Coffee crop coefficient prediction as a function of biophysical variables identified from RGB UAS images

L.M. Santos¹*, G.A.S. Ferraz¹, A.V. Diotto², B.D.S. Barbosa¹, D.T. Maciel², M.T. Andrade¹, P.F.P. Ferraz¹ and G. Rossi³

¹Federal University of Lavras, Department of Agricultural Engineering, University Campus, BR37.200-000 Lavras-MG, Brazil
²Federal University of Lavras, Department of Water Resources and sanitation, University Campus, BR37.200-000 Lavras, Brazil
³University of Florence, Department of Agricultural, Food, Environment and Forestry (DAGRI), Via San Bonaventura, 13, IT50145 Florence, Italy
*Correspondence: luanna_mendess@yahoo.com.br

Abstract:

Because of different Brazilian climatic conditions and the different plant conditions, such as the stage of development and even the variety, wide variation may exist in the crop coefficients (𝐾𝑐) values, both spatially and temporally. Thus, the objective of this study was to develop a methodology to determine the short-term 𝐾𝑐 using biophysical parameters of coffee plants detected images obtained by an Unmanned Aircraft System (UAS). The study was conducted in Travessia variety coffee plantation. A UAS equipped with a digital camera was used. The images were collected in the field and were processed in Agisoft PhotoScan software. The data extracted from the images were used to calculate the biophysical parameters: leaf area index (LAI), leaf area (LA) and 𝐾𝑐. GeoDA software was used for mapping and spatial analysis. The pseudo-significance test was applied with p < 0.05 to validate the statistic. Moran’s index (I) for June was 0.228 and for May was 0.286. Estimates of 𝐾𝑐 values in June varied between 0.963 and 1.005. In May, the 𝐾𝑐 values were 1.05 for 32 blocks. With this study, a methodology was developed that enables the estimation of 𝐾𝑐 using remotely generated biophysical crop data.

Key words:

Coffea arabica L., drone, irrigation, leaf area, uav (unmanned aerial vehicle)

Formation of photosynthetic and grain yield of spring barley (Hordeum vulgare L.) depend on varietal characteristics and plant growth regulators

A. Panfilova*, M. Korkhova, V. Gamayunova, M. Fedorchuk, A. Drobitko, N. Nikonchuk and O. Kovalenko

Mykolayiv National Agrarian University, Faculty of Agricultural technologies, 73 Karpenko street, UA54021 Mykolayiv, Ukraine
*Correspondence: panfilovaantonina@ukr.net

Abstract:

The aim of the study was to determine the efficiency of the barley treatment crops with modern retrograde preparations on the background of the mineral fertilizers introduction into the photosynthetic activity of crops and grain yield. The experiments were carried out in 2013 -2017 on the southern black soil in the conditions of the Ukrainian Steppe. On the basis of the study results, it was determined that the introduction of irrigated fertilizer barley in a dose of N₃₀P₃₀ (background) under pre-sowing cultivation and the application of extra-root crop supplements at the phases beginning of the barley outflow straw into the tube and the organoleptic fermentation of Organic D2 and natural microbial complex Escort – Bio creates favorable conditions for the formation at the optimal levels of photosynthetic parameters and grain yield. Thus, on average, over the years of research and by factor variety, grain yield on these experimental variants was 3.37–3.41 t ha^-1, which exceeded its level on uncontrolled control by 0.71–0.75 t ha^-1 or 26.7–28.2%. Based on the study results, the use of modern regenerating agents against the background of mineral fertilizers can be recommended as an expedient and effective measure of spring barley raising the productivity.

Key words: