Growth, radiation use efficiency and yield potential of enset (Ensete ventricosum) at different sites in southern Ethiopia

Abstract

Knowledge on the physiological parameters that determine the growth of enset (Ensete ventricosum) and on how these parameters develop over time and affect yield under field conditions is scarce. Field experiments were carried out at three sites in southern Ethiopia using suckers of several clones to generate crop physiological parameters and to describe the time course of leaf number, leaf area and plant height. Yield potentials at different sites were estimated using these parameters and weather data, and compared with the actual yield.Plant height and LAI increased faster at Awassa and Areka than at Hagereselam because of a higher leaf appearance rate associated with temperatures being closer to the optimum. The trend in plant height was best described by a logistic function, whereas the trend in LAI was best described by a logistic function only at Awassa and Areka.A high leaf appearance rate (0.18 leaves day -1 ) during early growth at Awassa and Areka made it possible that leaves that were senesced during unfavourable climatic conditions could be rapidly replaced without strong fluctuation in leaf area index. At Hagereselam, however, the rate of leaf appearance (0.09 leaves day -1 ) was too small to compensate for the decline in the number of green leaves per plant during adverse conditions and thus LAI fluctuated over the whole growing period.The trend in fraction of PAR intercepted was best described by a generalised logistic function. At 300 days after transplanting the suckers, LAI reached a value of 4.5 and enset clones intercepted 92-97% of incoming PAR. The mean extinction coefficient was between 0.56-0.91 and radiation use efficiency (RUE) ranged from 1.43-2.67 g MJ -1 . Dry matter kocho yield potentials of 17.1 to 33.9 t ha -1 yr -1 were estimated for enset clones. Important yield potential differences existed between clones mainly because of differences in radiation use efficiency that was probably partly associated with viral infection. The average ratio of actual yield:yield potential (0.24) was low mainly because of large losses associated with traditional fermentation techniques, yield reducing cultivation methods such as repetitive transplanting and leaf pruning, presence of diseases, lack of adequate fertilisation and shortage and uneven distribution of rainfall.

Allometric equations for yield predictions of enset (Ensete ventricosum) and khat (Catha edulis) grown in home gardens of southern Ethiopia

“…Bula yield was best predicted by combined measurements of diameter and height variables, indicating that the yield is influenced by both diameter and height growth. This is in line with Tsegaye and Struik () who reported a strong correlation of pseudostem circumference and height variables with pseudostem and corm, which are the enset components from which bula is extracted. This is also in line with the observations that bula is only harvested from older plants (>4 years).…”

Response of taro (Colocasia esculenyta (L.)) to variation in planting density and planting dates on growth, radiation interception, corm and cormels yield in Southern Ethiopia

“…Accordingly, the fraction of incoming Photosynthetic Active Radiation (PAR) intercepted by the canopy was recorded by measuring the ground cover at ten days interval using grids of 40×65, 50×75, 60×85 and 70×95 cm divided into 100 equal rectangles for planting densities of 38461, 26667, 19607 and 15037 plants per hectare, respectively. At every ten days, the grids were put between rows and three measurements were taken at each plot by counting the number of rectangles more than half filled with green leaf and the fraction of intercepted PAR (f) by the canopy was determined assuming 1:1 relationship between percentage of ground cover and percentage of intercepted radiation (Tsegaye and Struik, 2003;Worku and Demissie, 2012):…”

Yield and mineral content of ten enset (Ensete ventricosum) varieties

“…It is a perennial plant and has leaves, a large underground corm and pseudostem. It grows mainly at higher altitudes ranging from 1500 to 3100 m (Tsegaye and Struik 2003;Birmeta et al 2004). Desta and Oba (2004) showed that about 85% of the farmers in the Bale highlands of Ethiopia provide enset leaves, corm, pseudostem, fluid and processed by-products to livestock during the dry season.…”