It seems that perennial ryegrass seed crops are more advanced than usual for this time of year. This will have an impact on closing dates.
It appears that perennial ryegrass growth stages are running earlier than expected, particularly in South Canterbury, south of Timaru. A cultivar ‘Nui’ crop was observed at an average of growth stage (GS) 31, with approximately 30 % of developing tillers being further advanced with their growing points about 7 cm above ground level. A second paddock of ‘Colosseum’ was also observed to be between GS 30 and 31, again further advanced than expected. Obviously this will have an impact on closing dates.
Growers should check the growth stages of perennial ryegrass seed crops to ensure that no more than 5 % of growing points are being grazed off. This can be done by cutting tillers lengthwise and observing where the growing point is located. Where greater than 5 % of growing points are at risk of being removed, options include; lax grazing (above the height of growing points), topping or closing the crop now and managing lodging via an increased plant growth regulator programme.
Crops that have not been grazed or have only been laxly grazed over winter should be checked first.