29 September 2000

Good yields for crops despite the odd bout of torrential rain

MANY southern crops have now been harvested and despite this year being the most difficult for a decade, growers are reporting good yields of both plant biomass and cobs. When growers see the maize yields in a poor year like this it gives them greater confidence in growing the crop, believes Grainseeds Neil Groom.

Weather conditions since the last set of samples were taken have been poor, with cloud cover and torrential rain.

This has slowed dry matter accumulation so that crop DMs from samples taken on Sept 22 have only risen on the more difficult sites, and have dropped on good sites this week (see table) due to the crops vegetative state.

When we do get some good weather crop DM will rapidly increase and so its essential that they are looked at regularly and your contractor is kept informed of maturity.

Once fields have been harvested it is important to consider over-wintering. When maize is off by mid-October theres a chance of establishing Italian ryegrass or Westerwolds behind maize. If grass is unlikely to establish well then the field should be cultivated to prevent soil wash into watercourses and onto roads.

Even flat fields will produce run-off when maize stubble is left over winter because trailers and harvesters compact soil during harvest, slowing water penetration into soil.

Fields should be cultivated across the slope to help slow water movement down hill. Deep cultivations or ploughing are best since these will remove any pans in the soil structure, but even shallow cultivations help since they open up soil and aid water penetration.

Italian ryegrass or Westerwolds will provide some early spring grass for feeding livestock or silaging.

Grazing is preferable because if grass is cut and ensiled, maize stalks are often included in the clamp, introducing soil and reducing silage quality.

It is essential that this grass is not considered to be more important than the following maize crop and that the field is sprayed off and cultivated to allow maize to be sown at the optimum time. &#42

Maize harvest progress


Site Ht above sea level (m) Crop DM Sept 22 DM increase

Petworth, Sussex 50 26.4% -1.4%

Harleston, Norfolk 50 19.5% -2.0%

Crediton, Devon 118 23.7% +1.9%

Ticknall, Derbys 67 20.9% +1.1%

Gelli Aur, Dyfed* 23 21.0% +2.4%

Leyburn, N Yorks 107 19.3% +1.5%

SAC, Dumfries* 45 20.8% -0.1%

*Variety Nancis, all other sites are Sophy.