Assessing of Some Summer Forage Crops to Infection by Common Smut and Downy Mildew Diseases for Forage and Silage Production

Abstract

The present study was carried out at Sakha Agricultural Research Station in the summer 2020 and 2021 seasons. Ten summer forage crops namely, Millet Saudia Arabia, Selection Millet1, Selection Millet2, Millet Shandawel 1, Sudangrass Giza1, Sudangrass Piper black ,Sorghum SX-17 were evaluated for downy mildew and common smut diseases and forage yield and some traits. Three cuts were taken from the seven fresh forage crops and only one cut for silage from maize (95 days), Teosinte and maize × teosinte (100days). Mean values of forage crops genotypes revealed significant to highly significant differences. Piper black had the highest fresh and dry forage yields at the three cuts and total over the two seasons which had (26.4,22.3,17.1 and 65.7kg/plot) for fresh and 5.3,2.8,2.5 and 10.59 for dry yield ,respectively . For combined data millet Shandawal 1 had 46.7 kg/plot, and 7.8 kg/plot ,while Saudia Arabia Millet gave 31.3 and 4.9 kg/plot, for total fresh and dry forage yields, respectively, so Shandawal 1 surpass Saudia Arabia by 49.2 and 59.2% for fresh and dry yield . Also, sorghum, piper black surpass SX-17 by 19.2 and 26.5 % for total fresh and dry yield, respectively. Maize SC168 x Teosinte Sakha was the highest for plant height (298 cm) ,stem diameter (2.9 cm) ,fresh/leaf stem percent(81%) and fresh forage yield (69 kg/plot) and exceed teosinte by 5.7,93.3,24.6 and 8.7% ,respectively . Meanwhile, exceed maize SC168 by 11.2, 16.0, 72.3 and 122.6%for plant height ,stem diameter ,fresh/leaf stem percent and fresh forage yield ,respectively. Saudia Arabia Millet and hybrid SX -17 were susceptible (s) to downy mildew disease on the other hand pearl millet 2,3,Giza 1 and piper black were resistance ( R ) to downy mildew disease at the three cuts in the two seasons . The local pearl millet1 , pearl millet2 , and pearl millet 3 (Shandawal 1) recorded the lowest percent of total infection by downy mildew disease1.666,0.000 and 1.333% respectively, also Giza 1 and piper black genotypes recorded the lowest percent of total infection by downy mildew disease which had 2.13 and 4.13% ,respectively. These tested local pearl millet and Giza 1 and piper black , were resistant(R) to downy mildew disease and can be used in breeding programs as sources of resistance to tested disease, In the revers , the imported pearl millet (Saudia Arabia pearl millet) and hybrid sorghum SX -17 were susceptible and recorded 20.33and 34.26, respectively. These results indicated dangerousness of importing susceptible materials. On the other hand, teosinte genotype was resistant to infection by downy mildew disease and the total infection percent was 0.000 in the first reading and 0.666% in the second , but maize was susceptible and recorded (16.70%) as total infection. Therefore the crossing between maize and teosinte resulted in moderate resistant (MR) whereas, 5.966% and 5.166% in the first and second reading. As common smut, teosinte was susceptible (s) but maize and maize x teosinte hybrid were moderate resistant (MR) for common smut infection disease. Finely, the local genotypes are better than the imported Saudi Arabia millet. Hybrid maize x teosinte was the best had more than twice maize silage yield (122.6%).