Relationship of red and red-edge reflectance-based vegetation indices with stalk and fiber yield of energy cane harvested at different dates

ABSTRACT

The application of remote-sensing technology is relatively new and limited in energy cane (Saccharum spp.) production in Louisiana. This study was conducted at LSU AgCenter Sugar Research Station in St. Gabriel, Louisiana, from 2013 to 2015, to evaluate the relationship of spectral reflectance readings with stalk, nitrogen (N) uptake and fiber yield of energy cane harvested at different dates and to identify vegetation indices (VIs) that can be used for stalk and fiber yield prediction. Treatments included variety (Ho 02-113, US 72-114), N rate (0, 56, 112 and 224 kg N ha⁻¹) and harvest dates arranged in split–split plot in a randomized complete block design with four replications. Canopy reflectance readings were collected from nine spots per plot using Jaz® hyperspectral spectrometer from 3 to 16 weeks after N application. Stalk yield for different harvest dates was estimated based on 15-stalk sampling or plot harvesting. The Pearson correlation analysis showed a strong dependence between VIs (computed from reflectance readings at 670 and 705 nm) and stalk yield, N uptake and fiber yield across cane age, demonstrating the potential use of optical remote sensing in energy cane stalk and fiber yield prediction.

KEYWORDS:

• Yield estimation
• energy cane
• vegetation indices
• fiber yield

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the USDA-NIFA-AFRI and published with the approval of the Director of the Louisiana Agricultural Experiment Station with Publ. no. 2018-306-31785.