International Journal of Plant & Soil Science

Enhancing transpiration efficiency (TE), defined as biomass accumulation per unit water transpired, may be an effective approach to increasing sorghum yield in arid and semi-arid regions under drought conditions. Water use efficiency was compared among 12 sorghum cultivars collected from the ICRISAT Genebank and representing diverse origins. Plants were cultivated in a split plot experimental design using pots with two factors in 5 replications. An irrigation system with two levels: the "well water”, and “water stress” were applied. Plastic bags were used to wrap the pots after the phase of water saturation. Transpiration Efficiency (TE) was used to evaluate the performance of a genotype in water deficit conditions. The parameters such as leaf weight, stem weight and root weight were measured and the data were analyzed using the statistical software tool GenStat version 19. Leaf weight, stem weight and root weight varied significantly between genotypes under well water conditions while under water stress conditions only the stem weight measured was significantly different among the genotypes. Significant differences between genotypes for leaf canopy conductance were found. The leaf canopy conductance was weakly correlated to the stem weight and root weight in both well-watered and water stress conditions.

Phosphorus deficiency is widespread in the soils in Nigeria which makes phosphorus fertilizer application at appropriate rates a component of the improved technologies needed for hot pepper (Capsicum annuum L) production. Atarodo (rodo) variety of hot pepper is cultivated in all agro-ecological zones and gives low fruit yields of variable quality which should be maximized with phosphorus fertilizer use but the information on the requirements is limited. The growth and fruit yield responses of rodo to phosphorus fertilizer were evaluated in 2013 and 2014 at Ado-Ekiti, southwest Nigeria in order to determine the optimum rates. The phosphorus fertilizer was applied at 0, 20, 40 and 60 kg P₂O₅ ha^-1 in four replicates arranged in randomized complete block design. Data were collected on growth parameters from 2 weeks after fertilizer treatment and at 2-week intervals, number and weight of ripe fruits, fruit parameters and proximate composition, vitamin C and mineral contents. The growth parameters increased with age; plant height, number of leaves, leaf area and dry matter yield of plant portions showed linear increase up to the 60 kg P₂O₅ ha^-1 rate. The 60 kg P₂O₅ ha^-1 rate gave the highest fruit and seed yields in both years but the agronomic efficiency was maximized at 60 and 20 kg P₂O₅ ha^-1 in 2013 and 2014 respectively. The fruit proximate composition, minerals and vitamin C contents increased to the highest values at 60 kg P₂0₅ ha^-1. The linear responses to 60 kg P₂O₅ ha^-1 in soils containing low available P suggest that higher rates and soils with variable P contents should be the focus to attain the optimum rates.

Teff [Eragrostis tef (Zucc.) Trotter] is the main staple food of Ethiopia. It ranks the first among cereals in the country in area coverage and second in the production volume; however, its productivity is almost stagnant. The Quncho (Dz-Cr-387) teff variety was sown during the main cropping season of 2017 at the Limo District, Southern Ethiopia. The objective of this research was to study the effect of four nitrogen fertilizer rates (0, 32.5, 65 and 97.5 kg N/ha) and three inter-row spacings (15, 20 and 25 cm), to evaluate the effects on yield and yield components of teff and to identify the economically appropriate nitrogen rates and inter-row spacing that maximize the yield of teff. A factorial experiment was laid out in Randomized Complete Block Design (RCBD) with 12 treatment combinations and three replications. Phenological and yield-related parameters were measured. The main effects of N rate and inter-row spacing showed significant differences (P≤0.05) for all yield and yield components. The effects of N rate by inter-row spacing interaction were not significant for some traits except for the lodging index, biomass yield, grain yield, and straw yield and harvest index. Application of N rate at 97.5 kg/ha and inter-row spacing with 25 cm significantly (P≤0.01) increased grain yield of teff. Moreover, both N fertilizer rates and wider inter-row spacing increased the magnitudes of the important yield attributes including plant height, panicle length, number of effective tillers per plant, thousand seed weight, biomass yield and straw yield significantly (P≤0.01) and also inter-row spacing increased the magnitudes of important yield attributes significance (P≤0.05). From the results of the study, it is possible to conclude that increased application of nitrogen fertilizer rate and row spacing improves yield and yield components of teff. Therefore, the application of 97.5 kg N/ha and inter-row spacing of 25 cm gave maximum yield which can be recommended for the study area.

The present study was conducted to know the effect of leaf nutrient status on fruit yield and quality of sweet orange (Citrus sinensis (L.) Osbeck) in YSR district of Andhra Pradesh, India. In this investigation fifty sweet orange orchards aged between 12 to 13 years were selected and plant samples such as index leaves and matured fruits were collected from 10 per cent of plants in each orchard. Leaf Zn deficiency (62%) was the most severe among the 10 mineral elements tested and followed by Fe (54%), Mn (52%) and Cu (26%). Fruit yield showed significant positive correlation with leaf N (r =0.519**) and P (r =0.409**). Fruit weight had significant positive correlation with leaf Nitrogen (r = 0.469**), Phosphorus (r = 0.446**) and Potassium (r = 0.415**). Fruit juice percent was significantly and positively correlated with leaf N (r =0.353**) and P (r =0.364**). Titrable acidity had significant negative correlation with leaf Fe (r = -0.371**) and leaf Mn (r = -0.292*). Total Soluble Solids (TSS) showed a significant positive relation with leaf P (r = 0.438**) and significant negative correlation with leaf Mn (r = -0.311*). Vitamin C content of the sweet orange fruit had significant positive correlation with leaf N (r = 0.437**), P (r = 0.516**) and K (r = 0.398**).

The low nutrient availability rainfall patterns regimes are the main constraints to agricultural production in Niger. This was a study of the decomposition and mineralization of nutrients of four types of composts (M1P, M2P, M1H and M2H) in a sandy soil. It was carried out at the experimental N'Dounga station (CERRA Kollo) located about 15 km from Niamey. A randomized blocks design with five repetitions was used. For the evaluation of yield, two doses (1 t ha^-1 and 1.5 t ha^-1) were applied per millet. Decomposition and mineralization were assessed after burial at 10 cm depth between of a small bag containing 100 g (five small bags / compost). The characterization of the physico-chemical elements of composts samples after incubation has shown that composts are rich in nutrients. Nitrogen ranged from 0.8% to 1.1%, phosphorus from  9.99 mg.kg^-1 to 12.76 mg.kg^-1 and potassium from 19.94 cmol_c dm^-3 to 26.26 cmol_c dm^-3. All four composts are basic (pH> 7). Compost M2H lost more than 80% of its weight during the 10 weeks of the experiment compared to 48% for the M1P. the mineralization of N, P and K is greater at compost M1P (83.6% N, 72.72% P and 89.5% K). This compost also gave the highest yield (1272.5 kg ha^-1). The decomposition and mineralization of the main elements (N, P and K) allow the synchronization between the release of nutrients from these composts and the nutrient requirements of millet in a sandy soil.