Correlation between thermal indices of melon under sustained irrigation (SI) and regulated deficit irrigation (RDI) - DOI: 10.7127/rbai.v1901379

Resumo

The aim of this study was to present correlations between thermal indices in the response of the flowering and fruiting phase (phase III) of yellow melons subjected to sustained deficit irrigation (SI) and controlled deficit irrigation (RDI). The experimental design adopted was a randomized block design with 4 replications of 9 irrigation treatments, 4 referring to SI (T1 - 125%, T2 - 100%, T3 - 75%, T4 - 50%) and 5 characterizing RDI [T5 (75% in phases I and IV and 100% in phases II and III); T6 (50% in phase I, 100% in phase II and 75% in phases III and IV); T7 (100% in phase I, 75% in phases II and III and 50% in phase IV); T8 (50% in phase II and 100% in the others); and T9 (75% in phase I, 100% in phase III and 50% in phases III and IV)]. The thermal indices (∆Tcanopy-air, CWSI and IG) were calculated from thermographic images captured at 8:00 am, 12:00 pm and 4:00 pm. The thermal indices showed high correlations (R2> 0.7) with each other at all the times assessed. In the context of irrigation management, the thermal indices evaluated can be used for the basic question of “when to irrigate?”, with ∆Tcanopy-air being the most practical, as it does not require the reference temperatures Tdry and Twet.