STRATEGY AND METHODOLOGY FOR DEVELOPING TRUE POTATO SEED (TPS) TECHNOLOGY IN SINDH

Abstract

TITLE: STRATEGY AND METHODOLOGY FOR DEVELOPING TRUE POTATO SEED (TPS) TECHNOLOGY IN SINDH True Potato Seed (TPS) is a low cost planting material, only about 100 g of TPS are needed to plant one hectare as compared to two tons of commercial seed tubers. Moreover it is technological alternative that offers farmers an option to overcome the perceived weaknesses of clonally propagated tubers as a source of planting materials. This study therefore was conducted first time in Sindh, Pakistan to determine how true potato seed could be implemented through genotype selection, growth substrates, planting time, plant spacing and packing material for storing tubers. The field experiments were conducted at Agriculture Research Institute, Tandojam, Pakistan located at 25.24, 46.00,’N, 68.32, 12.00E during 2009 and 2010. Experiment-1 was meant to observe the effect of different substrates for nursery raising of TPS genotype. In this study, three TPS viz. TPS=9802, TPS=9804 and TPS=9805 were grown in five growth substrates viz. Soil + Sand, Soil + FYM, Soil + Sand + FYM, Soil + PM (Poultry manure) and Soil + Sand + PM). Seeds of different genotypes sown in various substrates had significantly different results. The maximum germination, plant height, number and size of micro, small, medium and larges tubers were found in TPS-9804 grown in soil+sand+FYM (1:1:1). This genotype and same substrate also showed maximum total tuber yield on hectare basis. Experiment-2 was conducted to evaluate the effect of planting date and plant spacing on growth and yield of TPS nursery raising. In this study seeds of same genotypes were tested under three planting dates (15th October, 30th October and 15 th November) and three plant spacing (2, 4, and 6 cm). The maximum germination percent, plant height, number and weight of micro, small, medium and large tubers observed in TPS-9804. On hectare basis, the tuber yield was also higher in TPS-9804 genotype planted on 30th October with plant to plant distance of 4 cm. Experiment-3 was concerned to assess the impact of storage packing material on various genotypes viz, TPS=9802, TPS=9804, TPS=9805 and standard Diamant potato variety. To achieve the outcomes, different five packing material viz. gunny bag, polythlene bag, cloth bag, netted bag and wooden crate were used. The results obtained from 500 g standard weight of sample showed maximum tuber weight and tuber sprouting percentage after storage of TPS-9804 genotype kept in gunny bags. The results concluded that TPS-9804 genotype grown in the substrate containing soil + sand + FYM (1:1:1) was more efficient for obtaining maximum tuber number, size and yield. Comparing all true potato genotypes, TPS-9804 performed better in recording maximum tuber number and yield sown on 30th October with 4 cm plant spacing. In cold storage, maximum tuber weight and tuber sprouting was noted after storage in TPS- 9804 genotype kept in gunny bags. However, maximum rottening was found in Diamant standard potato variety kept in polytheline bag as packing material during storage. Hence TPS- 9804 genotype is recommended for Potato growers of Sindh province due to its better yield performance and storage capability under gunny bag as packing material.