Crop water stress index for beans obtained from temperature difference between canopy and air.

Canopy temperature (Tc), besides serving as a parameter to estimate crop evapotranspiration (ETc), can also be used to define water stress indexes that have the advantage to serve as a reference for the rational scheduling for irrigation for a crop. One of these indexes, which has been well disseminated, is the crop water stress index (CWSI), based on the ratio between crop resistance and aerodynamic resistance (rc/ra), whose value can be estimated by the difference between the cropy canopy and the air (Tc - Ta). A study was carried out with the objective of obtaining CWSI values for beans (Phaseolus vulgaris L.), under field conditions, in which the crop was under different irrigation scheduling; 2, 4, 8, 12 and 16 day intervals. The experiment was conducted at Sete Lagoas, Minas Gerais State, Brazil, in the period from July through October, 1995. Tc values were measured by means of infrared thermometry at two times of the day; between 10:00 and 11:00 am, and between 01:00 and 02:00 p.m. The obtained results pointed to a limit of 0,15 as a reference for the beginning of water stress to occur, which is consistent with other work and other index obtained under similar conditions.

Bibliographic Details

Main Authors:	ALBUQUERQUE, P. E. P., GOMIDE, R. L., KLAR, A. E.
Other Authors:	PAULO EMILIO PEREIRA DE ALBUQUERQUE, CNPMS; REINALDO LUCIO GOMIDE, CNPMS.
Format:	Parte de livro biblioteca
Language:	English eng
Published:	2011-04-10T11:11:11Z
Subjects:	Estresse, Drought stress., Água, Evapotranspiração, Feijão, Irrigação, Phaseolus Vulgaris, Temperatura., evapotranspiration, irrigation, temperature.,
Online Access:	http://www.alice.cnptia.embrapa.br/alice/handle/doc/481821
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