No description available.

Increasing maize production in Trinidad & Tobago could reduce imports and lessen dependency on foreign markets for food and feed. A review of large maize development projects and a survey of maize farmers on small landholdings indicated that mechanized production of maize grain is technically and economically impractical. Maize is normally grown and harvested in the green immature stage by small-scale farmers as a fast, easy, and relatively profitable sideline vegetable crop. An imported hybrid and an improved local landrace (ICTA Farm Corn) yielded more green maize than a Mexican-bred locally-distributed variety, following early (June) rainy season plantings. Hybrid and local unimproved open-pollinated maize were grown with two levels of weed control and with two levels of fertilizer application following late (November) rainy season plantings. For commercial carnival season production of green maize on productive soils in Trinidad, the purchase of imported hybrid seed is economically justifiable, but high inputs into weed control and fertility management may not be needed. A consumer preference study of the main varietal types eaten as boiled ears indicated panelists could not discern differences when seasoned with Creole seasoning, but preferred yellow, large-eared varieties when not seasoned. In a series of 11 variety trials on Inceptisolic and Ultasolic soils in Trinidad, imported hybrids and ICTA Farm Corn consistently yielded greater than 9 other varieties. Grid mass selection for ear weight and ear size was carried out in ICTA Farm Corn. Green maize ear length (1.9% cycle$ sp{-1}$), width (1.5% cycle$ sp {-1}$), and ear weight (2.4% cycle$ sp{-1}$) increased linearly with selection, leading to increases in green marketable (4.4% cycle$ sp{-1}$), green total (3.0% cycle$ sp{-1}$), and grain yield ha$ sp{-1}$ (4.3% cycle$ sp{-1}$). Phenotypic correlations indicated high levels of association between grain yield and both green marketable ear weight (r = 0.91

No description available.

Three varieties of sweet corn (Zea mays L.) , including two supersweet (Crisp 'N Sweet 710 and Rogers 3376) and one normal sweet (Jubilee), were harvested at six stages of maturity (80-72% moisture for supersweet and 75-68% moisture for normal sweet) at three days intervals. Changes in physical and chemical properties over the 15 day harvest period and effects of steam blanching on carbohydrate composition of both genotypes of sweet corn were determined. Moisture content of the kernels decreased with maturity. A quick microwave oven moisture method for determining moisture content of normal sweet and supersweet corn was evaluated and found to be a good alternative method for the time-consuming standard AOAC vacuum oven method. Yield (as represented by average ear weight) increased linearly with maturity. Percent soluble solids was determined to be a satisfactory maturity index for normal sweet corn but not for supersweet corn. The pericarp content in the normal sweet corn Jubilee increased 25% over the 15-day harvest period compared to a mean of 5-6% in the supersweet varieties. Values of the shear press tests were not significantly correlated to % moisture, and only values of compression work showed a positive trend to increase with maturity. Total sugars of supersweet corn averaged 2-3 times higher and decreased more slowly than those of normal sweet corn in the comparable maturity range for processing. Sucrose was the major sugar in both corn genotypes and represented about 80% of the total sugars (9-20% dry weight) in normal sweet corn versus 90% of the total sugars (30-45%) in supersweet corn. Polysaccharides consisted mainly of starch in supersweet corn and of water soluble polysaccharide (WSP) in normal sweet corn. Normal sweet corn contained about twice as much polysaccharides as did supersweet corn. Percent total polysaccharides increased with maturity. Although higher in sugars, supersweet corn had lower % total carbohydrates than normal sweet corn due to its low polysaccharide content. Blanching of corn-on-the-cob for 10 minutes in 99°C steam resulted in a significant loss of sugars. Blanching did not significantly reduce total polysaccharides of sweet corn. / Graduation date: 1990

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1990. / Includes bibliographical references (leaves 338-348) / Microfiche. / xx, 348 leaves, bound ill. (some col.) 29 cm

Typescript. Thesis (Ph. D.)--University of Hawaii, 1954. Bibliography: leaves [156]-159.

An experiment was carried out at Redland Bay on the south-eastern coast of Queensland from (16/2/1991 to 27/6/1991) in an attempt to relate the performance of maize (Zea mays L.)/cowpea (Vigna unguiculata (L) Walp.) intercrops to radiation interception and to radiation availability to cowpea and to ascertain the effects of cowpea morphological characteristics. A quick maturing maize cultivar (DK529) and two cowpea cultivars (Red Caloona and 672330) were used. Changes in light availability to cowpea in intercrops were made by varying maize density. Three plant population densities were used: 22,000 plants ha^-1, 44,000 plants ha^-1, and 67,000 plants ha^-1. Both cowpea cultivars were very vegetative and vigorous in growth with little difference in their morphological characteristics. Cowpea cultivar 1 (Red Caloona) was however a better climber and retained green leaves for a longer duration. Increasing maize plant population density effectively reduced the amount of light reaching the cowpea canopy. Light availability was reduced to a minimum of 13% and 15% in the high maize plant population density and to a minimum of 47% and 42% in the low maize plant population density in cowpea cultivar 1 and 2 respectively. Intercropping reduced growth and yield of both cowpea cultivars through reductions in cowpea leaf area index (LAI), light interception and pod number. It also caused reductions in seed size in cowpea cultivar 2 (67233). Increasing maize plant population density further reduced all the above parameters. Maize growth and yield was affected by intercropping but to a lesser extent. Maize yields were reduced by 16% and 14% under cowpea cultivar 1 and cowpea cultivar 2 respectively, compared to an average reduction of 68% and 82% in cowpea cultivars 1 and 2 across the 3 maize plant population density. Radiation use efficiency (RUE) of the intercrops was lower than that of maize sole crop but higher than that of cowpea sole crop. Intercropping proved to be more advantageous in the vegetative stages of growth than in the reproductive stage except in the medium maize plant population density treatment. This was attributed to better light use efficiency in the early growth in intercrops than sole crops which was estimated to be between 1.1 and 2.9 time higher in intercrops than in sole maize in the first 20 days after sowing (DAMS) . Results indicated that LAI and leaf longevity had a large effect on radiation interception and use in cowpea. Cowpea cultivar 2 was better yielding in sole crop that cowpea cultivar 1 (954 Vs 621 Kgha^-1) but was more affected by intercrop (157 Vs Kgha^-1). An advantage of intercropping was only obtained in the medium maize plant population density intercrops. These were however small advantages (13% and 11%) in cowpea cultivar 2 and cultivar 1 respectively. Intercropping maize with these two cowpea cultivars would therefore be of advantage only, where the interest of the farmer is in the production of maize grain and cowpea leaf, wither for consumption, livestock feed or as green manure.

An experiment was carried out at Redland Bay on the south-eastern coast of Queensland from (16/2/1991 to 27/6/1991) in an attempt to relate the performance of maize (Zea mays L.)/cowpea (Vigna unguiculata (L) Walp.) intercrops to radiation interception and to radiation availability to cowpea and to ascertain the effects of cowpea morphological characteristics. A quick maturing maize cultivar (DK529) and two cowpea cultivars (Red Caloona and 672330) were used. Changes in light availability to cowpea in intercrops were made by varying maize density. Three plant population densities were used: 22,000 plants ha^-1, 44,000 plants ha^-1, and 67,000 plants ha^-1. Both cowpea cultivars were very vegetative and vigorous in growth with little difference in their morphological characteristics. Cowpea cultivar 1 (Red Caloona) was however a better climber and retained green leaves for a longer duration. Increasing maize plant population density effectively reduced the amount of light reaching the cowpea canopy. Light availability was reduced to a minimum of 13% and 15% in the high maize plant population density and to a minimum of 47% and 42% in the low maize plant population density in cowpea cultivar 1 and 2 respectively. Intercropping reduced growth and yield of both cowpea cultivars through reductions in cowpea leaf area index (LAI), light interception and pod number. It also caused reductions in seed size in cowpea cultivar 2 (67233). Increasing maize plant population density further reduced all the above parameters. Maize growth and yield was affected by intercropping but to a lesser extent. Maize yields were reduced by 16% and 14% under cowpea cultivar 1 and cowpea cultivar 2 respectively, compared to an average reduction of 68% and 82% in cowpea cultivars 1 and 2 across the 3 maize plant population density. Radiation use efficiency (RUE) of the intercrops was lower than that of maize sole crop but higher than that of cowpea sole crop. Intercropping proved to be more advantageous in the vegetative stages of growth than in the reproductive stage except in the medium maize plant population density treatment. This was attributed to better light use efficiency in the early growth in intercrops than sole crops which was estimated to be between 1.1 and 2.9 time higher in intercrops than in sole maize in the first 20 days after sowing (DAMS) . Results indicated that LAI and leaf longevity had a large effect on radiation interception and use in cowpea. Cowpea cultivar 2 was better yielding in sole crop that cowpea cultivar 1 (954 Vs 621 Kgha^-1) but was more affected by intercrop (157 Vs Kgha^-1). An advantage of intercropping was only obtained in the medium maize plant population density intercrops. These were however small advantages (13% and 11%) in cowpea cultivar 2 and cultivar 1 respectively. Intercropping maize with these two cowpea cultivars would therefore be of advantage only, where the interest of the farmer is in the production of maize grain and cowpea leaf, wither for consumption, livestock feed or as green manure.

Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisor: Charles E. Mason, Dept. of Entomology & Wildlife Ecology. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.