Section 4: Check lists for problem identification

When you are in the field looking at your crop, check it initially by running down the eyeball checklist (page 12). After your first attempt you will be able to do the eyeball check automatically. That check should provide you with enough information about the crop to use the following four check lists which deal with successive crop stages. The checklists will guide you to detailed descriptions of the problems and their solutions.

Check list for planting to the two-leaf stage (Z0.0 to Z1.2)

Is the young crop stand poor?

Problem where?	What you see	What may be wrong	see page

In whole crop	Emerged leaves look weak	seed planted was old	39
	- with poor colour	seed planted too deep	40
		seedlings are diseased	76
		herbicide damage	60
		high soil temperature	27, 42
		too little water at sowing	35

In patches	unemerged seedlings bent	soil crusted	37
	uneven emergence	water stress	41
		seed depth not uniform	40

	emerged leaves look weak	poor soil preparation	38
		residues incorporated unevenly	62
		waterlogging	68
		insects	70
		diseases	76

	emerged leaves look normal	low seeding rate	42
	- but too few plants	some seeds were dead	39
		weeds are dominant	59
		birds removed seedlings	40
		Insects removed seeds	70
Browse p 35-42 for general information about this stage

Check list for three-leaf stage to spike emergence (Z1.3 to Z5.0)

Is crop ground cover low?
Are there too few shoots?
Are there too few spikes?

Problem where?	What you see	What may be wrong	See page

In whole crop	thin canopy	seed planted too deep	40
		low seeding rate	42
		too little water	66
		poor nutrition	51
		low radiation and high temperature	29
		frost	26

In patches	thin canopy	diseases	73
		insects	70
		weeds are dominant	59
		waterlogging	68

Does the crop not look healthy?

Problem where?	What you see	What may be wrong	See page

In whole crop	lighter coloured band across expanding leaves	frost	25
	banding on spikes	frost	25
	wilted leaves	too little water	66
	leaves look unhealthy	poor nutrition	51
	too many older leaves dead	saline soil or salty water	33
		frost	26

In patches	leaves look diseased	diseases	75
	leaves took diseased	poor nutrition	51
	plants or leaves are physically damaged	insects	70
	older leaves have yellow tips	waterlogging	68
	crop stems bent, plants lying down	lodging, foot rots	49
Browse pages 43-46 for general information about this stage

Check list for to early kernel growth (Z5.0 to Z7.02)

Do the spikes look abnormal? Is kernel number low?

What you see	What may be wrong	see page

Few small spikes, spikelets at tip and base of ear may be empty	water stress	64

band on spikes with empty spikelets	frost	25

dark spikes with no grain	low temperatures	25

florets gaping open with shrivelled anthers	frost	25
	boron deficit on alkaline soil	30

few grain number per spikelet	low radiation and high temperature	29
	nutrient deficit	51
empty spikelets randomly within spike	boron deficit on alkaline soil	30

	birds
patches of damaged spikes	diseases	78
	insects	70

Check list for to harvest ripeness (Z6.8 to Z9.2)

Are kernels small or shrivelled?

What you see	What may be wrong	see page

small kernels	water stress	64
	high temperature, winds	27
	lodged crop	49
	frost	25

too few green leaves (check pages 46-49)	water stress	64
	late nutrient deficit	51
	diseases	78
	insects	70