Water deficit and poor fertility of soil are among the main constraints to sustain production of sorghum in the semi-arid regions of northern Ethiopia. Thus, one experiment was conducted to determine the appropriate tied-ridging practice and planting method that maximizes sorghum productivity under rainfed conditions. It was carried out in 2015 and 2016 cropping seasons. Treatments comprised flatbed planting as control; open tied ridge, furrow planting; open tied ridge, planting on ridges; closed tied ridge, furrow planting; and closed tied ridge, planting on ridges were tested separately under fertilized and unfertilized conditions. These treatments were laid out in Randomized Complete Block Design with three replications. According to the current result, days to heading, plant height and panicle length were not significantly (P>0.05) influenced while grain and biomass yields were significantly influenced in both fertilized and unfertilized conditions. Accordingly, the maximum grain yield (3226.70 - 4621.00 kg ha-1) under fertilized and (2678.00 - 4318.80 kg ha-1) unfertilized conditions was obtained from closed tied ridge with planting in furrow. Moreover, the highest biomass yield (6844.40 - 11471.00 kg ha-1) was produced from closed tied ridge integrated with fertilizer in furrow planting. On the other hand, the minimum average yields were obtained from flat planting (farmers' practice) with and without fertilizer. It is concluded that closed tied ridge with planting in furrow can be recommended for sorghum growers in Raya Valley areas and other places with similar agro-ecologies to enhance sorghum yield.

Dekoko is a cool-season food legume cultivated in Tigray, Northern Ethiopia. It is highly appreciated by the local people for its taste and high market value. Yields of Dekoko, however, are limited by improper planting spacing. Thus, an experiment was conducted in 2013 and 2014 cropping seasons to determine the appropriate planting spacing of Dekoko that maximizes its productivity under rain fed conditions. Treatments comprised combinations of three plant spacing (10, 15 and 20 cm) and three levels of row spacing (40, 50 and 60 cm) and broad casting were done in a randomized complete block design with three replications. Plant spacing influenced plant height, grain yield and biomass yield. The greatest plant height (50.63 cm) was obtained at a spacing of 60x20 cm while the maximum mean grain (544.58 kg ha-1) and biomass yields (1562.65 kg ha-1) were obtained at spacing of 40x15 cm in both cropping seasons. A planting spacing of 40 x 15 cm is recommended for the growers in the study area.

Onion is one of the most important high market value bulb crops cultivated commercially in most parts of the world. It is the most cultivated and high market value of vegetable crops In Tigray Northern Ethiopia. However, bulb yield of onion is limited due to improper use of plant spacing. Therefore, field experiment was conducted to determine the optimum planting spacing of Onion to maximize its productivity in 2014 and 2015 under irrigation conditions. The trial contains treatment of singe planting pattern of 20 x 10, 40 x 10, 30 x 5, 30 x 7.5, 30 x 10 and 30 x 12.5 cm inter and intra spacing respectively and double planting pattern combinations of four intra plant spacing (5, 7.5,10 and 12.5 cm) and two levels of inter spacing (40 and 50 cm) by means of total fourteen treatments were carried out in Randomized Complete Block Design (RCBD) with three replications. The current findings showed that plant height, bulb size, bulb weight, total bulb yield and marketable bulb yield were significantly influenced by planting spacing. Accordingly, the tallest plant height (37.70 cm) was obtained at a spacing of single planting of 40 cm inter row and 10 cm intra row while the maximum total bulb yield of 27.01 ton ha -1) was recorded at a spacing of double planting pattern of 40 cm inter and 5 cm intra row in both years. Therefore, 40 cm inter row and 5 cm intra row spacing in double row planting manner is recommended for the growers to improve onion productivity in the study area.

Dekoko is highly appreciated by the local people for its taste and high market value. However, productivity of Dekoko is limited by improper planting time. An experiment on Dekoko planting time was, therefore, conducted in 2013 and 2014 cropping seasons to determine the appropriate planting time of Dekoko that maximizes its productivity under rain fed conditions. Treatments comprised combinations of four planting time (dry planting about 5-7 days before the beginning of main rain season, when the rain fall amount received greater or equal to 10 mm at once or cumulative, when the rain fall amount received greater or equal to 20 mm at once or cumulative and when the rain fall amount received greater or equal to 30 mm at once or cumulative) were carried out in Randomized Complete Block Design (RCBD) with three replications. The analyzed result showed that days to maturity, number of pods plant-1 , grain and biomass yields were significantly influenced (P<0.05) by planting time. Dekoko matured late during dry planting. Dekoko planted when the rain fall amount received is greater or equal to 20 mm at once or cumulative gave high (21) number of pods plant-1. Similarly, the maximum grain (533.53-638.00 kg ha-1) and biomass (1635.23-1820.06 kg ha-1) yields were produced during planting time when the rain fall amount received is greater or equal to 20 mm at once or cumulative, while the minimum values were due to dry planting. It is, therefore, concluded that planting of Dekoko when the rain fall amount received is greater or equal to 20 mm at once or cumulative can be recommended for the growers in the study area to improve Dekoko productivity. Moreover, further research works on different varieties along with different soil moisture levels, planting dates and soil types can be a step forward to identify best sustainable technology on the growth and yield improvements of Dekoko.