Resumen

GONZALEZ, F.A; VENTIMIGLIA, P; JOUVE, V.V  y  FERRI, C.M. Desarrollo morfológico de Digitaria eriantha Steud. ssp. eriantha y Panicum coloratum L. var. Coloratum. RIA. Rev. investig. agropecu. [online]. 2018, vol.44, n.2, pp.96-104. ISSN 1669-2314.

The measurement of pasture morphological development is critical to the purpose of implementing management practices. The objective was to quantify the mean stage of morphological development, to analyze its variation through thermal time and to establish the relationship between mean stage of development and green leaf blade proportion of digitgrass (Digitaria eriantha Steud.) and kleingrass (Panicum coloratum L.). In early October, three plots of 3.0 × 6.0 m were marked on a pasture of digitgrass, and another one of kleingrass, for ground-level cutting of 30 tillers per plot selected at random, every seven days during a period of 16 weeks of canopy growing season. Mean stage by weight (MSW), mean stage by count (MSC) and green leaf blade proportion were determined. Data were analyzed using linear regression and mixed linear models for repeated measurements. The MSW and MSC indexes, in digitaria and kleingrass, were highly related (p<0.01). The duration of the vegetative period was about 250 degree days (base 10 ºC) longer in digitgrass than in kleingrass, although they attained the reproductive stage at the same time. The MSW was a better predictor of green leaf blade proportion than MSC, with a higher R2 (0.89 vs. 0.83) and a lower root mean square error. Both MSW and MSC indexes allowed describing the mean morphological developmental stage and predicting green leaf blade proportion of digitgrass and kleingrass.

Palabras clave : Leaf blade proportion; Maturity; Morphology; Warm-season grasses.

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