SOME AGRICULTURAL TREATMENTS IN RELATION TO POTATO CROP

Abstract

This study was conducted at Sabahia Horticultural Research Station, Alexandria in two successive summer seasons of 1995 and 1996. The purpose of this work was to investigate the interactive effect of S compounds among with different nitrogenous fertilizers on growth, some chemical constituents of leaves and tubers, yield as well as tuber quality of potato plants. The second objective was to quantifY the carryover effect of the above-cited treatments on the performance and storability of potato seed tubers produced from the first experiment and stored under Nawwala conditions and their subsequent effects on growth and yield of potato plants when cultivated in El-Minufiya Governorate in the fall season. There were significant differences in each of plant growth characteristics, leaf contents from N, P, K, Ca, Mg, Na and N0-3 as well as tuber yield and its physical properties, tuber grading, tuber contents from starch, total proteins and N03, use efficiency of both S and N and finally harvest index. Generally, it could be concluded from the obtained results that the application of both gypsum as a source of S and ammonium sulfate + ammonium nitrate (1 : 1) recorded the highest values ofthe all studied traits. Also, gypsum supply and the fertilization with ammonium sulfate +ammonium nitrate (1 : 1) had a carryover effect in improving storability of potato seed tubers stored under Nawwala conditions, where both treatments gave the lowest values of sprouting index, No. of sprouted eyes/tuber, decay- and weight loss percentages besides the highest records of apical dominance period of tubers over the entire storage period. In addition, both gypsum and ammonium sulfate + ammomum nitrate (1 : 1) had also a pronounced carryover effect on growth parameters and tuber yield of potato plant when grown in the fall season.