No abstract

Field trials were replicated at four sites in the moist savanna ecological zone of West Africa to study the effect of maturity class and phosphorus (P) rate on grain yield and total protein yield (TPY) of some new soya bean varieties. Grain yield and TPY averaged 1.43 Mg ha )1 and 587 kg ha )1 , respectively. Without P application grain yield and TPY were not significantly different among the varieties. In addition, at zero P treatment, grain yield and TPY were not significantly different among three sites where available P was 6.2 mg kg )1 or less. P application depressed grain yield and TPY at a site where the available soil P was high (16.2 mg kg )1 ). With P application grain yield and TPY were in the range of 1.2-2.28 Mg ha )1 and 505-948 kg ha )1 , respectively, for the varieties compared with 0.99-1.12 Mg ha )1 and 454-462 kg ha )1 when P was not applied. The response of grain yield to 30 kg P ha )1 was substantial at Gidan Waya (113 %), Kasuwan Magani (63 %) and Fashola (60 %), three sites where available soil P was low. The application of 30 kg P ha )1 increased grain yield by 21 % in early, 26 % in medium and 58-70 % in the late varieties. Significant variety by P rate interaction effects were observed on grain yield and TPY but not on grain protein concentration (GPC). TPY showed greater response to P in the late varieties than in the early or medium. While seed size correlated significantly and positively with GPC, P application had no significant effect on GPC.

No abstract

Leaf area models are simple, accurate and non-destructive. They are important in many experimental comparisons where leaf area meters are not available. No such model exists for African eggplant (Solanum macrocarpon). This study was, therefore, conducted to develop a leaf area model for S. macrocarpon using linear measurements. A total of 80 fully opened leaves of different sizes were randomly selected. The maximum Lamina length (L) and width (W) of leaf samples were measured. Each leaf margin was traced on standard graph paper. Leaf area was subsequently estimated from the number of squares within each tracing. While the linear functions of length or width measurements, and their squares or products explained 79-92% of variations in leaf area, the linear functions of the inverse of length or width measurements, and their squares or products explained about 40-68% of the variations. Regression analysis of leaf area obtained from graph tracing as dependent variable, L and W as independent variables revealed several models 2 2 that can be used for estimating the area of individual leaf.

In order to fill the gap existing between the production and consumption of roselle in the humid