Produção e qualidade de propágulos de morangueiro em diferentes concentrações de nitrogênio no cultivo sem solo

Abstract

Production and quality of strawberry transplants in different nitrogen concentrations in soilless growing systemThe objective of this work was to evaluate the effects of nitrogen concentration on the production and quality of strawberry bare root transplants and runner tips in soilless growing system. Stock plants were planted on September 13 th , 2007. Transplants were harvested on February 18 th , 2008. Nitrogen concentrations of 8, 11, 14 and 17 mmol L -1 in the nutrient solution were evaluated. The experiment was arranged in a complete randomized design with five replications of 3.6m 2 plots. Number and crown diameter of bare root transplants and number of runner tips were evaluated at harvest. Number of bare root transplants and runner tips was not affected by N concentration in the nutrient solution. An average of 339 bare root transplants and 836 runner tips were harvest per stock plant. Increasing 1 mmol of N concentration of the nutrient solution decreases the crown diameter of bare root transplants in 0.4mm. In the soilless grown system with sand as substrate, the N concentration does not affect the production of bare root transplants and runner tips, but do affect crown diameter of strawberry bare root transplants.

Nitrogen for growth of stock plants and production of strawberry runner tips

“…In this study, only first order runner tips bearing one expanded leaf were collected and its crown diameter was higher than that reported by Oliveira et al (2010) and Giménez et al (2008). These authors used a growing sand bed for simultaneously producing bare root transplants on the bed surface and runner tips on suspended stolons growing downward between beds.…”

“…Present results agree with Durner et al (2002), to whom runner tips collected in weekly intervals are bigger and lead to more uniform transplants. According Oliveira et al (2010) , no difference was found in emission of runner tips at N concentrations from 8 to 17 mmol L -1 and it was attributed to competition for assimilates between plant and runner tip growth, as final plant density by mother and daughter plants on the bed surface reached 339 plants m -2 . In the present experiment, plant density was of 12 plants m -2 and stolons were not kept to grow, as a way to reduce such competition.…”

“…In the wild species Fragaria chiloensis, N increased runner emission and reduced stolon length, but this effect was genotype dependent (Tworkoski et al, 2001). In Santa Maria, RS, Brazil, Oliveira et al (2010) didn´t observe any effect of N concentration on production of bare root transplants in a growing sand bed. They attributed such result to competition for radiation among plants on the bed and/or for carbon assimilate among plant organs.…”

Deficiência De Nutrientes Com Efeitos No Desenvolvimento De Morangueiros

“…Em relação à massa seca de raiz, observou-se maiores reduções com a omissão dos macronutrientes (P, K, N, Ca e Mg). O fato do N reduzir a massa da raiz já era esperado, pois esse elemento é requerido em grande quantidade pelas culturas agrícolas e é o mais limitante para o crescimento e desenvolvimento das plantas (OLIVEIRA et al, 2010). O Mg tem como função ativar ou reguladar várias quinases, ATPases, carboxilase/oxigenase RuBP e outras enzimas do metabolismo de carboidratos (MARSCHNER, 2012) e dessa forma, a falta deste nutriente pode causar a redução do crescimento das raízes (YANG et al, 2013;CAKMAK, 2013).…”

“…O morangueiro (Fragaria x ananassa Duch.) é uma espécie cultivada em todo o mundo e a área de produção aumenta a cada ano (PALENCIA et al, 2010), em razão de ser uma fruta apreciada pelos consumidores, devido a coloração, aroma, sabor (GIMÉNEZ et al, 2008) e por ser considerada fonte de vitaminas e minerais (SINGH et al, 2010). No Brasil a área de produção é de aproximadamente 4 mil hectares e 120 mil toneladas de frutas (KIRSCHBAUM et al, 2017).…”