ABSTRACT The objective, in this research, was to evaluate the agricultural productivity and the financial performance of levels of irrigation in the cassava. For this, experiment was carried out, under a randomized block design, with six irrigation levels, as a function of crop evapotranspiration (L0 = 0% (rainfed), L1 = 40%, L2 = 80%, L3 = 120%, L4 = 160% and L5 = 200% of ETC) and four repetitions. Was evaluated: length and mass of roots, productivity of maximum physical and economic efficiency of roots and productivity of the aerial part. The irrigation level L5 or total useful water of 1,023 mm, got greatest productivity of the aerial part, 57 Mg ha-1. With a total useful water of 926 mm, this irrigation level, generated the greatest length and mass of roots per plant and the maximum physical productivity, 94 Mg ha-1. As well as the root yield of maximum economic efficiency, which is achieved with a total usable water, 914 mm. Among the irrigation levels studied, L3 (963 mm) is the one that provides the greatest productivity of roots, 90 Mg ha-1, and gross revenue 167% higher than in areas cultivated under rainfed conditions. Therefore, irrigation of cassava is economically viable. objective research out design L0 L (L 0 rainfed, , (rainfed) 40 40% 80 80% 120 120% 160 200 ETC repetitions evaluated part 1023 1 023 1,02 mm 5 ha1. ha1 ha 1. ha-1 92 9 91 studied 963 (96 ha1, 1, 167 conditions Therefore viable (rainfed 4 8 12 16 20 102 02 1,0 ha- 96 (9 2 10 (

RESUMO: Esta pesquisa avaliou os efeitos da irrigação no crescimento e na produtividade da mandioca irrigada nos Tabuleiros Costeiros alagoanos. O plantio foi feito em blocos casualizados, com seis tratamentos e quatro repetições. Os tratamentos foram níveis de irrigação em função da evapotranspiração da cultura - ETC (L0 = 0% (sequeiro), L1 = 40%, L2 = 80%, L3 = 120%, L4 = 160% e L5 = 200% da ETC). A lâmina total foi definida como o total da irrigação mais a chuva efetiva. A evapotranspiração anual da cultura da mandioca nos Tabuleiros Costeiros de Alagoas é 1.030 mm. O crescimento das plantas aumentou significativamente com a irrigação e os valores máximos das seguintes variáveis são: índice de área foliar = 7,6; comprimento de raízes comerciais = 49 cm; produtividades (física e econômica) máximas de raízes comerciais = 94 t ha-1 e biomassa total = 149 t ha-1 e o índice de colheita = 0,66, todos obtidos com lâminas de irrigação totais (chuva efetiva mais irrigação) entre 817 e 963 mm. Por fim, ratifica-se que entender o crescimento, as produtividades agrícola e economicamente viáveis da mandioca irrigada, é fator indispensável para se fazer um bom manejo da cultura, principalmente, em regiões com irregularidade de chuvas como o nordeste brasileiro.

ABSTRACT: This research evaluated the effects of the irrigation on growth and productivity of irrigated cassava in the Coastal Plateaus of Alagoas. The planting was done in randomized blocks, with six treatments and four replications. The treatments were irrigation levels in function of crop evapotranspiration - ETC (L0 = 0% (rainfed), L1 = 40%, L2 = 80%, L3 = 120%, L4 = 160% and L5 = 200% of ETC). The total water applied was defined as the total irrigation plus the effective rain. The annual evapotranspiration of the cassava plantations in the Costal Plateaus of Alagoas, was 1,030 mm. Plant growth increased significantly with irrigation and the maximum values of the following variables are: leaf area index = 7.6, length of commercial roots = 49 cm, maximum productivity (physical and economic) of commercial roots = 94 Mg ha-1 and total biomass = 149 Mg ha-1 and the harvest index = 0.66, all obtained with total irrigation depths (effective rain plus irrigation) between 817 and 963 mm. Finally, it is ratified that understanding the growth, the agricultural and economically viable productivity of irrigated cassava, is an indispensable factor for good management of the crop, especially in regions with irregular rainfall such as the Northeast of Brazil.

Abstract: Sugarcane cultivar RB961552 was developed by the Sugarcane Breeding Program of the Federal University of Alagoas, a member university of RIDESA. It was selected for being highly productive, responsive to fertigation and for the high leaf biomass and excellent inter-row closure. It is resistant to brown and orange rust and moderately resistant to leaf scald and smut diseases.

ABSTRACT The aim of this research was to evaluate the physiological and productive aspects of irrigated cassava crop. The statistical design used was randomised blocks, with six treatments and four replications. The used treatments were irrigation levels, based on the crop evapotranspiration – ETC – (L0 = 0% [rainfed], L1 = 40%, L2 = 80%, L3 = 120%, L4 = 160% and L5 = 200% of the ETC) and the analysed physiological variables were: gas exchange, the quantum efficiency of photosystem II (PSII) and the soil plant analysis development (SPAD) index. The growth and crop productivity were also evaluated through of the leaf area index (LAI), the number and productivity of commercial roots and total biomass. In this research, the total irrigation depth was defined as the irrigation depth plus the effective rainfall. The estimated ETC was 1,030 mm over the 12-month production cycle and the greatest value for LAI and SPAD were 7.6 and 57.4, respectively, obtained in irrigated areas with the level of 80% of the ETC. While, in the areas irrigated with 120% of the ETC, were obtained the highest values of root productivity (93 Mg·ha–1), total biomass yield (149 Mg·ha–1) and photosynthetic rate (22.4 μmol CO2·m–2·s–1). On the other hand, with irrigation equivalent at 200% of the ETC were obtained the greatest values of internal CO2 concentration (245 μmol CO2·m–2·s–1), stomatal conductance (0.35 μmol H2O·m–2·s–1) and effective quantum efficiency (0.68).

Abstract Sugarcane cultivar RB0442 has a high yield, late maturation and good drought tolerance. It is recommended for planting in restrictive environments, mainly with water-deficient soils, and is resistant to the major sugarcane diseases of the Northeastern region of Brazil.

ABSTRACT Maturation is a characteristic of sugarcane plant (Saccharum spp.) and even when grown under the same soil and climate conditions the varieties differ on the maturation curve. Thus, studies that allow establishing maturation curves of different sugarcane genotypes in the local soil and climate may indicate the proper harvesting period to ensure better quality of the raw material. This study aimed to analyze the levels of soluble sugars during the maturation phase and assess the technological and productivity indexes of four irrigated sugarcane genotypes in the region of Rio Largo, Alagoas. The experiment was conducted in randomized blocks in a 4 x 2 x 5 factorial: four genotypes (RB92579, RB98710, RB99395 and RB961003), two stem portions (internodes 1-4 and internodes 5-8) and five seasons (82, 49, 25, 13 and 3 days before harvesting), each treatment with three replications. Internodes 1-4 showed the highest levels of reducing sugars, while the largest accumulation of sucrose and total soluble solids occurred in internodes 5-8. RB99395 genotype showed more stability in the sugar levels during sugarcane maturation, which can indicate early maturation and high agricultural yield.

RB99395 cultivar was developed by the Sugarcane Breeding Program at the Federal University of Alagoas, which is part of RIDESA. In 1999, seeds were obtained from crosses between RB867515 cultivar and pollen from an unknown genotype in "Serra do Ouro" Crossing Station. The process of selection and experimentation was carried out in three Research Stations of Alagoas. RB99395 cultivar was released in Alagoas in May 2010, and has a high content of sucrose throughout the harvest period. Planting is recommended in fertile soils and in environments with no water deficiency, a condition which results in high agricultural yields. It is tolerant most diseases that occur in Northeast, Brazil.

RESUMOA água é um recurso natural que, nos últimos anos, tem sido alvo de inúmeras discussões quanto ao seu uso e disponibilidade. No setor agrícola o volume de água necessário à irrigação é calculado com base nas perdas ocorridas por evaporação e transpiração motivo por que este trabalho teve, como objetivo, determinar a evapotranspiração máxima e real da cana-de-açúcar irrigada por gotejamento. Os dados para esta pesquisa foram obtidos em um experimento conduzido na região de Rio Largo, AL, com sete tratamentos de irrigação (0; 25; 50; 75; 100; 125 e 150% da evapotranspiração de referência-ET0), em três ciclos de produção no período de janeiro de 2009 a fevereiro de 2012. A evapotranspiração real (ETr) foi estimada pelo Kc "dual". A ETr média na fase de crescimento máximo dos três ciclos variou de 1,73 a 5,04 mm d-1 nos tratamentos com 0 e 150% da ET0, respectivamente. A cana-de-açúcar em regime de sequeiro está, nesta região, exposta a médio risco climático, conforme classificação proposta na literatura.

ABSTRACTWater is a natural resource that has been the subject of much debate about its use and availability in recent years. In the agricultural sector, the volume of water needed for irrigation is calculated based on the losses incurred by evaporation and transpiration. Thus, this study aimed to determine the maximum and actual evapotranspiration of drip irrigated sugarcane. The data for this study were obtained in an experiment conducted in the region of Rio Largo (Alagoas, Brazil), with seven irrigation treatments (0; 25; 50; 75; 100; 125 and 150% of the reference evapotranspiration - ET0), in three production cycles from January 2009 to February 2012. The actual evapotranspiration (ETr) was estimated by "dual" Kc. The mean ETr in the maximum growth phase of the three cycles ranged from 1.73 at 5.04 mm d-1 in the treatments with 0 and 150% of ET0, respectively. The sugarcane, in rainfed conditions in this region, is exposed to average climatic risk, according to the classification proposed in the literature.

O objetivo deste trabalho foi avaliar as variáveis meteorológicas, a deficiência hídrica, o crescimento e a produtividade agroindustrial das variedades de cana-de-açúcar: RB72454, RB863129, RB867515, RB92579, RB93509, RB931003, RB951541 e RB971755, em cultivo de sequeiro, em duas safras, na região de Rio Largo - AL. As variáveis meteorológicas foram obtidas em uma estação automática, e o balanço hídrico foi feito pelo método de Thornthwaite & Mather. No período da pesquisa, a temperatura do ar variou de 16,6 a 35,9º C. No primeiro ciclo de produção, choveu 1.806 mm, e a cultura evapotranspirou 1.775 mm, e, no segundo ciclo, a precipitação pluvial somou 1.632 mm, e a evapotranspiração da cultura foi 1.290 mm. O excesso hídrico médio dos dois ciclos de produção foi 689 mm; e o déficit hídrico, 665 mm. Ou seja, mesmo resultando em uma precipitação pluvial superior à evapotranspiração da cultura, devido à má distribuição das chuvas, houve deficiência hídrica. A temperatura do ar não foi limitante para o crescimento da cana-de-açúcar. A produtividade agrícola média da cana-planta foi 86,8 t ha-1, em cana-soca foi 75,2 t ha-1, e o rendimento agroindustrial médio foi 12,9 e 10,9 toneladas de açúcar por hectare em cana-planta e cana-soca, respectivamente. As variedades mais produtivas foram a RB93509, a RB92579 e a RB863129.

The objective of this study was to evaluate the meteorological variables, water deficiency, growth, and agro-industrial yield of sugarcane varieties: RB72454, RB863129, RB867515, RB92579, RB93509, RB931003, RB951541, and RB971755, in rainfed crop in two harvests in the Rio Largo-AL region. The meteorological variables were obtained in an automatic station and water balance was done by Thornthwaite & Mather method. During the study period, the air temperature ranged from 16.6 to 35.9 ºC. In the first production cycle rained 1,806 mm and the crop evapotranspiration was 1,775 mm. In the second cycle, the rainfall totaled 1,632 mm and the crop evapotranspiration was 1,290 mm. The average water excess of two production cycles was 689 mm and the water deficit totaled 665 mm. The average agricultural productivity in the plant was 86.8 t ha-1, in the first ratoon was 75.2 t ha-1 and the agro-industrial yield average was 12.9 and 10.9 tons of sugar per hectare in the plant and first ratoon, respectively. The air temperature was not limiting to the growth of sugarcane and the rainfall was higher than the crop evapotranspiration, but due to poor distribution of the rains there was water deficit. The most productive varieties were RB93509, RB92579, and RB863129.

Este trabalho objetivou avaliar o crescimento e a produtividade de grãos da cultura do milho, submetida a diferentes doses de nitrogênio. O experimento foi conduzido com a cultura do milho híbrido Pioneer 30F35, no período de 25/06 a 28/10/2009, na região de Rio Largo, AL. O delineamento experimental foi em blocos casualizados e os tratamentos consistiram em seis doses de nitrogênio (0, 50, 100, 150, 200 e 250 kg ha-1 de N), com a fonte ureia, e cinco repetições. Os modelos logístico e pico log normal apresentaram ajustes estatísticos significativos (p<0,05) das variáveis de crescimento e coeficientes de determinação máximo de 0,994 e 0,990, respectivamente. Os valores observados e estimados pelos modelos apresentaram alta associação pelo índice de concordância de Willmott, com valores superiores a 0,953. As plantas apresentaram diferenças estatísticas significativas pelo teste F (p<0,05), entre os tratamentos, para altura e índice de área foliar, com crescimento máximo para a dose de 100 kg ha-1 de N. Os tratamentos mostraram diferenças estatísticas significativas (p<0,05) para a produtividade, sobressaindo-se a dose de 200 kg ha-1, que proporcionou maior produtividade de grãos (5,45 t ha-1). Os modelos de crescimento podem ser utilizados para auxiliar a análise de crescimento.

The objective of this work was to evaluate the growth and yield of maize subjected to different nitrogen rates. The experiment was conducted with maize cultivar Pioneer 30F35 from 25/06 to 28/10/2009, in the region of Rio Largo-AL. The experiment was arranged in a randomized block design, with six nitrogen rates (0, 50, 100, 150, 200 and 250 kg ha-1 of N in the form of urea) and five repetitions per treatment. The models logistic and log normal peak showed statistically significant adjustments (p<0.05) and maximum coefficient of determination of 0.994 and 0.990, respectively. The values observed and estimated by these models showed high association by the Willmot's index of agreement, with values greater than 0.953. The plants showed statistically significant differences by the F teste (p<0.05) between the treatments for height (h) and leaf area index (LAI), with a maximum growth corresponding to the rate of 100 kg ha-1 N. The treatments showed significant differences (p<0.05) for yield, with the rate of 200 kg ha-1 providing the highest yield (5.45 t ha-1). The growth models can assist the growth analysis.

O manejo de irrigação por gotejamento e a colheita mecanizada na cultura da cana-de-açúcar estão sugerindo espaçamento entrelinhas de plantio do tipo combinado. Neste contexto, o objetivo do estudo foi avaliar o crescimento da variedade RB98710 irrigada por gotejamento em dois tipos de espaçamentos entrelinhas de plantio; para isto foram realizados dois plantios em agosto de 2011, sendo um com espaçamento entrelinhas de plantio único (1,0 m) e outro combinado (0,6 e 1,4 m). Os dados analisados foram variáveis de crescimento (índice de área foliar, altura do dossel, comprimento dos colmos e plantas por metro quadrado), variáveis de produção e elementos meteorológicos. O valor do fator de forma para a área foliar foi igual a 0,65; em ambos os espaçamentos entrelinhas de plantio as variáveis de crescimento foram relacionadas com os graus-dia acumulados e tiveram equações ajustadas com aplicações satisfatórias. As variáveis de crescimento avaliadas não diferiram entre os espaçamentos de plantio utilizados. As produtividades de colmos frescos (100,9 t ha-1) e de açúcar (17,8 t ha-1) da cana-de-açúcar irrigada cultivada em Rio Largo, Alagoas, não foram influenciadas pelo uso dos diferentes tipos de espaçamentos entrelinhas de plantio.

The management of drip irrigation and mechanized harvesting in the sugarcane crop are suggesting combined row spacing. In this context the objective of this study was to evaluate the growth of RB98710 variety, with drip irrigation in two row spacing. For this, two plantings were performed in August 2011, with single (1.0 m) and combined row spacing (0.6 and 1.4 m). The analysed data were variables of plant growth (leaf area index, canopy height, length of stems and plants per square meter), production variables and weather elements. The form factor value for leaf area was equal to 0.65. In both row spacing, the variables of plant growth were related with accumulated degree-days and had adjusted equations with satisfactory applications. The evaluated variables of plant growth were not different by the used row spacing configurations. The fresh stalk yield (100.9 t ha-1) and sugar yield (17.8 t ha-1) of irrigated sugarcane crop cultivated in Rio Largo, Alagoas state, Brazil, were not influenced by the use of different row spacing configurations.

O milho foi cultivado em três sistemas de manejo: i) cobertura de capim; ii) plástico na entrelinha e iii) cultivo tradicional (solo nu). Com o objetivo de determinar a eficiência do uso da radiação (EUR) mediram-se componentes da radiação solar (incidente e transmitida) em dossel de milho. A irradiação fotossintética (HF) incidente foi considerada equivalente a 44% da irradiação solar global. A HF transmitida (HFT) foi estimada utilizando-se a lei de Beer para radiação aplicada a um dossel vegetal (HFT = HF exp(-k IAF)), com coeficiente de extinção da luz (k) ajustado de uma função exponencial, que relacionou a fração da HFT (HFT/HF) e o índice de área foliar (IAF). A HF interceptada (HFI) foi calculada por diferença (HFI = HF - HFT). Estimou-se a EUR por meio de regressão linear, forçada a passar pela origem, entre o acúmulo de matéria seca (MS) e a HFI. O k foi de 0,628 com coeficiente de determinação de 0,88. A EUR das plantas da parcela coberta com plástico foi de 3,85 g de MS MJ-1 de HFI, que mostrou eficiência superior à dos demais tratamentos (solo nu 3,31 g MJ-1 e capim 3,58 g MJ-1); entretanto, esta conferiu menor IAF e, consequentemente, teve menos HFI acumulada, o que resultou na menor produção de MS.

Maize was cultivated under three management systems: i) mulching (grass cover); ii) plastic cover in the inter rows and iii) traditional cultivation (bare soil). The components of the incident and transmitted solar radiation in a maize canopy were measured in order to determine the radiation use efficiency (RUE). The photosynthetic irradiation (HF) was considered as 44% of the solar global irradiation. The transmitted HF (HFT) was estimated using Beer's law applied to a plant canopy (HFT = HF exp (-k LAI)), with the light extinction coefficient (k) by fitting an exponential function, which related the fraction of HFT (HFT/HF) and leaf area index (LAI). The intercepted HF (HFI) was calculated by the difference (HFI = HF - HFT). The RUE was estimated using a linear regression (forced to pass through the origin) between the dry matter accumulation (DM) and HFI. The k was 0.628 with the determination coefficient of 0.88. The plants RUE in plots covered with plastic was 3.85 g DM MJ-1 of HFI, showing a higher efficiency compared to other treatments (bare soil 3.31 g MJ-1 and grass 3.58 g MJ -1). However, this promoted lower LAI and therefore had less accumulated HFI, resulting in lower production of DM.

O objetivo deste trabalho foi avaliar as interações entre variáveis meteorológicas e os componentes de produção e produtividade de seis variedades de cana-de-açúcar nos Tabuleiros Costeiros de Alagoas visando o manejo varietal adequado. O plantio da cana-de-açúcar foi realizado em setembro de 2005 na região de Rio Largo (AL) e as três colheitas foram feitas em novembro de 2006, novembro de 2007 e novembro de 2008. O delineamento estatístico utilizado foi o de blocos casualizados com o tratamento constituído pelas variedades RB863129, RB867515, RB92579, RB93509, RB931003 e RB951541, com quatro repetições. As variáveis de crescimento avaliadas foram número, comprimento e produtividade dos colmos, índice de área foliar e produtividade de açúcar. O balanço hídrico da cultura em média apresentou déficit hídrico de 869 mm nos meses de setembro a março e excesso hídrico de 837 mm nos meses de abril a agosto. A irregularidade das precipitações nos Tabuleiros Costeiros de Alagoas promove respostas diferenciais no desenvolvimento e na produtividade das variedades de cana-de-açúcar nos diferentes ciclos de cultivo. As variedades RB93509 e RB931003 são consideradas as melhores opções para o manejo varietal nessa região.

The aim of this study was to evaluate the interaction among meteorological variables and yield components of six sugarcane varieties and to establish appropriate varietal management at the Coastal Tablelands of the Alagoas State (Brazil). The sugarcane planting was carried out in September 2005, and three cane harvests were made in November 2006, 2007 and 2008. The experimental design was in randomized block with six treatments consisting of the varieties RB863129, RB867515, RB92579, RB93509, RB931003 and RB951541, with four replications. The growth variables evaluated were number and length of stalks, leaf area index, and productivity of stalks and sugar. On average, the crop water balance showed water deficit of 869 mm between September and March and excess of 837 mm from April to August. The irregularity of rainfall in the Coastal Tablelands promoted differential responses in the development and productivity of varieties of sugarcane. Varieties RB93509 and RB931003 are considered options for the varietal management in this region.

O crescimento da cana-de-açúcar pode ser obtido por modelos biofísicos em que a fotossíntese bruta (FB) é obtida em função da radiação solar. O objetivo do trabalho é avaliar variedades de canas-de-açúcar em regime irrigado em relação à radiação fotossinteticamente ativa interceptada (RFAINT) e a estimativa da FB acumulada. Para isto, conduziu-se um estudo na Universidade Federal de Alagoas, entre 2008 e 2009, com variedades de cana RB. Foram realizadas medidas biométricas, variáveis de produção e dos elementos meteorológicos. A irradiância fotossintética (RFA) interceptada foi obtida pela diferença entre RFA e RFA transmitida (RFAT). A RFAT foi determinada pela Lei de Beer. Na estimativa da FB diária usou-se uma integração numérica, com uma abordagem trapezoidal. As variáveis de produção tiveram correlações com a RFAINT acumulada e com a FB acumulada durante o ciclo. A média da irradiação solar global diária do período chuvoso da região (maio - agosto) foi igual a 14,9 MJ m-2. A variedade RB92579 teve os maiores variáveis de produção, como também maiores RFA interceptada e FB acumuladas no ciclo, devido à sua maior capacidade de rebrotação e conversão de energia em fotoassimilados.

Sugarcane growth can be obtained by biophysical models in which gross photosynthesis (GP) is obtained as a function of solar radiation. This work aims to evaluate sugarcane varieties under irrigation in relation to intercepted photosynthetic active radiation (PARint) and the estimated accumulative GP. To achieve that, a study was conducted at the Federal University of Alagoas during 2008 and 2009, with RB sugarcane varieties. Biometric measurements, production variables and meteorological elements were made. The intercepted photosynthetic irradiance (PAR) was obtained by the difference between PAR and transmitted PAR (PART), which was determined by Beer's Law. The daily GP was estimated numerically by the trapezoidal approach. The production variables had correlations with accumulated PARint and accumulated GP during the crop cycle. The average global solar radiation in the region for rainy season (May-August) was 14.9 MJ m-2. The variety RB92579 had the highest production variables as well as higher intercepted PAR and accumulated GP in the cycle due to its greater capacity for regrowth and energy conversion in photoassimilate.

O presente estudo teve como objetivo principal avaliar a influência de diferentes sistemas de irrigação na incidência e nas perdas ocasionadas pela virose mosaico-dourado na cultura do feijoeiro, causada pelo Bean golden mosaic virus (BGMV), gênero Begomovirus, família Geminiviridae. Foram avaliados três sistemas de irrigação (gotejamento, microaspersão e aspersão), instalados em faixas de 225 m², numa área experimental localizada no Centro de Ciências Agrárias da Universidade Federal de Alagoas, Rio Largo, AL. Dentro de cada faixa foram delimitadas 12 parcelas de 1 m², contendo 20 plantas em cada parcela. O experimento foi conduzido em duas safras: outubro de 2006 a janeiro de 2007 e outubro de 2007 a janeiro de 2008. A incidência do mosaico dourado foi avaliada pela inspeção visual de plantas sintomáticas, sendo as plantas assintomáticas testadas para a presença de begomovirus por PCR. Para avaliação da produção de grãos, quantificou-se o peso dos grãos maduros de todas as plantas, obtendo-se a média por planta em cada parcela. Verificou-se que o sistema de irrigação por gotejamento e aspersão resultaram na maior (62,13%) e menor (16,74%) incidência da virose nos feijoeiros respectivamente. Não houve correlação entre a incidência do mosaico dourado e a produção de grãos nas parcelas. No entanto, a comparação da produção de grãos entre feijoeiros sadios e infectados evidenciou que, as plantas sadias tiveram uma produção cerca de três vezes maior que as plantas doentes.

One of the most severe diseases in common bean (Phaseolus vulgaris L.) is golden mosaic caused by Bean golden mosaic virus (BGMV, genus Begomovirus, family Geminiviridae). This study aimed to evaluate the influence of different irrigation systems on the incidence and losses caused by BGMV in common bean. The experiment consisted of the evaluation of three irrigation systems (drip, sprinkler and micro sprinkler), installed as 225m² strips in the experimental area of the Federal University of Alagoas, Rio Largo, AL. Each strip contained 12 plots of 1m² each, with 20 plants per plot. The experiment was conducted over two seasons: October 2006 to January 2007 and October 2007 to January 2008. The incidence of golden mosaic was evaluated by visual inspection of symptomatic plants, and the asymptomatic plants were tested for the presence of begomoviruses by PCR. For yield evaluations, the weight of mature grains from all plants was quantified, and the average weight per plant in each plot was calculated. The results indicate that drip and sprinkler irrigation resulted in the highest (62.31%) and lowest (16.74%) incidence, respectively, of golden mosaic. There was no correlation between the incidence of golden mosaic and yield. However, healthy plants yielded three times more grain than diseased plants.