Contribution to the Ecology of Dactyloctenium aegyptium (L.) P. Beauv.

Dactyloctenium aegyptium, which is a nutritious fodder, grows abundantly in the campus of University of Ibadan, Nigeria, under tropical climate and supported by reddish-brown loamy soil. The species shows morphological variations and three forms have been recognized. Form A is small sized, Form B medium, while Form C is large. Each form grows with different associated species, though some of them are common to all forms. The three forms behaved differently with respect to germination requirements, biotic disturbance, and water stress. Cultural experiments revealed germination lower on filter paper than on soil, a progressive decrease in germination with depth, no germination at 4 cm and 5 cm depths, and a general increase in germination from 10 degrees C to 25 degrees C. Form C did not germinate at all in total darkness but had the highest germination in glass-house and it was the only one that germinated in continuous light. Most of the results of various germination experiments showed that Form A had the least germination, followed by Form B, while Form C had the highest germination. Experiments on water stress revealed that Form B showed the best growth but it was only Form C that had flowered. There are persistent differences in three Forms with regard to growth habit, period of maturity, spike coloration, and germination behavior, which indicate that they are likely to be ecotypes.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

The effect of 2,4-D, dicamba and hand weeding on witchweed density and maize yield

(African Crop Science Journal 1999 7(4): 455-464

EFFECT OF MAIZE DENSITY, BEAN CULTIVAR AND BEAN SPATIAL ARRANGEMENT ON INTERCROP PERFORMANCE

On-farm trials to determine the optimum combination of maize (Zea mays   L.) density, bean (Phaseolus vulgaris   L.) cultivar and bean spatial arrangement to produce high yields of the intercrop combination were conducted in Chinyika Resettlement Area (CRA) and at Domboshava Training Centre (DTC) during the 1996/97 and 1997/98 rainy seasons. The effects of maize at 37, 000 and 24, 000 plants ha-1, bean cultivars 'Natal Sugar' and 'Carioca', and bean arranged in one or two rows between rows of maize or bean planted in the same row as maize were evaluated in a completed factorial arrangement. Maize density, bean cultivar, bean spatial arrangement and their interactions significantly (P<0.01) affected maize and bean grain yields at both locations for the two seasons. Changing the maize density from 90 x 45 cm (24000 plants ha-1) to 90 x 30 cm (37000 plants ha-1) increased maize yield by 28 and 39% and reduced bean yields by 11 and 18% in the respective seasons. Maize yield was 19% less when intercropped with Natal Sugar than with Carioca. Same row and one row bean cultivar arrangements produced similar maize yields. Land equivalent ratios (LER) were greater than one for all but one intercrop arrangements at CRA but less frequently at DTC. The maize density of 90 x 30 cm with Carioca in the same row as maize produced the highest LER value at all sites, 1.73 at Chinyudze, and 1.53 at Domboshava. The same treatment gave the highest gross return ofZ$12 649 ha-1 at CRA. Carioca planted in the same row as maize at the maize density of 37,000 plants ha-1 is the most ideal approach to dryland maize/bean intercropping since it achieved high yields and allows easy weeding

Intercropping maize with grain legumes for Striga control in Zimbabwe

On-farm experiments were conducted in Chinyika Resettlement Area during the 1994/95 and 1995/96 rainy seasons at four sites to test the effectiveness of intercropping maize with cowpea, groundnut, field bean and bambara nut in suppressing Striga asiatica   (L.) Kuntze. During the 1994/95 rainy season maize/cowpea intercrop supported less Striga asiatica plant m-2 than sole maize, while other intercrops supported similar numbers of emerged Striga asiatica plants m-2 as sole maize. Combined analysis over sites showed that the numbers of emerged Striga asiatica plants in the intercrops were similar to those in sole maize during the 1995/96 season. However, during the same season the number of emerged Striga asiatica plants was significantly (P<0.05) lower in the maize/groundnut intercrop at 8 weeks after crop emergence (WACE) at one site but similar at the remaining sites. Due to moisture stress and severe competition from the parasitic weed, no maize grain was harvested during the 1994/95 season. The maize/cowpea intercrop had the lowest maize stover yield, while the maize/field bean intercrop had the highest stover yield. Maize grain yields were not significantly different for all treatments during the 1995/96 season but the partial land equivalent ratios (PLERs) ranged from 0.8 to 1.70 indicating that intercropping maize with legumes had an advantage over planting sole maize in Striga asiatica infested fields

Resistance to witchweed in Sorghum: parent characterisation and combining ability analysis

(African Crop Science Journal 1999 7(4): 321-326

The effect of rate and time of application of Nitrogen on maize yield in Chinyika Resettlement area, Zimbabwe

No abstract availabl