The objectives were to evaluate the efficiency of entomopathogenic fungi against Plutella xylostella (L.) and the compatibility of the most virulent isolates with some of the insecticides registered for use on cabbage crops. Pathogenicity tests used isolates of Beauveria bassiana, Metarhizium rileyi, Isaria fumosorosea, Isaria sinclairii, and Lecanicillium muscarium standardized at a concentration of 10(7) conidia/ml. Cabbage leaf discs were immersed in these suspensions, and after evaporation of the excess water, were placed 10 second-instar larvae of P. xylostella, totaling 10 leaf discs per treatment. Mortality was assessed 7 d after treatment, and the isolates that caused mortality>80% were used to estimate LC50 and LT50. The compatibilities of the most virulent isolates and the insecticides were tested from the mixture of these into the culture medium, and after solidifying, the medium was inoculated with an aliquot of the isolated suspension. The following parameters were evaluated: growth of the colony, number and viability of conidia after 7 d. The isolated IBCB01, IBCB18, IBCB66, and IBCB87 of B. bassiana, LCMAP101 of M. rileyi, and ARSEF7973 of I. sinclairii caused mortality between 80 and 100%, with LC50 and LT50 between 2.504 to 6.775×10(4) conidia/ml and 52.22 to 112.13 h, respectively. The active ingredients thiamethoxam and azadirachtin were compatible with the entomopathogenic fungi. The results suggest that the use of these isolates is an important alternative in the pesticidal management of P. xylostella, with the possible exception of the associated use of chemical controls using the active ingredients thiamethoxam or azadirachtin.

The efficiency of isolates from entomopathogenic fungus Beauveria bassiana, Lecanicillium muscarium and Metarhizium rileyi in the control of eggs and third-instar nymphs of whitefly, Bemisia tabaci biotype B, was evaluated by pathogenicity and virulence tests, under laboratory conditions. For the pathogenicity tests, five leaflets of bean (Phaseolus vulgaris) plants containing 20 nymphs or 20 eggs of B. tabaci biotype B were used. The leaflets were immersed in suspension containing a concentration of 108 conidia/ml of each fungus isolate. Nymph mortality and egg viability were evaluated after seven days. The isolates that caused nymph mortality and egg viability above 80% were submitted to virulence tests, in order to estimate the lethal concentration (LC50) of each isolate. All isolates were pathogenic to eggs and third-instar nymphs of B. tabaci Biotype B. JAB07 of B. bassiana and LCMAP3790 of L. muscarium isolates presented the best results, with nymphs mortality of 96.68 ± 2.25% and 97.74 ± 1.56%, respectively. Additionally, JAB07 was the most virulent isolate, both for eggs and third-instar nymphs, with LC50 estimated of 0.012 and 0.006 × 103 conidia/ml, respectively. We suggest, future field trials are required in order to analyze the real efficiency of this isolate in the control of eggs and nymphs of B. tabaci biotype B in field conditions.

Cassava (Manihot esculenta Crantz) is one of the most important crops in tropical and subtropical regions of the world, occupying the fourth position among basic crops and responsible for being the food base of millions of people around the world. Brazil is one of the largest world producers of this culture and the Northeast region contributes significantly to national production. In Alagoas, the municipality of Arapiraca stands out as an important producer of cassava, so it is pertinent to know the local productive dynamics. In this sense, the objective was to analyze the performance of the cassava production variables during the 21-year period (1998-2018) in the municipality of Arapiraca, thus seeking to contribute to the understanding of the dynamics of this productive segment. The production data were obtained from the database of Municipal Agricultural Production - Temporary Crops of IBGE, using the Automatic Recovery System (SIDRA). To simultaneously analyze the studied variables, a Principal Component Analysis (PCA) was used. There were strong fluctuations in the variables analyzed, especially regarding the planted and harvested area. Cassava production in Arapiraca suffered a reduction in its participation in state production, as well as losses in productivity. Principal Component Analysis (PCA) explained 85.16% of the original data variance in the first two axes, with the formation of three clusters that brought together years with similar productive characteristics. Given the importance of this culture for the municipality of Arapiraca, it is necessary to develop actions that seek to rescue and strengthen local cassava production.

O objetivo do trabalho foi analisar, em condições laboratoriais, a influência de princípios ativos de herbicidas utilizados na cultura da cana-de-açúcar sobre o desenvolvimento vegetativo e reprodutivo do fungo entomopatogênico Metarhizium anisopliae. Os ingredientes ativos utilizados foram diurom + sulfentrazona (5L * 100L-1) (Boral Duo® - FMC Química do Brasil Ltda.), clomazona (2L * 150L-1) (Gamit® - FMC Química do Brasil Ltda.) e tebutiurom (2,4L * 300L-1) (Combine® - Dow Agrosciences Industrial Ltda.). O efeito tóxico dos herbicidas sobre o entomopatógeno foi determinado em condição laboratorial, através da adição dos produtos químicos em meio de cultura BDA. Após solidificação do meio, foram inoculadas as estruturas reprodutivas do entomopatógeno, na concentração de 107 conídios/mL, totalizando oito repetições por tratamento. Após 24 h do início experimental foi analisada a viabilidade dos conídios, e após sete dias foi mensurada a área de crescimento da colônia (cm2), e contabilizado o número de conídios para cada tratamento, sendo as médias comparadas pelo teste de Tukey (P < 0,05), e padronizadas pela classificação de compatibilidade. O ingrediente ativo clomazona inibiu o crescimento vegetativo e a conidiogênese de M. anisopliae, enquanto que diurom + sulfentrazona e tebutiurom possibilitaram certo desenvolvimento do entomopatógeno. A maior viabilidade foi observada no tratamento com tebutiurom, representado por 92,6 ± 1,12% de conídios viáveis, enquanto que diurom + sulfentrazona e clomazona foram prejudiciais. Os ingredientes ativos diurom + sulfentrazona e clomazona foram tóxicos à M. anisopliae enquanto que tebutiurom foi classificado como moderadamente tóxico.

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