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SummarySoil inoculation was tried in field experiments during two seasons using different concentrations and amounts of bacterial suspension and compared with direct seed inoculation of chemically protected and unprotected peanut seed. Soil inoculation gave significantly better results than direct inoculation of chemically protected or unprotected seed.Large yields of high quality peanuts, which compared favourably with highly nitrogen-fertilized peanuts, were obtained after the application of relatively small amounts (10–40 gm.) of enriched peat inoculant in 5 litres of water per dunam (1/10 ha).

Modifications were made in the configurations of the unitizing, nonselective wire cutters used by Alper et al. (1992) for mass cuttings of Stage II Citrullus lanatus cv. Charlee (watermelon) plant tissue cultures to further enhance productivity. Mounting the cutter in an inverted position over the receiving vessel eliminated time required for filling. This cut-and-dump technique became 4.8 times more productive for the total transfer process than the conventional scalpel and forceps technique when both time and yield of cut segments with visible buds were considered. A concept for growing fewer, larger tissue clusters per vessel in mini-trays with orienting cells and cutting with correspondingly sized oriented cell wire cutters yielded as much tissue fresh weight as conventional agar vessels and afforded the potential to reduce time required for the removal job function with the cut-and-dump technique. Keywords, Micropropagation, Plant tissue culture. Cutters, Mechanization. M icropropagation has become an important method to multiply rapidly virus-free varieties of crops that are difficult to propagate by conventional methods, e.g., seeds, cuttings, and divisions. The major factor limiting the cost competitiveness of micropropagation is the expense of labor inherent in the intense manual handling currendy required (Kurtz et al., 1991; Chu, 1992). Most of this labor is dedicated to Stage II proliferation. Expansion of the micropropagation industry into the vast market of vegetable, fruit, and forest species can only be achieved by mechanization and automation of the micropropagation process (Vasil, 1991). Tests conducted in this study represent an extension of the work of Alper et al. (1992) with unitized, nonselective mass cutting of in vitro watermelon. The former studies compared various designs of wire cutting devices as alternatives to conventional scalpel and forceps cutting through time studies and product characteristics. The scope of this study includes modification of the wire cutter device to enhance the transfer to new vessels as well as the cutting process, exploration of the influence of agar concentration on yield of nonselectively cut watermelon tissue, and investigation of the potential of trays with cell space restrictions to influence physical properties of wire-cut tissue.

SummaryAn experiment was conducted on peanut inoculation with Rhizobium inoculum, introduced below the planting level at three different soil depths (8, 12 and 15 cm.), to ensure more favourable moisture conditions for proliferation of the root nodule bacteria, and to obviate the need for frequent irrigation. Inoculation on both sides of the peanut rows, after the plants had emerged, was also tested. The number and weight of nodules per plant decreased with increase in placement depth. Side inoculation after emergence of the plants resulted in significantly less plant infection than placement of the inoculum at 8 and 12 cm. depths. Peanut yield and quality after inoculation at 15 cm. depth were significantly lower than at 8 cm. inoculation.

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