Maize update

Published 19 July 13

While the recent spell of dry and very warm weather has all but stopped grass growth, it has boosted maize crops in all but a very few circumstances, says John Morgan from the Maize Growers Association.

As a general rule, the height of maize plant above ground is similar to the depth of the root down below (assuming good soil structure of course).  For this reason, early established crops which were at or close to the “Knee high by the fourth of July” should have had knee deep roots and have been able to access moisture and grow spectacularly over the last couple of weeks.  

As these well established crops grow taller, their roots go deeper and chase the water down though the soil profile.  For this reason, crop yields are likely to be back on or even set to exceed targets this coming harvest.  In contrast, crops drilled later or established in poorly structured soils are suffering from lack of moisture, in a similar manner to grass.  Soil moisture has either evaporated from above or fallen below these smaller plants’ rooting zones and as a result leaves have started to curl as moisture deficits start to show.  While maize is exceptionally good at making use of limited water supplies it cannot thrive without any and as a result these droughted crops are unlikely to do anything until we get more rain. 

Further good news in relation to the maize crop is the lack of eyespot in this year’s crops.  Maize eyespot likes moist and cool conditions, typical in marginal maize growing areas where crops have had to be treated routinely in recent years. This year’s dry and hot conditions have not just kept the disease at bay but in effect knocked it on the head, allowing farmers to save some valuable fungicide costs. 

Looking ahead, the bulk of the country’s maize crops look set to produce good yields on time or even a little early this year.  Particularly impressive are crops grown under plastic film which, having had a great start earlier in the year, have been ideally suited with large leaf canopies to make the most of the sunshine. 

Last week’s MGA study tour to Southern Ireland and more local visits to West Devon this week saw seven-foot tall maize with tassels, emerging from maize that was drilled under plastic in early April. 

Drought-affected maize needs walking to see the extent of any problems, and decisions made now, where options exist, to boost winter forage stocks with wholecrop cereals or alternatives.