A NEW ENVIRONMENTAL FRIENDLY PRODUCTION METHOD IN SUNFLOWER FOR HIGH SEED AND CRUDE OIL YIELDS

Abstract

Biotic (pests, diseases and weeds) and abiotic (drought, cold, heat and salinity) stress factors cause to yield loss. Improvement of resistant or tolerant cultivar against these stress factors is the main target of plant breeding. Pesticides and other chemicals have been widely used to obtain high yield by fighting biotic stress factors (pests, diseases and weeds). However, use of chemicals in agriculture causes extra financial cost and environmental pollution. That is why, improvement of new methods for high yield is obligatory. Leaves in plants form active surface of photosynthesis. High photosynthetic activity affects yield directly by increasing matter production. The aim of this study was to increase photosynthetic activity in sunflower via leaf-removal (defoliation) and consequently to increase seed, crude protein and crude oil yields by increasing photosynthetic activity. Oil type sunflower cultivars used in the study ('08-TR-003', 'TR-3080' and 'TARSAN-1018') were obtained from "Trakya Agricultural Research Institute". When plants reached to star-shaped head stage which is the beginning of generative stage, 4 different leaf removal treatments which were control (no leaf removal), 2 leaves-removal, 4 leaves-removal and 6 leaves-removal, were performed. Half of the leaves was removed from just below the head while other half was removed from the middle part of the plant in each treatment. After harvest, seed yield per plant, seed yield per decare, crude protein percentage, crude oil percentage, crude protein yield per decare and crude oil yield per decare were calculated. At the end of the study, it was observed that a certain number of leaf-removal for each cultivar compared to control affected all agronomic characters positively.