Feed Your Lemon Right! Quiz

Explore key principles of citrus fertilization, including nutrient management and common challenges for healthy orchard yields. Useful for growers, gardeners, and students interested in optimal citrus production.

1. Understanding Nitrogen Application

   What is the primary reason for applying nitrogen fertilizer to lemon trees in early spring?

   1. To enhance fruit color development
   2. To support new leaf and shoot growth
   3. To increase cold resistance for winter
   4. To control soil-borne pests

   Explanation: Nitrogen is most beneficial for supporting vigorous vegetative growth, especially in early spring when lemon trees begin producing new leaves and shoots. Enhancing fruit color development and increasing cold resistance are not direct functions of nitrogen. Controlling soil-borne pests is not achieved with nitrogen application.

2. Detecting Nutrient Deficiencies

   Yellowing of older leaves on a citrus tree is most commonly a sign of which nutrient deficiency?

   1. Iron
   2. Phosphorus
   3. Potassium
   4. Nitrogen

   Explanation: Yellowing (chlorosis) of older leaves typically indicates nitrogen deficiency, as nitrogen is mobile and moves from older leaves to new growth. Potassium deficiency usually causes leaf edge discoloration, phosphorus results in stunted growth, and iron deficiency appears as yellowing in new leaves rather than old.

3. Safety in Fertilizer Use

   Why should citrus fertilizer be spread evenly around the drip line rather than placed close to the trunk?

   1. To decrease evaporation loss
   2. To avoid root burn and ensure uniform nutrient uptake
   3. To keep fertilizer dry
   4. To accelerate trunk thickening

   Explanation: Even distribution around the drip line prevents root burn and promotes uniform nutrient uptake, as feeder roots are concentrated there. Trunk thickening is unrelated to fertilizer placement, keeping fertilizer dry is not a concern, and evaporation loss is negligible for granular fertilizers.

4. Organic Matter Benefits

   How does adding well-rotted compost benefit fertilization of citrus trees?

   1. Eliminates the need for irrigation
   2. Increases soil nutrient retention and microbial activity
   3. Repels insect pests from roots
   4. Provides immediate high doses of nitrogen

   Explanation: Compost improves soil structure, enhances nutrient retention, and fosters beneficial microbes. It does not provide a quick high dose of nitrogen, cannot replace needed irrigation, and does not directly repel insect pests from roots.

5. Timing of Potassium Application

   At what citrus growth stage is supplemental potassium most critical for optimal lemon fruit production?

   1. During fruit development and enlargement
   2. In the dormant winter period
   3. At bud break in early spring
   4. Immediately after harvest

   Explanation: Potassium is essential during fruit development and enlargement for good yield and fruit quality. Application at bud break or after harvest is less beneficial for the current crop, while trees are generally less responsive to nutrients in winter dormancy.