The tools and equipment fabricated locally by farm families themselves or by rural artisans mainly perform post-harvest processing of groundnuts in the traditional manner. Commercial machinery is normally manufactured in urban factories or overseas. The introduction of commercial machinery signals a decline in demand for the products of rural artisans. This potentially diverts cashflow away from the rural economy. As well, it will probably increase the drain on the country's scarce supply of foreign exchange for imported machines, spare parts and fuels. Please see Figure 2. In many cases, suitable machines could be made locally by the use of simple machines, tools and welding equipment.

 Figure 2: Artisan fabricating a thresher in a local market.

Training of rural artisans, upgrading of technology in rural workshops, provision of credit plus other support services may encourage local manufacture of necessary machines. Small-scale farmers regard the groundnut as a very labour-intensive and high-risk crop. The high labour allocated for weeding, harvesting, drying, threshing and shelling makes the crop economically unattractive to the younger generation of farmers. Research is needed to provide the farmers with better implements. Farm operations comparable to digging or harvesting, curing, drying, shelling, grading and storage are must be suitably modified to reduce the quantitative and qualitative harvest and post-harvest losses.

The basic idea used to develop a crop management strategy is to provide an environment that allows maximum yield with reduced risk of losses, proper use of pesticides and other petrochemicals and minimal environmental contamination. In short, a successful plant health management strategy must include management of all the following:

To be practicable at the farm level, plant health management strategies must be integrated as a package approach. Some guidelines for the cultivation of groundnut are mentioned below.

 Figure 3: Groundnut pod, inside shell and kernal colouration determines the right maturity stage. Dark tan colour inside the shell indicates maturity.

Groundnut pod development takes place in the soil making it difficult to correctly judge the maturity of the crop. Farmers are obliged to have considerable experience and great vigilance to carry out the harvesting operations efficiently without much loss of quality and yields. A proper time to commence the harvest is when a good number of pods are fully developed and are fairly intact. This condition is normally achieved when the vine begins to turn yellow and leaf shedding starts. The actual maturity of the pod is determined when they attain normal size with prominent veins, the inside of the shell turns dark and the kernels reach maximum growth accompanied by good colouration of the seed coat.

A fully mature pod can often be difficult to spilt open with the pressure of the fingers. Meanwhile an immature pod can be split easily revealing the white inside surface of the pod which appears also to be spongy in texture. These criteria may help in assessing the correct stage of the harvest of groundnut crop. Harvesting at the proper time ensures that a high percentage of mature pods remain on the plants and the maximum number of pods has attained their greatest weight or physiological maturity (Figure 3). Delay in maturation may also occur because of late-season drought stress. Long periods of rain immediately prior to harvest may result in both yield loss and deterioration of quality of groundnuts. Several methods have been described for determining the maturity of the groundnut crop i.e. shell-out maturity and hull-scrap maturity testing methods. The prevailing attitude among the groundnut production specialist is that the hull-scrap method is not accurate for Virginia and Spanish types groundnut and may predict a harvest time that is too early. Following are the tips of the shell-out maturity testing method:

• If leaf spot or other diseases are problem in the field, do not delay harvest.
• If there is a weather forecast that would delay the harvest, this must be taken into account.
• Harvest must be done when sufficient labour and adequate equipment are available.
• Failure of peg strength and well-filled pods with pink seed coat indicate maturity in large-seeded Virginia type. Signs of weakening peg strength indicate immediate need for harvest if excessive losses are to be avoided. Check groundnut crop closely as the average number of days to maturity approaches.

Seed-hull ratio and shelling percentage as indicator of groundnut maturity:

The seed-hull ratio as an index of groundnut maturity was first proposed by Pattee, et al. (1977) and is obtained by dividing the mass of the seed by the mass of hull (shell). The ratio may be determined on the basis of fresh as well as dry seed mass. Shelling percentage is the proportion of the mass of the seed in a given mass of seed in a given mass of pods. It is usually measured on the basis of dry mass. Shelling percentage is an important attribute in the evaluation of varieties and in trade transactions, which involve unshelled groundnut. Troeger, et al. (1976) were apparently the first to use the seedpod ratio as a maturity indicator for individual pods. The mathematical relations of this method are given below:

Table 6. Groundnut cultivars and elite germplasm being used in various developing countries for their useful traits.

(P=polyunsaturated and s= saturated acids)

It is evident that shelling percentage could also be used as an index of maturity in addition to seed-hull ratio (Abdul and Ahmadi, 1994).

Promising cultivars: Some promising cultivars and elite groundnut germplasm being used in the developing countries were shown in Table 6.