Floriculture - Disease and Pesticides

Which of these LD numbers would be the most toxic pesticide?

LD50 number of 51

Root growth bio-stimulants do all of the following except:

Increase respiration

Most plants grow best at pH of

6.2-6.8

The process whereby nitrogen is lost from the soil to the atmosphere is called __________________________.

denitrification

Which of the following is NOT a plant hormone that can be used as a plant growth regulator?

anthocyanin

Soil pH is based on the concentration of _____________ ions in the soil.

hydrogen

Lime furnishes _____________________, one of the most important of the macro food elements.

calcium

Auxin is responsible for apical dominance in plants. Auxin is produced in three places in the plant located in the_______________.

shoot tips, young leaf blades, and root tips

A complete fertilizer is recommended for a greenhouse crop. Which fertilizer analysis below is NOT a complete fertilizer?

10-0-10

Indolebutyric acid (IBA) is commonly used to:

promote rooting of cuttings

An acid loving plant grows best at a pH of ___________________.

4.5-5.8

Which of these groups contain the three secondary elements needed for plant growth?

Calcium, Magnesium, and Sulfur

Which plant hormone stimulates cell division?

Cytokinins

Foliage turning purple on a greenhouse plant shows a deficiency of:

phosphorus

IGR in horticulture is:

Insect Growth Regulator

Some cut flowers can benefit from a pre-treatment of citric acid. Citric acid is an acidifier. An acidifier can cause what benefit to some cut flowers?

It adjusts the acidity of the stem to a level that encourages the uptake of water and nutrients

Stunted and slow growth, yellowing of lower leaves of the plant, and a poor root system are symptoms of _____ deficiency.

nitrogen

What is a miniature arachnid that sucks sap from plants?

mite

What is the number one pest problem with poinsettias?

whiteflies

What are floral preservatives?

A combination of sugars, a biocide, and an acidifier

A chemical compound used as an additive to prevent the growth of bacteria in vase water is considered to be a

biocide

Of the following nutrient list which one includes only micronutrients?

Boron, zinc, copper, molybdenum, iron, manganese, and chlorine

Applying too much nitrogen to plants can cause adverse effects on plant growth. Of the following four items which is not a plant's response to excessive nitrogen:

Yellow or light green leaves on the plant

Auxin is produced in the shoot tips by a plant. The purpose of auxin in the plant is to:

Inhibit lateral branch development

Which pesticide LD50 number listed below is the most toxic?

LD50 of 45

A pesticide label cautions against dermal contact; this means the poison could enter the body by

contact with skin

_____________________ deficiency appears as a marginal yellowing or scorch on the edges of leaves on the lower portion of the plant.

Potassium

____________ are responsible for cell division and differentiation. They are produced in the roots and transported throughout the plant through the xylem.

Cytokinins

The pigment _____________ produces orange-yellow flowers.

carotene

Most essential elements for plant growth are available to most plants when the soil pH is between

5.5-7.0

Poinsettias are very susceptible to root rot diseases caused by Pythium, Rhizoctonia, and Thielaviopsis fungi. How can these disease problems be reduced?

Apply fungicides when appropriate and adhere to proper watering.

What is the best explanation why bedding plant seeds are sown in rows?

to reduce the possible spread of disease across an entire flat

If a plant is showing a yellowing in the leaves, it is most likely deficient in the nutrient:

Nitrogen

In the following list of pesticides the ________________ must be mixed with water to apply.

Emulsifiable concentrate

An acid loving crop grows best at a pH of ____________.

4.5-5.8

Auxins and gibberellic acid are hormones in plants that promote growth through ___________________.

cell enlargement

Botrytis often presents itself on flowers as gray mold. This disease is caused by a(an) __________.

fungus

When a plant is showing signs of ___________ deficiency, you might notice the leaves turning a dark to reddish leaf color.

phosphorus

_______________ is when a plant secretes a substance to inhibit growth of another plant.

Alleopathy

The first thing to do before applying a pesticide is ____________________.

read the label

Aluminum can affect the color of what florist's flower?

Hydrangea