PHOTOSYNTHETIC INDICES AND YIELD OF SWEET CORN EARS DEPENDING ON TRANSPLANTING DATES AND MULCHING MATERIAL TYPE UNDER THE CONDITIONS OF THE MIDDLE CIS-URAL REGION
This paper discusses three-year data of photosynthetic activity indices of sweet corn and their influence on the yield of sweet corn ears depending on the dates of transplanting open-ground and different types of mulching materials. The studies were conducted at the scientific training center UNTs “Lipogorye” of the Perm State Agricultural Academy from 2011 to 2013. The following mulching materials were used: peat; transparent polyethylene film 120 µm GOST 103-54; black polyethylene film 120 µm OST 103-54; white horticultural fleece (Spantex) TU 839001-75-748288-2005 N 60; black horticultural fleece (Spantex) TU 839001-75-74-8288-2005 N 60. No mulching material was used in the control variant. Sweet corn seedlings were transplanted open-ground on May 15, May 25, June 5 (control), and June 15. The research target was sweet corn F1 hybrid “Utrennyaya pesnya”. The experiment was conducted in five replications; the layout of the variants was systematic. The planting layout was 70 × 30; planting density - 4.8 plants per sq. m. The cultivation of seedlings and plants open-ground was common for tilled crops of this zone. The three-year long research has found that the maximum yield of marketable ears is formed when seedlings are transplanted open-ground on May 25, and transparent polyethylene film and white horticultural fleece are used as mulching materials; the yield makes 28.8-30.3 t ha. It is during this time when higher photosynthetic activity indices are revealed, and this confirms the main patterns of the crop yield formation.