Effect of different organic manures on oil flax dry matteraccumulation, distribution and yield

To realize oil flax (Linum usitatissimum Linn) high yield and good quality, field experiments were conducted in Baiyin and Lanzhou Cities of Gansu Province and Ordos City of Inner Mongolia Autonomous Region. The study compared the effects of the applications of four different fertilizers on oil flax dry matter accumulation and distribution and yield. The four fertilizers included farmyard manure (T3), oil flax residue (T4), and "Qingtiaobu" (T5) and "Woliheng" (T6) bio-fertilizers. Treatments without fertilizer (T1) and with chemical fertilizer (T2) were used as controls. The results showed similar trends in oil flax dry matter accumulation under all the fertilizer treatments in three different experiment sites with the order of T4 > T2 > T3 > T6 > T5 > T1. Fitted logistic equations of oil flax dry matter accumulation in all the three sites were significant at P < 0.01. The maximum rate of dry matter accumulation generally occurred at squaring stage, or at young fruit stage when planting date was delayed. Days for dry matter accumulation increasing with time in straight line and maximum accumulation rate in the three sites were in the order of T3 > T2 > T4 > T5 > T6 > T1 and T4 > T2 > T3 > T6 > T5 > T1, respectively. Dry matter distribution ratios of flowers and fruits at ripping stage under different organic fertilizer applications were higher than that under the controls. Pod number per plant, seed number per pod and thousand-grain weight of T4 were significantly (P < 0.01) higher than those of the controls. Pod number per plant, seed number per pod and thousand-grain weight of T3 were higher than those of T2, but the differences were insignificant across the three experi-mental sites. Both T3 and T4 yields increased by 22.85%~45.40% and 62.83%~88.13% over treatments without fertilizer. Also yields of T5 and T6 increased by 15.14%~18.10% and 17.65%~21.01% over treatments without fertilizer. Yield of T4 signifi-cantly increased by 9.58%~39.49% over the treatment with chemical fertilizer. Yields of T5 and T6 significantly decreased by 14.63%~20.52% and 12.77%~18.57% over treatments with chemical fertilizer. Though yield of T3 decreased by 1.50%~8.91% over treatments with chemical fertilizer, the difference was not significant. Oil residue and farmyard manure were therefore the recommended fertilizers for enhanced development of organic production of oil flax.