Abstract

RUIZ SALAZAR, José Guadalupe et al. Vegetation index to estimate the growth of tomato plants (Lycopersicon esculentum Mill.) stressed by water and nitrogen deficiencies. Terra Latinoam [online]. 2011, vol.29, n.1, pp.47-56. ISSN 2395-8030.

Three vegetation indexes (VI) were proposed and evaluated: total chlorophyll (TCL); middle infrared with near infrared (MIRNIR) relationship, and near infrared with blue (NIRB), based in the blue, green, red, near infrared and middle infrared spectral bands with the goal of estimating the growth of Big River variety tomato plants, stressed by water and nitrogen deficiency, using remote perception. The evaluation was conducted in greenhouse conditions in function of their ability to estimate changes in growth indicators (WI): leaf area index and dry matter of aerial part, in eight sampling date. Both WI, were satisfactorily estimated by all VI considered, from the first to the fourth sampling date, 36 days after transplanting. Afterwards, the magnitude of reflectance data practically did not change nor did the VI formulated with these bands (TCL and NIRB). This reduced its predictive value in the following sampling. The MIRNIR Index was the best for estimating the WI, because it was formulated with bands from the infrared spectrum which reach saturation slower than the visible spectrum. It was also better than the normalized difference vegetation index NDVI, used as a reference.

Keywords : spectral reflectance; fertigation; greenhouse.

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