Primary symptoms

Poor, uneven or weedy stands occur due to poor land preparation, poor seed, poor planting practices (too deep or too shallow) and/or delays in planting.

Poor crop stands arise due to a number of problems.

Summary

Poor planting

Wheat has the useful growth habit that it tillers. A few plants can therefore produce many leaves in a relatively short time to exploit the resources of a land surface. This means that seedlings do not have to be spaced perfectly as tillers will eventually fill most of the gaps in a crop canopy. However, it takes longer to fill gaps by tillering than if all seedlings emerge at the same time and at uniform spacing, and time can be important to yield. Poor crop canopies are the major constraint to yield, particularly in warm areas (Ageeb 1994, Olugbemi 1994). Poor canopies result from one or more of the following: poor seedbeds; seedbed too dry; poor seed; and poor planting technique. Planting at the ‘wrong time’ can make these problems worse.