RTV-induced lowland rice productivity as influenced by amelioration effect of foliar fertilizers

Four separate sets of experiments were conducted to confirm the claims of Bukidnon [Philippines] farmers about the amelioration effected of foliar fertilizers that are applied to RTV-infected lowland rice. The sets of experiments coincided during an outbreak of RTV in the tungro-prone rice bowl of Bukidnon at Region 10 [Northern Mindanao, Philippines]. The first set consisted of planting an aromatic and fancy CMU selection proven of its yield and local market demand but was moderately susceptible to the RTV; the second involved direct-seeding and transplanting of IR64 under an RTV-induced condition; the third used the same aromatic and fancy CMU selection but applied with four sources of foliar fertilizer supplements after 30-40 percent RTV infection; the fourth included three varieties: the susceptible IR64; the moderately resistant CMU selection and the moderately resistant PSB Rc-18. The CMU selection in Experiment 1 obtained an adjusted yield ranging from 3.5-5.0 tons per hectare at 15 percent MC through basal application of inorganic Triple 14 and supplemental folial application of an algae-based fertilizer. The yield of the control was significantly lower compared to any of the treatments involving an INM plus the RTV dose of the algae-based foliar fertilizer. The plants in Experiment 2 responded to foliar treatment alone. There was also a pronounced reduction in severity rating of the RTV after the RTV dose of the algae-based foliar fertilizer was applied. The four sources of foliar fertilizers showed comparable yield advantage although the organic and algae-based Vitagrow source exhibited some degree of improvement due to some macro- and micro- nutrient present. The fourth experiment proved the claims of farmer about recovery and yield advantage of the RTV infected lowland rice supplied with any source of the tested foliar fertilizers that the CMU selection and PSB Rc-18 are not as susceptible to RTV as IR64. The studies further confirmed the claims of Bukidnon rice growers regarding improved rice grain quality when applied with foliar fertilizers instead of topdressing with urea before panicle initiation stage