Potential of Sunflowers for Silage in Double-Cropping Systems Following Small Grains

Sunflowers (Helianthus annus L.) are a drought tolerant and high dry matter producing crop. Due to these properties, sunflowers might find use as a silage crop in double-cropping systems where moisture supplies are limited. The objective of this study was to evaluate cultural practices and sunflower cultivars which would enhance forage quality and yield. Oil and confectionary sunflower cultivars were handplanted in a factorial experiment at populations of 71.8, 143.6, and 287.2 thousand plants/ha in 1973; and 86.1, 172.1, and 344.3 thousand plants/ha in 1974. Fertilizer was applied at rates of 56-49-93 (low) and 112-98-186 (high) kg N-P-K/ha. The experiment was conducted in the field on a Chester silt loam (fine-loamy, mixed mesic Typic Hapludults) in 1974 and an Elsinboro loam (fine-loamy mixed mesic Typic Hapludults) in 1975. In a second field experiment conducted from 1973 to 1975, sunflowers, corn (Zea mays L.), and sorghum (Sorghum bicolor L. Moench) were no-tillage planted into barley (Hordeum vulgare L.) stubble using conventional farm machinery following the removal of the small grain. Populations of sunflowers, corn, and sorghum were 128, 46, and 366 thousand plants/ha, respectively. In 1973 and 1974, the experiment was located on a Delanco silt loam (fine-loamy, mixed mesic Aquic Hapludults) and in 1975 on a Chester silt loam (fine-loamy, mixed mesic Typic Hapludults). Confectionary cultivars produced more dry matter/ha than oil cultivars. All sunflowers had low forage quality. Dry matter yields were greater at higher populations up to 344.4 thousand plants/ha, but at higher populations lodging occurred. Fertilizer application had no effect on silage yield or forage quality. In the second experiment sunflowers were found to be as productive as corn and matured in a shorter period of time. Results from these experiments indicate that sunflowers can be competitive with corn in terms of dry matter production when planted in a double-cropping system; however, low-forage quality is a limiting factor in potential use of sunflowers for silage in the northeast.