Nitrogen fertilizer continues to be the major input influencing corn (Zea mays L.) yield in the Midwest. Improved N recommendations should result in greater N use efficiency and producer profit while reducing surface and groundwater contamination. This study was conducted to develop a plant-based technique to detect and correct N deficiencies during the season. Chlorophyll meter readings and gr...

Rapid and non-destructive diagnostic tools to accurately assess crop nitrogen nutrition index (NNI) are imperative for improving crop nitrogen (N) diagnosis and sustaining crop production. This study was aimed to develop the relationships among NNI, leaf N gradient, chlorophyll meter (CM) readings gradient, and positional differences chlorophyll meter index [PDCMI, the ratio of CM readings betw...

The aim was to determine chlorophyll content index (CCI) and leaf chlorophyll (Chl a) content of a rush, Juncus roemerianus, a grass Spartina alterniflora, and a tree, Rhizophora mangle, occurring in coastal wetlands. Mean CCI values were 11.98 in J. roemerianus, 29.87 in S. alterniflora, and 30.68 in R. mangle. Mean chlorophyll content was 8.85 μg/cm in J. roemerianus, 9.72 μg/cm in S. alterni...

The Belizean reef coral Agaricia tenuifolia Dana forms aggregations in which rows of thin, upright blades line up behind each other. On average, the spacing between blades increases with depth and hence with decreasing ambient irradiance. We designed and built a small, inexpensive light meter and used it to quantify the e€ect of branch spacing on light levels within colonies at varying distance...

Leaf color is a good indicator of plant’s health status. In this study, new image acquisition technique was developed to estimate chlorophyll content lettuce leaves. The images leaves grown under artificial light were acquired using smartphone. Leaves captured by directly attached the camera lens with aid background illumination from SMD LED. Red, green, blue (RGB) indices extracted and some ve...

Chlorophyll degradation is vital during leaf senescence and fruit ripening, as it allows for recycling of nitrogen and other nutrients and for protection from buildup of phototoxic chlorophyll intermediates (Hörtensteiner, 2006). The first steps in chlorophyll breakdown are the removal of the phytol tail (dephytylation) and the central Mg atom. It has been thought that dephytylation typically o...

A new non-destructive index of absorbance difference (IAD), calculated with different wavelengths as references, near the chlorophyll peak or that for anthocyanin, has been used to determine fruit ripening several species using portable devices such Standard DA-Meter® and Kiwi-Meter®. In this study, first time, application IAD was evaluated on single, intact olives Leccino cultivar, a single ma...