Abstract

ZEGBE, Jorge A.  and  HOSSEIN BEHBOUDIAN, M. Water relations, gas exchange, and yield of processing tomato under reduced irrigation. Rev. Mex. Cienc. Agríc [online]. 2010, vol.1, n.3, pp.445-450. ISSN 2007-0934.

Partial root zone drying is a reduced irrigation technology to save water. The objective of this research was on measurement of hitherto unreported values of root water potential along with of processing tomato (Solanum lycopersicum L.) under reduced irrigation. Four irrigation treatments were applied: treatment 1, daily full irrigation as control, where both sides of the root system were well watered; treatment 2, daily irrigation on one side of the root system with half the volume of water given to daily full irrigation; treatment 3, full irrigation every other day of both sides of the root system (deficit irrigation); and treatment 4, irrigation on one side of the root system every other day with half the volume of water given to daily full irrigation. Root water potential was the same for both sides of root system in the treatments 2 and 4. Leaf water potential of treatment 2 was the same as that of treatment 1. Partial stomatal closure and lower transpiration and photosynthetic rates were observed in treatment 2 plants compared of treatment 1. Dry mass of fruit was higher in treatments 1 and 2, than in 3 and 4 treatments. It is concluded that any alteration in the physiological parameters of treatment 2 could have resulted from root signals because leaf water potential was the same in the treatments 1 and 2.

Keywords : CO₂ assimilation; root and leaf water potential; stomatal conductance; transpiration.