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Silva-Junior G.J.,University of Sao Paulo | Sposito M.B.,University of Sao Paulo | Marin D.R.,Fundo de Defesa da Citricultura Fundecitrus | Amorim L.,University of Sao Paulo
Crop Protection | Year: 2014

Citrus postbloom fruit drop (PFD) caused by Colletotrichum spp. occurs in several countries in the Americas reducing yields by as much as 80%. Fungicide application is the main strategy for PFD control. Two field trials were performed to assess the timing of applications and another two were set up to investigate the efficacy of fungicides for PFD control in São Paulo State, Brazil. The percentage of symptomatic flowers per branch, the number of persistent calyces per branch, the number of fruit per branch and yield were evaluated. Four sprays of trifloxystrobin+tebuconazole, carbendazim, difenoconazole or cyprodinil+fludioxonil were effective in reducing yield losses due to PFD, however the trifloxystrobin+tebuconazole mixture was significantly more effective than all other treatments. The conventional PFD control programme, with one spray of difenoconazole followed by up to three carbendazim applications at different intervals, showed variable results, probably due to rainfall. The trifloxystrobin+tebuconazole mixture was effective at controlling PFD under favourable conditions for infection and can be recommended in PFD control programmes. © 2014. Source


Fonseca A.E.,Fundo de Defesa da Citricultura Fundecitrus | Arf O.,Sao Paulo State University | Junior V.O.,Sao Paulo State University | Buzetti S.,Sao Paulo State University | Rodrigues R.A.F.,Sao Paulo State University
Pesquisa Agropecuaria Tropical | Year: 2012

The influences of soil management and nitrogen fertilization are not well defined for upland rice. Thus, this research was carried out to evaluate the yield components, milled grain yield, and grain yield of upland rice cultivars under sprinkler irrigation, according to soil management and topdressing nitrogen doses. The experiment was conducted in Selvíria, Mato Grosso do Sul State, Brazil, under field conditions, for two consecutive harvest times: 2003/2004 (BRS Talento cultivar) and 2004/2005 (IAC 202 cultivar). The randomized blocks design was adopted, consisting of the combination of three soil management systems (disc harrow + leveling disc harrow, scarifier + leveling disc harrow, and no-till) and six topdressing nitrogen doses (0 kg ha-1, 25 kg ha-1, 50 kg ha-1, 75 kg ha-1, 100 kg ha-1, and 125 kg ha-1), with four replications. The leaf N concentration, plant height, yield components, milled grain yield, and grain yield were evaluated. The scarifier + leveling disc harrow system provided the highest grain yield for both cultivars, while the topdressing nitrogen fertilization just affected the IAC 202 cultivar yield, without affecting the milled grains yield. Source


de Araujo D.,Sao Paulo State University | Raetano C.G.,Sao Paulo State University | Ramos H.H.,Instituto Agronomico CEA IAC | Sposito M.B.,Fundo de Defesa da Citricultura Fundecitrus | Prado E.P.,Sao Paulo State University
Summa Phytopathologica | Year: 2013

The chemical control of the causal agent of citrus black spot (CBS) has been highlighted for the excessive required number of sprayings, considerably increasing citrus production costs. Improvements in the spray efficiency and reductions in the quantity of phytosanitary products have already been searched, but the results of that practice are not consistent yet for its use at commercial scale. Thus, the aim of the present study was to evaluate the interference of reduced spray volumes in black spot control in citrus fruits. The experiment was carried out in commercial citrus orchard with 16-year-old plants of 'Valencia' variety, during 2007 agricultural season. Treatments consisted of three spray volumes: 3.5; 4.5 and 8.5 liters.plant-1, applied with Arbus 2000/Export airblast sprayer with special manifold of hydraulic nozzles, using fungicides and periods recommended for the disease control, totaling four sprayings plus a control treatment (without spray). The disease incidence and severity were evaluated by visual diagrammatic scale of notes in two different periods (preharvest and harvest), at three plant heights (low, middle and top) and three horizontal sections (entrance, frontal and exit) in two sides of the plant. The fallen fruits were counted every fifteen days, for previously selected plants, from the beginning of maturation to harvest, and the production was quantified (kg.plant-1). The disease incidence and severity were significantly lower when sprayings were done with 8.5 liters.plant-1 in the first evaluation period (pre-harvest), but in the harvest period there were not differences between the same parameters when 4.5 or 8.5 liters.plant-1 were sprayed. None of those treatments reduced the disease on the top section of plants, compared to control. The plant sections with fruits more exposed to sun rays, top and right side of the plant, demonstrated higher disease incidence and severity. The volume reduction from 8.5 to 4.5 liters.plant-1 can be adopted for citrus orchards without damaging the CBS control level. Source


Patent
Instituto Valenciano Of Ivestigaciones Agrarias and Fundo De Defesa Da Citricultura Fundecitrus | Date: 2010-10-26

The invention provides a method for controlling Huanglongbing (HLB) disease of citrus plants through expressing genes encoding synthases for sesquiterpenes such as -caryophyllene, and -copaene, and combinations thereof, in citrus plants. Methods of controlling HLB comprising applying at least one purified sesquiterpene, which repels


Patent
Fundo De Defesa Da Citricultura Fundecitrus and Instituto Valenciano Of Investigaciones Agrarias | Date: 2015-06-08

The invention provides a method for controlling Huanglongbing (HLB) disease of citrus plants through expressing genes encoding synthases for sesquiterpenes such as -caryophyllene, and -copaene, and combinations thereof, in citrus plants. Methods of controlling HLB comprising applying at least one purified sesquiterpene, which repels

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