ１、Ｆｅ仅为中等积累     

不同品种椰子凋落叶的营养成分分析

测定6个不同品种椰子凋落叶中的营养成分。结果表明,6个品种椰子凋落叶的叶柄中C、N、P、K、Na、Ca、Mg、Mn、Zn营养元素之间差异显著,其中Fe和Cu含量差异不显著;小叶中,C、N、P、K、Na、Ca、Mg、Fe、Mn、Zn营养元素之间差异显著,其中Cu含量差异不显著。同时,小叶中的C、N、Fe、Mn、Zn含量高于叶柄,而叶柄中的P、K、Na、Ca、Mg含量高于小叶。     

Changes in the concentration of avenanthramides in response to salinity stress in CBF3 transgenic oat

Oat avenanthramides have long been known to possess potential nutraceutical and therapeutical properties. The change in avenanthramides 2p, 2c and 2f concentration in four salinity tolerant transgenic oat plants containing CBF₃ gene and non-transgenic control exposed to different levels of salinity stress was investigated. Determination of oat avenanthramides at the nano-scale level was performed using a well-optimized and highly sensitive sequential injection chemiluminescence (SIA-CL) method enhanced by eco-friendly gold nanoparticles biosynthesized from oat biomass extract. Under the conditions of this study, the predominant avenanthramide, which also exhibited the strongest scavenging capacity, was 2c followed by 2p and 2f. At no stress, there was no significant (p ≤ 0.05) difference between the transgenic lines and control regarding the concentrations of the three determined avenanthramides. After exposure to 250 mmol L⁻¹ NaCl, avenanthramide 2c dramatically increased by 170.9%, 580%, 353.6%, 457.6% and 229.1% in the control and the four transgenic lines, respectively. Among the transgenic lines, Agrogle-1 maintained the highest avenanthramides concentration under all salinity levels with maximum values of 71.5 mg kg⁻¹ for 2p, 221.0 mg kg⁻¹ for 2c and 62.0 mg kg⁻¹ for 2f detected at 250 mmol L⁻¹NaCl. The results of this study demonstrated that oat avenanthramides might have a potential role in enhancing abiotic stress tolerance in oats.     

Nutritional characteristics of the leaves of native plants growing in adverse soils of humid tropical lowlands

Acid sulfate, peat, sandy podzolic, and saline soils are widely distributed inthe lowlands of Thailand and Malaysia. The nutrient concentrations in theleaves of plants grown in these type of soils were studied with the aim ofdeveloping a nutritional strategy for adapting to such problem soils. In sagoand oil palms that were well-adapted to peat soil, the N, P, and Kconcentrations were the same in the mature leaves, while the Ca, Mg, Na,and Fe concentrations were higher in the mature leaves of the oil palm thanof the sago palm. Melastoma malabathricum and Melaleuca cajuputi plantsthat were well-adapted to low pH soils, peat, and acid sulfate soils were alsostudied. It was observed that a high amount of Al accumulated in the M.marabathricum leaves, while Al did not accumulate in M. cajuputi leaves.M. cajuputi plants accumulated large amounts of Na in their leaves or stemsregardless of the exchangeable Na concentration in the soil, while M.malabathricum that was growing in saline-affected soils excluded Na.Positive relationships between macronutrients were recognized between Pand N, between K and N, and between P and K. Al showed antagonisticrelationships with P, K, Ca, Mg, Fe, Zn, Cu, and Na. Na also showedantagonistic relationships with P, K, Zn, Mn, Cu, and Al. Fe showed weakantagonistic relationships with Zn, Mn, Cu, and Al.     

Interspecific competition,N use and interference with weeds in pea–barley intercropping

Field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) were intercropped and sole cropped to compare the effects of crop diversity on productivity and use of N sources on a soil with a high weed pressure. ¹⁵N enrichment techniques were used to determine the pea–barley–weed-N dynamics. The pea–barley intercrop yielded 4.6 t grain ha⁻¹, which was significantly greater than the yields of pea and barley in sole cropping. Calculation of land equivalent ratios showed that plant growth factors were used from 25 to 38% more efficiently by the intercrop than by the sole crops. Barley sole crops accumulated 65 kg soil N ha⁻¹ in aboveground plant parts, which was similar to 73 kg soil N ha⁻¹ in the pea–barley intercrop and significantly greater than 15 kg soil N ha⁻¹ in the pea sole crop. The weeds accumulated 57 kg soil N ha⁻¹ in aboveground plant parts during the growing season in the pea sole crops. Intercropped barley accumulated 71 kg N ha⁻¹. Pea relied on N₂ fixation with 90–95% of aboveground N accumulation derived from N₂ fixation independent of cropping system. Pea grown in intercrop with barley instead of sole crop had greater competitive ability towards weeds and soil inorganic N was consequently used for barley grain production instead of weed biomass. There was no indication of a greater inorganic N content after pea compared to barley or pea–barley. However, 46 days after emergence there was about 30 kg N ha⁻¹ inorganic N more under the pea sole crop than under the other two crops. Such greater inorganic N levels during early growth phases was assumed to induce aggressive weed populations and interspecific competition. Pea–barley intercropping seems to be a promising practice of protein production in cropping systems with high weed pressures and low levels of available N.     

Environmental and genotypic influences on trace element and mineral concentrations in whole meal flour of einkorn (Triticum monococcum L. subsp. monococcum)

Trace elements (Zn, Fe, Cu and Mn) and minerals (Ca, Mg, P and K) concentrations were determined in whole meal flour of five einkorn accessions and one bread wheat cultivar, cropped in four different locations for two years. The major factors influencing mineral levels were year and genotype, as well as their interaction. Einkorn varieties exhibited higher Zn (7.18 ± 0.76 mg/100 g DM), Fe (5.23 ± 0.47), Mn (4.65 ± 0.23), Cu (0.90 ± 0.08), Mg (151.2 ± 9.00) and P (541.1 ± 35.37) concentration than bread wheat. Mg concentration correlated positively with that of other bivalent cations (Zn and Ca). The relevant amount of trace elements consistently found in einkorn further confirms the potential of this cereal in human nutrition, either by direct consumption or by introgression of superior alleles into enhanced polyploid wheat cultivars.     

Lime and phosphorus influence Kennebec potato yield and chemical composition

An experiment conducted in 1970 and 1971 with Kennebec potatoes on a Typic Cryothod near Willow Creek in Alaska compared the effects of seven P rates, with and without lime, on yields and chemical content of foliage and tubers. Each P increment increased plant vigor, foliage and tuber yields, P percentage in both foliage and tubers, K, Ca, and Sr concentration in the foliage and tubers, K, Ca, and Sr concentration in the foliage, and N, P, K, Ca, and Mg uptake by both foliage and tubers. The higher P rates depressed the A1 and Fe concentration in the foliage and the Ba in the tubers. Additions of high rates of P also tended to increase available P in the soil. Lime application decreased soil acidity, increased plant vigor, practically eliminated physiological leaf necrosis, and increased Ca and depressed Mn and Zn concentrations of both foliage and tubers. Lime further depressed the concentrations of A1, Ba, B, Cu, Fe, and Sr in the foliage and the Ba of the tubers. The uptake of N, P, K, Ca, Mg, and Na were also increased with lime applications because yields were greatly increased. Comparison of Ca/Mn and Mn/Fe ratios with those of another researcher (5) suggested a possible Mn toxicity. The concentrations of N and Cr in both foliage and tubers, and the amount of P, K, Na, A1, B, Cu, Fe, and Sr in the tubers were not influenced significantly by lime.     

Effects of genotype and environment on avenanthramides and antioxidant activity of oats grown in northwestern China

To investigate the effects of genotype and growing environment on avenanthramides and antioxidant activity of oats, the total phenolic content (TPC), avenanthramide compositions, and antioxidant activity were determined for whole oat from 39 cultivars grown in four locations in northwestern China (Inner Mongolia, Qinghai, Shanxi and Gansu). The results demonstrated that environment (E), genotype (G) and the interaction of these factors (E × G) significantly affected TPC, concentration of avenanthramide 2c (2c, ranged from 6.24 to 136.20 mg kg⁻¹), avenanthramide 2p (2p, 6.07–112.25 mg kg⁻¹), avenanthramide 2f (2f, 7.26–222.77 mg kg⁻¹) and antioxidant activity of oats. The effect of E was considerably greater than that of G or E × G. Based on G plus G × E interaction biplots (GGE biplots) analysis, the four locations in northwestern China can be divided into either two or three regions. Qinghai was determined to be distinct from the other locations. Cultivar Bayou 9 and oats grown in Gansu exhibited the highest TPCs, concentrations of 2c, 2p, 2f and antioxidant activity. The results suggest that oats containing more avenanthramides and exhibiting high levels of antioxidant activity could be obtained by selecting an appropriate genotype and growth location.     

First report on the presence of Alloxan in bleached flour by LC-MS/MS method

In this work the presence of Alloxan in bread, pastry and cake bleached flour was investigate in order to verify possible risk for consumers related to the use of chemicals for flour bleaching. A selective UHPLC–MS/MS method has been developed and validated for the purpose. Alloxan is one of the possible minor side products of oxidation after chemical bleaching of wheat flours, when several chemical agents are used. One hundred and seventy-five flour samples were analyzed for Alloxan determination. The validation of the method was performed in accordance with the ISO/IEC/EN 17025 for linearity, detection limit, quantification limit, accuracy, precision and ruggedness determination. Satisfactory performances were obtained for the analyte, with a Limit of Detection (LOD) of 0.73 mg kg⁻¹, a Limit of Quantification (LOQ) of 0.85 mg kg⁻¹ and recovery values between 94% and 102%. The present work report for the first time the presence of trace levels of Alloxan in 24% of the analyzed samples, with mean values of 0,95 ± 0,04 mg kg⁻¹. The presence of Alloxan was detected only in cake flour samples. Further studies on toxicological levels of Alloxan are needed in order to evaluate possible risks for consumers linked to the consumption of bakery products.     

叶面喷施硒酸钠对不同小麦品种(系)籽粒硒及其他矿质元素含量的影响

为了解叶面喷施硒酸钠对不同小麦品种(系)籽粒硒含量及其他矿质元素的影响,对114个不同小麦品种(系)进行叶面喷施硒酸钠,试验设4个梯度,分别为0 mg·kg~(-1)(CK)、100 mg·kg~(-1)(Se10)、200mg·kg~(-1)(Se20)、300mg·kg~(-1)(Se30),利用离子发射光谱-原子吸收仪测定了籽粒硒、钙、镁、铜、铁、锰、锌、硫含量。结果表明,叶面喷施硒酸钠可以提高小麦籽粒的硒含量,增幅因品种(系)而异;CK、Se10、Se20及Se30处理下,籽粒的总硒含量分别为1.54、5.70、10.01和13.10mg·kg~(-1)。籽粒中不同矿物质元素对叶面喷施硒酸钠的响应不同;籽粒中硒与其他元素的积累既有协同也有拮抗作用,因元素种类、小麦品种(系)和施硒量而异。总体而言,高浓度硒处理降低了籽粒中钙、镁、铜、铁、锰和硫的含量,但提高了锌的含量。     

Chemical fractionation of seven heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, and Zn) in selected paddy soils of Iran

The content and fractionation of seven heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, and Zn) were determined in 28 surface soil samples (0–20 cm) of agricultural topsoil from Isfahan Province in central Iran. The order of abundance of metals in the soils was Fe (1240.4 mg kg^?1) > Mn (95.7 mg kg^?1) > Pb (51.6 mg kg^?1) > Zn (23.8 mg kg^?1) > Ni (13.4 mg kg^?1) > Cu (7.0 mg kg^?1) > Cd (2.8 mg kg^?1). Iron, Mn, Ni, Pb, and Zn existed in paddy soils mainly in Fe-Mn oxides (53.6 %, 65.2 %, 40.4 %, 40.8 %, 53.3 %, respectively), whereas Cu and Cd occurred essentially as residual mineral phase (41.4 %) and carbonate (36.1 %), respectively. The mobile and bioavailable fractions of Cd, Cu, Fe, Mn, Ni, Pb, and Zn in paddy soils averaged 48.8, 20.8, 0.79, 29.2, 28.5, 41.1, and 24.8 %, respectively, which suggests that the mobility and bioavailability of the seven metals probably decline in the following order: Cd > Pb > Mn ≥ Ni > Zn > Cu ? Fe, suggesting greater contribution of anthropogenic Cd. As Cd in soil is easily accumulated by plants through the root system, the concentration of Cd in these paddy soils could be a concern to human health.     

Accumulation of arsenic and its distribution in rice plant (Oryza sativa L.) in Gangetic West Bengal, India

The presence of arsenic in irrigation water and in paddy field soil were investigated to assess the accumulation of arsenic and its distribution in the various parts (root, straw, husk, and grain) of rice plant from an arsenic effected area of West Bengal. Results showed that the level of arsenic in irrigation water (0.05–0.70 mg l⁻¹) was much above the WHO recommended arsenic limit of 0.01 mg l⁻¹ for drinking water. The paddy soil gets contaminated from the irrigation water and thus enhancing the bioaccumulation of arsenic in rice plants. The total soil arsenic concentrations ranged from 1.34 to 14.09 mg kg⁻¹. Soil organic carbon showed positive correlation with arsenic accumulation in rice plant, while soil pH showed strong negative correlation. Higher accumulation of arsenic was noticed in the root (6.92 ± 0.241–28.63 ± 0.225 mg kg⁻¹) as compared to the straw (1.18 ± 0.002–2.13 ± 0.009 mg kg⁻¹), husk (0.40 ± 0.004–1.05 ± 0.006 mg kg⁻¹), and grain (0.16 ± 0.001–0.58 ± 0.003 mg kg⁻¹) parts of the rice plant. However, the accumulation of arsenic in the rice grain of all the studied samples was found to be between 0.16 ± 0.001 and 0.58 ± 0.003 mg kg⁻¹ dry weights of arsenic, which did not exceed the permissible limit in rice (1.0 mg kg⁻¹ according to WHO recommendation). Two rice plant varieties, one high yielding (Red Minikit) and another local (Megi) had been chosen for the study of arsenic translocation. Higher translocation of arsenic was seen in the high yielding variety (0.194–0.393) compared to that by the local rice variety (0.099–0.161). An appreciable high efficiency in translocation of arsenic from shoot to grain (0.099–0.393) was observed in both the rice varieties compared to the translocation from root to shoot (0.040–0.108).     

Demographic changes in Helicoverpa armigera after exposure to neemazal (1% EC azadirachtin)

We estimated the effect of 5, 10, 15 and 20 mg l⁻¹ of neemazal (1% EC azadirachtin) on life table parameters of Helicoverpa armigera (Hübner) developing on chickpea (Cicer arietinum L.). The effects were assessed on the survivals emerged from 6th instar larvae that had ingested neemazal-treated chickpea pods. Survivorship (I) and expectancy of life (e_x) were highest with the commencement of age (egg) and decreased gradually with the advancement of age with all the concentrations of neemazal including unexposed cohort. All the eggs hatched in the unexposed group while highest numbers of unhatched eggs (10%) were recorded with 20 mg l⁻¹. Mortality of 1st instars was higher at 20 and 15 mg l⁻¹ than that of other concentration tested. Potential fecundity (pf) was reduced in concentration dependent manner and was lowest with 20 mg l⁻¹ (418 eggs/female/generation) and highest in control (898 eggs/female/generation). Net reproductive rate (R₀) was significantly reduced with the increase in concentration of neemazal. The intrinsic (r_m) and finite rate of increase (λ) were significantly decreased at 20 mg l⁻¹ than that of unexposed population. The mean generation time (T_c) was prolonged at 20 mg l⁻¹ and significantly differed with non-treated individuals. Development of immature stages was prolonged to 38 days with 20 mg l⁻¹ while reduced to 32 days with 15 mg l⁻¹ of neemazal as compared to 37 days in untreated individuals. Doubling time (DT) was significantly extended to 5.02 days with 20 mg l⁻¹ as compared to 3.84 days in the non exposed ones.