LATVIA UNIVERSITY OF AGRICULTURE - Latvijas ...

Mihails Vilcāns, Jūlija Volkova, Zinta GaileINFLUENCE OF SOWING TYPE, TIME AND RATEON THE BUCKWHEAT YIELD FORMING ELEMENTSSowing rate, seeds, m 2Sowing dateFigure 6. Plant survival in plots depending on different sowing times, rates and methods.A■ – column sowing; B□ – drill sowing.effect was observed in the trials sown by drill sowingmethod. Plant losses were lesser when lower sowingrates (200 seeds m -2 ) were used. Conditions were notsuitable for the establishment of an optimum plantdensity for sowings of 15 th and 20 th of May. Thegreatest difference was obtained in the trial with ahigher seeding rate (Fig. 6).Evaluating the plant density we found that theplant survival was higher in trials sown by columnsowing method if compared with the drill sowingmethod. This trend is attributed to the fact that columnsowing method is more suited to the optimal growth ofbuckwheat (Upmanis, 1957). There is an evidence ofthe plant competition which leads to losses of the partof the emerged plants if compared with the plots sownwith different sowing rates for each sowing method.As a result of the higher density it is more likelihoodto plant losses.Productivity of plants. Sowing rate is the primarycause of plant density, but plant density is closelyrelated to individual plant productivity. It follows thatincreased sowing rate results in a reduced individualplant productivity, and vice versa, a reduced sowingrate causes increase in the individual plant productivity.The choice of a correct sowing rate is an importantprecondition to obtain on optimal plant density, aswell as the corresponding plant productivity. It shouldbe noted that buckwheat yield not always depends onplant density in a sowing. Buckwheat yield formationelements in 2010 developed in close relationship withmeteorological conditions. Plants sown in earliersowing times suffered from moisture insufficiency andhigher air temperature from beginning of flowering tobeginning of the nutlets filling, if compared to plantssown at later times (30th of May to 9th of June). Itwas also found that meteorological conditions duringthe 2010 growing season were not suitable for a highbuckwheat yield formation. Investigations will becontinued.Conclusions1. Plants of late sowing dates pass developmentphases faster and accelerate the term of buckwheatripening.2. It was observed that the plant survival was higherin trials sown by column sowing method ifcompared with the drill sowing method.3. Use of lower sowing rates (150 seeds. m -2 forcolumn sowing and 200 seeds. m -2 for drillsowing) contributed to increased individualplant productivity - the number of branches andinflorescences per plant. A close relationship(p