Productivity of Acacia angustissima accessions at two sites in the subtropics

Low leaf biomass yields coupled with small land sizes are some of the major constraints faced by smallholder farmers that grow protein-rich fodder trees and shrubs. Given these challenges, availability of highly productive seed sources would be important to enable farmers to produce leaf fodder in sufficient quantities. 14 accessions of Acacia angustissima were evaluated for leaf, wood and total biomass production at two subtropical sites with uni-modal rainfall in Zimbabwe, with the objective of identifying high leaf biomass yielding accessions. There were up to fourfold difference in biomass yield between the accessions. Leaf dry matter yield ranged from 1.65 to 8.81 Mg ha-1 and 3.7 to 12.4 Mg ha-1 for wood biomass at the higher altitude site (1530 m a.s.l.) but were much lower at 1272 m a.s.l. where they ranged between 0.37 and 4.88 Mg ha-1 for leaf and 0.4 and 7.2 Mg ha-1 for wood. The most productive accessions for leaf biomass were 16231 and 18579 at the higher altitude site, while 18586 and 18501 had the highest yields at the lower altitude. Although no one accession was consistently high yielding across the two sites, the least productive accessions were consistently poor at both sites. The advantage of using selected superior accessions over the unselect bulk seed was up to 85%. These findings underscore the need to promote the use of only high yielding accessions rather than unselect bulk seed. This study identified new, more productive accessions of A. angustissima that potentially widens the genetic base of the germplasm assembled in Zimbabwe.Key words: Leaf biomass, accession, accession × site interaction, Acacia angustissima

Barriers and coping mechanisms relating to agroforestry adoption by smallholder farmers in Zimbabwe

PURPOSE: The purpose of the present study was to investigate agroforestry adoption by smallholder farmers in Gutu District, Zimbabwe. DESIGN/METHODOLOGY.APPROACH: The methodology was based on field data collected through household questionnaires, key informant interviews and direct observations. FINDINGS: Major findings reveal that traditional agroforestry was common in the study area. There were no cases of innovative agroforestry other than dwindling remnants from a former trees-withpasture project. Majority of respondents were willing to adopt innovative agroforestry technologies to improve yields and income. Damage and destruction of plants by pests and animals due to lack of fences emerged as the major challenges to the adoption of agroforestry. Other challenges included seed availability and labour requirements. Possible coping strategies, identified through consulting farmers and other stakeholders, would include local initiatives and support from outside the community. Local and external efforts are required especially to secure inputs and raise awareness, knowledge and skills with respect to specific agroforestry technologies. PRACTICAL IMPLICATIONS: The paper presents pointers on the involvement of women in agroforestry and on the cultural significance of indigenous and exotic fruit trees. It provides practical lessons useful to extension or rural development workers in a localised set-up. ORIGINALITY/VALUE: The case study gives an insight into the problems faced by peasant farmers and the requirements to make agroforestry successful. Practitioners in southern Africa could learn a great deal about issues relating to smallholder farmers from reading this paperhttp://www.tandfonline.com/loi/raee2

Business Mathematics: AMB 111

Business Mathematics: AMB 111, supplementary examination July 2011