We have worked on Petiole, a leaf area meter in a smartphone, for more than 5 years. Hence, we obtained many insights about our customers. We know how we can help to do leaf area analysis. Petiole Leaf Area is a real example of capturing plant leaf data using digital technologies. Hence, what we are doing now – exploring. We collect feedback from our customers to understand what other feature of Petiole is better to work on.
This review presents recent developments in plant photobiology and lighting systems for horticultural crops, as well as potential applications for cannabis (Cannabis sativa and C. indica) plant production. The legal and commercial production of the cannabis plant is a relatively new, rapidly growing, and highly profitable industry in Europe and North America.
However, more knowledge transfer from plant studies and horticultural communities to commercial cannabis plant growers is needed. Plant photosynthesis and photomorphogenesis are influenced by light wavelength, intensity, and photoperiod via plant photoreceptors that sense light and control plant growth. Further, light properties play a critical role in plant vegetative growth and reproductive (flowering) developmental stages, as well as in biomass, secondary metabolite synthesis, and accumulation. Advantages and disadvantages of widespread greenhouse lighting systems that use high-pressure sodium lamps or light-emitting diode (LED) lighting are known.
Some artificial plant lighting practices will require improvements in cannabis production. By manipulating LED light spectra and stimulating specific plant photoreceptors, it may be possible to minimize operation costs while maximizing cannabis biomass and cannabinoid yield, including tetrahydrocannabinol (or Δ9-tetrahydrocannabinol) and cannabidiol for medicinal and recreational purposes.
The basics of plant photobiology (photosynthesis and photomorphogenesis) and electrical lighting systems are discussed, with an emphasis on how the light spectrum and lighting strategies could influence cannabis production and secondary compound accumulation.
Recently we got a question from the customer of Petiole mobile application related to his need to refer to the app in his dissertation. He was doing research in agriculture science and needed to quote Petiole as an instrument of leaf area measurement.
We get many questions about fixing a problem of camera calibration at Petiole, a mobile application for specific leaf area measurement. That’s why we decided to suggest two general solutions for this issue.
Why I cannot calibrate camera in Petiole mobile application?
There are many reasons for this question. After some research, we have clarified three of them. These aspects tell us why people cannot use Petiole mobile application properly.
Our plant scientists face the problem with camera calibration in Petiole. This may be a result of:
An old version of Petiole mobile application or
A specific operating system of the smartphone or
Problem with the same height and fixed position for measurement.
Solution 1 – Software Updates
Actually, this is one of the most popular solution to the problem of how to calibrate camera in Petiole. You must go to the Petiole mobile application page at Google Play Market and check for any updates.
Honestly, we do our best to fix different problems.
Traditionally, they appear in the mobile application after every new release of OS Android or any its library. That’s why – try to update your mobile application manually if it is not automatic.
Solution 2 – Follow our step-by-step video instruction
We have produced a range of videos about calibration and the next steps of measurements. Hopefully, these materials will be helpful for you:
Step #1. Setup Calibration pad
Step #2. Then, setup Camera with Calibration pad
Step #3. Afterwards, place a leaf on the measuring stand
Step #4. Finally, measure leaf area in square centimetres. Just in one tap!
We hope these solutions will help you. If not – let us know, we will do our best to help you.
We know that there is a range of mobile phones with average productivity. As a result, this creates extra problems. It seems that Petiole does not work properly. We try to fix these problems too.
Please, stay calm. Hopefully, in the next release, we will solve the unique problem that you have.
Anyway, you can always ask an Android phone of your friend. Just to install this app.
Probability is higher that it will work on your friend’s phone.
In this video, we made a brief how-to measure leaf area with a smartphone and a mobile application Petiole. It clear shows that specific leaf area measurement is not a problem and even to measure total leaf area is not an issue – less than in a minute with nothing special. Only Petiole and its Petiole kit (measuring stand and calibration pad) and three leaves of the olive tree.
There are three main stages of leaf area measurement using a smartphone.
The analysis of the three measurement methods of leaf blade area of young bi-axis apple trees on rootstock 54-118 was made. High accuracy of the measurement results by a method of area calculation within a leaf contour on millimeter graph paper (31, 21 sq.cm ) and with help of a method of computer sight using application “Petiole” on Smartphone with operational system Android (31, 28 sq.cm ) was established. The gravimetric method and the use of mobile application “Petiole” appeared to be the most productive as to time consumption to carry out the operation.
Key words: leaf blade area, definition methods, computer sight, millimeter graph paper method, gravimetric method, “Petiole” application, bi-axis apple tree.
Authors: O. V. Polunina, Post-graduate Student, Uman National University of Horticulture (Uman), Ukraine V. P. Maiboroda, PhD in Agricultural Sciences, Associate Professor, Uman National University of Horticulture (Uman), Ukraine A. Y. Seleznov, Chief Technology Officer at Petiole LTD, Ukraine
Fertilizer plays an important role in increasing rice yield. More than half of all fertilizer applied to the field is not taken up, resulting in environmental damage and substantial economic losses. To address these concerns, a low-cost, coated compound fertilizer named “Xiang Nong Da” (XND), requiring only a single basal application, was studied. A two-year field experiment was conducted to test the effects of XND application on rice yield and nitrogen fertilizer use efficiency. An ordinary uncoated compound fertilizer (UNCF), with 20% more nutrients and split application was selected as the control. The yield of XND-treated rice was only 3.1% lower than that of the control, an insignificant difference. There were no significant differences between N use efficiency indices of the two fertilizer treatments except for N partial factor productivity (PFP N). PFP N of XND treatment was 19.7%–23.2% higher than the control, a significant difference. This result indicates that a 20% decrease in N application rate is possible with XND without yield reduction and with savings in both labor and time.