Influence of Silicon on Reduction of Methane Emissions for Sustainable Rice Production

The increasing human population requires greater rice production and methane is the second most potent greenhouse gas emitted from rice soils under anaerobic conditions. To address this, an experiment was carried out in two phases. In the first phase of the experiment, Si content accessed in the rice index leaves and recorded the mean values of 2.50, 2.48, 2.51 and 2.43% at Jagtial, Warangal, Rajendranagar and Rudrur varietal display plots in Telangana. For the second phase of field experiment, one with high Si (JGL-3855) and another with low Si (RNR-2354) content genotypes were selected with each four levels of N (0, 80, 120 & 160 kg ha-1) and Si (0, 200, 400 & 600 kg ha-1) in strip plot design. Conjunctive application of N and Si to both genotypes, JGL-3855 recorded significantly higher grain and straw yield compared to RNR-2354, among the different combinations of Si and N, application 160 kg N + 600 kg Si ha-1 recorded significantly higher grain and straw yields (7180 and 9693 kg ha-1). The treatments which received a higher dose of Si@600 kg ha-1 in combination with N@ 80, 120 and 160 registered the lower emission of methane@ 25.7, 24.6 and 24.3 mg m-2 hr-1 and there was a significant scaling down of pest and disease incidence was noticed in treatments wherever increased Si doses (0, 200, 400 and 600 kg ha-1) were included.

Association of "green spot" and defoliation to Tenuipalpus heveae incidence and chemical control screening of Hevea brasiliensis diseases / Associação da presença de "pinta verde" e desfolha com presença do ácaro Tenuipalpus heveae e avaliação de fungicidas para controle de doenças em painéis de seringueira Hevea brasiliensis

According to IBGE data, in 2016, Brazil produced closer to 56 thousand hectares of rubber tree generating a total latex production of 315.62 tons in commercial areas and 1.6 thousand tons in native forests. But this growth in crop production is related to the raise of economic losses generated by foliar and bark (panel) diseases caused by Phytophthora spp, Colletotrichum sp., Lasiodiplodia spp., Colletotrichum sp., Ceratocystis fimbriata, Microcyclus ulei (leaf blight) and the leaf anomaly that we call here as "Green Spot". Also, due to the tapping method and the incisions or "injuries" made in this process, opportunistic pathogens can usually infect and end up growing in the bark. This type of infection that is also difficult to control with the adoption of chemical fungicides, can create additional damage to the rubber panels. Pathogens such as Oidium heveae, C. gloeosporioides (anthracnosis), Phomopsis sp. and Phytophthora spp. were identified in 42% of the areas of growers or farms. Treatments T3- (thiophanate-methyl (350 g.ha-1 active ingredient) and T4- (metiram (1.75 kg.ha-1 active ingredient)) were superior against rot diseases in the bark of rubber trees. It was described for the first time the anomaly of the green spot associated to the Tenuipalpus heveae mite in 65% of the samples and had its etiology confirmed by artificial inoculation in rubber tree seedlings. In the USP-ESALq, Dr. Kitajima, E., did not confirm the presence of rhabdovirus-like particles common to tenuipalpids that transmit the virus in coffee and citrus (nuclear and cytoplasmic viruses).

Segundo dados do IBGE, em 2016, o Brasil registrou uma área cultivada de 156,06 mil hectares, dos quais 146,4 mil hectares foram colhidos, promovendo uma produção total de 315,62 toneladas em lavouras comerciais. Já a exploração em áreas de vegetação natural, resultou em 1,6 mil toneladas de látex e coágulo. Microcyclus ulei também chamado de Mal-de-Folhas é conhecida mundialmente como a doença mais grave da seringueira, mas a intensificação do cultivo permitiu prejuízos econômicos promovidos por doenças foliares como Phytophthora spp, Colletotrichum sp., Alternaria spp., Oidium sp. Entre outros, além da anomalia de Pinta Verde. No tocante às doenças de sapé, são citadas as patologias fúngicas nos painéis Lasiodiplodia spp., Colletotrichum sp., Ceratocystis fimbriata, Erythricium salmonicolor e Phytophthora spp.,. Muitos patógenos permitem a entrada nas lesões de outros fungos oportunistas. Devido ao modo de exploração (corte) causar lesões no tronco que facilitam a inoculação de patógenos principalmente através de instrumentos de sangramento, causando danos nos painéis de seringueiras e são patógenos de difícil controle e poucos resultados significativos com o uso de fungicidas ou produtos químicos. Os patógenos, como Oidium heveae, C. gloeosporioides (antracnose), Phomopsis sp. e Phytophthora spp. foram identificados em 42 % das áreas de produtores ou fazendas. Os tratamentos 3 e 4 foram os melhores do controle dos fungos e esta podridão de painel nas seringueiras (T3- (tiofanato-metílico(350 g / ha ingrediente ativo), T4- (metiram (1,75 kg / ha ingrediente ativo). Foi descrita pela primeira vez a anomalia da pinta verde associada ao ácaro Tenuipalpus heveae¨em 65% das amostars e teve a sua etiologia confirmada por inoculação artificial em mudas de seringueira. Análises em microscopia eletrônica realizadas na USP-S-ESALq pelo Dr. Kitajima, E., não confirmaram a presença de partículas tipo rabdovírus comum aos tenuipalpídeos que transmitem a virose em cafeeiro e citros (vírus tipo nuclear e citoplasmático).

Indigenous Knowledge and Management of Yam (Dioscorea Cayenensis –Dioscorea Rotundata Complex) Pests and Diseases in Northern Benin.

Yam (Dioscorea spp.)production in Northern Benin is severely affected by pests and diseases resulting in poor yields and cultivars diversity loss in spite of the importanceof thiscommodity.In order to develop efficient integrated pestsand diseases management approaches, twenty seven (27) villages of the yam production zone of northern Benin were surveyed using participatory research appraisal to document farmers’indigenous knowledge, and traditional management practices of yam pests and diseases. Results indicated that farmers have good knowledge of the yam pests and diseases that were even reported as the third most important production constraints in the study area. Among the pests and diseases nematodes, termites, mealybugs and wilt diseases were the most signaled. Farmers surveyed have traditional methods for mealybugs but nothing for the other pests and diseases apart from the use of resistant/tolerant cultivars. An undetermined disease locally called Ban was reported as expanding at alarming rate throughout villages and yam fields seriously affecting the food quality of the tubers. Urgent intervention zones were identified with multivariate analysis and recommended to the national protection service. The sensitization of the yam producers of the necessity of treating both soil and tuber seeds before planting, the development and the use of pests and diseases tolerant cultivars were proposed as management strategies. Also, the extension of the study to other yam producing regions of the country for identifying more cultivars tolerant to pests and diseases was recommended.