Yield and quality of guava in Jordan as affected by two chemical defoliants (urea and ethephon)
1990
Harb, J.Y.M.
4 and 5 old guava seedling trees were subjected to chemical defoliation with ethephone (500 and 1000) and urea (12.5% and 25%) in combination with thinning out pruning or with ethephon (1500 and 3000 ppm) and urea (10% and 20%) in combination with heading bach pruning. Foliar urea application significantly increased the percentage of abscised leaves compared to ethephon application. Combining heading back pruning and ethephon 1500 and 3000 ppm defoliation induced more bud break, decreased the length of new growth and drastically lowered yield, while combining thinning out pruning and ethephon 500 and 1000 ppm defoliation significantly increased yield. On the other hand, urea defoliation significantly lowered yield. The effect of defoliation and pruning treatments was negligible on titratable acidity percentage (TA%), fruit flesh firmness and ascorbic acid (Vitamin C) content, while their effect on average fruit weight and total soluble solids percentage (TSS%) was inconsistent
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