Sunflower Growth and Nutrient Uptake: Response to Tillage System, Hybrid Maturity and Weed Control Method
- Edward J. Deibert and
- Rodney A. Utter
Limited information is available on the influence of reduced tillage systems, weed control methods and hybrid maturity on growth and nutrient uptake of sunflower (Helianthus annus). A study was conducted during 1985 to 1986 on a Fargo clay (fine, frigid, montmorillonitic Vertic Haplaquoll) to evaluate plant growth, drymatter production, and N, P, and K content at vegetative stage (V-16), reproductive stage (R-5), and seed at harvest of early and late maturity hybrids as influenced by conventional tillage (fall plow) or reduced tillage (fall sweep, fall intertill, and no-till) and weed control by herbicides or herbicides plus cultivation. Plant height and dry-matter at V-16 were higher with reduced tillage in 1985 with limited precipitation, but lower than conventional tillage in 1986 with above normal precipitation. Hybrids performed similarly at V-16, but by R-5, height and drymatter were greater for the late hybrid. No-till and intertill systems produced more drymatter than plow at R-5. Maximum seed drymatter was produced with intertill and no-till in 1985, but in 1986 the plow system gave the highest seed production. Nutrient content in sunflower plants and seeds was similar between hybrids, weed control methods, and years. Nutrients in sunflower plants and seeds were similar among tillage systems even though lower nitrate-N and stratification of P and K in the soil was measured with reduced tillage. Results indicate that reduced tillage sunflower production with adequate weed control is similar to conventional plow systems and that early maturing hybrids produced yields comparable to late hybrids under these tillage and climatic conditions.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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