SYMPTOMS
Leaves turn yellow, hang, and then turn brown and die. Look for stipples (pinpricks) and fine webs on leaves.
DIAGNOSIS
mites: two-spotted spider mite (Tetranychus urticae), carmine spider mite (Tetranychus cinnabarinus), hemp russet mite (Aculops cannabicola)
SOLUTIONS
• Sanitize
• Use beneficial insects
• Use beneficial mites
• Use beneficial fungi
• Use kaolin
• Use insecticidal soap
• Use neem
• Use horticultural oil
• Manage humidity
SYMPTOMS
Leaves turn yellow and droop, then become puckered and distorted. Plant may wilt and die. Leaves coated with clear, sticky, varnishlike substance on which gray-black mold grows. Look for small, pear-shaped insects with two “tailpipes” on their rear ends clustered on the undersides of leaves. They can be any color. Ants may also be present; they bring and protect aphids.
DIAGNOSIS
aphids: green peach aphid (Myzus persicae), black bean aphid (Aphis fabae), hops aphid (Phorodon humuli), hemp louse (Phorodon cannabis)
SOLUTIONS
• Sanitize
• Use screens on doors, vents, and windows
• Use traps
• Use beneficial insects
• Use beneficial fungi
• Use kaolin
• Use hot-pepper spray
• Use insecticidal soap
• Use neem
• Use horticultural oil
If there are ants:
• Use traps
• Use diatomaceous earth
SYMPTOMS
Leaves turn yellow and wilt. They become coated with clear, sticky, varnishlike substance on which gray-black mold grows. A cloud of tiny, bright white insects flies up when plants are disturbed. Insects cluster on leaf undersides.
DIAGNOSIS
whiteflies: greenhouse whitefly (Trialeurodes vaporariorum), sweet potato or tobacco whitefly (Bemisia tabaci), silverleaf whitefly (Bemisia argentifolii)
SOLUTIONS
• Sanitize
• Use traps
• Vacuum adult insects from the air
• Use beneficial insects
• Use beneficial mites
• Use beneficial fungi
• Use garlic spray
• Use insecticidal soap
• Use neem
• Use horticultural oil
• Use pyrethrin
• Do not plant near eggplant, sweet potato, tobacco, or cotton
SYMPTOMS
Leaves are coated with clear, sticky, varnish-like substances on which gray-black mold grows. Tiny, white, cottony, waxy bumps appear on the undersides of leaves and on axils (where leaves attach to stems).
DIAGNOSIS
mealybugs: long-tailed mealybug (Pseudococcus longispinus)
SOLUTIONS
• Sanitize
• Remove pests by hand
• Use beneficial insects
• Use insecticidal soap
• Use neem
• Use horticultural oil
SYMPTOMS
Leaves are coated with a clear, sticky, varnish-like substance on which gray-black mold grows. You find reddish brown, mottled brown, tan, or white to reddish pink bumps on leaf undersides and axils (where leaves attach to stems).
DIAGNOSIS
scale: cottony cushion scale (Icerya purchasi), European fruit titanium (Parthenolecanium corn), hemispherical scale (Saissetia coffee), white peach scale (Pseudaulacaspis pentagonal)
SOLUTIONS
• Sanitize
• Remove pests by hand
• Use beneficial insects
• Use insecticidal soap
• Use neem
• Use horticultural oil
SYMPTOMS
Young leaves at the tops of plants turn yellow. Stems are thin, brittle, stiff, and break easily. The plant is stunted and may wilt.
DIAGNOSIS
sulfur (S) deficiency
SOLUTIONS
• Create healthy soil
• Measure and modify pH
• Manage essential nutrients
SYMPTOMS
Leaves are dark blue-green and smaller than usual. Leaf tips curl downward and turn brown. The plant is stunted and slow to flower, and yield is poor.
DIAGNOSIS
phosphorus (P) deficiency
SOLUTIONS
• Create healthy soil
• Measure and modify pH
• Manage essential nutrients
SYMPTOMS
Leaves turn yellow and may exhibit gray specks. Leaves twist and become deformed. Apical buds at the top of the plant and lateral buds in leaf axils (where leaves attach to stems) turn brown and die.
DIAGNOSIS
boron (B) deficiency
SOLUTIONS
• Create healthy soil
• Measure and modify pH
• Manage essential nutrients
SYMPTOMS
Young leaves at branch tips turn pink, grow very pale, twist and deform, and then wither.
DIAGNOSIS
molybdenum (Mo) deficiency
SOLUTIONS
• Create healthy soil
• Measure and modify pH
• Manage essential nutrients
SYMPTOMS
Leaf tips and edges turn brown, but plants have plenty of water. You see no black specks in brown tissues.
DIAGNOSIS
pesticide damage: phytotoxic reaction
SOLUTIONS
• Stop using pesticides
• Wash pesticide residue off plants