Grass growth in Northern Ireland for the season so far is down almost a third compared to the 10-year average.
The figures relate to plots at the Agri-Food and Biosciences Institute (AFBI) Hillsborough, which are used as a control site for grass growth research in Northern Ireland.
AgriSearch general manager Jason Rankin said: "Normally, at this time of year, we would have grown 4.2t on our plots. We've only grown 2.6t so far - so that's only 68% of what we would normally have grown."
The latest GrassCheck bulletin shows growth rates of 72.7kg/ha/day on the control plots, and averages of 58.8kg/ha/day on dairy farms and 64.7kg/ha/day on beef farms across Northern Ireland.
"Growth on farms would be broadly similar," Rankin said. "For the last week or two, the plots have been almost ahead in terms of growth, but just before that the farms would have been.
"The difference is that the plots have a rigid three-week interval, while the farms would be more flexible with their grazing."
Growth surge expected
Rankin explained it was the result of a combination of both colder weather and less rainfall, but with temperatures starting to rise growth is expected to take off over the next few weeks.
Growth is expected to soar over the next two weeks with the seven-day forecast at 93.5kg/ha/day and 14-day forecast at 115.7kg/ha/day
The most recent management notes suggest that, if possible, grass should be measured every five days.
"Be prepared to react quickly to surplus grass," this week's GrassCheck advisory notes state.
"Due to the recent heavy rain, achieving target residuals has become challenging, prioritise drier paddocks if possible.
"Depending on average farm cover, it could be an option to skip paddocks on heavier ground and harvest with first cut silage, or as round bales, when ground conditions improve.
"Try to take advantage of the forecasted settled spell of weather to harvest first-cut silage. Once seed heads appear in the crop, the D-value of the silage will reduce by 1% every two to three days."