Effect of Vegetation Rainfalls on Grain Yield from Lentil (Lens culinaris Medic) under the Conditions of Dobroudja (Bulgaria)

G. MILEV

Institute for Wheat and Sunflower “Dobroudja”, BG-9520 General Toshevo, Bulgaria

Abstract

MILEV, G., 1999. Effect of vegetation rainfalls on grain yield from lentil (Lens culinaris Medic) under the conditions of Dobroudja (Bulgaria). Bulg. J. Agric. Sci., 5: 561-566

In the period 1996 – 1998 at the experimental field of the Institute for Wheat and Sunflower “Dobroudja”, a field trial was carried out with three lentil varieties – Naslada, Stanka 2 and Nadejda on a slightly leached chernozem. The aim of the study was to determine the effect of vegetation rainfalls on grain yield from the lentil varieties bred in IWS “Dobroudja”. Three sowing norms were tested – 350, 400 and 450 germinating seeds/m² with a nitrogen dressing norm of 3 kg/dka. The trial was conducted according to the method of split plots in four replications of the variants, the harvest plot size being 12 m².
The analysis of yield in accordance with the factors considered in this study revealed that the yield is most strongly related to the vegetation rainfalls in the respective year, followed by the genetic potential of the variety, and to a lesser degree – to the sowing norm. Excessive rainfalls during flowering decreased the grain yield. The main reason for the yield decrease under the effect of excessive moisture supply during the second half of lentil vegetation was the occurrence of unfavorable conditions for flowering, as well as the abundant growth of vegetation mass leading to diseases. The variety Naslada was relatively tolerant to excessive moisture supply. The varieties Stanka 2 and Nadejda demonstrated a strong negative reaction to moisture supply above the norm. Rainfalls over 100 mm during flowering and pod formation are above the norm for normal growth and development of lentil.

Key words: lentil (Lens culinaris Medic), vegetation rainfalls, Dobroudja (Bulgaria), grain yield