Some aspects of pod characteristics predisposing pigeonpea (Cajanus cajan (L.) Millsp.) to infestation by Callosobruchus chinensis (L.)

Investigations with pigeonpea (Cajanus cajan) genotypes ‘Apio-elina’ and ‘PI-397566’ showed that certain pod characteristics influenced both infestation in the field by Callosobruchus chinensis and damage caused by this pest. Compared to pods with no or sparse hair, pods with thick hairs suffered greatly reduced field infestation due to the barrier effect of the hairs on oviposition and larval penetration. Even on pods with no or few hairs, the pod wall appeared to offer some resistance to both larval penetration and adult emergence. High levels of infestation by C. chinensis were recorded on pigeonpea pods with no or few hairs, those with pods damaged through shattering, and those with pods that had been previously damaged by pod borers. From the results of the study, it was recommended that pigeonpea selection should include screening for high pod hair density and thicker pod wall

Effect of field infestations of immature pigeonpea (Cajanus cajan (L.) Millsp.) pods on production of active (flight) and sedentary (flightless) morphs of Callosobruchus chinensis (L.)

A study conducted in Uganda on Callosobruchus chinensis showed that adults emerging from dry seed-infested and immature pod-infested pigeonpea differed in a number of morphological and biological characteristics in one or both sexes. Adults emerging from dry seed-infested pigeonpea were more or less uniform in a number of these characteristics; in contrast, adults emerging from green pod-infested pigeonpea differed depending upon when they emerged: the differences were greatest between those emerging during the 2nd to the 6th days from first emergence, and those emerging from the 8th to the last days of emergence. In one or both sexes, these differences were expressed in terms of elytral hue and size, body length, distance between the compound eyes, length of pygidium, body water content, pre-maturation periods, fecundity and adult longevity. We suggest that these differences are due to polymorphism, and specifically the predominance of flight forms among late emergers from pod-infested pigeonpea. The differences observed in the two morphs of C. chinensis and ascribed to the flight and flightless forms, are thought to be adaptations for survival and propagation under field and storage conditions, respectively. The predominance of emerged adults of the flightless forms from dry seed and the flight forms from green pods were associated with low moisture content in dry seed and high moisture content in green pods, respectively. These observations show that bruchid control measures are needed in the field as well as in storage

Efficacy of some cu.ltural management methods on Callosobruchus chinensis (L) infestation during storage of pigeonpea seed

Studies were conducted at Kawanda Agricultural Research lnstiuite to determine the efficacies of three storage practices viz: traditional mud-straw-cowdung silo " tua" storage, pod storage and storage of split seeds, on the management of Callosobruchus chinensis infestations in dried pigeon pea seeds. Lowest pigeonpea seed infestation was observed in sealed "tua", followed by loosely covered "tua" (2,512 insects and 3.81% seed damage), and the highest in .sack stored pigeonpea. Higher temperatures were observed in the " tua" (scaled " tua" 36.2°C, loosely covered "tua" 31.8°C) than in sack storage (25.5°C). Seed viability was also higher in " tua" (sealed 72.7% , loosely covered 76.3%) than in sack stored seeds (35.0%). Pod stored pigeonpea was effective in controlling C. chinensis populations, with infestation and seed damage of only 3.9 insects (all dead) and 0.04% respectively, compared to 45,000 insects and 19.8% respectively, in seed stored trials. Pod stored pigeonpea also ma intained higher seed viability (85.8%) than sack stored pigeonpea (45.1 %). Pigieonpea splitting depressed infestation by C. chinensis, reducing pest numbers, from 320 insects on the first month of storage to 10 insects on the third month. Whereas in whole stored seeds, there wns a sharp rise in pest population from 900 in first month of storage to over 10,000 on third mouth.Key words: Cultural management, Callosobruchus chinensis, Cajanus caja

Assessing the Impact of the National Agricultural Advisory Services (NAADS) in the Uganda Rural Livelihoods

The National Agricultural Advisory Services (NAADS) program of Uganda is an innovative public-private extension service delivery approach, with the goal of increasing market oriented agricultural production by empowering farmers to demand and control agricultural advisory services. Although initial evaluations of NAADS have been quite favourable, these evaluations have been primary qualitative in nature. This study quantifies the initial impacts of NAADS in the districts and sub-counties where the program was operating by 2005. It is based on descriptive analyses of results of a survey of 116 farmer groups and 894 farmers in sixteen districts where the program was operating at the time and four districts where NAADS had not yet begun operating to control for factors that may have contributed to differing initial conditions among the communities. Based on observed differences across the NAADS and non-NAADS sub-counties, it appears that the NAADS program is having substantial positive impacts on the availability and quality of advisory services provided to farmers, promoting adoption of new crop and livestock enterprises as well improving adoption and use of modern agricultural production technologies and practices. NAADS also appears to have promoted greater use of post-harvest technologies and commercial marketing of commodities, consistent with its mission to promote more commercially-oriented agriculture. Despite positive effects of NAADS on adoption of improved production technologies and practices, no significant differences were found in yield growth between NAADS and non-NAADS subcounties for most crops, reflecting the still low levels of adoption of these technologies even in NAADS sub-counties, as well as other factors affecting productivity. However, NAADS appears to have helped farmers to avoid the large declines in farm income that affected most farmers between 2000 and 2004, due more to encouraging farmers to diversify into profitable new farming enterprises such as groundnuts, maize and rice than to increases in productivity caused by NAADS. NAADS appears to be having more success in promoting adoption of improved varieties of crops and some other yield enhancing technologies than in promoting improved soil fertility management. This raises concern about the sustainability of productivity increases that may occur, since such increases may lead to more rapid soil nutrient mining unless comparable success in promoting improved soil fertility management is achieved. Continued emphasis on improving the market environment, promoting adoption of more remunerative crop enterprises, and applied agronomic research identifying more effective ways to profitably combine inorganic and organic soil fertility measures in different crop systems can help to address this problem. Shortage of capital and credit facilities was often cited by farmers as a critical constraint facing them, in addition to scarcity of agricultural inputs, lack of adequate farmland, unfavorable weather patterns and problems of pests and diseases. These emphasize that the quality of advisory services is not the only important factor influencing technology adoption and productivity, and the need for complementary progress in other areas, especially development of the rural financial system. Implications are drawn for enterprise targeting and ensuring sustainability of improvements in productivity, as well as for designing and implementing service provision programs in other parts of the Uganda and in other countries