This study carried out to investigate the effect of pollen germination and fruit set by spraying agricultural chemicals to apple and pear cultivars during full bloom and pink stages, The results obtained were summarized as follows.
Pollen germination and pollen tube growth were little influenced compared with control by spraying agricultural chemicals during pink stage.
During full bloom stage, all agricultural chemicals influenced pollen germination and pollen tube growth. Especially, Difolatan and Captan were severely inhibited.
Occurrence of russeting in Jonathan was severed by spraying Gusathion and EPN. But Daconil, Captan and Polyoxin were little influenced.
Sevin exerted the most influenced on apple dropping. Difolatan and Captan were slightly increased in dropping rate compared with other chemicals.
Number of seed was decreased by spraying Dimecron and Difolatan in Jonathan and Ralls Janet.
In Gumchonchu variety, there were significant correlations between pollen germination and pollen tube growth and seed weight and fruit weight.
In Jonathan variety, there were significant correlations between pollen germination and pollen tube growth, pollen tube growth and rate of dropping, seed number and fruit weight and seed weight.
In Ralls Janet variety, there were significant correlations between seed number and seed weight, pollen germination and pollen tube growth, fruit weight and pollen tube growth, rate of dropping pollen tube growth and pollen germination and rate of dropping
Judging from above results, author thought that Difolatan, Captan, Sevin, Dimecron, EPN and Gusathion except Dikar, Omite, Daconil, Polyramcombi, Jinditox and Prethylene were badly influenced pollen germination and fruit set by spraying during full bloom stage.
|