The objective of this study was to measure ammonia volatilization from surface application of pig slurry, poultry litter, urea and no fertilization. An experiment was conducted in a randomized block design, in plots repeated over time, with four treatments and four replications. The fertilizers tested were: mineral fertilizer (70 kg ha-1 N, 100 kg ha-1 P2O5 and 30 kg ha-1 of K2O, as urea, triple superphosphate and potassium chloride, respectively), pig slurry (200 m³ ha-1 applied in November 2008 and 200 m³ ha-1 applied in April 2009) and poultry litter (10 t ha-1 applied in November 2008 and 10 t ha-1 applied in April 2009). Five evaluations were performed with 24-hour intervals. Foams were used with glycerin and sulfuric acid, internally fixed in PET bottles for collecting ammonia. After collected, the samples were sent to the laboratory to determine volatilized ammonia levels by the semi-micro Kjedahl distillation method. Fertilization with chicken litter had lower ammonia volatilization in relation to urea and pig slurry. Most of the ammonia volatilization from pig slurry occurred within 48 hours after application, totaling losses of 630 g kg-1 of a total of 8.25 kg ha-1 of volatilized ammonia. The biggest loss by ammonia volatilization was from fertilization with urea, totaling approximately 80 g kg-1 of N applied.

O tratamento de sementes com inseticidas é um método eficiente que auxilia o manejo integrado de pragas, porém, há escassez de informações de produtos que apresentem seletividade para a cultura do sorgo. O objetivo deste trabalho foi o de avaliar a influência do tratamento de sementes de sorgo com inseticidas, contendo um ou dois princípios ativos, sem e com o armazenamento por 30 dias, na fase inicial de desenvolvimento das plantas. O experimento foi conduzido na Fesurv-Universidade de Rio Verde, em Rio Verde-GO com dez inseticidas (thiodicarb, fipronil, acephate, thiametoxam, imidacloprid, [imidacloprid+thiodicarb], imidacloprid+thiodicarb, imidacloprid+fipronil, thiametoxam+thiodicarb, thiametoxam+fipronil, acrescido da testemunha sem inseticida) sem e com o armazenamento das sementes por 30 dias. Os resultados obtidos permitiram constatar que o armazenamento por 30 dias das sementes de sorgo tratadas com inseticidas diminui o percentual de germinação. A mistura imidaclopridrid+thiodicarb apresenta maior potencial para uso no tratamento de sementes de sorgo. O inseticida acephate causa fitotoxicidade às plântulas de sorgo ao contrário do fipronil, thiametoxam e a mistura thiametoxam+thiodicarb que não prejudicam o vigor das sementes de sorgo.

Seed treatment with insecticides is an effective tool in integrated pest management, but information on selective products to treat sorghum seeds is limited. The objective of this study was to evaluate the effects of treating sorghum seeds with insecticides containing one or two active ingredients, with and without storage for 30 days, on the early plant development. The experiment was conducted at Fesurv-Universidade de Rio Verde, in Rio Verde-GO, using ten insecticides (thiodicarb, fipronil, acephate, thiamethoxam, imidacloprid, [imidacloprid+thiodicarb], imidacloprid+thiodicarb, imidacloprid+fipronil, thiamethoxam+thiodicarb, thiamethoxam+fipronil, plus a non-insecticide control, with and without 30 day seed storage. The results showed that storage of sorghum seeds treated with insecticides for 30 days reduced the germination percentage. The imidacloprid+thiodicarb mixture has more potential for treating sorghum seeds. The insecticide acephate causes more phytotoxicity to the sorghum seedlings compared to fipronil, thiamethoxam and the thiamethoxam+thiodicarb mixture. The insecticides did not adversely affect sorghum seed vigor.