Throughout history, the cocoa crop (Theobroma cacao L.) has been affected by countless diseases, some of these caused by Lasiodiplodia theobromae (Pat.) Griffon & Maul. Although three Lasiodiplodia species have been reported affecting cocoa plants, L. theobromae is the most studied species both in cocoa and other crops. In recent years this phytopathogen has been gaining importance. In cocoa, L. theobromae can survive in soil and culture remains in the form of pycnidia and chlamydospores, spreading by different factors until reaching the plant tissues, remaining there as an endophyte. The pathogenic fungus can cause young twigs death (a characteristic symptom found in field conditions), fruits rot and mummification, and even vascular dieback. In general, the management of pathogens of the Botryosphaeriaceae family is complex, even more so when the pathogen is already present in the crop area. However, there are genetic, cultural, biological, chemical control measures, among others, that could be integrated and used in cocoa crops. As there is little information about L. theobromae in cocoa crops, we believe that this review will be very helpful for both technicians and researchers. A lo largo de la historia, el cultivo del cacao (Theobroma cacao L.) se ha visto afectado por innumerables enfermedades, algunas de estas causadas por Lasiodiplodia theobromae (Pat.) Griffon & Maul. Aunque han sido reportadas tres especies de Lasiodiplodia afectando plantas de cacao, L. theobromae es la especie más estudiada tanto en cacao como en otros cultivos. En los últimos años este fitopatógeno ha venido tomando importancia. En cacao, L. theobromae puede sobrevivir en el suelo y restos de cultivo en forma de picnidios y clamidósporas, diseminándose por diferentes factores hasta alcanzar los tejidos vegetales, permaneciendo ahí como endófito. El hongo patogénico puede causar muerte de ramillas jóvenes (síntoma característico encontrado en campo), pudrición y momificación de frutos, e incluso muerte regresiva. De manera general, el manejo de patógenos de la familia Botryosphaeriaceae es complejo, más aún cuando el patógeno ya está presente en el local de cultivo. Sin embargo, existen medidas de control genético, cultural, biológico, químico, entre otras, que podrían ser integradas y usadas en el cultivo de cacao. Al existir poca información sobre L. theobromae en el cultivo de cacao, creemos que está revisión será de mucha ayuda tanto para técnicos como para investigadores.

Meloidogyne incognita root-knot nematode is one of the main causes of tomato root damage and consequently crop production losses. Thus, in in vitro conditions, the number of nematodes hatched eggs (%) at 4 and 6 days and nematode mortality (J2 stage) at 8, 18, and 24 h, were evaluated in Petri dishes containing the candidate rhizobacteria Enterobacter asburiae (BA4-19 and PM3-14), Acinetobacter calcoaceticus (BM2-12), Klebsiella variicola (BO3-4) and Serratia marcescens (PM3-8). The well-known Pseudomonas protegens (CHA0) and P. veronii (R4) were used as controls. In greenhouse conditions, plant height, root weight, and symptoms, as well as gall and nematode numbers, were determined in tomato plants infected by M. incognita and treated with the seven rhizobacteria. In addition, all variables were correlated using Pearson's analysis. In general, a significant correlation was observed among the variables of both experiments, showing the antagonistic capacity of the strains against nematode. It seems, that PM3-8 and PM3-14 strains reduce hatching, and cause mortality of nematodes J2 if compared with CHA0 and R4 strains. Likewise, tomato treated with BM2-12 strain shows a higher height and root weight, as well as a smaller number of galls and nematodes in their roots. This study provides evidence that PM3-8 and PM3-14 strains reduce the M. incognita egg hatching, and that the BM2-12 strain can be a plant growth-promoter potential of tomato plants.

The objective of the work focused on characterizing the biodiversity of Phytophthora spp. and rhizobacteria with potential for biocontrol in black pod disease in CCN-51. Nine plant samples with symptoms of the disease were collected from cocoa-producing areas, evaluating their morphological characteristics and identification by PCR. Different morphotypes of colonies are observed: cottony, regular and starry edge characteristic for Phytophthora spp. Electrophoresis profiles reveal an amplicon of 159 bp for P. palmivora, demonstrating its distribution in the nine zones. The tests on mycelial inhibition in vitro to P. palmivora, determined high levels of antagonism of 78 and 60% by direct confrontation with the rhizobacteria. These results in bio-protection to CCN-51 by applications of P. veronii R4, A. calcoaceticus BMR2-12, S. marcescens PM3-8 and P. protegens CHA0 are effective in the control of P. palmivora strain (BL15), without the application of bacteria the disease progress is evidenced at the level foliar at 15 and 19 dpi with (2.00E + 05) zoospores. The edaphic application of rhizobacteria in CCN-51, the promoter capacity to plant growth and suppression of P. palmivora disease.

La latencia es un bloqueo para la germinación y representa un mecanismo adaptativo que permite a la semilla de papaya retrasar su emergencia. Las rizobacterias mejoran el crecimiento de las plantas de diversas formas, la producción de fitohormonas, la fijación de nitrógeno, la solubilización de fosfatos y aumenta la morfología de las raíces. La presente investigación se realizó para determinar la eficiencia de las rizobacterias (PGPR´s) Pseudomona protegens (CHA0) y Pseudomona putida (BMR 2-4) inoculadas dentro de tres bioformulados para ser evaluadas dentro del porcentaje de germinación, incremento de pelos absorbentes utilizando rizotrones y plántulas bajo consorcios o en combinación de fertilizantes fosforados. En condiciones in-vitro la co-inoculación BIOIMPULSE fue muy eficaz para aumentar el porcentaje de germinación con promedio 80%. En rizotrones se exhibieron mayor aumento de pelos absorbentes de 5,67 mm y área de raicillas 0,86 mm² por BIOIMPULSE comparable al tratamiento expuesto con AIA (25 mg/mL). En plántulas son altamente efectivas para mejorar la morfología de las raíces y altura emendando 5 g/L fosforo se observó dimensiones Ø del hipocótilo entre (5,12 a 4,62 mm) y hojas funcionales (9,75 a 11,75). BIOIMPULSE modifican el funcionamiento de las raíces, mejoran la nutrición de las plantas e influyen en la fisiología vegetativa siendo versátil sobre todos los demás bioformulados por aumentar el porcentaje de germinación, aparición temprana de pelos radicular e incremento radicular en presencia de fertilizantes fosforados. Lo que repercute que pueden ser útiles para reducir el costo de los fertilizantes químicos.

Agricultural productivity in the Ecuadorian Amazon is def icient due to poor soil quality caused by various pollutants. The aim of this study was to identify the agricultural potential of soils in the region of the Ecuadorian Amazon, from variable physicochemical, biological and environmental. The soil samples were taken major agroecosystems. The physicochemical variables were determined by standard techniques. Bacteria (CFU/gr) were determined by counting methodology used in plate. Environmental variables spatial (distance to populated centers) and spectral (normalized dif ference vegetation index NDVI, near infrared NIR, enhanced vegetation index EVI) variables were used for environmental description. From pH, organic carbon and relative saturation (Bases and A+H) the potential fertility indexes (IFP) were def ined. An acid pH was presented in all the soils and percentage of organic matter was lower to 2%. with an average level of A and A+H of 3.7 and 5.7 mEq 100 mL-1. Relations of Ca Mg-1, Mg K-1 and (Ca + Mg) K-1 were 7.7, 10.2 and 83.4. Signif icant direct relationship between pH and Ca and Mg, with correlation coef f icients of 0.67 and 0.80 were observed. IFP average of soil was 0.46, ranging from 0.33 to 0.65. The concentration of Cd and Pb was 0.13 and 59.35 mg kg-1. The bacteria count showed no dif ference; however, two soils showed the highest values ​ (2.64×108 and 2.13×108 UFC). 70% of areas were in agricultural-pasture land use. The lowest variation was observed in the normalized dif ference vegetation index which had an average of 0.77. The central area of the sampling area had high levels of pollutants (Al, Cd, Pb) and the zone of inf luence around these points. It is necessary to implement remediation strategies in the sampling area, to promote agricultural practices.