Asian Research Journal of Agriculture

Globally the taro leaf blight (Phytophthora colocasiae) disease causes between 50 to 70% yield loss. Four taro landraces were planted in three agroecological zones of Cameroon; the Western Highlands (Bambui), Mono-Modal Humid Forest (Ekona), and the Bimodal Humid Forest (Nkolbisson) and evaluated for taro blight severity in four successive growing seasons in March and July, 2018 and 2019. Different concentrations of copper oxide (600 g)–Metalaxyl (120 g) fungicide were applied to control taro blight before and during plant growth. Results showed that, in all the field sites, the disease severity of Phytophthora colocasiae greatly decreased below 1.5 with varying concentrations of copper oxide (600 g)–Metalaxyl (120 g) fungicide applied at two-week intervals. The control field at Ekona recorded the highest taro blight severity of 7.8. There was no significant difference in taro blight severity (P≤0.05) between landraces treated with the different concentrations of copper oxide (600 g)–Metalaxyl (120 g) fungicide. Therefore, lower concentrations (0.33% and 0.27%) of copper oxide (600 g)–Metalaxyl (120 g) can be effectively used in the pre and post control of taro blight in the field. All the landraces in the screen house experiments were susceptible to P. colocasiae.   In all the zones, Landrace L2 (red petiole small leaves) was highly resistant to P. colocasiae and should be recommended to farmers for optimum taro production in the three agro-ecological zones and zones with similar characteristics.

Upland rice production at South Sumatra is still low compared to national average production level due to low soil fertility. Therefore, effort to increase soil fertility level is needed such as through application of Trichocompost and NPK fertilizers at dry land area. This research objective was to determine the application effect of Trichocompost produced from rice straw and NPK fertilizers on the growth and yield of upland rice crop of henic strain at dry land area. The methods used in this research was a 2 by 3 Factorial in Completely Randomized Design with two treatment factors and three replications for each treatment. Trichocompost fertilizer treatments (T) were consisted of: T0 (without Trichocompost: 0 ton/ha; T1: 10 ton/ha Trichocompost; T2: 20 ton/ha Trichocompost and T3: 30 ton/ha Trichocompost, whereas NPK fertilizer treatments (P) were consisted of: P1: 200 kg NPK/ha; P2: 300 kg NPK/ha and P3: 400 kg NPK/ha. All data from this research was analyzed using Analysis of Variance to determine the given treatment effect by using SPSS 17.0 software.  The results showed that application of Trichocompost produced from rice straw and NPK fertilizers had effect on the growth and yield of upland rice of henic strain at dry land area. Application of Trichocompost fertilizer produced from rice straw at dose of 30 ton/ha and NPK fertilizer at dose of 400 kg/ha tend to produce higher rice yield with magnitude of 4.6 kg/plot than that of other treatments.

Data on tomato fitness improvement by arbuscular mycorrhizal fungi (AMF) remain patchy. The present study was initiated to evaluate the effect of the period of AMF inoculation as well as the level of mineral manure on tomato growth. The experiment took place from June to October 2016, in the West African Science Service Center on Climate Change and Adapted Land Use greenhouse. AMF inocula were applied to seeds and/or transplants, each receiving three different levels of chemical fertilizer. The impact of the inoculation period and the level of fertilization, were assessed on plant growth parameters, including height, number of functional leaves, root-collar diameter, and root length. Observation of hyphae, arbuscules and vesicles was carried out by roots staining method and anabled the determination of mycorrhization parameters. Plants Mycorrhizal dependence was assessed with their fresh and dry mass. An analysis of variance and post ANOVA analysis was performed using the Newman-Keuls test (P= .05) for the comparison of means. The findings pointed that, when transplanting, the difference between mycorrhized plants and non-mycorrhized ones was very highly significant in terms of the height of the stem (P= .00), the length of the taproot, and the root collar diameter. The lower the level of manure was, the higher the frequency of infection has been (73.33% for MS1 and MSR1; 76.67% for MR1).Transplants growing without a supply of mineral manure expressed greater mycorrhizal dependence (66% for MSR1). Arbuscular mycorrhization of the tomato is profitable for its optimal development. The endomycorrhization of tomato can be done during sowing or transplanting with the same benefits but, with a low level of fertilizer. So, it’s necessary to controll the intake of mineral manure because it influences the natural mycorrhization of plants.

Conservation agriculture has been proposed as an alternative to conventional agriculture to mitigate the climate change impact and ensure food security. This study examined the effect of conventional tillage (CT) and no tillage (NT) on mycorrhization and mineral elements uptake of durum wheat for three cultivation years during the tillering stage. The experiment was conducted in a referential farm (Krib, Siliana, North West Tunisia). The results showed that tillage practices (T) had significant effect on mycorrhization rate (MR) for the first cultivation year and the highest mycorrhization rate was noted for NT with 24%. Moreover, tillage (T) had no significant effect on plant mineral composition in tillering stage for the three cultivation years. The cultivation year (Y) had showed significant effects on P and K amounts for both tillage practices when it had no effect on Ca and Na amounts. The interaction T x Y had no significant effect on mineral elements concentration. Mycorrhization rate (MR) showed significant negative correlation with K. For partial correlation based on Tillage practices, MR showed significant negative correlations with P and K.  Considering the partial correlation based on cultivation year, MR had no significant correlations with the studied parameters (P, K, Ca and Na concentrations). This work expands our knowledge on durum wheat natural mycorrhization and mineral elements uptake as influenced by tillage practices helping decision makers in upscaling the adoption of no tillage in Tunisia under rainfed conditions

One of the proposed solutions to face climate change impact and to maintain food production sustainability is conservation agriculture. This study tries to determinate the effect of conventional tillage (CT) and no tillage (NT) on secondary metabolites such as total phenolics content (TPC), total flavonoids content (TFC) and antioxidants capacity (DPPH %) in relation to natural mycorrhization of durum wheat during the tillering stage for three cultivation years. The experiment was conducted in a referential farm (Krib, Siliana, North West Tunisia). The results showed that TPC, TFC and DPPH% were not influenced by tillage system (T). However, cultivation year (Y) had a significant effect on the studied parameters independently of tillage system. In addition, for the first cultivation year, tillage system (T) had significantly influenced the mycorrhization rate (MR%) and NT presented the highest mycorrhization rate (24%). DPPH% showed high significant positive correlations with MR% and TPC. For partial correlation based on Tillage system, high positive correlations were noted between DPPH%, MR% and TPC.  Considering the partial correlation based on cultivation year, only a significant positive correlation between TPC and TFC was observed. In conclusion, durum wheat quality was not affected by tillage system and there are not reasons against no tillage adoption in this region for a sustainable wheat production.