A question we get from time to time is how to control Onion or Guildford Grass (Romulea rosea) in pasture:
Note: this is not the same as Onion weed or Nut Grass (rarely seen in pasture, mainly undervine). Onion grass is a perennial herb with distinctive growth behavior. It looks like a grass, grows like an annual, and can spread rapidly . The plant not only produces abundant seed, but also corms underground to survive the hot and dry summers in Mediterranean environments of temperate Australia. Originated from South Africa.Generally found in areas with low competition from other perennial plants due to low fertility, overgrazing, fire or poor seasonal conditions. Causes:The two main causes of onion grass infestation are autumn bare ground and lack of competition from desirable pasture species. Prevention involves managing pastures to maintain above 70 per cent ground cover and maximising growth during autumn and winter. Make sure you have a high proportion of desirable perennial specie…
DJ's agronomist Sam Freeman looks at why olive trees turn yellow in winter.
Olive foliage is naturally green, persisting for about two years on the branches in all seasons. There are two main reasons that an
olive tree may have yellow leaves at this time of the season.
If there are justa few yellow leaves scattered throughout the canopy,
it may be natural senescence. Since olive trees are not deciduous, they
have continual leaf loss through the season. Most olive leaves have a
lifespan of two to three years, at which point they will yellow and fall
If themajority of the canopy is yellow, it may be a nutrient deficiency that is causing the yellow leaves. Olives do not need a particularly nutrient rich soil, but yellow leaves is an indicator of low plant nutrient levels. A little
additional fertiliser once a year early in late winter or spring does improve plant nutrient status, leaf colour and boost the
production of your olive trees.
If the yellowing is no…