Techniques for using sprouts for potato production in the tropics
A series of experiments were conducted in Vietnam to develop a system whereby detached sprouts from physiologically old green sprouted seed tubers could be used to grow potatoes. Three node segments from the mid or basal portion of the detached sprout produced the greatest percentage of shoots and roots. Growth was best in a medium of equal parts of sub-soil, pig manure and brick kiln ash. Sprout cuttings produced plantlets ready for transplanting in 14–20 days with mean daily temperatures of 22 to 24°C. When transplanted in mid-November, yields from sprout cuttings in field experiments were 10 to 18 t/ha which were 33% lower than from healthy seed tubers but more than the national average yield using degenerated seed tubers. Tubers produced by plants grown from sprout stored well and gave good yields when replanted the following year.
Potato production using tissue culture in Vietnam: The status after four years
Farmers in Dalat, Vietnam, (1500 m asl) have established a unique method of using in vitro plants as a source for planting material (1). The rapid adoption of this approach was attributed to several factors. Farmers had been using degenerated seed of cultivars susceptible to Phytophthora infestans, resulting in low yields and decreasing area under cultivation. Three new high yielding cultivars were introduced as clones: CFK 69.1, B71-240.2 and Atzimba and were named as V4, V8 and VI2, respectively after having shown good P. infestans resistance and given high yields. No seed tubers were available for these new cultivars. This communicat ion reports the evolution of the demand for and use of cutting technology in the spread of these new cultivars f rom late 1980 to late 1984.
Assessment of some agro-technological parameters of cactus pear fruit ( Opuntia ficus-indica Mill . ) in Morocco cultivars
Cactaceae had always attracted attention by their strange shapes and important adaptability supporting extreme conditions. For this reasons, Fruit traits were measured on 13 cultivars growing in different locations in Morocco. Results show significant differences between the cultivars. The source of this variation was probably genetic without excluding the geographic effects. The Tamri, Berkan, Ait Baha cultivars showed small fruit dimensions and weight. In contrast, Sidi-Ifni M, Nador, Mohammedia and Ben Guerir were greater than 100 g by fruit. Sidi-Ifni M, Hoceima, Mohammedia and Nador, although larger, contained few seeds, about 200 seeds per fruit; while Tamri, Ait Baha, Safi, Meknes and Tafraout contained over than 230 seeds per fruit. High levels of juice about 62 ml/100 g pulp were obtained with Sidi-Ifni M, Nador, Mohammedia and Ben Guerir cultivars. Total sugars of the 13 cultivars were quite similar and pH was low in Tamri and close to neutrality in the rest of cultivars. Therefore, oil extracted from Opuntia ficus-indica seeds constituted 13.6% of the whole seed. Thin-layer chromatography in conjunction with gas-liquid chromatography-mass spectrometry revealed a relatively high degree of unsaturation, 83.32% and 16% for saturated fatty acid, with a linoleic acid content of 63.66% followed by oleic 18.34%, palmitic 12.84% and stearic acid 2.81%. Based on these results, O. ficus-indica seed oil appears to be a good potential source of edible oil for human and (or) animal consumption. Our investigation describes that Tamri and Tafraout cultivars are not really a commercial viable fruit due to low total soluble solids value and highest seeds number per fruit. Against Mohammedia, Sidi Ifni M and Nador cultivars proved to have the highest fruit weight, very good total soluble solids value and low number of seeds, these cultivars can therefore be planted for both fruit production and for harvesting of cladodes for animal feed.