Nader Assad*(1) Safaa Kumari(2) Amin Haj-Kassem(3) Salah Al-Chaabi(4) and Attia Arab(4)
(1). AlGhab Research Center, General Commission for Scientific Agricultural Research (GCSAR), Damascus, Syria.
(2). Torbol Station, International Center for Agriculture Research in Dry Area (ICARDA), Albekaa, Lebanon.
(3). Department of Plant Protection, Faculty of Agriculture, Aleppo University, Aleppo, Syria.
(4). General Commission for Scientific Agricultural Research (GCSAR), Damascuse, Syria.
(*Corresponding author: Nader Assad. E-Mail: firstname.lastname@example.org).
Received: 21/03/2020 Accepted: 12/05/2020
Field experiments were carried out during 2017/2018 cropping season to study the effect of three planting dates (5 December, 25 December and 15 January) and five seed rates (80, 100, 120, 140 and 160 kg/ha) in two different sites/locations (Al Ghab Research Center and Jeb Ramleh Research Station/ Syria) on the chickpea infection with luteoviruses (aphid-born persistently transmitted viruses), which causing yellowing and stunting symptoms under natural infections. Tissue blot-immunoassay (TBIA) results showed that luteoviruses (family Luteoviridae) were the main causal of stunting and yellowing symptoms on randomly selected chickpea plants. High level of significant differences (P < 0.001) were recorded within the two experimental sites/locations. The early sowing date (5 December) reduced the percence of virus incidence by 75 and 85%, and grain yield were increased by 3.5 and 30.9% compared to other sowing dates (25 December and 15 January, respectively). Also, incidence of luteoviruses was reduced by 41% and remarkable enhancement of grain yield up to 28% was recorded on the second sowing date (25 December) compared to 3rd planting date (15 January). Disease incidence differed significantly (P< 0.001) at all levels of seeding rates, and it decreased gradually (2.7> 1.9> 1.5> 0.97> 0.63 %) in contrary to increased seeding rates (80< 100< 120< 140< 160 kg/ha, respectively). In addition, significant interactions were recorded between planting date and seed rate treatments, whereas the best treatment which was recorded when planting at the rates of 100 and 120 kg/h in early date (5 September), and the highest grain yield were 2,495 and 2,487 kg/ha, respectively, with low luteovirus incidence (0.5 and 0.45%, respectively). On the other hand, increasing of seed rates up to 140 and160 kg/ha played a positive role by decreasing the rate of virus infections by 64.3 and 76.7%, respectively, and enhancing the grain yield up to 25.7 and 30%, respectively when planting date was late on (15th January), to the contrary of early planting date where high seed rates resulted into negative effects on the grain yield. The highest parameters (except the disease severity levels) were significantly recorded (P<0.001) in Al Ghab Research Center in comparison to that of Jeb Ramleh Research Station with rates of 12, 40 and 39.5% for grain yield, infected plants per plot and disease incidence %, respectively; and in general, the performance of parameters were somehow similar in both locations with some differences.
Keywords: TBIA, chickpea, seed rate, planting dates, Syria, Luteoviruses.
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