In this study, the growth and glucosinolate (GSL) profiles of rocket salad Eruca sativa (Mill.) and Diplotaxis tenuifolia (L.) DC. were determined during 30 days growing under different lighting ...regimes; T5_ peak at 545 nm, LED1_ peak at 631 nm and LED2_ peak at 598 nm. The biggest increase of dry weight (DW) was measured in E. sativa under T5 (0.657 g DW/plant) and the lowest in D. tenuifolia under LED1 (0.080 g DW/plant). GSL content was found to vary significantly, regardless of the light treatment, but it is related with genotype (E. sativa, r = 0.802**). On average, the highest amount of 4-methylsulfinylbutyl-GSL (glucosativin) (7.3248 mg/g DW) was quantified in E. sativa and D. tenuifolia (6.7428 mg/g DW) under the T5. The regression analysis between different light wavelengths and glucosinolates showed the strongest correlation between photosynthetic photon flux density (PPFD_B) and 4-methylthiobutyl-GSL (glucoerucin) in E. sativa (r = 0.698*) and D. tenuifolia (r = 0.693*), respectively, which indicates the effect of light on the response of plants to induced stress and changes in GSL biosynthesis.
In the process of applying a plant protection product mixed with water (spray mixture) at the prescribed concentration with conventional sprayers for chemical protection of tree canopies in an ...orchard, standard models are used to express the dose rate of the plant protection product. Characteristic properties of the tree canopy in an orchard are not taken into consideration. Such models result in fixed quantities of spray mixture being sprayed through individual nozzles into a tree canopy. In this research work, an autonomous system is presented, which ensures a controlled quantity of spray mixture sprayed through the nozzles onto different tree canopy segments. The autonomous system is based on a fuzzy logic system (FLS) that includes information about the estimated leaf area to ensure more appropriate control of the spray mixture. An integral part of the FLS is a fuzzy logic controller for three electromagnetic valves operating in the pulse width mode and installed on the axial sprayer prototype. The results showed that, with the FLS, it was possible to control the quantity of spray mixture in the specific range depending on the estimated value of the leaf area, with a quantitative spray mixture average saving of 17.92%. For the phenological growth stage BBCH 91, this method represents a powerful tool for reducing the quantity of spray mixture for plant protection in the future.
Autonomous modular system mounted on a conventional (CON) sprayer operating on the principle of pulse-width modulation (PWM) control of electromagnetic valves represents state-of-the-art technology ...for implementation controlled application of spray mixture without changing the operating parameters of the sprayer (e.g. spray pressure, nozzle size). In accordance with the principles of precision viticulture, the pulse width modulation control is the primary technology, which allows the application of the required amount of spray mixture exclusively to the target areas of the vine without changing the droplet size spectrum and allows for even deposit quality and reducing the drift outside the target areas. In the vineyard, we tested an autonomous axial sprayer prototype throughout the entire spraying season in 2021 on which we have installed an autonomous modular system with enabled pulse-width control. We tested two modes of operation of the sprayer prototype, namely autonomous (continuous duty cycle control (DC: 0 to 100%)) and conventional (nozzle fully open at all time), at a steady spray speed of 6 kmh-1. We compared the amount of PPP expressed as a percentage between autonomous and conventional mode of operation of the sprayer through individual nozzles on the sprayer. The maximum saving of the spray mixture of 69.8%, through an individual nozzle was measured at phenological stage of the vine BBCH 55. A comparative analysis between the CON and PWM mode of the spray mixture application showed that we saved 626.24 l per year in the automated mode of operation.
Autonomni modularni sustav postavljen na konvencionalnu (CON) prskalicu, koji operira na principu kontrole elektromagnetskih ventila modulacijom širine impulsa (PWM), predstavlja najsuvremeniju tehnologiju za provedbu kontrolirane primjene mješavine za prskanje bez promjene operativnih parametara prskalice (npr. pritisak prskanja, veličina mlaznice). U skladu s principima precizne vitikulture, kontrola modulacijom širine impulsa je primarna tehnologija, koja omogućava primjenu potrebne količine mješavine za prskanje isključivo na ciljana područja vinove loze, bez mijenjanja spektra veličine kapi, te omogućava ujednačenu kvalitetu nanosa i smanjenje zanošenja van ciljanih područja. U vinogradu je kroz cijelu sezonu prskanja u 2021. testiran prototip autonomne aksijalne prskalice, na koji je bio instaliran autonomni modularni sustav s omogućenom kontrolom širine impulsa. Testirana su dva načina rada prototipa prskalice, autonomni (kontinuirana kontrola radnog ciklusa (DC: 0 to 100%)) i konvencionalni (mlaznica potpuno otvorena sve vrijeme), pri standardnoj brzini prskanja od 6 kmh-1. Usporedili smo količinu sredstva za zaštitu bilja izraženu kao postotak između autonomnog i konvencionalnog načina rada prskalice kroz individualne mlaznice prskalice. Maksimalna ušteda mješavine za prskanje od 69,8%, kroz individualnu mlaznicu izmjerena je u fenološkoj fazi vinove loze BBCH 55. Komparativna analiza između CON i PWM načina primjene mješavine za prskanje pokazala je da je s automatiziranim načinom rada u godinu dana ušteđeno 626,24 L.
This research demonstrates the basic elements of a prototype automated orchard sprayer which delivers pesticide spray selectively with respect to the characteristics of the targets. The density of an ...apple tree canopy was detected by PROWAVE 400EP250 ultrasound sensors controlled by a Cypress PSOC CY8C29466 microcontroller. The ultrasound signal was processed with an embedded computer built around a LPC1343 microcontroller and fed in real time to electro-magnetic valves which open/close spraying nozzles in relation to the canopy structure. The analysis focuses on the detection of appropriate thresholds on 15 cm ultrasound bands, which correspond to maximal response to tree density, and this was selected for accurate spraying guidance. Evaluation of the system was performed in an apple orchard by detecting deposits of tartrazine dye (TD) on apple leaves. The employment of programmable microcontrollers and electro-magnetic valves decreased the amount of spray delivered by up to 48.15%. In contrast, the reduction of TD was only up to 37.7% at some positions within the tree crown and 65.1% in the gaps between trees. For all these reasons, this concept of precise orchard spraying can contribute to a reduction of costs and environmental pollution, while obtaining similar or even better leaf deposits.
U praktičnom eksperimentu u voćnjaku zasađenom jabukama sorte 'Gala' ocijenjena je površina lišća na tri različita segmenta krošnje s lijeve i desne strane. Rezultati ručnih mjerenja uspoređeni su s ...laserskim (LIDAR) mjerenjima primjenom vlastitog algoritma koji je omogućio digitalnu rekonstrukciju krošnje pojedinačnih stabala. Pomoću regresijske metode, odnos između ovisne varijable (digitalni broj oblaka točaka) i neovisne varijable (površina lista, ručno mjeren) procijenjen je za pet segmenata krošnje. Analiza na pet nasumično odabranih voćnjaka u voćnjaku pokazala je maksimalnu vrijednost koeficijenta korelacije r = 0,73 za lijevu polovicu i r = 0,72 za desnu polovicu krošnje.
In practical experiment in the orchard, the leaf area of ‘Gala’ apple trees was evaluated on three different tree canopy segments from left and right side. The results of manual measurements were compared with laser (LIDAR) measurements by applying our own algorithm, which enabled digital reconstruction of individual tree canopy. By using regression method the relationship between dependent variable (digital number of point clouds) and independent variable (leaf area, manually measured) were evaluated for five segments of tree canopies. The analysis on five randomly selected tree orchards in the orchard showed the maximum value of the correlation coefficient r = 0.73 for the left half and r = 0.72 for the right half of the crown.
Autonomni modularni sustav postavljen na konvencionalnu (CON) prskalicu, koji operira na principu kontrole elektromagnetskih ventila modulacijom širine impulsa (PWM), predstavlja najsuvremeniju ...tehnologiju za provedbu kontrolirane primjene mješavine za prskanje bez promjene operativnih parametara prskalice (npr. pritisak prskanja, veličina mlaznice). U skladu s principima precizne vitikulture, kontrola modulacijom širine impulsa je primarna tehnologija, koja omogućava primjenu potrebne količine mješavine za prskanje isključivo na ciljana područja vinove loze, bez mijenjanja spektra veličine kapi, te omogućava ujednačenu kvalitetu nanosa i smanjenje zanošenja van ciljanih područja. U vinogradu je kroz cijelu sezonu prskanja u 2021. testiran prototip autonomne aksijalne prskalice, na koji je bio instaliran autonomni modularni sustav s omogućenom kontrolom širine impulsa. Testirana su dva načina rada prototipa prskalice, autonomni (kontinuirana kontrola radnog ciklusa (DC: 0 to 100%)) i konvencionalni (mlaznica potpuno otvorena sve vrijeme), pri standardnoj brzini prskanja od 6 kmh-1. Usporedili smo količinu sredstva za zaštitu bilja izraženu kao postotak između autonomnog i konvencionalnog načina rada prskalice kroz individualne mlaznice prskalice. Maksimalna ušteda mješavine za prskanje od 69,8%, kroz individualnu mlaznicu izmjerena je u fenološkoj fazi vinove loze BBCH 55. Komparativna analiza između CON i PWM načina primjene mješavine za prskanje pokazala je da je s automatiziranim načinom rada u godinu dana ušteđeno 626,24 L.
Precision agriculture (PA) through the use and utilization of innovative technologies is a concept in agricultural management that enables long-term efficiency gains, control of unforeseen changes, ...and a reduction of negative impacts on the environment. However, there are even more reasons and benefits to using precision agriculture technologies (PATs) on farms, but the actual use on small farms is often questionable. The main objective of this research was to evaluate and analyze the current state of PA and its potential on a set of small farms. In addition, a comparison was made between small farms located in less favored areas (LFAs) and more favored areas (MFAs) to find if specific characteristics of the surrounding environment affect the (non-) implementation of these technologies by farm owners, with respect to the given regional possibilities. The result shows that 57.5% of respondents on these farms have never implemented PATs before and 20% are beginners in their respective fields. It was found that there were no statistically significant differences in the integration between fewer LFAs and MFAs technologies and their use in this study. The majority of respondents believe that the main changes need to occur on the level of politics. The results show that the level of cost or initial investment is the main reason and the main obstacle in the implementation of PATs on the surveyed farms.
A dosage rate reduction of plant protection products mixed with water, i.e. spray mixture, in a prescribed concentration in the vineyard will only be possible in the future, if the natural ...characteristics of vine canopy structures (leaf wall area) and canopy management are taken into account. In a practical experiment in the vineyard we evaluated the leaf wall area of the vine cv. Sauvignon on different segments on the left and right side of the vine canopy. We compared the results of manual measurements and laser measuring technology (LIDAR) with the corresponding algorithm, with which we enabled the digital reconstruction of the leaf wall area of the vine. The manual measurement of the leaf wall area was carried out using an automated image analyser. The digital system for measuring the leaf wall area on different segments consisted of a LIDAR sensor and a Differential Global Positioning System (hereinafter DGPS). To determine the exact DGPS position of the LIDAR sensor during the measurement, we set up a DGPS base station. Using the Excel software (CORREL function), we estimated the relationship between the dependent variable (digital number of points in the cloud) and an independent variable (leaf wall area, manually measured). An analysis of six randomly selected vines in the vineyard revealed the maximum value of the correlation coefficient r = 0.80 for the left side and r = 0.90 for the right side of the leaf wall area of the vine, respectively. In the near future the virtual three-dimensional space will provide more even control of spray mixture over the entire structure of the leaf wall area in the vineyard based on autonomous decision-making models.
Smanjenje količine utroška sredstava za zaštitu bilja i same smjese za prskanje u budućnosti će biti moguće samo ako se uzmu u obzir prirodne karakteristike krošnje vinove loze tj. lisne površine krošnje trsa. U praktičnom pokusu u vinogradu procijenjena je lisna površinu krošnje vinove loze cv. Sauvignon na različitim segmentima s lijeve i desne strane krošnje uz pomoć ručnih mjerenja i laserske mjerne tehnologije (LIDAR). Dobiveni rezultati uspoređeni su s pripadajućim algoritmom čime je dobivena digitalna rekonstrukcija lisne površine vinove loze. Ručno mjerenje površine listova provedeno je u laboratoriju pomoću digitalnog lisnog skenera nakon što je lišće ručno pobrano s trsova i dopremljeno u sam laboratorij. Digitalni sustav za mjerenje lisne površine na različitim segmentima krošnje sastojao se od LIDAR senzora i DGPS navigacijskog sustava. Da bi se odredio točan DGPS položaj LIDAR senzora tijekom mjerenja, postavljena je DGPS bazna stanica. Pomoću regresijske metode utvrđen je odnos između zavisne varijable (digitalni broj točaka u oblaku) i nezavisne varijable (površina listova izmjerena skenerom). Rezultati analize imeđu dvije uspoređivane metode na šest slučajno odabranih trsova vinove loze otkrivaju vrijednost koeficijenta korelacije r = 0,80 za lijevu i r = 0,90 za desnu stranu krošnje. U bliskoj budućnosti virtualni trodimenzionalni prostor pružit će ravnomjerniju kontrolu smjese raspršivača preko cijele strukture područja stijenke lišča u vinogradu na temelju autonomnih modela odlučivanja.
The concept of precision farming is wide, and it represents the efficiency which is achieved with the help of precision. For the navigation of field machines, the RTK (Real Time Kinematic) navigation ...is needed. In order to verify the positive effects in practice, RTK navigation system equipped with Fentd 828 was applied to test the width of overlap, and fuel and time that could be saved compared with manual driving. The experiment was conducted on two areas of land size of 172 m x 58 m with two working machines width 3 m and 6 m. Results indicated that 15.7% of the time and 8.66% of the fuel were saved on a working machine of 3 meters width, and 12.6% of the time and 8.28% of the fuel were saved on a working machine of 6 m width. The width of the overlap represent 10% of the working width of the machine, and with the method of turning, which RTK navigation allows, additional time was saved. Ecological footprint, CO2 emissions and global warming potential (GWP) was estimated under different guiding systems. The largest footprint was related to manual tillage with 3 m width working machine, while estimation on CO2 (kg) emissions and GWP obtained the same result. The use of precision agriculture technologies allows better planning and analyzing of working procedures. The air, water and soil pollution are less intensive.
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