Estimation of green bean yield, water deficiency and productivity using spectral indexes during the growing season

Abstract

Field experiments were carried out in the 2004 and 2005 growing seasons on drip irrigated dwarf green beans (Phaseolus vulgaris, humilis). Soil water content (SWC), spectral reflectance and yield were monitored. Based on these data crop evapotranspiration (ETc), soil water deficit index (SWDI), water use efficiency (WUE) and four separate spectral indexes were calculated. In order to determine use opportunities of spectral indexes for estimation of yield, SWDI and WUE, some statistical analyzes were made. Results showed that spectral indexes could be used for monitoring of yield, SWDI and WUE. Especially, Soil Adjusted Vegetation Index (SAVI) had the highest correlations with all three of the parameters. The estimation procedure which was given in this study has a potential use either during, or at the end of the growing season. Estimated values of WUE and SWDI were 3.2 (kg m −3 ) and 0.12, respectively, through SAVI and the given procedure, indicates the optimal water use and yield conditions for dwarf green beans. At this situation, probably ETc was 580 mm and yield was 25.5 t ha −1 .

Changes in yield components, morphological, physiological and fruit quality traits in processing tomato cultivated in Italy since the 1930’s

“…Normalised Water Index allows an estimation of the water status of the crop (Hanks, 1988). The plant water status is an important parameter as it gives information that can be used to select tolerant cultivar to drought stress in breeding (Köksal et al, 2008;Munjal and Dhanda, 2005). In fact, low values of NWI consistently provided the best relationships with grain yield (Prasad et al, 2007) and in agreement also with what observed in the present work (Figs.…”

Determination of Yield and Quality of Different Snap Bean Varieties Under Deficit Irrigation

“…Linear relationship between ET and snap bean yield were indicated by several researches as Gençoğlan et al (2006), Köksal et al (2008), Sezen et al (2008) and Saleh et al (2018). Polynomial relationships between irrigation level and snap bean yield were also indicated by Bozkurt & Mansuroglu (2018).…”

Proximal sensing and vegetation indices for site-specific evaluation on an irrigated crop tomato

“…Precision agriculture also increases crop productivity and farm profitability through improved management of farm inputs, leading to better environmental quality [Larson and Robert, 1991;Mulla, et al, 1996;Mulla et al, 2002;Tian, 2002;Zhang et al, 2002;Mukherjee et al, 2010]. Among all the inputs, water (management, frequency, amount, spatial distribution) plays the most critical role in most crops, as in the case of tomato that needs irrigation throughout the growing season, since water stress may lead to significant reduction in crop yield [Obreza et al, 1996;Pulupol et al, 1996;May and Gonzalerz, 1999;Köksal, 2008;Patanè et al 2011]. For this reason, quantitative and rapid methods for evaluating leaf water status are required for plant water stress management in tomato.…”