Relationships between stomatal behaviour, spectral traits and water use and productivity of green peas (Pisum sativum L.) in dry seasons

Abstract

Six green pea varieties (Pisum sativum L.) with different maturity and leaf type were grown under three irrigation conditions (irrigated, water deficit, non-irrigated) in dry seasons with the objective to examine the relationship among stomatal resistance, stomatal density, chlorophyll content expressed by SPAD value, normalized difference vegetation index (NDVI) and the yield during the growing season. During flowering and pod ripening, significant difference was found in stomatal resistance between the mid- and late-ripening varieties. Those varieties had high stomatal resistance during flowering and pod development produced low yield under water deficiency. In drought under non-irrigated conditions, close significant correlations were found between stomatal resistance and SPAD, as well as NDVI measured during flowering and the yield and water use efficiency for green seeds (WUEy). Under this condition, when the stomatal resistance does not exceed 3 s cm−1 during green pea flowering, 4.3 t ha−1 of yield can be expected. In a dry season, under water deficiency, the SPAD values can be considered drought stress marker and it is more appropriate for evaluation of water use ability and productivity of pea varieties than the extent of stomatal resistance. The results can be used for the selection of pea genotypes adapted to water deficit under field conditions.