ABSTRACT: The study evaluated potato tuber yield and quality, using cultivar Atlantic, as a function of organomineral fertilizer doses applied in the planting furrow. The experiments were done in Cristalina, Goiás, in winter and summer cultive. The experimental design was randomized blocks, with six doses in the winter experiment and seven doses in the summer one, both with four replications. The doses were fixed according to the recommendation for mineral fertilizer. The doses evaluated were 2800 kg ha-1 of formulation 3-32-6, 1629.10, 2443.60, 4072.70 and 4887.30 kg ha-1 of organomineral fertilizer, corresponding to 40, 60, 80, 100 and 120% of the mineral fertilizer dose. A treatment with no fertilizer (control) was included in the summer experiment. Fertilizers were applied in the planting furrow. Side dressing fertilization was done 30 DAP, in winter crop, with 300 kg ha-1 of formulation 20-00-20. Tubers were harvested, classified, weighed and yield (kg ha-1) was determined at the end of the experiment. Results of winter crop were greater than those of summer, for yield and tuber classification. Organomineral fertilizer, in the dose 4072.70 kg ha-1, representing 100% of the mineral one, increased the yield of tubers Class Special. Winter crop presented good results for soluble solids contents. | RESUMO: O objetivo deste estudo foi avaliar a produtividade e a qualidade dos tubérculos da batateira em função da redução das doses do fertilizante organomineral em diferentes safras de plantio. Os experimentos foram conduzidos em Cristalina-Goiás nas safras de inverno (2013) e das águas (2013/2014). O delineamento experimental foi em blocos ao acaso, com 6 doses e 4 repetições na safra de inverno, totalizando 24 parcelas. Na safra das águas o experimento constituiu de 7 doses e 4 repetições, totalizando 28 parcelas. As doses de organomineral foram fixadas de acordo com a recomendação mediante análise do solo para fertilizante mineral. As doses testadas foram: 2800 kg ha-1 do formulado 3-32-6; 1629,10; 2443,60; 4072,70; e 4887,30 kg ha-1 do fertilizante organomineral correspondente a 40, 60, 80, 100 e 120% da dose de fertilizante mineral. Na safra das águas foi incluído um tratamento testemunha (sem adubação). Os fertilizantes organomineral e mineral foram aplicados em sulco de plantio. Aos 30 DAP, na safra de inverno, foram acrescidos 300 kg ha-1 do formulado 20-00-20, em cobertura. A produtividade e classificação dos tubérculos foram estimadas na massa fresca e no diâmetro dos tubérculos, respectivamente. Os resultados obtidos na safra de inverno foram superiores para todas as características avaliadas. A dose 4072,70 kg ha-1 de organomineral equivalente a 100% da dose mineral proporcionou maior produtividade e melhor qualidade de tubérculos nas safras avaliadas. Em relação ao teor de sólidos solúveis, a safra de inverno apresentou resultados mais satisfatórios.

ABSTRACT In semiarid regions with greater climatic variability, including prolonged droughts and delayed rainy seasons, supplemental irrigation is critical to ensuring yields of forage cactus pear. The objective was to evaluate root distribution and nutrient concentration and accumulation in ‘Gigante’ forage cactus pear subjected to different irrigation regimes. Seven irrigation regimes were tested: no irrigation (rainfed); five liters of medium-salinity water, with an electrical conductivity (EC) of 0.75 dS m−1, applied per linear meter every 15 days; 7% reference evapotranspiration (ETo) with a 15-d irrigation interval (II); 15% ETo with a 7-d II; 33% ETo with a 3-d II; 50% ETo with a 2-d II; and 100% ETo, irrigated daily - high-salinity water, EC of 3.6 dS m−1, was used in the last five treatments. The treatments were laid out in a randomized block design with four replicates. Roots developed best in plants irrigated at 50% ETo with a 7-d II. Applying high-salinity water at 15% ETo with a 7-d irrigation interval promotes higher concentrations of P, Ca, Mg and S in cladodes of cactus pear. Applying high-salinity water at 33% ETo with a 3-d II promotes higher uptake/accumulation of P, Ca, Mg, S and Zn in cladodes of ‘Gigante’ forage cactus pear.