Statistical Methods For Agricultural Workers

THE JOURNAL OF BIOLOGICAL CHEMISTRY: The Biochemical Behavior of LeadL I. Influence of Calcium, Phosphorus, and Vitamin D on Lead in Blood and Bone

DNA sequencing with chain terminating inhibitors

中国拥有数目庞大、种类繁多的动植物,也有很多珍贵、濒危生物,这些更是异常宝贵的科学资源。DNA条形码技术的出现可以更好的帮助鉴别这些物种,了解其分支来源,甚至可以预知其进化方向。笔者简述了DNA条形码的技术原理与操作步骤及这项技术的产生与发展情况;简要列出了DNA条形码发展过程中的重要进步与研究相对集中的物种;概述了DNA条形码的应用途径及目前DNA条形码研究中存在的主要问题、矛盾、研究思路与发展方向,并对其发展前景做出展望。

国际生命条形码计划—DNA Barcoding

World crop pests (editor-in-chief W. Helle). Volumes 1A and 1B: Spider Mites: Their Biology, Natural Enemies and Control

Oligonychus coffeae Nietner (Acari: Tetranychidae), the red spider mite (RSM), is a major pest of tea (Camellia sinensis) in most tea-producing countries. Nymphs and adults of RSM lacerate cells, producing minute characteristic reddish brown marks on the upper surface of mature leaves, which turn red in severe cases of infestation, resulting in crop loss. The pest is present on tea all the year round, although numbers vary depending on season. Their number increases as the weather warms up and decreases markedly once rains set in. Under optimal conditions there may be 22 overlapping generations in a year. Parthenogenesis is known to occur; consequently, all mite stages can be found at a given time. Their infestation is mainly confined to the upper surface of the mature leaves and could readily be identified by the bronzing of the leaf. There are several naturally occurring insect predators, such as coccinellid and staphylinid larvae, lacewing larvae, and mite predators, most importantly species of the families Phytoseiidae and Stigmaeidae. Integrated management has been adopted to control this mite pest, involving cultural, mechanical, physical, biological and chemical methods. This review collates the most important works carried out on biology, ecology and management of O. coffeae. Also the scope of future studies for better management of this regular mite pest of tea is discussed.

The red spider mite, Oligonychus coffeae (Acari: Tetranychidae): its status, biology, ecology and management in tea plantations

Helopeltis theivora Waterhouse (Heteroptera: Miridae) or the tea mosquito bug (TMB) is a major sucking pest of tea (Camellia sinensis L.) in most tea-producing countries. The nymphs and adults of the TMB suck the sap from tender leaves, buds and young shoots, which results in heavy crop losses. The damage to tea plants caused by the TMB is not limited to the sucking of plant materials and extra-oral digestion by salivation. Damage is also caused by the insertion of eggs into plant tissues during oviposition. More than a dozen alternate host plants and only a few natural enemies of the TMB have been recorded. For control of this pest, synthetic pesticides are widely used. There are many reports regarding the excessive application of insecticides that has resulted in the development of high tolerance and even resistance in this pest to certain insecticides. This review collates the most important works conducted on the bio-ecology of the TMB and includes a discussion of the problems encountered in the manag...

The tea mosquito bug, Helopeltis theivora Waterhouse (Heteroptera: Miridae): its status, biology, ecology and management in tea plantations

India is the second largest producer of black tea in the world. The biggest challenge for tea growers of India nowadays is to combat pests and diseases. Tea crop in India is infested by not less than 720 insect and mite species. At least four sucking pests and six chewing pests have well established themselves as regular pests causing substantial damage to this foliage crop. Various synthetic pesticides are widely used for the management of tea pests in India. Applications of such large quantity of pesticides could cause various problems such as development of resistance, deleterious effects on non-target organisms such as insect predators and parasitoids, upsetting the ecological balance, and accumulation of pesticide residues on tea leaves. There is a growing demand for organic tea or at least pesticide residue free tea in the international market which affects the export price. There is also a higher emphasis of implementation of new regulations on internationally traded foods and implementation of Plant Protection Code (PPC) for tea by the Government of India. This necessitates a relook into the usage pattern of synthetic pesticides on this crop. There are various non-chemical interventions which are being worked out for their sustainability, compatibility, and eco-friendly properties which can gradually replace the use of toxic chemicals. The application of plant extracts with insecticidal properties provides an alternative to the synthetic pesticides. Botanical products, especially neem-based products, have made a relatively moderate impact in tea pest control. Research has also demonstrated the potential of 67 plant species as botanical insecticides against tea pests. The majority of plant products used in pest management of tea in India are in the form of crude extracts prepared locally in tea garden itself, and commercial standardized formulations are not available for most of the plants due to lack of scientific research in the area. Apart from systematic research in this area, to facilitate the simplified and trade friendly registration procedures with quality assurance of the products, there is an increasing need of regulatory authority and national norms in India.

Use of plant extracts for tea pest management in India

Influence of spent mushroom substrate (SMS) of oyster mushroom and button mushroom on the improvement of health status of Capsicum annuum L. was investigated. Analysis of growth promotion in terms of height, no of branches, yield and no of leaf drop indicated that the use of the spent mushroom substrate of oyster mushroom and spent compost of button mushroom had a positive effect on the overall growth of the tested plants. SMS had a role in mobilizing the soil phosphate which was evident by a decrease in soil phosphate level and increase in root and leaf phosphate following treatment with SMS. Chlorophyll content of plants increased when treated with oyster mushroom fresh substrate and button mushroom leachate compost. Fruits of plants treated with button mushroom leachate compost and oyster mushroom fresh substrate showed an increase in protein content of about 2.5 times over control. Similarly, carotenoid contents of fruits also increased significantly in the treated plants, but increases in leaves were not significant. It is evident from the present study that the use of different form of spent mushroom substrate of oyster mushroom and spent compost of button mushroom led to the overall increase in growth of Capsicum annuum L.

Evaluation of Spent Mushroom Substrate as biofertilizer for growth improvement of Capsicum annuum L.

The toxicity of four concentrations (1, 5, 10 and 20% w/v) of an aqueous extract from the weed, Clerodendrum viscosum Ventenat (Verbenaceae) was investigated under field conditions of the North Bengal University, Darjeeling, West Bengal, India for managing two major pests of tea, Camellia sinensis (L), namely the tea mosquito bug, Helopeltis theivora Waterhouse, (Heteroptera: Miridae) and the tea red spider mite, Oligonychus coffeae Nietner, (Acarina: Tetranychidae). Four field trials, two for red spider mite and two for tea mosquito bug, were conducted during April–May 2008 and October–November 2009 following a Randomized Block design. The aqueous extract of C. viscosum effectively and significantly reduced the mite population as well as infestation of tea mosquito bug by 68–95% and 73–86%, respectively, and their bioefficacy is comparable to synthetic and neem pesticides. No phytotoxic effect (score 0–5% and grade 1) was observed in the tea bushes sprayed with different doses of aqueous extract of C. viscosum in the field. Made tea samples were taint free. Organoleptic test revealed leaf-infusions and liquor strength as good, scoring 6.5–7.0 on a 10 point scale. Availability and distribution of this weed (C. viscosum) in and around tea-growing areas of sub Himalayan region, along with its processing for the feasibility of including C. visosum extracts in the current IPM programme is discussed.

Field efficacy of a biopesticide prepared from Clerodendrum viscosum Vent. (Verbenaceae) against two major tea pests in the sub Himalayan tea plantation of North Bengal, India

Somnath Roy

Papers

The red spider mite, Oligonychus coffeae (Acari: Tetranychidae): its status, biology, ecology and management in tea plantations

The tea mosquito bug, Helopeltis theivora Waterhouse (Heteroptera: Miridae): its status, biology, ecology and management in tea plantations

Use of plant extracts for tea pest management in India

Evaluation of Spent Mushroom Substrate as biofertilizer for growth improvement of Capsicum annuum L.

Field efficacy of a biopesticide prepared from Clerodendrum viscosum Vent. (Verbenaceae) against two major tea pests in the sub Himalayan tea plantation of North Bengal, India