H. Insects, Pollinators, and Birds:
Bees are beneficial to sunflower yield because they carry pollen from plant to plant which results in cross pollination. Some sunflower varieties will not produce highest yields unless pollinators are present. All varieties will produce some sterile seed (without meats), but varieties differ in their degree of dependence on insect pollinators. Autogamous sunflower hybrids do not require bees for maximum yield and will yield the same when covered by bags as uncovered. In non-autogamous sunflower varieties, pericarp (bull) development is normal but no ovules or meat develop. Wind is relatively unimportant in cross-pollination of sunflower. Some of the older open-pollinated varieties such as Peredovick set only 15 to 20% of seed without pollinators, whereas many hybrids set 85 to 100% seeds without pollinators.
Insect pests have become major potential yield-reducing factors in sunflower production in the northern Midwest (Table 4). Insects specific to sunflower that feed on the heads include the larvae of three moths; sunflower moth, banded sunflower moth and sunflower bud moth. Sunflower midge has caused widespread damage in some years. Sunflower headclipping weevil, sunflower beetle, sunflower maggot, wireworm, grasshopper, cutworm, sugarbeet webworm, ragweed plant bug, woolybear and painted.lady caterpillar have caused occasional damage to sunflower. Adults of insect pests of other crops (such as corn rootworm beetle and blister beetle) can be found as pollen feeders on sunflower heads, but usually cause little injury.
H. Insects, Pollinators, and Birds:
Bees are beneficial to sunflower yield because they carry pollen from plant to plant which results in cross pollination. Some sunflower varieties will not produce highest yields unless pollinators are present. All varieties will produce some sterile seed (without meats), but varieties differ in their degree of dependence on insect pollinators. Autogamous sunflower hybrids do not require bees for maximum yield and will yield the same when covered by bags as uncovered. In non-autogamous sunflower varieties, pericarp (bull) development is normal but no ovules or meat develop. Wind is relatively unimportant in cross-pollination of sunflower. Some of the older open-pollinated varieties such as Peredovick set only 15 to 20% of seed without pollinators, whereas many hybrids set 85 to 100% seeds without pollinators.
Insect pests have become major potential yield-reducing factors in sunflower production in the northern Midwest (Table 4). Insects specific to sunflower that feed on the heads include the larvae of three moths; sunflower moth, banded sunflower moth and sunflower bud moth. Sunflower midge has caused widespread damage in some years. Sunflower headclipping weevil, sunflower beetle, sunflower maggot, wireworm, grasshopper, cutworm, sugarbeet webworm, ragweed plant bug, woolybear and painted.lady caterpillar have caused occasional damage to sunflower. Adults of insect pests of other crops (such as corn rootworm beetle and blister beetle) can be found as pollen feeders on sunflower heads, but usually cause little injury.
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