Sesame (Sesamum indicum L.) is one of the chief foreign exchange earning oil crops in Ethiopia. However, its productivity remains low due to lack of appropriate agronomic practices. The aim of this research was to study the effect of organic mulches on sesame productivity and in situ moisture conservation. This experiment was carried out in Humera Agricultural Research Center, Western Tigray, during 2015 growing season. The experimental design was Randomized Complete Block Design with three replications. There were four types of organic mulches; rice straw, sorghum straw, sesame straw, and Sudan grass were compared with control. Sesame, variety Setit-1 was used in the experiment. The organic mulching rate of application was 10 ton ha −1 and this was applied evenly to the soil immediately after germination. Soil water content, phonological characteristics yield, and yield components of sesame were collected. The analyzed results indicated that organic mulching had significant effect on soil moisture content at 0-0.2 m, 0.21-0.4 m, and 0.41-0.6 m in every two-week interval after sowing and grain yield of sesame. Sesame straw conserved highest soil moisture content as compared with respective mulch material. The highest yield (664 kg ha −1 ) was recorded with Sudan grass while the lowest grain yield (190 kg ha −1 ) was recorded with no mulch.

Sesame production under irrigation is limited in Ethiopia because of in availability of high yielding varieties, inadequate and inefficient irrigation schemes, and insignificant awareness of producers. This study, comprising 13 sesame genotypes, was conducted around Humera and Werer during 2018 and 2019 under irrigation. The design was randomized completely block design with three replications and the objectives were to develop high yielding genotypes and identify important agronomic traits. Multivariate statistical methods like Additive Main Effect and Multiplicative Interaction (AMMI) model, Principal Component Analysis, Cluster and factor analyses were used. The genotypes (6.22%), environments (42.62) and Genotype × Environment Interactions (25.09%) were statistically (p < 0.001) significant for the agronomic traits. The grain yield in each observation varied from 383 kg/ha to 2044 kg/ha and the grand mean yield was 820.19 kg/ha. The highest mean yield was recorded from G12 (948.6 kg/ha) followed by G4 (938.9 kg/ha) while the lowest was recorded from G8 (703.1 kg/ha). G1, G4, G12, G5, G8, G11 and G13 are identified as unstable genotypes while G2, G3, G6, and G9 are stable genotypes. The genotypes were grouped in to four clusters and cluster-II was characterized as the high yielding cluster and it was also associated with grain yield, pods per plant, branches per plant and thousand seed weight. Branches per plant, pods per plant and thousand seed weight may be most determinant and crucial in developing high yielding sesame varieties. This finding recommends that G4 and G6 are desirable genotypes and can be used for irrigation production.

The yield f cotton (Gossypium hirsutum L.) in Tigray is very low because of the lack of improved agronomic practices. Cotton producing farmers (if in row) adopt 90 × 20 cm. However, it is too wide for rain-fed cotton, which means more empty space left in-between the rows, which affect the yield negatively. Objective of this study was to estimate the optimum inter-row and intra-row spacing of cotton under rain fed condition. The experiment was laid out in split-plot design having three replications. The different levels of inter-and intra-row spacing have affected the agronomic traits and the seed cotton yield significantly. The narrow inter row and closer intra row have a higher plant population. The 90 cm inter row have taller (~90 cm) plant than the 60 cm inter row. The wider intra row (25 cm) scored higher (11-13) opened bolls in all the inter rows. The wider plant geometry recorded a higher number of unopened bolls (6). Heavier bolls (11 g) were recorded on the narrow inter-row spacing under all levels of intra-row spacing. Lighter boll weight was in 90 cm row spacing irrespective of the intra rows. Normally, boll weight was reduced as the inter-row spacing increased. Maximum seed cotton yield was recorded on 60 × 10 cm. Lower seed cotton yield was found on 90 × 25 cm. Generally, seed cotton yield was reduced as inter-and intra-row spacing increased. Therefore, the 60 × 10 cm inter and intra row should be recommended for maximum seed cotton yield under rain fed condition.

North western and Western zone of Tigray are the most suitable for agricultural mechanization and investment for different crops such as sesame, cotton, sorghum, Mungbean and other. Now days different investments and agro-industries are emerging to consume and process the agricultural products and this is a good opportunity for the crop producers. This new emerging industrial parks helps to produce quality products, value-add process, to get reasonable price, to introduce modern agriculture and agricultural mechanization. The Humera type sesame is one of the branded white seeded sesame in the world, meets the world criteria; it has high demand in the world market for different purposes. In northern Ethiopia, sesame is producing purely organic and it is very essential for different international and domestic purposes. Humera agricultural research Center released different crop varieties under wide commercial production in different agro-ecologies of Ethiopia such as sesame; Setit-1(2011), Setit-2 (2016), Setit-3 (2017), Humera-1 (2011) and Mungbean (Arkebe, 2014), Okra (Bamya-Humera in2016), Tomato (Tekeze-1, 2016) for low land areas of northern Ethiopia and other similar agro-ecology of the country. Those released crop varieties are under wide commercial production and small-scale farmers in northern Ethiopia and producing for export, agro-industrial purposes and local consumption.

Sesame is the second in oil crop produced in Ethiopia next to Niger seed and it is also second foreign currency generator in the country. Weeds are the most significant problem in sesame producing areas. This research was conducted with the aim of reducing weed infestation and boost yield. The experiment was conducted in 2016 cropping season at Humera Agricultural Research Center in RCBD design. Growth performance, yield and yield components of sesame and weed data were collected. Less abundant and dense Rahynochosia malacophylla weeds (33) and (132/m2) were recorded at Sudan grass, where the most abundant and dense Rahynochosia malacophylla weeds (60.5) and (242/m2) were recorded from no-mulch plot. The highest sesame yield (695 kg ha-1) was recorded from Sudan grass treatment, while the lowest yield (225 kg ha-1) was recorded from no mulch. Farmers need to apply grass mulch to suppress weed growth and boost sesame yield.