Premium
Establishment of the soil water potential threshold to trigger irrigation of K yoho grapevines based on berry expansion, photosynthetic rate and photosynthetic product allocation
Author(s) -
Lou Y.,
Miao Y.,
Wang Z.,
Wang L.,
Li J.,
Zhang C.,
Xu W.,
Inoue M.,
Wang S.
Publication year - 2016
Publication title -
australian journal of grape and wine research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.65
H-Index - 77
eISSN - 1755-0238
pISSN - 1322-7130
DOI - 10.1111/ajgw.12208
Subject(s) - berry , veraison , photosynthesis , environmental science , irrigation , horticulture , geometric phase , agronomy , mathematics , biology , botany , physics , quantum mechanics
Background and Aims Irrigation is an important management practice in viticulture. Irrigation scheduling established by previous researchers was based mainly on the irrigation level for optimal berry composition and size at harvest. Because eventual berry size and composition depend on the accumulation of daily growth, a more precise study must be implemented to establish the soil water potential (ψ soil ) threshold to trigger irrigation at different development stages of the berry. Methods and Results Photogrammetry, 13 C isotope labelling and other techniques were applied to study the relationship between ψ soil and real‐time change of berry expansion, net photosynthetic rate, and the distribution of photosynthetic products in 3‐year‐old Kyoho grapevines. The diurnal variation of berry size presented a regular pattern, shrinking in daytime and expanding at night. Analysis of a time series model revealed a close correlation between berry growth and ψ soil . With the decline in ψ soil , berry growth presented four phases of change: high speed growth phase, rapid growth phase, slow growth phase and shrinking phase. Conclusions The optimal ψ soil threshold to trigger irrigation at different berry developmental periods was established: −10 k P a after berry setting (berry diameter < 10 mm), −15 k P a during berry pea size (berry diameter 10–20 mm) and −20 k P a after veraison (berry diameter > 20 mm). Significance of the Study The established ψ soil threshold in this study has significant value for the implementation of precision irrigation, which favours normal berry expansion and composition while saving water.