Normalized difference vegetation index obtained by ground-based remote sensing to characterize vine cycle in Rio Grande do Sul, Brazil

<div><p>ABSTRACT The normalized difference vegetation index (NDVI) obtained by remote sensing is widely used to monitor annual crops but few studies have investigated its use in perennial fruit crops. The aim of this study was to determine the temporal NDVI profile during grapevine cycle in vineyards established in horizontal training systems. NDVI data were obtained by the ground-based remote sensing Greenseeker in Chardonnay and Cabernet Sauvignon vineyards located in the Serra Gaúcha region, Rio Grande do Sul, Brazil, from September to June in the 2014/2015 and 2015/2016 vegetative seasons. The grapevine canopies were managed in horizontal training systems (T-trellis and Y-trellis). The results indicated that the temporal NDVI values varied during the grapevine cycle (0.33 to 0.85), reflecting the changing in vigor and biomass accumulation that resulted from the phenological stages and management practices. The temporal NDVI profiles were similar to both horizontal training systems. The NDVI values were higher throughout the cycle for Cabernet Sauvignon compared to Chardonnay indicating Cabernet Sauvignon as the cultivar with greater vegetative vigor. The NDVI obtained by ground-based remote sensing is a fast and non-destructive tool to monitor and characterize the canopy in real time, compiling into a single data several parameters related to vine development, like meteorological conditions and management practices that are difficult to be quantified together.</p></div

Schematic structure of the hypothesized determinants of pregnancy rate (PR).

Full lines represent direct effects, dotted lines represent indirect effects through change in body weight during breeding, and dashed lines represent indirect effects through body weight prior to breeding.</p

Interaction between body weight at the beginning of the breeding season and Breed to pregnancy rate of heifers and primiparous cows (Sint: Crossbred, Taur: <i>B</i>. <i>taurus</i> females).

Shaded strips represent 95% confidence intervals for the expected value. Body mass average and standard deviation were 318 and 69 kg.</p

NDVI and meteorological data as indicators of the Pampa biome natural grasslands growth

<div><p>ABSTRACT The present study aimed to characterize the dynamics of NDVI and meteorological conditions, relating both to the annual dynamics of biomass accumulation in natural pastures of the Pampa biome as a way of subsidizing growth modeling. Forage accumulation rate data from a long-term experiment, NDVI data from the MODIS images, and meteorological data measured at the surface were used. We verify that the agrometeorological element associated to the accumulation of forage in the natural grasslands is different according to the season, which is typical of the subtropical climate. Winter is the critical season for livestock production due to the lower forage accumulation rate and lower values of NDVI, conditioned by the decrease of solar radiation and air temperature. In the summer, the limiting factor to forage accumulation is the hydric condition. It was also verified that the variability in the growth of grasslands can be associated with the ENSO phenomenon, being the El Niño favorable and the La Niña unfavorable, especially in the spring-summer period. Considering the verified associations, spectral indices combined with agrometeorological elements are recommended to the adjustment of models of forage accumulation in the Pampa biome natural grasslands.</p></div

Partial selectivity levels (mean ± standard error) for inter-tussock stratum by ewes.

<p>The continuous line represents the feeding station to bite scale and the dashed line represents the search path or patch scale. Values >1.0 mean that the inter-tussock was selected more than expected by random encounter.</p

Wald’s Chi-sq tests for terms in the model for probability of biting intra-tussock in ewes.

<p>Wald’s Chi-sq tests for terms in the model for probability of biting intra-tussock in ewes.</p

Wald’s Chi-sq tests for terms in the model for probability of biting tussock in heifers.

<p>Wald’s Chi-sq tests for terms in the model for probability of biting tussock in heifers.</p

Probabilities of grazing tussocks (mean and 90% confidence interval) by heifers as a function of treatment (nominal tussock cover at the plot level) and tussock cover in each 1-m² cell grazed (n = 1,132).

<p>The thin dotted line shows the no-selection expectation where probability of grazing tussock equals the proportion of area covered by tussock. Note that lines for 50 and 75% plot-level tussock cover are almost identical. Vertical lines are 90% confidence intervals. Symbols are raw proportions calculated by pooling data across animals, time of day and sessions.</p

Probabilities (mean and 90% confidence interval) of grazing intra-tussocks by ewes as a function of treatment (nominal tussock cover at the plot level) and tussock cover in each 1-m² cell grazed (n = 2,217).

<p>The thin dotted line shows the no-selection expectation where probability of grazing tussock equals the proportion of area covered by tussock. Vertical lines are 90% confidence intervals. Symbols are raw proportions calculated by pooling data across animals, time of day and sessions.</p

F tests for terms in the model for sward grazed by ewes.

<p>F tests for terms in the model for sward grazed by ewes.</p