General Questions on Vegetable Gardening

Thanks for sharing Sundari.

 

Ami Dear
Sorry I saw so late... I searched for this on the internet... looks like the problem is worms.. only thing I can think of is maybe spraying with insecticide spray..
Really hope this helps

 

Found these sources for you Ami. Its my opinion the plant and especially the leaves are infected. Please spray before the infection spreads. Hope this helps


Disease on Sunflower plants and leaf

ALTERNARIA LEAF AND STEM SPOT, Alternaria zinniae and Alternaria helianthi
Symptoms. Circular to angular spots develop on the leaves. The spots are uniformly dark and often associated with the main veins. Dark-colored elliptical spots, streaks, flecks, or diamond-shaped spots without a definite margin may occur on the stem or leaf petiole. Dark circular spots may also occur on the back of the head. Seedling blight may occur if seedlings emerge in rainy weather in a field with infected crop residue.
Survival and Spread. Survives on infected crop residue. Spread is by airborne spores. Favored by wet weather and warm temperatures.
Other Crops Affected. Safflower and cocklebur.
Control. Crop rotation and burial of infected crop residue. Avoid planting into field with infested sunflower stubble.


SEPTORIA LEAF SPOT, Septoria helianthi
Symptoms. Watersoaked spots develop on the leaves. These spots are roughly circular and develop gray to tan centers with dark brown margins surrounded by an area of yellow. Spots may merge, producing irregular dead areas on the leaves.
Survival and Spread. Survives on infected sunflower crop refuse. Spread is by water-splashed spores and is favored by rainy weather or center pivot-irrigation.
Control. Crop rotation and burying crop refuse.


Stem and Leaf Diseases � Bacterial
APICAL CHLOROSIS, Pseudomonas tagetis
Symptoms. Severe yellowing develops on the uppermost leaves of sunflower plants. Part or most of the leaf may be yellowed. This condition may develop anytime from emergence until the flower buds appear. Affected plants usually recover, but seedlings may be killed.

Survival and Spread. Seed-borne.
Control. Unknown, but at present the disease is not severe enough to require control.

Problems affecting foliage of Sunflowers

Light brown to black, spiny caterpillars, with a pale yellow stripe on each side, feeding on leaves in late June or early July. Larvae can often be detected by webbing.
………………………………………………………………………………………….Thistle caterpillar

Defoliation caused by ¼ to ½ inch long beetles with reddish‑brown head, cream‑colored back with three dark reddish‑brown stripes on each wing cover and/or yellowish‑green, hump‑backed larvae during June and July. ………………………………………………………………………………………….Sunflower beetle

Sudden death of plants (sunflower and weeds) in the affected circular area (50 to 100 feet in diameter). Stalks often have a brown to black pith.
…………………………………………………………………………………………..Lightning

Brown pustules on lower leaves and sometimes stems later in the season. Severely diseased leaves yellow, dry up, and die.
………………………………………………………………………………………….Rust

Creamy white, blisterlike pustules on lower leaves. Tissue on upper leaf surface opposite the pustule is raised and yellow green.
…………………………………………………………………………………………White rust

Lower leaves mottled by yellow or brown tissue between veins. Black areas on stem near soil line. Stem interior brown to black. Severely infected plants are stunted and may ripen prematurely or die before flowering.
…………………………………………………………………………………………Verticillium wilt

Water‑soaked, circular spots, gray with a dark margin and perhaps surrounded by a diffuse narrow yellow ring. Defoliation may occur.
…………………………………………………………………………………………Septoria leaf spot

Lighter green to definite yellowing of leaves. Definite chlorotic yellowing of lower leaves later in season. ………………………………………………………………………………………….Nitrogen deficiency

Stunted plants. Necrotic gray lesions possible on older leaves.
……………………………………………………………………………………….Phosphorus deficiency

Plants stunted, upper leaves distorted, leaves may wilt.
………………………………………………………………………………………….Zinc deficiency