Which of the following elements are responsible for delay in flowering?

In plants,a common symptom caused by the deficiency of $P, K, Ca$ and $Mg$ is the

It is observed that the deficiency of a particular element shows its symptoms initially in older leaves and then in younger leaves. How is the aspect of mobility of elements important to horticulture and agriculture?

Mottle leaf in citrus plants is due to the deficiency of:

The deficiency of calcium is observed in the absence of vitamin ...............

Plants grow in a magnesium-deficient soil,but what happens if urea is added to the soil?