Ismene amancaes “amancay” is a bulbose species typical of the central coast vegetation of Peru called “lomas”. This species sprouts in June during the beginning of the winter-fog period. It has large yellow, aromatic flowers valued for their ornamental value. Our goal was to examine the reproductive development of Ismene amancaes in its natural environment, and we recorded monthly observations during a yearlong study. Observations of the interior of the bulbs allowed recording of the beginning of floral bud formation and development, relating them to leaf formation and edaphic humidity. We found that the first floral buds develop the year before their emergence in December, reaching a maximum number of floral buds in February, during the Summer. Floral bud differentiation starts after leaves that will emerge the following year have developed. This occurs during a period of maximu...

Lepidium meyenii Walp. (Brasicaceae) “maca” is an Andean plant appreciated for its hypocotil which has high medical and nutritional value, and among these, its high iron content. In order to test the possibility of increasing the iron content, an experiment was carried out at greenhouse conditions in Lima, Peru, from May to November 1999, in which solutions containing three levels of natural iron (5, 15 and 25 ppm) were used to grow maca. Seeds of accession ARB5441 (CIP) were used. The iron content was measured after 50 and 179 days of treatment (dat) by the phenantroline method. Meaningful differences were found in the iron content in leaves and the hypocotil after 50 dat, which increased with the concentration of iron in the solutions, whereas at 179 this trend was noticed only for leaves. The concentration of iron in the hypocotil for each treatment do not increase in time whereas...

Puya raimondii Harms is an endemic especie of the highlands of Peru and Bolivia, whose population and area of distribution are being reduced. Aiming at contributing to the knowledge of the mechanisms of propagation of this species, a study of the effects of the illumination and stratification on the germination of the seed was carried out. The seed was collected in the rodal of Puya raimondii in Huashta Cruz (Pueblo Libre, Ancash) in December 1999 and were stored under laboratory conditions in Lima until the tests. The seeds were desinfected with sodium hipochloride 2,6% and for the germination test seeds were placed in petri dishes with distilled and sterilized water during 2000. The preliminary results show that the seed of Puya raimondii has a high percentage and velocity of germination when exposed to light. A similar effect was achieved by stratifying them for two months at 11 °C o...

Ismene amancaes “amancay” is a bulbose species typical of the central coast vegetation of Peru called “lomas”. This species sprouts in June during the beginning of the winter-fog period. It has large yellow, aromatic flowers valued for their ornamental value. Our goal was to examine the reproductive development of Ismene amancaes in its natural environment, and we recorded monthly observations during a yearlong study. Observations of the interior of the bulbs allowed recording of the beginning of floral bud formation and development, relating them to leaf formation and edaphic humidity. We found that the first floral buds develop the year before their emergence in December, reaching a maximum number of floral buds in February, during the Summer. Floral bud differentiation starts after leaves that will emerge the following year have developed. This occurs during a period of maximu...

Lepidium meyenii Walp. (Brasicaceae) “maca” is an Andean plant appreciated for its hypocotil which has high medical and nutritional value, and among these, its high iron content. In order to test the possibility of increasing the iron content, an experiment was carried out at greenhouse conditions in Lima, Peru, from May to November 1999, in which solutions containing three levels of natural iron (5, 15 and 25 ppm) were used to grow maca. Seeds of accession ARB5441 (CIP) were used. The iron content was measured after 50 and 179 days of treatment (dat) by the phenantroline method. Meaningful differences were found in the iron content in leaves and the hypocotil after 50 dat, which increased with the concentration of iron in the solutions, whereas at 179 this trend was noticed only for leaves. The concentration of iron in the hypocotil for each treatment do not increase in time whereas...

Puya raimondii Harms is an endemic especie of the highlands of Peru and Bolivia, whose population and area of distribution are being reduced. Aiming at contributing to the knowledge of the mechanisms of propagation of this species, a study of the effects of the illumination and stratification on the germination of the seed was carried out. The seed was collected in the rodal of Puya raimondii in Huashta Cruz (Pueblo Libre, Ancash) in December 1999 and were stored under laboratory conditions in Lima until the tests. The seeds were desinfected with sodium hipochloride 2,6% and for the germination test seeds were placed in petri dishes with distilled and sterilized water during 2000. The preliminary results show that the seed of Puya raimondii has a high percentage and velocity of germination when exposed to light. A similar effect was achieved by stratifying them for two months at 11 °C o...

Puya raimondii Harms (Bromeliaceae) is a monocarpic plant, that can produce about 6 to 12 million seeds, nevertheless is very rare to find seedlings in their natural habitat, indicating difficulties for its establishment. In this work, the conditions for establishment of P. raimondii under laboratory conditions were determined carrying out experiments to determine the better substrate. It was compared the survival and vigour of P. raimondii seedling that were transplanted in peat, moss, peat-soil and moss-soil substrates. The peat substrate showed high survival and was better for establishment of seedlings because it maintains steady and suitable humidity and pH conditions, this allowed that seedlings presents a good vigour. Substrates with very little (case peat-earth) or too much (case moss) humidity retention had a negative effect over vigour and development.

Lemna gibba was grown in outdoor to determine the effect of three N-NH4 + :N-NO3 - proportions (1:3, 1:1 and 3:1), as well as the phosphorus (1,5; 3,0 and 4,5 mg.L-1) and potassium (3,0; 6,0 and 9,0 mg.L-1) concentrations added to the culture medium, on the yield and nitrogen, phosphorus and potassium content. Both, fresh and dry weight yields decreased as N-NH4 + proportion increased. Increasing culture medium potassium concentration favored the fresh weight yield. Dry matter content decreased with both N-NH4 + proportions higher than N-NO3 - and increasing the potassium concentration in the culture medium. Nitrogen uptake and content enhanced with high N-NH4 + proportions; and, by increasing phosphorus and potassium concentrations in the culture medium. Phosphorus and potassium uptake and content increased as their respective culture medium concentration increased. High proportions of ...

To determine the optimum nutritive solutions for strawberry, Fragaria x ananassa, Duchesne cv. Chandler under a system that uses fine gravel was evaluated two nutritive solutions formulas during vegetative period and three during the fructification period of de plant from December 1996 to August 1997. Destructive samplings were done at 60, 90, 160 and 220 days after treatment to evaluate the growth of the plant, absortion ot nutrients and the reducing sugar content in the fruit. No significant differences were tound between treatments in the vegetative period but there were in the reproductive's for the plant's height, flower and fruit number and percent of reducing sugar of the fruit and its weight. Neither there were significative differences in N, P, K, Ca, Mg and Fe percentages. Combinations of 200:40:300 ppm of NRK in the reproductive period give the best plant yield.

The beginning of humidity months in the "lomas" is in June, in normal climatic conditions. The bulblet species Ismene amanea es is one of the first in germinate in relation to others herbaceous species, that is the reason it is considered an indicator of the beginning of humidity in the "lomas". The present work achieved in National Reserve of Lachay, Prov. Huaura, Dpto. Lima, present records among July of 1997 and May of 1998. The periodic evaluation in situ of seedlings let to determine the foliage area variation, number of leaves, diameter and high ofthe bulb neck. Also, it was quantified the soil humidity. The cycle phase was registered in adult plants. A relation of humid months delay in "lomas" (August of 1997) and its last until 1998, was made. The fluctuating temperature and humidíty recorded during "El Niño" had a consequence in rapídly development of specimens. The seedlings...

Puya raimondii Harms (Bromeliaceae) es una planta monocárpica que puede producir entre 6 y 12 millones de semillas, sin embargo es muy raro encontrar plántulas en su hábitat natural, lo que significaría la existencia de factores limitantes en el proceso de establecimiento. En el presente trabajo muestra los resultados de experimentos para determinar el sustrato más adecuado para el establecimiento de P. raimondii bajo condiciones de laboratorio. Se comparó la sobrevivencia y vigor de plántulas de P. raimondii en los substratos de turba, musgo, turba-tierra y musgo-tierra. El sustrato turba presentó la mayor supervivencia, mostrando que es el más adecuado para el establecimiento de las plántulas, porque mantiene una humedad adecuada y pH estable lo que permitiría que las plántulas presenten un mayor vigor; los sustratos con muy poca (caso turba–tierra) o demasiada (caso musg...

Lemna gibba was grown in outdoor to determine the effect of three N-NH4 + :N-NO3 - proportions (1:3, 1:1 and 3:1), as well as the phosphorus (1,5; 3,0 and 4,5 mg.L-1) and potassium (3,0; 6,0 and 9,0 mg.L-1) concentrations added to the culture medium, on the yield and nitrogen, phosphorus and potassium content. Both, fresh and dry weight yields decreased as N-NH4 + proportion increased. Increasing culture medium potassium concentration favored the fresh weight yield. Dry matter content decreased with both N-NH4 + proportions higher than N-NO3 - and increasing the potassium concentration in the culture medium. Nitrogen uptake and content enhanced with high N-NH4 + proportions; and, by increasing phosphorus and potassium concentrations in the culture medium. Phosphorus and potassium uptake and content increased as their respective culture medium concentration increased. High proportions of ...

To determine the optimum nutritive solutions for strawberry, Fragaria x ananassa, Duchesne cv. Chandler under a system that uses fine gravel was evaluated two nutritive solutions formulas during vegetative period and three during the fructification period of de plant from December 1996 to August 1997. Destructive samplings were done at 60, 90, 160 and 220 days after treatment to evaluate the growth of the plant, absortion ot nutrients and the reducing sugar content in the fruit. No significant differences were tound between treatments in the vegetative period but there were in the reproductive's for the plant's height, flower and fruit number and percent of reducing sugar of the fruit and its weight. Neither there were significative differences in N, P, K, Ca, Mg and Fe percentages. Combinations of 200:40:300 ppm of NRK in the reproductive period give the best plant yield.

En años de condiciones climatológicas normales el inicio de los meses de humedad en las lomas es en junio; la especie bulbifera Ismene amaneaes "amancaes" es una de las primeras en rebrotar en relación a otras herbáceas, por lo que resulta ser una indicadora del inicio de la humedad en las lomas. El presente estudio realizado en la Reserva Nacional de Lachay, Prov. Huaura, Opto. Lima, presenta datos de los registros realizados entre julio 1997 y mayo 1998. Las evaluaciones periódicas in sítu de plantas juveniles permitieron determinar la variación del área foliar, número de hojas, diámetro y altura del cuello del bulbo, asimismo, se cuantificó la humedad del suelo. En las plantas adultas se registró las etapas de su ciclo. Los resultados obtenidos fueron relacionados con el retraso de los meses húmedos de "lomas" (agosto 97) y su duración hasta 1998. La temperatura y humeda...

En la región altoandina de Ancash la mayor diversidad de flores ornitófilas se encuentran en ambientes de matorral, en contraste a roquedales y pajonales, en los que encontramos rodales de bromelias del género Puya, cuyo néctar podría constituir un importante recurso para picaflores altoandinos en estos tipos de ambiente. Para documentar esta hipótesis, entre el 2004 y el 2005 se realizaron un total de 264 horas de observación de picaflores de dos rodales de Puya, ubicados encima de los 3000 m de altitud. El primer rodal fue de Puya raimondiien un pajonal del Parque Nacional Huascarán (9º39’ S—77º13’ W), el segundo fue de Puya rauhii en roquedales del Callejón de Conchucos (8º10’ S—77º52’ W). La frecuencia de visita de los picaflores a las inflorescencias de Puyafue evaluada desde 10 puntos fijos de observación, además capturas con redes de niebla permitieron i...

Puya raimondii Harms is an endemic species of the highlands of Peru and Bolivia between 3200 to 4800 m of altitude with noticeable great size and beauty. It is considered threatened species; therefore it is urgent to know the factors that affect its viability and germination of their seeds; aspects focused work presently. The seeds were collected in 1999 and 2000 in Huashta Cruz (Pueblo Libre, Ancash, Peru) and they classified as lots (considering their origin and appearance). They were determined their moisture content and the viability (quality). By means of germination tests, it was evaluated in 5 lots the effect of the light and temperature. The seeds presented different viability which depended on the conditions they were exposed in situ and that it is correlated inversely with its content of humidity, affecting its appearance inclusive. The seeds exposed to the light presented high...

Krapfia weberbaueriStandl. & J. F. Macbr. is an endemic species from Peru, categorized as vulnerable, and distributed in the departments of Ancash, Huanuco, Junin and San Martin. This work reports the reproductive development of the species under controlled conditions of light and temperature (12 hours light/12 hours darkness, 12 °C during light hrs and 8 °C during dark hrs). Entire plants at reproductive stage were collected at Cordillera Blanca (Ancash), where it is found forming patches, at an elevation of 4200 to 4800 m. The species has large and showy flowers, which from anthesis to the onset of senescence remain responsive, however at a greater extent in the mature flower, stage at which the dehiscence of stamens and release of pollen grains reaches 100%. This period lasts a total of 13 days. Nectar production begins when the flower matures and continues until the total senes...

En la región altoandina de Ancash la mayor diversidad de flores ornitófilas se encuentran en ambientes de matorral, en contraste a roquedales y pajonales, en los que encontramos rodales de bromelias del género Puya, cuyo néctar podría constituir un importante recurso para picaflores altoandinos en estos tipos de ambiente. Para documentar esta hipótesis, entre el 2004 y el 2005 se realizaron un total de 264 horas de observación de picaflores de dos rodales de Puya, ubicados encima de los 3000 m de altitud. El primer rodal fue de Puya raimondiien un pajonal del Parque Nacional Huascarán (9º39’ S—77º13’ W), el segundo fue de Puya rauhii en roquedales del Callejón de Conchucos (8º10’ S—77º52’ W). La frecuencia de visita de los picaflores a las inflorescencias de Puyafue evaluada desde 10 puntos fijos de observación, además capturas con redes de niebla permitieron i...

Puya raimondii Harms is an endemic species of the highlands of Peru and Bolivia between 3200 to 4800 m of altitude with noticeable great size and beauty. It is considered threatened species; therefore it is urgent to know the factors that affect its viability and germination of their seeds; aspects focused work presently. The seeds were collected in 1999 and 2000 in Huashta Cruz (Pueblo Libre, Ancash, Peru) and they classified as lots (considering their origin and appearance). They were determined their moisture content and the viability (quality). By means of germination tests, it was evaluated in 5 lots the effect of the light and temperature. The seeds presented different viability which depended on the conditions they were exposed in situ and that it is correlated inversely with its content of humidity, affecting its appearance inclusive. The seeds exposed to the light presented high...

Krapfia weberbaueriStandl. & J. F. Macbr. is an endemic species from Peru, categorized as vulnerable, and distributed in the departments of Ancash, Huanuco, Junin and San Martin. This work reports the reproductive development of the species under controlled conditions of light and temperature (12 hours light/12 hours darkness, 12 °C during light hrs and 8 °C during dark hrs). Entire plants at reproductive stage were collected at Cordillera Blanca (Ancash), where it is found forming patches, at an elevation of 4200 to 4800 m. The species has large and showy flowers, which from anthesis to the onset of senescence remain responsive, however at a greater extent in the mature flower, stage at which the dehiscence of stamens and release of pollen grains reaches 100%. This period lasts a total of 13 days. Nectar production begins when the flower matures and continues until the total senes...