Effect of genotype and rhizobium inoculation on root nodulation, growth and yield performance of garde pea (pisum sativum l.) grow in two soils of contrasting ph

Abstract

The garden pea (Pisum sativum L.) is an important vegetable crop in the high potential areas of Kenya. However, yields realised locally are typically lower than those reported from other pea growing areas in the world. This situation is attributable to among others, varietal, edaphic and management factors. This study was therefore carried out to determine the effect of genotype and Rhizobium inoculation on growth and yield performance of garden pea in two soils of contrasting pH. A Rhizobium strain, Rhizobium leguminosarum bv viciae was assayed on four pea cultivars namely Greenfeast (certified seed) and local landraces-Kiriitho, Kagoci, and Kigogrown in soil of either low (pH 4.0) or moderate (pH 6.5) levels of soil acidity. These were I contrasted with calcium ammonium nitrate (CAN 26% N) topdressed plants and non-applied treatments in a randomized complete block design experiment with four replications. There were significant main factor interactions for parameters such as yield and yield components, N content, and growth factors such as root length and shoot dry matter. No interactions were observed for parameters such as final plant height, nodule number, date of maturity and flowering. content. Similarly, statistical evidence adduced showed positive and significant co-rrelation (P_<0.05) between Rhizobium inoculation, yield and yield components such as number of branches, number of pods and the 100 seed weight in all varieties tested. There were strong linear links between the main yield components and seed yield components and seed yield components and seed yield; such branches per plant 100 seed mass and pods per plant. Fixed or availed N increased the number of branches, pods per plant, 100 seed weight and grain yield by about 8, 6 and 30% respectively over the N deficient control treatment. A yield advantage of at least 70%- 100% was obtained by the high yielding Greenfeast over the yielding ~ Kagocj, and Kiriitho varieties. Inoculated plants invariably gave higher grain yields than applied N and control (nonapplied) treatments. For the applied treatments number of branches, pods and the 100 seed weights were intermediate between those for control and inoculated treatments. The certified variety Greenfeast significantly out yielded local landraces, such as Kiriitho,Kigo, and Kagoci. Evidence adduced showed that inoculation, along with certified varieties was a yield enhancing, sustainable, economical, and ecologically friendly management strategy that ensured higher cash returns on investments.