Feasibility of using pyranometers for continuous estimation of ground cover fraction in table grape vineyards

Antonio Martinez-Cob, Jose M. Faci, Olga Blanco, Eva T. Medina, Kosana Suvočarev

Abstract


This paper evaluates the feasibility of using pyranometers for continuous estimation of ground cover fraction (GCF) at remote, unattended sites. Photographical techniques were used for measuring GCF (GCFref) at a table grape vineyard grown under a net. Daily pyranometer-driven GCF estimates (GCFpyr) were obtained from solar radiation measurements above and below the canopy. For GCFpyr computation, solar radiation was averaged for two hours around solar noon (midday periods) and for daylight periods (8:00 to 18:00 Universal Time Coordinated). GCFpyr and GCFref (daylight periods) showed a good agreement: mean estimation error, 0.000; root mean square error, 0.113; index of agreement, 0.967. The high GCF attained, the large measurement range for GCF and the presence of the net above the table grape were the likely reasons for the good performance of GCFpyr in this crop despite the short number of pyranometers used. Further research is required to develop more appropriate calibration equations of GCFpyr and for a more detailed evaluation of using a short number of pyranometers to estimate GCF.


Keywords


shading; PAR; Vitis vinifera; global solar radiation

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References


Allen RG, Pereira LS, 2009. Estimating crop coefficients from fraction of ground cover and height. Irrig Sci 28: 17-34. http://dx.doi.org/10.1007/s00271-009-0182-z

Allen RG, Pereira LS, Raes D, Smith M, 1998. Crop evapotranspiration: guidelines for computing crop water requirements. FAO Irrig Drain Paper No. 56. Rome, Italy, 300 pp.

Ayars JE, Johnson RS, Phene CJ, Trout TJ, Clark DA, Mead RM, 2003. Water use by drip-irrigated late-season peaches. Irrig Sci 22: 187-194. http://dx.doi.org/10.1007/s00271-003-0084-4

Blanco O, Faci JM, Negueroles J, 2010. Response of table grape cultivar 'Autumn Royal' to regulated deficit irrigation applied in post-veraison period. Span J Agric Res 8 (S2): S76-S85. http://dx.doi.org/10.5424/sjar/201008S2-1350

Bojaca CR, García SJ, Schrevens E, 2011. Analysis of potato canopy coverage as assessed through digital imagery by nonlinear mixed effects models. Potato Res 54 (3): 237-252. http://dx.doi.org/10.1007/s11540-011-9189-y

Goldhamer DA, Synder RL, 1989. Irrigation scheduling - A guide for efficient on-farm water management. Publication 21454. Univ. of California, Div. Agr. Nat. Resour., Oakland, CA, USA.

Kiniry JR, 1999. Response to questions raised by Sinclair and Muchow. Field Crop Res 62: 245-247. http://dx.doi.org/10.1016/S0378-4290(99)00012-X

Li-COR, 2010. Using the LAI-2200 in sunny conditions. NewsLine. Available in http://www.licor.com/env/newsline/tag/lai-2000/. [26 November 2013].

López-Urrea R, Martín de Santa Olalla F, Montoro A, López-Fuster P, 2009. Single and dual crop coefficients and water requirements for onion (Allium cepa L.) under semiarid conditions. Agr Water Manage 96: 1031-1036. http://dx.doi.org/10.1016/j.agwat.2009.02.004

López-Urrea R, Montoro A, Ma-as F, López-Fuster P, Fereres E, 2012. Evapotranspiration and crop coefficients from lysimeter measurements of mature 'Tempranillo' wine grapes. Agr Water Manage 112: 13-20. http://dx.doi.org/10.1016/j.agwat.2012.05.009

MAGRAMA, 2013. Sistema de Información Agroclimática para el Regadío (SIAR). Spanish Ministry of Agriculture, Food and Environment. Available in http://eportal.magrama.gob.es/websiar/Inicio.aspx. [11 June 2013].

Marsal J, Johnson S, Casadesus J, Lopez G, Girona J, Stöckle C, 2014. Fraction of canopy intercepted radiation relates differently with crop coefficient depending on the season and the fruit tree species. Agric For Meteorol 184: 1- 11. http://dx.doi.org/10.1016/j.agrformet.2013.08.008

Moratiel R, Martínez-Cob A, 2012. Evapotranspiration of grapevine trained to a gable trellis system under netting and black plastic mulching. Irrig Sci 30: 167-178. http://dx.doi.org/10.1007/s00271-011-0275-3

Moratiel R, Martínez-Cob A, 2013. Evapotranspiration and crop coefficients of rice (Oryza sativa L.) under sprinkler irrigation in a semiarid climate determined by the surface renewal method. Irrig Sci 31: 411-422. http://dx.doi.org/10.1007/s00271-011-0319-8

Suvočarev K, Blanco O, Faci JM, Medina ET, Martínez-Cob A, 2013. Transpiration of table grape (Vitis vinifera L.) trained on an overhead trellis system under netting. Irrig Sci 31(6): 1289-1302. http://dx.doi.org/10.1007/s00271-013-0404-2

Williams LE, Ayars JE, 2005. Grapevine water use and the crop coefficient are linear functions of the shaded area measured beneath the canopy. Agr Forest Meteorol 132: 201-211. http://dx.doi.org/10.1016/j.agrformet.2005.07.010

Willmott CJ, 1982. Some comments on the evaluation of model performance. Bull Am Meteorol Soc 63(11): 1309–1313. http://dx.doi.org/10.1175/1520-0477(1982)063%3C1309:SCOTEO%3E2.0.CO;2




DOI: 10.5424/sjar/2014123-5453