8.3
Observation of transpiration and photosynthesis of spring—summer tomato in the growing season under high temperatures and low humidities in greenhouse
Enrique G. Sosa, Univ. of Queretaro, Queretaro, Mexico; and V. R. Ocampo, R. J. Ramirez, O. A. Lopez, and G. Aurelio
Observation of transpiration and photosynthesis of winter-summer tomato in the growing season under high temperatures and low humidities in greenhouse
González-Sosa E., Ocampo V. R., Ramírez R. J., López O. A,
University of Querétaro, C. U. Cerro de la Campanas S/N , Centro 78000 Queretaro. Qro. México egs@sunserver.uaq.mx
Abstract
The high temperatures and low humidities conditions in the central region of Mexico are very important to management of consummation of water in the production of vegetables under greenhouse as the tomato. The valley of Queretaro is a zone semiarid where the water often scarce natural resource and there are warm spring and summer seasons. This article presents some measurements transpiration data of tomato grown under high temperatures (up to 37 °c) and low humidities (25%). The climatic parameters measured were dry and wet bulb air temperature (wire resistance thermometers in aspirated boxes). Observations of transpiration and photosynthesis were collected weekly with a steady state LICOR porometer, leaf temperature and air at five points during the first three weeks and two points all time on tree rows. The radiation intercepted by the canopy was measured in the same points. The observations were during 16 weeks after the plantation. The plants of tomato was transplanted 27 days after sow into 30 cm diameter pots in different dates to profit the radiation energy and reduced the shaded effect. The first row on 21 April and second and third 11 and 31 may respectively. The first results showed that effect of air humidity and temperature on canopy conductance no was important. However the conductance shown decreased from 200 m mol m-2s-1 and no reduction with temperature. The daily evaporation was derived from porometer measurements and the leaf area index (LAI) estimated during the growing period.
Session 8, Weather and climate effects on vegetation growth
Wednesday, 22 May 2002, 1:30 PM-3:30 PM
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