Nitrogen Deficiency
This problem spreads through handling, insects or soil rather than the weather, so there is no live forecast risk — focus on prevention below.
When it strikes
About
Nitrogen deficiency is one of the most common nutrient problems, since nitrogen is mobile and leaches readily from soil, leaving plants pale and slow-growing, especially in wet springs and sandy soils.
Symptoms
Uniform pale green to yellow colour starting on the oldest lower leaves and moving up, spindly slow growth, and small pale new leaves; older leaves may drop early.
Organic Treatment
Feed with blood meal, fish emulsion, composted manure or a balanced organic fertiliser, and mulch with compost. Plant legume cover crops to fix nitrogen.
Chemical Treatment
A quick-release nitrogen fertiliser (such as ammonium sulfate or a balanced soluble feed) corrects acute deficiency within days.
Prevention
Build soil organic matter, use cover crops and compost, avoid leaching by not over-watering, and feed hungry crops through the season.