33 research outputs found

    Effects of Four Host Plants on Biology and Food Utilization of the Cutworm, Spodoptera litura

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    Effects of four host plants, tobacco, Chinese cabbage, cowpea and sweet potato, on larval and pupal development and survival, and longevity and fecundity of adults of Spodoptera litura (F) (Lepidoptera: Noctuidae), were studied under laboratory conditions (26° C, 60–80% RH), as was the utilization of the four host plants and adaptation on tobacco. All of the biological parameters included in the study were affected by the host plants. In a choice test, S. litura females oviposited most on Chinese cabbage, least on tobacco, and intermediate on cowpea and sweet potato. S. litura larvae developed differently on the four host plants, from shortest to longest in the following order: Chinese cabbage, cowpea, sweet potato, and tobacco. Pupal development was shorter on cowpea than on the other three host plants, and males generally developed longer than females. More females than males were found among emerged adults, and male adults lived 1–2 d longer than females. Larvae survived best on cowpea (81.6%), followed by Chinese cabbage (75.5%), then sweet potato (66.1%), and worst on tobacco (49.2%). Pupal survival rates were relatively high (91.4 – 95.9%) in all four host plant treatments, although that on sweet potato was lower than those on the other three host plants. Pupal weights on tobacco and sweet potato were similar, but both were lower than those on Chinese cabbage and cowpea. Generally, male pupae weighed less than female pupae. Numbers of eggs oviposited by female S. litura were highest on sweet potato, followed by those on cowpea, Chinese cabbage, and lowest on tobacco. Relative food consumption rate was highest on sweet potato, followed by that on cowpea, Chinese cabbage, and lowest on tobacco. In contrast, S. litura larvae that fed on tobacco had higher efficiency of conversion of digested food, highest efficiency of conversion of ingested food, and lowest approximate digestibility as compared with larvae that fed on other host plants. The potential causes for S. litura outbreaks on tobacco are discussed

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

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    Not AvailableSoil cracks can enhance water recharge through preferential flow during the rainy season and enhanced evaporation loss during the post-rainy season. Despite their significance, a limited information is available on the management of surface cracks in Vertisols. The frequency, size, and rate of development of cracks greatly affect the movement of soil water and nutrient and exchange of gases in the soil profile and also influence plant growth processes in Vertisols. To find out the suitable soil amendments and land use for reducing the rate of crack formation in medium-deep black soils of the region, a 4-year field experiment was conducted to evaluate the effect of different soil amendments and land uses on surface cracks, soil properties and crop yields on Vertisols under semiarid conditions. Field experiment consisted of three different land uses [i.e., agriculture [intercropping of sorghum (Sorghum biocolor L.) + pigeon pea (Cajanus cajan L.) at 1:1 ratio], grassland (dhaman grass—Cenchrus ciliaris L.), fallow land (no cultivation fallow)] as main plots with four different soil amendments [i.e., S0—control, S1—fly ash @ 10 Mg ha−1, S2—crop residue (wheat straw) @ 5 Mg ha−1, S3—gypsum (100% of gypsum requirement), S4—FYM @ 5 Mg ha−1] as subplots. The data showed that application of soil amendments had a beneficial effect on soil properties such soil pH, available nutrients, labile C and total organic carbon and stocks. In the 0–15-cm layer, SOC stocks varied from 15.17 to 20.04; 16.13–20.67; 14.25–19.58 Mg ha−1 for agriculture, grassland and fallow land, respectively. The labile C and total organic carbon contents were in the order of grassland > agriculture > fallow land. Further, soil under grassland system recorded the higher mean weight diameter than that under crop and fallow land. Among different soil amendments applied, wheat straw and FYM had a significant effect (P  agriculture (− 7 to − 18%) > fallow land (− 2 to − 23%). Wheat straw application registered the lowest crack volume followed by that under FYM, fly ash and gypsum, regardless of the land use systems. Crop and grass biomass yields were significantly (P < 0.05) affected by the application of soil amendments. Application soil amendments not only reduced crack volume but also favorably influenced soil properties and crop yields in VertisolsNot Availabl

    Not Available

    No full text
    Not AvailableSoil cracks can enhance water recharge through preferential flow during the rainy season and enhanced evaporation loss during the post-rainy season. Despite their significance, a limited information is available on the management of surface cracks in Vertisols. The frequency, size, and rate of development of cracks greatly affect the movement of soil water and nutrient and exchange of gases in the soil profile and also influence plant growth processes in Vertisols. To find out the suitable soil amendments and land use for reducing the rate of crack formation in medium-deep black soils of the region, a 4-year field experiment was conducted to evaluate the effect of different soil amendments and land uses on surface cracks, soil properties and crop yields on Vertisols under semiarid conditions. Field experiment consisted of three different land uses [i.e., agriculture [intercropping of sorghum (Sorghum biocolor L.) + pigeon pea (Cajanus cajan L.) at 1:1 ratio], grassland (dhaman grass—Cenchrus ciliaris L.), fallow land (no cultivation fallow)] as main plots with four different soil amendments [i.e., S0—control, S1—fly ash @ 10 Mg ha−1, S2—crop residue (wheat straw) @ 5 Mg ha−1, S3—gypsum (100% of gypsum requirement), S4—FYM @ 5 Mg ha−1] as subplots. The data showed that application of soil amendments had a beneficial effect on soil properties such soil pH, available nutrients, labile C and total organic carbon and stocks. In the 0–15-cm layer, SOC stocks varied from 15.17 to 20.04; 16.13–20.67; 14.25–19.58 Mg ha−1 for agriculture, grassland and fallow land, respectively. The labile C and total organic carbon contents were in the order of grassland > agriculture > fallow land. Further, soil under grassland system recorded the higher mean weight diameter than that under crop and fallow land. Among different soil amendments applied, wheat straw and FYM had a significant effect (P  agriculture (− 7 to − 18%) > fallow land (− 2 to − 23%). Wheat straw application registered the lowest crack volume followed by that under FYM, fly ash and gypsum, regardless of the land use systems. Crop and grass biomass yields were significantly (P < 0.05) affected by the application of soil amendments. Application soil amendments not only reduced crack volume but also favorably influenced soil properties and crop yields in VertisolsNot Availabl
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