Sunflower for Strip, Row, and Relay Intercropping 1

Yield is greater for some intercropping systems than from sole cropping. The culture and morphology of sunflower ( Helianthus annuus L.) indicated that it had potential for intercropping. Consequently, sunflower was evaluated as a component of strip, row, and relay intercropping systems that would be practical for mechanized farming. Trials were conducted on Typic Hapludoll soils. Strip intercropping sunflower with corn ( Zea mays L.) or soybean [ Glycine max (L.) Merr.] compared with sole cropping showed that the percentage gain in sunflower yield was offset by about the same percentage reduction in corn or soybean yield. Increased yields of sunflower and mustard ( Brassica hirta Moench) from intercropping over sole cropping were confined to the border rows of the sunflower strips and the two border rows of the mustard strips. Yields from intercropped sunflower and soybean in alternate rows 38 cm apart were less than from sole cropped soybean, but 450 kg ha −1 higher than from sole cropped sunflower. Fieldbean ( Phaseolus vulgaris L.) as a row intercrop with sunflower increased in yield as sunflower population decreased, but its highest intercrop yield was 59% that of sole cropped fleldbean. Relay intercropping involved broadcast sowing of winter rye ( Secale cereale L.) in sunflower and fleldbean. Rye stands in sunflower were unsatisfactory, those in fieldbean ranged from poor to satisfactory, and those established alone on prepared seedbeds were excellent. Sunflower is not a promising species for intercropping. Sunflower‐mustard strip intercropping may be useful in honeybee ( Apis mellifera L.) management and in reducing harvest losses of mustard.