Oil and Protein in Field Crops Treated with Morphactins and other Growth Regulators for Senescence Delay

Studies were conducted to determine whether growth regulators which delay senescence also affect oll and protein in flax (Linum usitatissimum L.), soybean [Glycine max (L.) Merr.], wheat [Triticum aestivum (L.) em. Thell.], and oats (Avena sativa L.). Treatment with a morphactin, chlorflurenol (methyl 2-chloro-9-hydroxytiuorene-9-carboxylate), significantly increased percent oil in all four crops. Levels of increase were 0.1 to 0.3 percentage units for the cereals, 0.3 to 1.6 units for soybean, and 0.8 to 4.8 units for flax. Dichlorflurenol (methyl 2,7-dichloro-9-hydroxyfluorene-9-carboxylate) also increased percent oil but to a lesser degree than chlorflurenol. Optimum treatments were 25 g/ha (chlorflurenol) and 100 g/ha (dichlorflurenol) applied postbloom for flax or at R6 stage for soybean, and 1000 g/ha (either chemical) applied 4 to 5 days postanthesis for the cereals. The increase in percent oil was consistent over several years of testing for flax and soybean. Percent protein declined as percent oil increased in flax and soybean but not in the cereals. Yield of oil per hectare was more closely associated with seed yield than with percent oil for all crops. As a result, oil yield of flax was significantly increased by chlorflurenol treatment in two of seven trials and significantly decreased in one trial. Seed size of flax declined as percent oil increased, except when treatment was late in the life cycle, when rate was reduced, or when dichlorflurenol was used instead of chlorflurenol. No relations between seed size and change in oil percent were observed for the other crops. Treatments which raised percent oil also delayed canopy yellowing for flax and soybean but not for the cereals. Iodine value of flax usually was not affected by morphactin treatment. Further research is needed to determine causes of the changes in chemical composition and to adapt the technique to commercial practice.