Response of arbuscular mycorrhizal fungi on wheat (triticum aestivum L.) Grown conventionally and on beds in a sandy loam soil

The present study was undertaken to assess the benefit and compare the functioning of AM fungi on wheat grown conventionally and on beds. Ten treatment combinations were used, treatments 1 and 2: no fertilizers with and without arbuscular mycorrhizal (AM) fungi (In vitro produced Glomus intraradices); 3:100% of recommended NPK: (120 kg ha(-1) N; 60 kg ha(-1) P; 50 kg ha(-1) K), and 4 and 5: 75% of recommended NPK dose with and without AM inoculation in a 5 x 2 split-plot design on wheat using conventional/flat system and elevated/raised bed system. The maximum grain yield (3.84 t ha(-1)) was obtained in AM fungi inoculated plots of raised bed system applied with 75% NPK and was found higher (although non- significant) than the conventional (3.73 t ha(-1)) system. The AM inoculation at 75% fertilizer application can save 8.47, 5.38 kg P and 16.95, 10.75 kg N ha(-1), respectively, in bed and conventional system. While comparing the yield response with 100% fertilizer application alone, AM inoculation was found to save 20.30, 15.79 kg P and 40.60, 31.59 kg N ha(-1), respectively, in beds and conventional system. Mycorrhizal inoculation at 75% NPK application particularly in raised bed system seems to be more efficient in saving fertilizer inputs and utilizing P for producing higher yield and growth unlike non-mycorrhizal plants of 100% P. Besides the yield, mycorrhizal plants grown on beds had higher AM root colonization, soil dehydrogenases activity, and P-uptake. The present study indicates that the inoculation of AM fungi to wheat under raised beds is better response (although non-significantly higher) to conventional system and could be adopted for achieving higher yield of wheat at reduced fertilizer inputs after field validation

Uma análise do efeito do aquecimento global na produção de batata no Brasil An analysis of the potato production in Brazil upon global warming

Face às prováveis mudanças climáticas afetando as áreas agricultáveis do planeta, foi feita uma revisão bibliográfica sobre os efeitos do aumento da temperatura no metabolismo da planta de batata, enfatizando suas consequências no desenvolvimento vegetativo e na produtividade da cultura. Embora a ênfase maior desse artigo se prenda ao efeito do clima na redução de alimentos, alerta-se ainda para o risco de erosão genética pelo desaparecimento de espécies silvestres, de grande importância para programas de melhoramento genético. A partir dessas informações e de dados climáticos das regiões produtoras publicados em literatura nacional, foi realizada uma análise prospectiva da produção de batata no Brasil. Para tal, tomou-se como base o aumento da temperatura de até 5ºC até o final deste século e uma faixa ótima de produtividade da batata de 10ºC a 25ºC, conforme indicado em literatura especializada. Foram selecionados seis municípios representando as regiões geográficas onde se cultiva a batata: São Joaquim-SC; Guarapuava-PR; Cristalina-GO; Mucugê-BA; Vargem Grande do Sul-SP e Araxá-MG. Para municípios com prevalência de temperaturas mais baixas, como São Joaquim, o aumento de temperatura preconizado não deverá restringir a produção, porém serão necessárias adequações de épocas de plantio. Por outro lado, a situação é preocupante em regiões e épocas de cultivo sujeitas a temperaturas altas, como Mucugê e Cristalina, onde o cultivo deverá se restringir a poucos meses do ano, contrastando com o plantio contínuo, durante o ano todo, ora sendo realizado. O intuito deste artigo é alertar, e não alarmar, a cadeia produtiva de batata no sentido de se preparar para os ajustes fitotécnicos visando a preservar a bataticultura nacional face a um eventual aquecimento global. Considerações sobre o melhoramento genético para atenuar, pelo menos em parte, esta situação é discutida.<br>The future of the potato production in Brazil is discussed upon prediction of temperature rise due to global warming. A literature review was carried out on the effects of high temperatures on the potato plant metabolism, and their consequences upon vegetative development and yield. Although higher emphasis was devoted to the climate effect on food production, the risk of genetic erosion by disappearance of wild species is stressed, with consequences to the future of plant breeding. Based on this information and on climate data from the main growing regions published on Brazilian documents, we carried out a prospective analysis of the potato production in Brazil. For that, a temperature rise of up to 5ºC was considered to the end of the century, and the range of 10ºC to 25ºC as the optimum for potato growth, according to specialized literature. For the study, six counties, representative of the main growing regions, were selected: São Joaquim, Santa Catarina State; Guarapuava, Paraná State; Cristalina, Goiás State; Mucugê, Bahia State; Vargem Grande do Sul, São Paulo State and Araxá, Minas Gerais State. For cooler counties, such as São Joaquim, major drawbacks on potato production are not expected, even though adjustments in planting season should be required. However, cropping on those counties subject to high temperatures which today allow potato production all year round, like Mucugê, and Cristalina, is expected to be restricted to few months of the year. The aim of this article was to alert, not alarm, the Brazilian potato chain in order to promote the management changes to preserve the crop in case the expected temperature rise comes true. In addition, the role of plant breeding to counteract the negative effects of high temperature is discussed