Minhocas e Fusarium oxysporum: efeito no crescimento e produção do morangueiro

Earthworms are soil invertebrates that play an important environmental role and are often referred to as “ecosystem engineers”. These invertebrates can influence several organisms, from microscopic life forms to plants. Although many works had reported positive effects of earthworms on plant growth, studies combining these invertebrates and soil pathogens showed numerous positive interactions. Fusarium wilt is a global disease that can cause severe damage to strawberry fields. The aim of this study was to evaluate the effects of inoculation of earthworms (Lumbricus terrestris) and Fusarium wilt (Fusarium oxysporum f. sp. fragariae) in strawberry plants. This greenhouse experiment was carried out in the University of Seville School of Agricultural Engineering, Utrera City, Spain. Strawberries (Rooted cuttings) were planted in plastic pots and administered the following treatments: Control (absence of F. oxysporum f. sp. fragariae and earthworms), T1 (absence of F. oxysporum f. sp. fragariae, two L. terrestris per pot), T2 (inoculum of F. oxysporum f. sp. fragariae, absence of L. terrestris), and T3 (inoculum of F. oxysporum f. sp. fragariae and two L. terrestris). Weekly fruit production was measured for seven months. After this period the shoot fresh weight and the leaf nutrient content was measured. The results obtained showed no interaction between L. terrestris and F. oxysporum f. sp. fragariae on strawberry production. T1 treatment resulted in fruit production superior to other treatments, including the control. An absence of differences in dry shoot matter was observed with earthworm treatment, and small differences were found in the leaf nutrient content. The earthworm inoculation was unable to suppress the negative effects of Fusarium wilt in strawberry production. However, positive effects such as a reduction in the disease severity were found in the earthworm treated plants. In treatments without F. oxysporum f. sp. fragariae inoculation, the presence of earthworms increased plant productivity by 44.21 g per pot, compared with the control

Un estudio muestra la eficacia de composts de residuos agroindustriales para reducir enfermedades de las plantas

Algunos residuos agroindustriales ya compostados y usados como sustratos pueden presentar supresividad a distintas enfermedades de las plantas. Algunos de estos sustratos son el compost de corcho (usado solo o mezclado con cascarilla de arroz), orujo de uva compostado, alperujo con residuo de desmotadora (2/3, v/v) compostado y posteriormente formulado con cascarilla de arroz (1/1, v/v) y sustrato de champiñón agotado compostado y mezclado con turba (1/1, v/v). Esta supresividad se ha evaluado en ensayos con inoculación artificial de patógenos y posterior evaluación del desarrollo de cada enfermedad, siendo el compost de orujo de uva maduro el que mejores resultados presenta.Ministerio de Ciencia y Tecnología AGL 2002-04313, 2005-08137, 2008-05414 y 2010-21982Junta de Andalucía P06-AGR-0231

Detection of fusarium wilt-induced physiological impairment in strawberry plants using hyperspectral imaging and machine learning

Strawberry (Fragraria x ananassa) is a crop affected by various soil-borne fungal pathogens with mostly non-specific foliar symptoms and often requiring laboratory isolation for correct diagnosis. Moreover, these nonspecific foliar symptoms, appreciated by the human eye, appear after some time following infection by the pathogen. Early detection of plant diseases is one of the primary objectives in agriculture because it may contribute to identifying more tolerant cultivars in breeding programs and optimise pesticide use in agricultural production with earlier applications in emerging disease foci. New technologies, such as remote sensing and machine learning (ML) algorithms, have arisen as potential tools to improve the ability to detect and classify different crop diseases. The combined use of hyperspectral imagery and ML algorithms were investigated to detect and classify the physiological stress caused by early infections of Fusarium wilt in strawberry plants. Six ML models, namely artificial neural network, decision tree, K-nearest neighbour, support vector machine, multinomial logistic regression and Naïve Bayes were developed to estimate physiological stress associated with Fusarium wilt disease. The results showed that stomatal conductance (gs) and photosynthesis (A) declined even without visual symptoms of the disease. Among the six ML models evaluated, the artificial neural network model showed the highest classification performance with an overall accuracy of 81%, regardless of the physiological parameter utilized for model training. Moreover, the artificial neural network accurately predicted the absolute values of both physiological parameters (gs and A) based on the complete spectral signature from visually healthy foliar tissue, achieving coefficients of determination of 84% and 81%, respectively. Consequently, ML models utilizing physiological response data and hyperspectral imaging exhibited remarkable robustness, facilitating the estimation of Fusarium wilt severity in strawberry plants even without visual symptoms.Premio Anual Publicación Científica Destacada de la US. Escuela Técnica Superior de Ingeniería Agronómic

Susceptibility to water-borne plant diseases of hydroponic vs. aquaponics systems

Waterborne diseases pose a significant risk in hydroponic crops, especially those caused by some species such as Fusarium, Pythium and Phytophthora. However, there is evidence of an increase in suppressiveness when using aquaculture effluents, as is the case with aquaponic systems. In this work, the incidence of diseases in hydroponic and aquaponic systems inside a greenhouse located in Seville (Spain) has been compared for two pathosystems: strawberry - Phytophthora cactorum - and tomato - Fusarium oxysporum f. sp. lycopersici (Fol). The results obtained show greater suppressiveness in early stages against P. cactorum in aquaponic systems. On the contrary, the suppressivity against Fol was higher in the hydroponic systems, although in this case a significant influence of the nutritional status of the plants was observed. This negatively affected the aquaponic systems. These findings open an interesting line for the use of biological control agents (BCA) from aquaponic systems for the control of plant diseases in hydroponic systems, avoiding the use of pesticides. This can have a negative effect on the health of consumers and the environment

The determination of Hesperidae

Volume: 4Start Page: 142End Page: 14