|Title:||玉井檬果結果不良原因之調查||Other Titles:||An Investigation on the Factors Causing the Yield Reduction of Irwin Mango (Mangifera indica L.) in Yu-chin Area of Tainan County||Authors:||張振宙
|Issue Date:||Sep-1979||Publisher:||臺灣園藝學會||Journal Volume:||25||Journal Issue:||4||Start page/Pages:||140-149||Source:||中國園藝||Abstract:||
In recent years the reducing yields of the Irwin mango in Yu-Ching area has become worse. In this investigation, two factors were found to he mostly related to the yield reduction: (1) Poor growth of the plant due to over-crowded crown without prunning and thinning at proper time as well as no application of fertilizer to the soil for seveal consecutive years, so that most of the shoots of the plant became too weak to set fruits. (2) Damage of chemical agents: For controlling diseases and insect pests, fungicides and insecticides were usually mixed in solutions for spraying at the same time, and the concentrations of individual agent were usually much higher than the regulation permitted. Spraying of such mixed solution reoulteP in the damaging of the foliage, flower and fruitsetting. Several days after spraying, it could be easily found that the leaves became discolored, thicker and hardier, and the growth of young leaves were inhibited. The damaged leaves always shed much earlier. In time of blooming, the flower usually became wilting and during the period of fruit-setting, the development of the fruit was inhibited. Afterwards, the fruits dropped seriously. Moreover, if too much N fertilizer was applied even under good management a large amount of small fruits (nubbins) would appear, but not increase in number of normal fruits.
Solutions of Sevin (85% W. P. diluted to 400 times with water), Azodrin (55% E., diluted to 2000 times with water) and Lannate (90% W. P. diluted to 2000 times with water) were test to spray individually on the foliage, flower and setting-fruit of the Irwin mango throughout all periods of blooming, and no damages were found to occur on the foliage, flower and no fruit-thinning effect was detected either. It is suggested that the fruit dropping and the occurrence of small fruits (nubbins) of the plant under good management might be dun to the damage caused by too heavy concentration of the chemical agents used.
|Appears in Collections:||園藝系|
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