Dry matter production curves of Ariki ryegrass pastures at Pretoria

Abstract

Irrigated Ariki ryegrass produced 13,7 and 9,2 m t/ha green dry matter during the first and second growing seasons respectively. It was most productive in spring, because the growth rate decreased throughout the growing season. This necessitated increasingly long periods of absence of 23, 39, 39 and 48 days under grazing conditions, to maximize dry matter production. During the same growing periods growth rates were 94, 73, 56 and 43 kg DM/ha/day respectively.

A highly significant, negative correlation was obtained between dry matter production and mean minimum temperature. The poorer late season production is probably associated with local temperature regime characteristics. More of this type of research under better controlled conditions is required.

Uittreksel

Besproeide Arikiraaigras het 13,7 en 9,2 m t/ha groen droëmateriaal in die eerste en tweede groeiseisoene, onder‐skeidelik, gelewer. Dit was mees produktief in die lente, omdat die groeltempo gedurigdeur afgeneem het tydens die loop van die groeiseisoen. Gevolglik was toenemend longer afwesigheidsperiodes van 23, 39, 39 en 48 dae onder beweide toestande nodig om droëmateriaalproduksie te maksimaliseer. Gedurende dieselfde groeiperiodes was die groeitempos 94, 73, .56 en 43 kg DM/ha/dag, onderskeidelik.

‘n Hoogsbetekenisvolle, negatiewe korrelasie is verkry tussen droëmateriaalopbrengs en gemiddelde minimum temperature. Die laer laatseisoen produksie is waarskynlik gekoppel aan lokale temperatuurregime eienskappe. Meer navorsing van die soort onder beler heheerde toestande word benodig.

Notes

New Address: Computer Section, Department of Agricultural Technical Services, P.B. XI116, P.O. Vallis, Pretoria.