Effects of Nitrogen Source on Growth and Development of Strawberry Plants

Abstract

An experiment was conducted to study the effects of nitrate (NO − 3 ) and ammonium (NH + 4 ) ratios in nutrient solutions on the growth and production of fruits, runners, and daughter plants of strawberry Fragaria x ananassa Duch., grown in a hydroponic system. Five treatments were applied, consisting of different proportions of NH + 4 and NO − 3 in the nutrient solution. The NH + 4 :NO − 3 ratios were: T0 = 0:4, T1 = 1:3, T2 = 2:2, T3 = 3:1, and T4 = 4:0, at a constant nitrogen (N) concentration of 4 mol m −3 . Growth and morphogenesis were characterized by monitoring leaf-area increase, number of flowers and fruits per plant, and number of daughter plants of first and second generations. Nitrogen and carbon (C) content were measured at the end of the experiment in the organs of both mother and daughter plants. None of the variables related to the growth of the mother plant was affected by the treatments. However, the number of fruits increased with the proportion of NH + 4 in the nutrient solution. The number of daughter plants produced was affected only at high NH + 4 proportions, and their size (dry matter per daughter plant) and fertility (number of second-generation plants per first-generation plants) were reduced. The N or C content of the plants was not significantly affected by the treatments, but the C/N ratio in the crowns of mother plants was higher in treatments with 25% and 50% NH + 4 in the nutrient solution.

Effect of the inoculation with Glomus intraradices and nitrogen fertilization on growth of strawberry plants

“…El nitrógeno (N) es uno de los elementos minerales de mayor demanda en el cultivo de fresa (Taghavi et al, 2004;Bull et al, 2005;Cárdenas-Navarro et al, 2006;Santos y Whidden, 2007), debido a que la calidad y la producción del fruto se ven directamente afectados por la disponibilidad de éste elemento (Bull et al, 2005;Vázquez-Gálvez et al, 2008). Los fertilizantes nitrogenados que se emplean en éste cultivo son en la forma iónica de amonio (NH 4 + ) o nitrato (NO 3 -).…”

“…El NH 4 + es la forma nitrogenada más utilizada, porque es más barata que el NO 3 y presenta una mayor disponibilidad para las plantas al ser retenido por las partículas con cargas negativas del suelo (Taghavi et al, 2004). Además, después de ser absorbido por la planta es directamente asimilado en aminoácidos, mientras que el NO 3 -, después de su absorción, debe pasar por una serie de procesos enzimáticos con alto costo energético para su incorporación en aminoácidos (Miller y Cramer, 2004;Cárdenas-Navarro et al, 2006).…”

Tolerancia de lisianthus (Eustoma grandiflorum (Raf.) Shinn.) a elevadas concentraciones de amonio en la solución nutritiva

“…El mayor peso seco de planta en las dos fases de desarrollo con una relación de 50:50 puede ser debido a una mayor actividad fotosintética, lo que beneficia el crecimiento y rendimiento, como se ha reportado en fresa (Tabatabaei et al, 2006). Sin embargo, las altas concentraciones de NH 4 + redujeron el crecimiento de las plantas (Cárdenas-Navarro et al, 2006), lo cual es un síntoma de toxicidad por NH 4 + . El aumento de la concentración de NH 4 + en la SN estuvo relacionado con un incremento de las concentraciones de los macronutrimentos, a excepción de S, en todos los órganos de la parte aérea de la planta.…”

Runner Production of Strawberry Plants in Soilless Suspended System: Nitrogen Rate, GA3 and Genotype Effects

“…The ability of nitrogen and phosphor assimilation of seven strawberry genotypes was studied by Li et al (2010) and it was reported that higher nitrogen and phosphor acquisition was corresponding to higher runner number (23 runners per mother plant) and ramets (42 ramets per mother plant). Cárdenas-Navarro et al (2006) studied the effects of ammonium/nitrate ratio on strawberry stock plant growth and fruiting in hydroponic system. It was shown that the number of ramets produced per plant was affected only at high NH 4 proportions, and their size (dry matter per ramet) and number of second generation plants were reduced.…”