ABSTRACT
The present study was carried out on daughters and grand daughters (1stand 2ndratoons) of Williams banana cv. grown in sandy soil under drip irrigation system during 1999-2000 and 2000-2001 seasons. Three experiments were conducted aimed to investigate K fertigation level i. e., 200; 400; 600; 800; and 1000 gms. K2SO4 / plant yearly on growth; nutritional status; yield and both physical and chemical characteristics of fruits (experiment, I). However, second and third experiments were devoted for studying the effect of spraying the inflorescences with GA3 and bunch sleeving with blue polyethylene combined with GA3 application, respectively on yield (bunch weight) and fruit quality. The complete randomized block design with either 5 replications (1stand 3rd experiments) or 3 replicates (2nd experiment) was used, whereas each replicate was represented by 10 / 5 mats (20 /10 plants).
Obtained data revealed the following: -
I. Effect of K fertigated level (1st experiment): -
1-All vegetative measurements i. e., pseudostem (height and girth); number of healthy leaves and suckers at bunch shooting; as well as fruit physical and chemical characteristics (bunch weight; finger weight; length & diameter; pulp %; T.SS. %; total sugars and starch %) were positively responded to the K fertigation rate. Whereas, the greatest values of the aforesaid measurements were significantly in closed relationship to both higher K rates (800 &1000 gms. K2SO4 /plant) while the reverse was true with the lowest K applied rate (200 gms.).
2-The trend of response took the other way around with the phenological stage of shoot to shoot time, whereas the shortest duration expended from peeper emergence to bunch shooting was always in concomitant to the highest K fertilizer level (800 and / or 1000 gms. K2SO4).
3-Leaf N, P, K, Mn and Zn contents were significantly increased with raising the K fertigation level, however Fe content was not influenced.
II. Effect of GA3 spray (2nd experiment): -
GA3 spray at either 20 or 40 ppm. increased significantly the average bunch weight and number of both hands & fingers per bunches compared to control, however the highest GA3 concentration (40 ppm.) was statistically the superior in this respect.
III. Effect of bunch sleeving combined with GA3 (3rd experiment): -
All studied fruiting characteristics i. e., bunch weight; (finger weight, length & diameter); pulp %; T.SS; total and reducing sugars % except acidity responded significantly to specific effects of either bunch sleeving or GA3 spray and the interaction effect of their combinations. Hence, the greatest values of these measurements were exhibited by sleeving bunches of the 40 ppm. GA3 sprayed plants.
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