Doses de boro no desenvolvimento de copo-de-leite em solução nutritiva

Abstract

RESUMOO boro desempenha funções importantes em processos biológicos das plantas, como a síntese e estruturação da parede celular, lignificação, metabolismo e transporte de carboidratos, além de participar da divisão e diferenciação celular em tecidos meristemáticos. No entanto, as necessidades nutricionais para o cultivo de copo-de-leite, especialmente de boro, ainda são pouco conhecidas. Assim, objetivou-se avaliar os efeitos de diferentes doses de boro no crescimento e desenvolvimento, teor e acúmulo desse nutriente em plantas de copo-de-leite cultivadas em solução nutritiva. Mudas micropropagadas foram submetidas aos tratamentos com as doses de 0,05; 0,25; 0,50; 0,75; 1,00 e 2,00 mg L -1 de boro em solução nutritiva de Hoagland & Arnon diluída a 30% de sua força iônica. O delineamento experimental foi o inteiramente casualizado, com dez repetições. As plantas não manifestaram sintomas visuais de deficiência ou de toxidez de boro, no entanto, o sistema radicular das plantas cultivadas na dose de 0,05 mg L -1 de boro apresentou-se com o crescimento reduzido. A melhor dose para o desenvolvimento adequado de plantas de copo-de-leite em solução nutritiva é de 1,20 mg L -1 de boro. Termos para indexação:Zantedeschia aethiopica (L.) Spreng, micronutrientes, flor de corte. ABSTRACTBoron has essential functions in plant biological processes such as cell wall synthesis and structuralization, lignification, carbohydrates metabolism and transport. This element also acts in cell division and differentiation in meristematic tissues. However, the nutritional needs for calla lily cultivation, and especially boron needs, are still poorly known. Thus, the objective of this work was to evaluate the effects of different boron doses on growth and development, content and accumulation of boron in calla lily plants grown in a nutrient solution. Micropropagated seedlings were submitted to treatments with the doses 0.05; 0.25; 0.50; 0.75; 1.00 and 2.00 mg L -1 boron in Hoagland & Arnon nutrient solution diluted to 30% of its ionic force. The experimental design used was completely randomized blocks with ten replicates. Plants showed no visual deficiency or toxicity symptoms, however, the root system of plants cultivated in 0.05 mg L -1 boron showed reduced growth. The best development of calla lily plants was observed in 1.20 mg L -1 boron in nutrient solution. INTRODUÇÃORecomendações sobre o manejo da nutrição e adubação para o cultivo de copo-de-leite, ainda são bastante escassas, o que tem ocasionado o uso inadequado de fertilizantes, os quais têm sido aplicados em quantidades elevadas (Silberbush & Lieth, 2004) ou reduzidas, comprometendo o bom desenvolvimento e a produtividade da espécie.Nutrientes essenciais devem estar prontamente disponíveis, uma vez que possuem funções indispensáveis para o adequado crescimento e desenvolvimento das plantas. Dentre esses, o boro está envolvido em muitos dos processos fisiológicos das plantas, como a síntese e estruturação da parede celular, lignificação, metabolismo e transporte de carboid...

Development and dry mass accumulation in callalily at the initial cultivation stage

“…The final value differs from the observations of Almeida (2007) and Souza (2010), who observed in calla lily cultivation in nutrient solution, average heights of 44.57 cm at 210 days and 17.88 cm after 360 days, respectively. This difference can be attributed to the different origin of plants that gave origin to explants for micropropagation of seedlings.…”

“…The highest total dry mass production was observed at 210 days, on average 131.71 g plant -1 (Figure 8). The dry mass accumulated in the plants was higher compared to that reported by Souza (2010) which, at 210 days after transplantation, obtained an average of 29.6 g plant -1 . The highest accumulation rate occurred in the period between 180 and 210 days, when the increment observed was 1.24 g day -1 .…”

“…Comparatively, Souza (2010) A constant increase in the fresh mass of flower stalks was observed, corresponding to the number of days after planting. At 210 days, 102.76 g / flower stalk, with an increment of 15.60 g on average per month (Figure 11) was recorded.…”

“…At 210 days, spathes had 16.55 cm in length and 14.92 cm in width, on average, featuring large-size flowers and with excellent market potential, although there is no defined quality standard for the marketing of this species (ALMEIDA et al, 2008;ALMEIDA et al, 2009). Souza (2010), growing The production of leaves increased up to 210 days of cultivation, as well as its dimensions, up to 90 days, stabilizing after this period.…”

“…Analyzing the average number of flowers per plant, no significant difference between the evaluation months was observed; however, plants bloom more than once over the study period (Table 2). Souza (2010), growing calla lily in nutrient solution, obtained the issue of 1.24 flower stalks, on average, per plant, within a period of 210 days and Almeida (2007) observed the average issue of 3 stalks per plant over a period of 12 months. However, despite the higher production of flower stalks, the issue of only 2.67 flower stalks per plant was observed.…”