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Abstract This study was carried out during 1999-2000 and 2000- 2001 seasons on fruitful mango trees (about 30 year old) of four cultivars varied in their susceptibility to the malformation disorder (Taymour; Zebda: Hindi Be-Sinnara and Alphonse cvs.). Taymour is the most susceptible one, Zebda is the highly resistance while two other ones are intermediate. The first part (field) of study was devoted to investigate some remote sensing measurements for distinguishing between mango cultivars concerning their susceptibility to malformation; sprouting nature (leafy or floral) and photosynthesis activity of their leaves at different ages. However, the second part (field) of study was dealing with investigating the chemical composition (nutritional states, chlorophyll content and endogenous growth regulators levels) in relation to mango cultivar and its susceptibility to malformation. v. I. Part one ”remote sensing measurements”: V. I. A. Field / open remote sensing measurements: v. I. A. 1. Field spectrometric measurements: Spectral reflectance% of Taymour terminal buds were measured monthly (from Oct. tell Feb. / March) (50 terminal buds of spring flushed shoots / each tree) using the field hand radiometer (Exotech model 100 AX) during 1999-2000 and 2000-2001 seasons. Spectral reflectance% of Taymour terminal buds (of the fifty tagged spring flushed shoots per each tree) from the V SUMMARY AND CONCLUSION - 191- selected five trees devoted for this study were monthly measured (from Oct. tell Feb. / March) during both 1999-2000 and 2000- 2001 seasons. After sprouting of these tagged buds had been taken place in Feb. or March during both seasons, they were classified according to nature and states of their sprouting into four groups (a- healthy/normal leafy buds, b- normal floral buds; c- malformed leafy buds and d- malformed floral buds). Thereafter, reflectance% at various specific wave length (from 0.5-1.1tim) was estimated separately for each case (groups) per every tree (replicate). Data obtained revealed that: 1- It was so difficult to distinguish between floral and leafy terminal buds through variance in their spectral reflectance % of the October sampled buds, regardless of domain of spectrum (visible or invisible). However, the reverse was true to distinguish between the normal and malformed terminal buds, whereas it was so easy to observe that the reflectance% of October measured buds was greatly higher in normally sprouted buds than malformed ones (in both spectral domains). 2- At all measuring dates (month) spectral reflectance% of both normally sprouted leafy and floral buds exceeded obviously those of the analogous ones (malformed leafy and floral terminal buds). 3- The normally sprouted floral buds surpassed to some extent the healthy leafy buds regarding their reflectance% in both visible and invisible domains from one hand, but the variance was more pronounced and reached level of significance in the invisible domain especially the near infrared (0.8-1.1pm) from the other. V. SUMMARY AND CONCLUSION - 192- V. I. A. 2. Field thermometric measurements: Thermal emission of new sprouted shoots: In this regard the emissivity of new sprouted shoots in response to specific and interaction effects of growth state (normal or malformed) and mango cultivars was investigated at 8.0 Am and 4.0 Pm. Data obtained revealed the following: Specific effect: 1- Differences due to sprouting state proved that emitted thermal infrared radiation by malformed shoots was significantly higher than the corresponding value of normal shoots of measurements at either 8.00 Am or 4.0 Pm 2- Variances between mango cultivars were less pronounced, however Alphonse was the superior and other 3 cvs. were similar. Interaction effect: The highest value of thermal emission was in concomitant to malformed shoots of Alphonse, but the reverse was true with the normal shoots of both Zebda and Alphonse mango cvs.; other combinations were in between. Thermal emission of mango leaves: Data obtained regarding the specific and interaction effects ofleafage (3, 6,18 month old) and mango cvs. showed that: Specific effect: As for the specific effect of leaf age, data obtained pointed out that thermal emission was significantly in positive relationship to leaf age. Moreover, emissivity was also responded to cultivar, whereas Zebda leaves were the superior V SUMMARY AND CONCLUSION -- followed in descending order by Alphonse, Hindi Be-Sinnara and Taymour. |