Rashid, M. T., Voroney, P. and Parkin, G. 2005. Predicting nitrogen fertilizer requirements for corn by chlorophyll meter under different N availability conditions. Can. J. Soil Sci. 85: 149–159. Nitrogen management strategies that enhance fertilizer use efficiency and maximize profitability in corn require a rapid and accurate method to determine the crop N needs of current hybrids. The object...

The effect of temperature and light intensity have been studied in relation to the greening of etiolated corn (Zea mays cv. Pioneer 309-B) seedlings. Chlorophyll accumulation is rapid at high temperature (28 degrees ) under all conditions of light intensity. At low temperature (16 degrees ), and particularly in combination with high light intensity (3000-4500 ft-c), the accumulation of both chl...

-In this study, impacts of vector quantization compression on prediction of leaf chlorophyll content of crops for the application to precision agriculture were evaluated. The compression algorithm tested in this paper is called successive approximation multi-stage vector quantization (SAMVQ). The hyperspectral data used were acquired by CASI over corn fields at L’ Acadie experimental farm (Agri...

A two-year field experiment was carried out to investigate the effects of nitrogen, composted manure, municipal waste compost, and weeds on yield and photosynthetic characteristics of corn. Experimental design was split split plot factorial with 3 replications. Main plots were weedy and weed-free, sub plots were nitrogen fertilizer levels [0 (N0) and 200 (N200) kg N ha -1 as urea], and sub sub ...

Variable fertilization for crops, like corn, depends on monitoring nutrition condition. Thus, hyperspectral reflectance was used to predict chlorophyll and total nitrogen content under different N,K treatments during corn growth. The area of the experimental field was divided into 3 strips with different nitrogen treatment (N1:0 kg/ha–low, N2:314 kg/ha–normal, and N3:653 kg/ha–high). In each st...

Studies were conducted to determine the effects of spent reagent from air pollution control scrubbers used at a brick manufacturing facility on emergence, growth, and physiological responses of corn and hybrid poplar plants. Scrubber by-product was obtained from General Shale Brick, Louisville, KY. Potting substrate was weighed and quantities of scrubber by-product were added to the substrate t...

A split-plot experimental study was conducted to evaluate the effect of different shade stresses on photosynthesis and chlorophyll fluorescence of maize leaves.The experiment was designed on the south farm of Special Corn Institute, Shenyang Agricultural University, China.Data was collected from the day maize tasseled (Jul. 21) to the beginning of grouting (Aug.12 ) under 18%, 28%, 38%, 60%, an...

Under natural sunlight illumination, the chlorophyll fluorescence emitted by the vegetation represents less than 3% of the reflected light in the near infrared part of the spectrum. This small amount is difficult to quantify except at certain wavelengths, where the solar spectrum is attenuated (Fraunhofer lines). An instrument measuring the in-filling of the atmospheric oxygen absorption band a...