R E S U M OO presente estudo teve como objetivo avaliar a produção de rabanete em função da adubação potássica e com diferentes fontes de nitrogênio. O delineamento experimental utilizado foi em blocos casualizados com os tratamentos arranjados em esquema fatorial 5 x 2 (cinco doses de potássio, e duas fontes de nitrogênio) com quatro repetições. As doses de potássio utilizadas foram 0, 40, 80, 120, e 160 kg ha -1 de K 2 O, e as fontes de nitrogênio foram o azoto amoniacal sob a forma de sulfato de amônio ((NH 4 ) 2 SO 4 ) e o azoto amídico sob a forma de ureia (CO(NH 2 ) 2 . Trinta e cinco dias após sementeira foram avaliadas as seguintes variáveis: diâmetro das raízes, massa fresca da raiz, massa seca da raiz, massa fresca da folha, massa seca da folha, teor de nitrogênio foliar, números de raízes comerciais e não comerciais e produtividade. A aplicação de potássio, independentemente do fornecimento de nitrogênio, apresenta efeito no desempenho da cultura do rabanete e a dose de 103 Kg ha -1 de K 2 O promoveu a máxima produtividade, nas condições do presente estudo. Conclui-se que, mesmo em condições de elevado teor de potássio nos solos, a adubação potássica deve ser recomendada para obtenção de aumento de produtividade na cultura do rabanete. Palavras-chave: Fontes nitrogenadas, Interação N x K, Raphanus sativus. A B S T R A C TThis study aimed to evaluate the response of radish to potassium fertilization and different nitrogen sources. The experimental design was a randomized block with treatments arranged in a factorial 5 x 2 (five doses of potassium, and two sources of nitrogen) with four replications. Potassium doses were 0, 40, 80, 120, and 160 kg ha -1 of K 2 O, and sources of nitrogen were ammonium sulfate ((NH 4 ) 2 SO 4 ) and urea (CO(NH 2 ) 2 ). 35 days after sowing the following variables were evaluated: root diameter, fresh root mass, root dry mass, leaf fresh mass, and leaf dry mass, leaf nitrogen content, number of marketable and non-marketable roots and crop productivity. Potassium application, regardless of the nitrogen supply, influenced radish performance and the dose of 103 kg ha -1 K 2 O promoted maximum productivity, under our experimental conditions. We conclude that, even in high soil potassium content, potassium fertilization should be recommended to obtain higher radish yield.

Forage cactus pear is considered a xerophilic plant, so it is adapted to harsh semiarid conditions and is a forage resource of significant importance for animal production in regions that are subject to food shortage and long dry periods. We aimed to evaluate the morphometric and physiologic characteristics and water-use efficiency of ‘Gigante’ forage cactus pear under different settings of irrigation depth and irrigation intervals with saline water. The treatments included seven conditions of water application: rainfed, 5 liters of water per linear meter every 15 days; 7% reference evapotranspiration (ETo) with a 15-day irrigation interval; 15% ETo with a 7-day irrigation interval; 33% ETo with a 3-day irrigation interval; 50% ETo with a 2-day irrigation interval; and 100% ETo with daily irrigation. Likewise, the use of saline water (3.6 dS m-1) as irrigation water on forage cactus pear did not stress the crop even in the presence of salts. The treatment with saline water and 33% ETo with a 3-day irrigation interval increased the plant height, number of cladodes, cladode area index, green mass and dry matter yields of forage cactus pear.

The objective of this study was to evaluate the physiological characteristics and yield of ‘Pérola’ pineapple subjected to irrigation with saline water in the semi-arid region of Bahia. The experiment was conducted in randomized blocks with five treatments, represented by irrigation depths: 100% ETc, using water with electrical conductivity (ECw) of 0.75 dS m-1, and 50, 75, 100 and 125% ETc, using water with ECw of 3.6 dS m-1. The experiment used a drip irrigation system and pressure-compensating emitters with a discharge of 8 L h-1. In the physiographic conditions of Guanambi-BA, pineapple has limitations of the physiological characteristics of chlorophyll fluorescence and chlorophyll index, under irrigation with both saline water and better-quality water. The irrigation depth corresponding to 100% ETc using water with ECw levels of 0.75 and 3.6 dS m-1 led to the best yields.

RESUMOEste estudo teve como objetivo avaliar o uso de água residuária de suinocultura como fonte alternativa de nutrientes no crescimento inicial do milho. O delineamento experimental utilizado foi o inteiramente casualizado constituído de quatro doses de água residuária (0, 112, 224 e 448 m³ ha -1 ) com quatro repetições. Aos 49 dias após o plantio foram avaliadas as variáveis altura, número de folhas, diâmetro do colmo, área foliar e no final do período de avaliações foi determinado matéria seca da parte aérea da planta. O aumento das doses de ARS possibilitaram incrementos lineares da altura, diâmetro do colmo e área foliar de plantas de milho. A aplicação de ARS mostrou ser uma alternativa para adubação da cultura do milho, pois, influenciaram diretamente variáveis importantes da cultura do milho. PALAVRAS-CHAVE: Adubação orgânica, água residuária de suinocultura, Zea mays GROWTH OF CORN IN APPLICATION OF WATER WITH LATOSOL SWINE WASTEWATERABSTRACT This study aimed to evaluate the use of swine wastewater as an alternative source of nutrients in the early growth of corn. The experimental design was completely randomized consisted of four wastewater doses (0, 112, 224 and 448 m³ ha-1) with four replications. After 49 days after planting were evaluated variables height, leaf number, stem diameter, leaf area and at the end of the ratings period was determined dry matter of the aerial part of the plant. Increasing doses ARS allowed linear increments of height, stem diameter, leaf area of corn plants. The application of ARS could be an alternative for fertilization of corn, therefore, directly influenced important variables of corn. KEYWORDS: Organic fertilizer, swine wastewater, Zea mays INTRODUÇÃO O milho (Zea mays L.) é cultivado em todo o Brasil e apresenta grande importância econômica, devido às diversas formas de sua utilização e ao fato de ser cultivado tanto pela agricultura empresarial quanto familiar. Dentre os aspectos que

Models for estimating leaf area of bananas found in the literature are not suitable for lanceolate type leaves occurring at the vegetative stage of ratoon suckers dependent of mother plant. The objective was to determine equations for estimating the leaf area of ‘Prata-Anã’ and ‘BRS Platina’ banana plants with lanceolate type leaves. 212 and 164 lanceolate type leaves having 10 cm-wide lamina or less were collected from ‘Prata-Anã’ and ‘BRS Platina’ banana plants of 90 days of age or less, respectively. Width (W), length (L), width/length ratio (WLR), and scanner-measured leaf area (LAscanner) were determined. Using the backward elimination procedure, simple and multiple linear regression equations were fitted to the relationship between leaf dimensions (W, L and WLR) and LAscanner. To evaluate how precise the equations are in predicting leaf area (LApredicted), Pearson correlation coefficients were calculated between LA and LApredictedscanner. The models highly correlated with LAscanner at 1% of significance level. The models are and LALL() = Prata-Anã = - 0,0133624 + 0,000489859**L - 0,00183182 **W and LALL(Platina) 0,00237026 + 0,004781**W - 0,096802** WLR.