Effect of Competition and Seed Rate on Some Range Plants and their Preference by Goats in Central Darfur State- Sudan

Abstract

The study was conducted during the period 2015- 2017 at Western Jebel Marra Locality (WJML), Central Darfur State, Sudan. Questionnaire and rangeland management were done firstly in order to candidate some plant species for weeded and re-seeding experiment. The results revealed that, Rizigat and Nawaiba tribes were the dominant livestock raisers in the study area since their percentage was22.4 and 21.2 % respectively. Most of livestock raisers were illiterate 55.3% while graduates were only 2.4% of the respondents. Most of livestock raisers were settled and utilize the rangeland all the year round without resting the resource. According to respondent’s opinion; the most palatable plant was Dactyloctinium aegyptium (Abuasabi) 45.9%, Setaria acromelaena (Lesagh)21.2% and Cyndondactylon L. (Najila) 10.6%, while the unpalatable plants were represented by Pennisetum pedicellatum (Um dofofo) 24.7%, Senna obtucifolia (Kawal) 21.2 %and Cassia occidentalis (simeldabib; Majerio) plants 12.9%. Botanical composition of herbaceous plants for both range sites north (N) and south (S) showed that forbs were more than grasses at study area reaching 82.9 and 78.3 % for the two sites respectively; while grasses composition was 17.44 and 21.52 % respectively. Plant species that showed the highest frequency in range site (N) were Spermacoce sp. DC. (80%), Pennisetum pedicellatum(74%) and Senna obtucifolia (64%). In range site (S) plants with highest frequency were Haemanthus multiflorus (82%), Acanthuspermum hispedum (78%) and Oxygonum atriplicifolium (76%).The mean plant density was159 and 232plants/m2 for the two sites respectively in season 2015.While in the second season 2016 the plant density was 182 and 161 plants/m2 respectively. The biomass productivity (browse and herbaceous) was (2666.2and 1748 kg/ha) in the northern range site (N) for the two seasons respectively, while in the southern range site (S) the productivity was IV (3236.5 and 3153.7 kg/ha) for the two seasons respectively. The trees and shrubs (combined) density was (450 and 470 trees and shrubs/ ha) in the range site (N) for the two seasons respectively, while in the range site (S) the density was (430 and 400 trees and shrubs /ha) for two seasons respectively. The main objective of the study was to determine the effect of weed reduction and seed rate on growth and other yield attributes of Dactyloctenium aegyptium L, Haemanthus multiflorus, Ipomoea sinensis and Crotalariasaltiana plants. A split plot design was used with four replications. The main plot included weed reduction (Weeded) and no weeding (un-weeded). Weeding was done via hand mowing. Three seed rates were also applied as sub-plot for each species: 2, 4 and 6kg/hafor (Dactyloctenium aegyptium), 4, 8 and 12 kg/ha for (Haemanthus multiflorus), 2, 4 and 6kg/ha for (Ipomoea sinensis), and 10, 20 and 30 kg/ha for (Crotalaria saltiana). The study showed that weeded× 6kg/ha seed rates treatment resulted in more tillers or shoots per plant in the first season 2016. Also it was found that the moderate seed rate (4kg/ha) involving weeds reduction treatment encouraged greater biomass production (551.8 and 2979.2kg DM/ha) during the two seasons respectively than all other treatments (580.5and 2808.2, 529and 1692, 304and 1547.7, 384.5and 2012.7, 418.3and 2030.2kg DM/ha respectively).There were significant differences between the treatment involving moderate seed rates and weed reduction and the un-weeded treatment involving 2kg/ha seed rates whichyielded304.0 and 1547.7kgDM/ha over two seasons. Regarding Haemanthus multiflorus the study revealed that; weeded ×12 kg/ha seed rate treatment demonstrated significant differences from un-weeded ×8 kg/ha seed rate and unweeded ×12 kg/ha seed rate treatments in season (2016) which reached (7.78, 5.38 and 5.03 tillers per plant respectively). Also weeded ×8 kg/ha seed rate treatment had a positive effect on number of leaves per plant more than other treatments in V season (2016), which showed significant differences between this treatment and weeded ×4 kg/ha, un-weeded×4 kg/ha, un-weeded×8 kg/ha and un-weeded×12 kg/ha seed rates respectively (187.53, 122.25, 93.25, 96.65 and 77.1 leaves per plant respectively). Weeded ×12 kg/ha seed rate treatment have shown superior results on biomass production than other treatments which caused differences among this treatment and un-weeded ×4 kg/ha and un-weeded ×12 kg/ha seed rates treatments in the first season which reached 846.3, 371.5 and 328.5 kg DM/ha respectively. In the second season the same treatment (Weeded ×12 kg/ha) had superior biomass yield and revealed highly significant effect between it and unweeded ×4 kg/ha treatment. There were also significant differences among this treatment and un-weeded ×8 kg/ha and un-weeded ×12 kg/ha seed rates treatments which reach 1537.3, 881.3, 1119.2 and 1128.0 kg DM/ha respectively. Ipomoea sinensis; weeded× 2kg/ha seed rate treatment had significant effect on biomass production as compared with un-weeded× 2kg/ha seed rate treatment in the first season, where their yield reach approximately 549.5 and 133.8 kg DM/ha respectively. Also it was found that in the second season the superiority was for weeded× 6kg/ha seed rate treatment than the other treatments, which exposes significant differences among it and un-weeded× 2kg/ha seed rate treatment in biomass yield where their production reached 2827.8 and 576.0 kg DM/ha respectively. Eventually the results indicated that weeded ×20 kg/ha seed rates treatment was significantly different from un-weeded ×30 kg/ha seed rates treatment. Also highly significant differences were shown between the same treatment and un-weeded ×10 kg/ha seed rate treatment on Crotalaria saltiana biomass production in the second season, where their average yield reach 2470.7, 1368.0 and1193.0 kg DM/ha respectively. These results confirmed the importance of weed control in forage production either in rain fed or even in extensive irrigation schemes. VI On the other hand the study covered preference of plant species by goats fed under cut and carry system and also when grazing in open range. Diet botanical composition of grazing goats has been estimated using the bite-count technique. Five mature female goats were followed by observers for three days each goat being followed for25 minutes a day. All bites of plant species were recorded for each animal. Ipomoea sinensis plant was more selected by goats at the first season 42.96% as compared to Dactyloctenium aegyptium and Crotalaria saltiana which recorded7.76 and 23.06% respectively. These may return to their chemical composition as Ipomoea sinensis contains 15.83% crude protein, much higher than the other species where Dactyloctenium aegyptium and Crotalaria saltianahad 10.45 and 14.22 % crude protein respectively. Generally goats preferred legumes more than grasses. Under open range results showed that goats favour forbs (52.68 %) more than shrubs/trees (43.66%) and grasses (3.67%). Faidehirbia albida, Ziziphus spina-christi, Albizia amara, Ipomoea sinensis Desr, Kohautia aspera and Pennisetum pedicellatum recorded highest percent in the diet selected (18.29, 7.77, 7.66, 7.17, 5.53 and 3.53 respectively). The (4 kg/ha) seed rate reported in this study together with weeding are recommended for forage production of Dactyloctenium aegyptium plant in (WJML), Central Darfur State-Sudan. Weeded ×12 kg/ha treatment was recommended for Haemanthus multifolorus establishment. Lower or higher seed rates (2 or 6 kg/ha) concomitant with weeds reduction were suggested for Ipomoea sinensis re-seeding in the study area. The treatment was stated earlier (weeded ×20 kg/ha) seed rate treatment is recommended for Crotalaria saltiana forage production in (WJML).