Heterocyst division in two blue-green algae

The heterocysts of Camptylonema lahorense and Aulosira fertilissima have been observed to undergo division, as distinct from germination, either by the constriction of the heterocyst wall and protoplast or by the formation of a transverse furrow. A two-pored heterocyst divides in this way to form two one-pored heterocysts

Weeds and weed control in finger millet in India - A review

Eleusine coracana (L.) Gaertn is a nutritious and under exploited minor millet with several edible and industrial uses. Finger millet is cultivated on 1.176 million ha, with average yields of 1.64 t/ha, in India (DMD), 2014)..

Increasing input resources use efficiency through appropriate weed management in Indian agriculture

Indian agriculture plays a major role in the country’s economy with 60% of India’s population depending on agriculture sector. The central concern of Indian agriculture is low productivity, evident in modest average crop yields. India may need at least 20 million tons of additional food every year to meet the minimum food and nutritional demands of the growing population which is expected to be 1.7 billion by 2050. Thus the greatest challenge for Indian agriculture is to produce more with minimal input resources without causing imbalance to environment and in a sustainable manner. One of the approaches to face the challenge is production of crops with increased input resource use efficiency by managing impediments such as weeds, which are adaptable to all adverse environments and compete with the crops for utilization of land, labor, light, nutrients and water resources (Yaduraju and Rao 2013). In this presentation, an effort is made to give an overall picture of resources used in Indian agriculture, extent of competition by weeds for resources with crops and extent of losses caused by weeds and appropriate weed management strategies for enhancing input resources use efficiency of crops for attaining increased crop productivity and production to meet the present and future demands of Indian population

Weed management research in India - an analysis of past and outlook for future

Agriculture is a critical sector of the Indian economy. Though agriculture's contribution to the overall Gross Domestic Product (GDP) of the country has fallen from about 30% in 1990-91 to <15 % in 2011-12, agriculture yet forms the backbone of development. Achieving an 8-9 % rate of growth in overall GDP would help in poverty reduction and in providing food and nutritional security to all Indians, only when agricultural growth accelerates...

Strengthening Farmers’ Knowledge for Better Weed Management in Developing Countries

Of more than 3 billion people (nearly half of the world’s population) who live in rural areas, around 2.5 billion derive their livelihoods from agriculture [1], which remains crucial to developing countries and their economies for meeting the demands of affordable food, feed, energy, and the security of their populations. Approximately, three quarters of the world’s agricultural value is generated in developing countries and, in many of these, the agriculture sector contributes as much as 30 % to gross domestic product (GDP). It has been observed that GDP growth from agriculture benefits the incomes of poor people two to four times more than th

Weeds and Weed Management of Rice in Karnataka State, India

Rice is one of the staple food crops of India, and Karnataka is one of the major rice-producing states. The primary method of rice establishment in Karnataka is transplanting, but farmers are opting to shift to direct-seeding of rice. Weed management is critical for realizing optimal yield of direct-seeded rice (DSR). The objective of this review was to synthesize the published literature on weeds and weed management in rice in Karnataka, identify improved weed-management technologies for delivery to farmers, and suggest research needs. Some 98 weed species are reported to be associated with rice in Karnataka. Weed control to date in Karnataka has mostly been based on herbicides. Hand-weeding was found to be effective in all methods of rice establishment. However, it is time-consuming, tedious, and costly because labor is becoming scarce and unavailable, and labor wages are higher. Several PRE and POST herbicides that were effective in other Asian countries were also found to be effective in managing weeds in rice established by different methods in Karnataka. Bensulfuron plus pretilachlor and pyrazosulfuron in aerobic rice and pendimethalin, thiobencarb, bispyribac-sodium, cyhalofop, fenoxaprop plus chlorimuron plus metsulfuron, and fenoxaprop plus ethoxysulfuron in dry-DSR were found effective in managing weeds. In wet-DSR, butachlor plus safener and pretilachlor plus safener were effective. Thiobencarb, pendimethalin, pretilachlor, azimsulfuron plus metsulfuron, bispyribac-sodium, butachlor, cinosulfuron, oxadiazon, and quinclorac were found promising for weed management in transplanted rice. Integration of herbicides with hand-weeding or intercultivation was found to be effective in rice established by different methods. Options that were found economical in managing weeds varied across the different rice-establishment methods. The need for developing location-specific, sustainable, integrated weed management and extension of available technologies for the farming community in Karnataka is emphasized

Weed management role in increasing crop yield and doubling rice farmers’ income in India - An analysis

India produces 24.8% of world rice by standing first in area (43.9 million ha) and second in production (106.5 million tons) globally. Rice plays vital role in Indian food security as it is staple food for two thirds of Indians supplying 33% of food energy.Rice productivity and production are to be increased to meet the demands of increasing population. Indian rice farmers are constrained by escalating farming cost and depleting income. The rice productivity in India is low (2.4 t/ ha) due to wide range of environmental conditions and ways it is grown and the biological and physical constraints that prevail. Among biological constraints weeds are major causing yield losses of 10 to 100% depending on method of rice establishment, associated weeds, cultural practices adopted, environmental and other associated factors (Rao and Nagamani 2010, Rao et al. 2015). Thus any effort involving improvement in food grain production to meet current and future food demands and double the farmers’ income must involve rice and weed management. The objective of the present analysis is to assess weed management role in attaining higher crop production and to double the income of rice farmers in India

Rice Production Systems

Rice is grown in more than 100 countries spread across six continents and in varying agroecological and socioeconomic conditions. Rice production systems were classified over years differently depending on the context. In this chapter, the method of rice establishment is considered as criteria for classifying rice production systems across the globe. An attempt is made here to summarize the information on rice production systems, resources used, crop productivity attained, the challenges encountered, and possible research needs for improving productivity in rice production systems, to meet the future food demands. Based on the major methods of rice establishment of the world, the rice production systems are categorized as (a) transplanted rice (TPR) production systems and (b) direct-seeded rice (DSR) production systems. DSR production systems are further categorized as (i) dry-seeded rice (dry-DSR) production system, (ii) wet-seeded rice (wet-DSR) production system, and (iii) water-seeded rice (water-DSR) production system. The productivity of TPR and DSR was reported to be similar when the best management practices are adopted. As already occurred in the developed world, a shift in adoption toward DSR production systems is occurring in developing world, due to advantages of DSR production systems such as lesser cost of production, increased resource (water, labor, and energy) use efficiency, and income compared to TPR. Lower environmental footprint was found to be another advantage of DSR production systems when they were combined with other conservation agricultural practices. The need for continuous research efforts was stressed for understanding the evolving rice production systems across the globe and to develop practical integrated crop management strategies that improve rice productivity and production effectively, sustainably, and economically with minimal environment footprint

Global nitrogen budgets in cereals: A 50-year assessment for maize, rice, and wheat production systems

Industrially produced N-fertilizer is essential to the production of cereals that supports current and projected human populations. We constructed a top-down global N budget for maize, rice, and wheat for a 50-year period (1961 to 2010). Cereals harvested a total of 1551 Tg of N, of which 48% was supplied through fertilizer-N and 4% came from net soil depletion. An estimated 48% (737 Tg) of crop N, equal to 29, 38, and 25 kg ha−1 yr−1 for maize, rice, and wheat, respectively, is contributed by sources other than fertilizer- or soil-N. Non-symbiotic N2 fixation appears to be the major source of this N, which is 370 Tg or 24% of total N in the crop, corresponding to 13, 22, and 13 kg ha−1 yr−1 for maize, rice, and wheat, respectively. Manure (217 Tg or 14%) and atmospheric deposition (96 Tg or 6%) are the other sources of N. Crop residues and seed contribute marginally. Our scaling-down approach to estimate the contribution of non-symbiotic N2 fixation is robust because it focuses on global quantities of N in sources and sinks that are easier to estimate, in contrast to estimating N losses per se, because losses are highly soil-, climate-, and crop-specific

Fluorodeoxyglucose and 11C-Choline positron emission tomography for distinction of metastatic plexopathy and neuritis: a case report

INTRODUCTION: Fluorodeoxyglucose positron emission tomography scanning has an established role in the diagnostic work-up of many malignant diseases and also in the evaluation of cancer treatment response. Fluorodeoxyglucose positron emission tomography may, however be non-specific as infectious processes are depicted as well. CASE PRESENTATION: We present a patient with longstanding leg pain and weakness due to plexopathy developed a few years after treatment for prostate cancer. Prostate-specific antigen was raised and magnetic resonance imaging showed contrast uptake in thickened sacral nerves, suspicious for metastasis. While fluorodeoxyglucose positron emission tomography showed increased uptake in the plexus region, (11)C-Choline- positron emission tomography did not show any uptake. It was concluded that the FDG uptake reflected plexus neuritis and no tumor. Treatment for pain relief was started. CONCLUSION: (11)C-Choline- positron emission tomography can be used to detect metastasis in patients with plexopathy suspicious for malignancy, while fluorodeoxyglucose positron emission tomography is more sensitive to inflammatory processes