Growth analysis of Cuba grass OM-22 (Pennisetum purpureum x Pennisetum glaucum) in the dry tropics

Abstract

Objective: To analyze a growth curve of the Cuba OM-22 grass (Pennisetum purpureum x Pennisetum glaucum), to find the optimum harvest time, in the dry tropics.

Design/methodology/approach: The variables were total yield and by leaf and stem component, height of the plant, intercepted radiation, growth rate, weight per stem, leaf: stem ratio and stem population. They were evaluated at 20 day intervals, over a period of 110 days, with the exception of the first sample that was at 30 days. The data were analyzed using the SAS GLM procedure, under an experimental randomized block design, with measures repeated over time, with three repetitions.

Results: The maximum production of total yield and growth rate was reached at 110 days after cutting with 38,600 kg DM ha^-1 and 435 kg DM ha^-1 d^-1, respectively.

Limitations on study/implications: After 70 days, a greater biomass accumulation of biomass is reported, but with a lower quality of structural characteristics. 

Findings/conclusions: The optimal cutting moment of the Cuba OM-22 grass is when it has higher leaf yield in this growth analysis was at 70 days after cutting, reporting a height of 132 cm and intercepted radiation of 95%.