Abstract

In Swaziland, cereals, legumes, and cucurbits (gourds) are usually intercropped with maize, the chief crop and principal food. The emphasis in Phase I of this project was on increasing productivity of mixed cropping patterns, especially through the use of intercropping early and late maturing crops. In phase II, there will be a continuation of efforts to improve intercropping patterns through a program of selection of high-yielding and adapted crop mixtures. Research will be conducted on the aggressivity of a range of locally selected pumpkin varieties as intercrops, in relation to weed suppression and control; yield losses due to delayed or no weeding; fertilizer requirements; pest and disease problems; economic importance of crops in the farm enterprise; and influence of existing and improved cropping patterns on the social attitudes, beliefs and institutions of the samll farmer.

Post-Project Summary

Researchers tested a number of variations of the intercropping models developed during Phase I (78-0112) in on-station (Luyengo Campus) and on-farm trials in four rural development areas. The on-station trials included the following combinations: dry maize and pumpkin; dry maize, green maize and pumpkin; and grain sorghum and groundnuts. It was noted that intercropped maize gave considerably higher yields than maize grown in a pure stand, up to 46% higher depending on the treatment (two rows maize, one row pumpkin). Pumpkin yields were highest in a pure stand and depressed by 60% when intercropped with two rows of maize to one row of pumpkin. In the dry maize-green maize-pumpkin experiment, maize yields were generally lower than in the maize-pumpkin experiment. The highest cash income was obtained from pure pumpkin, followed pure green maize. Sorghum produced considerably higher yields when intercropped with groundnut than in a pure stand, 40% higher under three rows sorghum, one row groundnut treatment. On the other hand, the groundnut yield was depressed by 90% under the same treatment. Again, the highest cash income was obtained from groundnuts alone. On-farm trials using two maize cultivars (Hickory King and CG4141) and a local pumpkin variety in four combinations (pure maize, two rows maize-one row pumpkin, three rows maize- one row pumpkin, pure pumpkin) were carried out. Maize yields varied significantly between sites but were not seriously affected by pumpkin as an intercrop. Pumpkin yields were very poor in three out the four sites, and good under both pure and intercropped treatment on the fourth. A simple study on nematode control was carried out using curator nematicide and krall manure. While the nematicide reduced levels of infestation in pumpkin, it did not increase yield. On the other hand, the manure increased the yield without reducing nematode infestation. It was concluded that the manure did not directly affect the nematode but rather enabled the plant to survive it. The final report presents the results of trials for which complete results were available.

Recipient Institution(s)