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Accueil du site → Doctorat → États-Unis → 1992 → Light interception, water use and dry matter production of faba bean (Vicia faba L. Major) and cotton as affected by planting density and irrigation in semiarid environments

University of California, Davis (1992)

Light interception, water use and dry matter production of faba bean (Vicia faba L. Major) and cotton as affected by planting density and irrigation in semiarid environments

Bamouh, Ahmed

Titre : Light interception, water use and dry matter production of faba bean (Vicia faba L. Major) and cotton as affected by planting density and irrigation in semiarid environments

Auteur : Bamouh, Ahmed

Université de soutenance : University of California, Davis

Grade : Doctor of Philosophy (PhD) 1992

Résumé
Field experiments were conducted to study (1) the effect of mild to moderate water stress on canopy development, light interception, and photosynthetic rate of cotton (Gossypium hirsutum L.) grown a semiarid environment at Davis, California and (2) the effect of planting density and irrigation on light interception, water use, growth and yield of faba bean (Vicia faba L. major) in the Mediterranean semiarid environment at Settat, Morocco. Water stress during canopy development reduced light interception and dry matter production of cotton growing at Davis on a deep clay soil. Light-use efficiency for dry matter production ($\epsilon$) was not affected by withholding irrigation up to 85 days, but was reduced by 33% when irrigation was withheld for 120 days. Limited measurements showed minimal effects on leaf photosynthetic rate. At Settat, increasing planting density (from 5 to 12.5 to 25 plants m$\sp-2$) and irrigation of faba bean permitted earlier attainment of greater leaf-area index, percent light interception (%L$\sb\rm i$), and total dry matter (TDM) production. Early season light use efficiency ($\epsilon$) was increased by irregular planting geometry but was reduced by up to 30% by water stress. Evapotranspiration (ET) during the first part of the season was not affected by planting density or irrigation. Soil water depletion revealed that the faba bean root system did not develop beyond 75 cm depth on that soil. Water use efficiency was reduced at the low planting density due to greater soil evaporation. Transpiration efficiency was similar among density and irrigation treatments as well as between seasons. Denser planting and irrigation increased TDM whereas grain yield was consistently increased only by irrigation. Although greater grain yield was associated with increased TDM, harvest indices at higher planting densities were smaller.

Accès au document : Proquest Dissertations & Theses

Page publiée le 14 février 2015, mise à jour le 30 décembre 2016