Avalia o de caracter赤sticas fisiol車gicas de cinco cultivares de Cynodon = Evaluation of physiological characteristics in five Cynodon cultivars

作者：Luis Roberto de Andrade Rodrigues; Teresinha de Jesus Deleo Rodrigues; Ricardo Andrade Reis; Cecilio Viega Soares Filho

来源：Acta Scientiarum - Animal Sciences, 2006.

• clorofila
• indice de area foliar
• taxa de crescimento
• graminea
• chlorophyll
• leaf area index
• growth rate
• grass

O experimento foi conduzido na Faculdade de Ci那ncias Agr芍rias e Veterin芍rias, Unesp, Campus de Jaboticabal, Estado de S o Paulo. Os tratamentos consistiram na avalia o de cinco cultivares de Cynodon, em onze idades de corte, para estudo das caracter赤sticas fisiol車gicas. O delineamento estat赤stico adotado foi o inteiramente casualizado em parcelas subdivididas, com tr那s repeti es, considerando-se nas parcelas os cultivares (C) e nas subparcelas as idades de corte (I). Foram avaliadas a taxa de crescimento relativo (TCR), o 赤ndice de 芍rea foliar (IAF), a raz o de peso foliar (RPF) e teor de clorofila. A TCR foi semelhante entre os cultivares, variando com a idade das plantas. Os cultivares Florona, Florakirk e Tifton 68 apresentaram os maiores valores m谷dios de 芍rea foliar, sendo que oTifton 68 proporcionou o mais elevado IAF (P%26lt;0,05), n o diferindo dos Tifton 85 e Florico. O cultivar Tifton 85 apresentou o maior valor de RPF. O teor de clorofila n o foi limitante para o crescimento das plantas. De acordo com as caracter赤sticas fisiol車gicas estudadas, oscultivares de Cynodon podem ser melhor manejados durante o per赤odo de 28 dias de crescimento. The experiment was carried out at Ci那ncias Agr芍rias e Veterin芍rias Faculty, UNESP, Jaboticabal, S o Paulo State, in order to evaluate five Cynodon cultivars. The plants, sampled once a week, were from 14 to 84 days, and the study focused on their physiological characteristics. A random design with split plot was adopted with three replications, considering cultivars as plot and cutting age as split plot. The following variables were studied: relative growth rate, specific leaf area, LAI, leaf weight/total dry matter ratio and chlorophyll contents. The relative growth rates were similar for the five cultivars studied, varying with the age of the plants. The cultivar Tifton 85 showed the highest values for leaf weight/total dry matter ratio and leaf area. The cultivars Tifton 68, Tifton 85 and Florico showed the highest LAI and values did not differ among each other. Chlorophyll content did not limit plant growth. Dataobtained allowed us to conclude that the five cultivars would be better managed during 28 days of plant growth.