8 research outputs found
Growth, Gas Exchange, And Harvest Index of Field-Grown Cassava in a Subtropical Short-Season environment
Cassava ( Manihot esculenta Crantz L.) is an important food and
industrial crop in the tropics and holds potential in the subtropics.
Cassava productivity is similar to C4 crop plants but its single-leaf
net photosynthetic rate (Pn) is lower than C4 plants. This field
investigation was conducted from 1982 to 1984 with seven cassava
genotypes to study growth and gas exchange in a short-season
environment. The Pn was determined on fully mature and attached leaves
in an open system and canopy photosynthesis (CPn) was determined in a
closed system between 1100 and 1500 hr using a portable plexiglass
chamber. Leaf area index (LAI) of all cassava genotypes was similar
except for Aug 1983 sampling and ranged from 2.40 to 6.16. The stomatal
density was about ten times higher on the abaxial than the adaxial
surface of cassava leaves. The abaxial stomatal conductance of water
ranged from 0.23 cm s-1 to 1.94 cm s-1. Canopy photosynthesis differed
significantly only during 1983 and varied from 1.31 to 1.97 mg CO2
m-2s-1. The Pn ranged from 0.48 to 1.21 mg CO2 m-2 s-1.
‘Senorita’ and ‘M Ven 218’, the two
semi-forking genotypes, had generally higher HI than the forking
genotypes. The HI was significantly correlated with CPn (r= 0.76*) and
storage root yield (r=0.92*) during 1984. Cassava HI in a short season
environment in the subtopics is similar to that in tropics. The
relatively high productivity of cassava may be attributed to its high
HI
growth, gas exchange, and harvest index of field-grown cassava in a subtropical short-season environment
Cassava ( Manihot esculenta Crantz L.) is an important food and
industrial crop in the tropics and holds potential in the subtropics.
Cassava productivity is similar to C4 crop plants but its single-leaf
net photosynthetic rate (Pn) is lower than C4 plants. This field
investigation was conducted from 1982 to 1984 with seven cassava
genotypes to study growth and gas exchange in a short-season
environment. The Pn was determined on fully mature and attached leaves
in an open system and canopy photosynthesis (CPn) was determined in a
closed system between 1100 and 1500 hr using a portable plexiglass
chamber. Leaf area index (LAI) of all cassava genotypes was similar
except for Aug 1983 sampling and ranged from 2.40 to 6.16. The stomatal
density was about ten times higher on the abaxial than the adaxial
surface of cassava leaves. The abaxial stomatal conductance of water
ranged from 0.23 cm s-1 to 1.94 cm s-1. Canopy photosynthesis differed
significantly only during 1983 and varied from 1.31 to 1.97 mg CO2
m-2s-1. The Pn ranged from 0.48 to 1.21 mg CO2 m-2 s-1.
‘Senorita’ and ‘M Ven 218’, the two
semi-forking genotypes, had generally higher HI than the forking
genotypes. The HI was significantly correlated with CPn (r= 0.76*) and
storage root yield (r=0.92*) during 1984. Cassava HI in a short season
environment in the subtopics is similar to that in tropics. The
relatively high productivity of cassava may be attributed to its high
HI