Some factors affecting the field establishment of sub‐tropical pasture legumes in Rhodesia.

Abstract

The establishment of Stylosanthes guyanensis cv. Oxley (fine‐stem stylo) into reverted sandveld grassland and of Oxley stylo, Macroptilium atropurpureum cv. Siratro, Desmodium intortum, and D. uncinatum cv. Silverleaf in arable land, was studied in a series of field trials at Marandellas, Rhodesia.

More efficient establishment was achieved when the seed was drilled at a depth of 1 cm rather than broadcast on the soil surface. Burning immediately before discing, thorough discing, and rolling before and after drilling also improved the establishment of stylo in grassland. Heavy grazing during the winter following establishment, did not reduce the survival of stylo plants.

On arable land soil sterilization with methyl bromide increased emergence and winter survival of seedlings. Mulching, too, improved establishment. A range of pasture legumes was established satisfactorily under a maize crop. Where weeds were effectively controlled, seeding immediately after maize sowing was most efficient, but otherwise it appeared desirable to eliminate the early flush of weeds and to undersow the legumes about six weeks after the maize was sown.

Uittreksel

Die vestiging van Stylosanthes guyanensis cv. Oxley (fine‐stem stylo) in teruggekeerde sandveld grasveld en van Oxley stylo Macroptilium atropurpureum cv. Siratro, Desmodium intortum, en D. uncinatum cv. Silverleaf in bewerkbare land, is in ‘n reeks veldproewe te Marandellas, Rhodesië bestudeer.

Meer effektiewe vestiging is verkry deur saad op ‘n diepte van 1 cm onder die grond te plaas as met breedwerpige saaïng op die grond oppervlakte. Die vestiging van stylo in grasveld is ook verbeter deur te brand voor geploeg word, ‘n deeglike ploeg met skottelploeg, en deur te rol voor en.na planting. Swaar beweiding gedurende die winter wat op vestiging volg, het nie die oorlewing van stylo plante verlaag nie.

Op bewerkbare lande het grond sterilisasie met metiel‐bromide ‘n verhoogde ontkieming en winter oorlewing van saailinge tot gevolg gehad. Die gebruik van ‘n deklaag het ook vestiging verbeter, ‘n Reeks weldings peulgewasse is tot ‘n bevredigende mate saam met mielies gevestig. Waar onkruid effektief beheer is was die mees doeltreffende metode saaiïng onmiddelik na die mielies gesaai is. Andersinds was dit wenslik om die vroeë onkruide uit te skakel en om dan die peulgewasse te saai ongeveer ses weke nadat die mielies gesaai is.