Response of jeriosalem artichoke to cut off irrigation before harvest and fertilization with Ca, Mg and B

الملخص EN

This investigation was carried out to determine the effect of cut off irrigation i.e., 4 and 7 weeks before harvest and fertilization with calcium nitrate (CN) at 100 kg/fed., magnesium sulphate (MS) at 5 kg/fed.

and boric acid (BA) at 1 kg /fed., as well as, their combinations on yield and its components (marketable and unmarketable yields), tuber quality (chemical constituents) and tubers storability of Jerusalem artichoke (Helianthus tuberosus, L.), cv.

Fusaeu.

The experiment was conducted during summer seasons of 2014 and 2015 on clay loam soil at Kaha Vegetables Research Farm, Horticulture Research Institute, Agriculture Research Centre.

The obtained results showed that cut off irrigation for short period (4 weeks before harvest) significantly increased the average tuber weight, average yield/plant, marketable, unmarketable and total yield/fed.

However, the cut of irrigation for long period (7 weeks before harvest) produced the highest dry matter percentage of tubers and the lowest values of unmarketable yield.

Moreover, the application of each of CN, MS and BA enhanced the total yield and its components, whereas, the combination between the three nutrients produced the best results, compared to each of them alone.

The interaction between the long period of cut off irrigation (7 weeks before harvest) and applying CN + MS+ BA together resulted in the lowest weight loss and decay percentage of tubers during storage period and the highest inulin, total carbohydrates, Ca and Mg contents of the tubers.

Conclusively, from these results it can be concluded that the cut off irrigation for a short period (4 weeks before harvest) exist beneficial effect in pre-harvest performance of Jerusalem artichoke plants, but cut of irrigation for a long period (7 weeks before harvest) was effective in post-harvest.

The maximum average tuber weight, total, marketable, and unmarketable yields were obtained from the cut off irrigation for short period, while, the highest dry matter percentage of tubers and the lowest values of unmarketable yield were achieved by cutting of irrigation for a long period.

Application of Ca + Mg + B together gave beneficial effect on the most tubers characteristics, marketable and total yields, as well as, reduces the percentages of weight loss and decay in tubers during storage period