The objective of this experiment was to determine the effects of foliage water extracts of purple nutsedge ( Cyperus rotundus L.) on seed germination and seedling growth of corn ( Cyperus rotundus L . ) o n s e e d g e r m i n a t i o n a n d s e e d l i n g g r o w t h o f c o r n ( Cyperus rotundus Zea mays L.) cv. Pioneer 3031. An extract was prepared with nutsedge foliage of 15 days at 15% w/v and for dilution, extracts of 2, 4 and 6% w/v were prepared, pH and electric conductivity (S.cm -1 ) were determined. Distilled water was uses as a control. Twenty seeds were sowed in a double layer of absorbent paper on trays, covered with two leaves of absorbent paper and they were watered three times per day using foliage extracts. A randomized complete block design was used with four extract concentrations (0, 2, 4 y 6% w/v) and fi ve replications. The traits were determined twelve days aft...

La investigación tuvo por fi nalidad determinar los efectos de extractos acuosos del follaje de Cyperus rotundus L. sobre la germinación de semillas y el crecimiento de plántulas de maíz ( Zea mays L.) cv. Pioneer 3031. Un primer extracto al 15% p/v fue preparado con el follaje de plantas mays L.) cv . Pioneer 3031. Un primer extracto al 15% p/v fue preparado con el follaje de plantas mays de C. rotundus de 15 días, se dejó reposar por 48 h y luego se obtuvo por dilución extractos al 0; 2,0; 4,0 y 6,0% p/v evaluándoseles pH y conductividad eléctrica (S.cm -1 ). Para la siembra se utilizaron bandejas cubiertas con una doble capa de papel absorbente sobre la que se colocó 20 semillas/bandeja, tapadas con dos hojas más de papel y regadas tres veces al día con los extrac- tos foliares. El tratamiento control recibió agua corriente. El diseño estadístico fue bloques al azar con...

Corn (Zea mayz L.) seeds of twelve lots of different acquisition years were used to study the relation among the measurements of electrical conductivity (EC) and pH of the soaking water and the germination in laboratory, under normal conditions (NC) and accelerated aging (AA) of seeds. A randomized complete block design was used with four replications, an analysis of variance was applied and differences among seed lots were detected by Least Significant Difference Test. Seed lots showed high percentage of germination at eight days of evaluation in (NC) and the unfavorable effect of AA was demonstrated. Dry shoot and radicle weights showed significant differences among the lots. Values of EC were related to percentage of germination in laboratory under AA. Seed lots that showed high percentage of germination in laboratory, previous AA, presented low values of electrical conductivity, ther...

Some chemical compounds released by plants can to control the presence of other plants in their environment both of their own species and different ones, allelopathy is an important factor in regulating the structure of plant communities, a better understanding of these relationships is critical for appropriate agricultural development. The objective was to determine the effects of aqueous extracts of leaves of tree marigold (Tithonia diversifolia) on seed germination and seedling growth of lettuce (Lactuca sativa L.) cultivar Parris Island. A 15% w/v extract was prepared with leaves of tree marigold gold, it was allowed to stand for 48 h. After, diluting extracts at 0.5, 1.0, 1.5 and 2.0% w/v were obtained and pH and electrical conductivity (S.cm-1 ) were determined. Sowing was carried out in trays covered with a double layer of absorbent paper on which were placed 25 seeds/tray. Irriga...

Corn (Zea mayz L.) seeds of twelve lots of different acquisition years were used to study the relation among the measurements of electrical conductivity (EC) and pH of the soaking water and the germination in laboratory, under normal conditions (NC) and accelerated aging (AA) of seeds. A randomized complete block design was used with four replications, an analysis of variance was applied and differences among seed lots were detected by Least Significant Difference Test. Seed lots showed high percentage of germination at eight days of evaluation in (NC) and the unfavorable effect of AA was demonstrated. Dry shoot and radicle weights showed significant differences among the lots. Values of EC were related to percentage of germination in laboratory under AA. Seed lots that showed high percentage of germination in laboratory, previous AA, presented low values of electrical conductivity, ther...

Some chemical compounds released by plants can to control the presence of other plants in their environment both of their own species and different ones, allelopathy is an important factor in regulating the structure of plant communities, a better understanding of these relationships is critical for appropriate agricultural development. The objective was to determine the effects of aqueous extracts of leaves of tree marigold (Tithonia diversifolia) on seed germination and seedling growth of lettuce (Lactuca sativa L.) cultivar Parris Island. A 15% w/v extract was prepared with leaves of tree marigold gold, it was allowed to stand for 48 h. After, diluting extracts at 0.5, 1.0, 1.5 and 2.0% w/v were obtained and pH and electrical conductivity (S.cm-1 ) were determined. Sowing was carried out in trays covered with a double layer of absorbent paper on which were placed 25 seeds/tray. Irriga...